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Association of common variants on chromosome 8q24 with gastric cancer in Venezuelan patients
Gene 566 (2015) 120–124
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Short communication
Association of common variants on chromosome 8q24 with gastric cancer in Venezuelan patients Luis Labrador a, Keila Torres a, Maria Camargo a, Laskhmi Santiago a, Elvis Valderrama b, Miguel Angel Chiurillo a,⁎ a b
Laboratorio de Genética Molecular “Dr. Jorge Yunis-Turbay”, Decanato de Ciencias de la Salud, Universidad Centroccidental Lisandro Alvarado (UCLA), Barquisimeto 3001, Venezuela Departamento de Anatomía Patología, Hospital Antonio María Pineda-UCLA, Barquisimeto 3001, Venezuela
a r t i c l e
i n f o
Article history: Received 21 February 2015 Received in revised form 17 April 2015 Accepted 30 April 2015 Available online 2 May 2015 Keywords: Gastric cancer 8q24 SNPs Histologic differentiation Susceptibility
a b s t r a c t Gastric cancer remains one of the leading causes of death in the world, being Central and South America among the regions showing the highest incidence and mortality rates worldwide. Although several single nucleotide polymorphisms (SNPs) identified in the chromosomal region 8q24 by genome-wide association studies have been related with the risk of different kinds of cancers, their role in the susceptibility of gastric cancer in Latin American populations has not been evaluated yet. Hereby, we performed a case–control study to explore the associations between three SNPs at 8q24 and gastric cancer risk in Venezuelan patients. We analyzed rs1447295, rs4733616 and rs6983267 SNPs in 122 paraffin-embedded tumor samples from archival bank and 129 samples with chronic gastritis (obtained by upper endoscopy during the study) from the Central Hospital of Barquisimeto (Lara, Venezuela). Genotypes were determined by PCR–RFLP reactions designed in this study for efficient genotyping of formalin-fixed/paraffin-embedded tissues. No significant differences in genotype frequencies between case and control groups were found. However, carriers of the homozygous TT genotype of SNP rs4733616 had an increased risk of developing poorly differentiated gastric cancer according to the codominant (OR = 3.59, P = 0.035) and the recessive models (OR = 4.32, P = 0.014, best-fitting model of inheritance), adjusted by age and gender. Our study suggests that the SNP rs4733616 is associated with susceptibility to poorly differentiated gastric cancer in Venezuelans. Additional studies are needed to further interrogate the prognostic value of the rs4733616 marker in this high-risk population for gastric cancer. © 2015 Elsevier B.V. All rights reserved.
1. Introduction Gastric cancer incidence and mortality have been decreasing in most Western countries over the last few decades, however, it still remains the fifth most common cancer and the third leading cause of cancerrelated death in both sexes worldwide after lung and breast cancer (723,000 deaths in 2012) (Ferlay et al., 2010, 2013). Eastern Asia exhibits the highest estimated mortality rates in both sexes worldwide, followed by nations from Central and Eastern Europe and Central and South America (Ferlay et al., 2013). Gastric cancer is a complex disease resulting from the interaction between genetic and environmental risk factors at the stomach mucosa Abbreviations: SNP, Single Nucleotide Polymorphisms; PCR, Polymerase Chain Reaction; RFLP, Restriction Fragment Length Polymorphism; OR, Odds Ratio; GWAS, Genome-Wide Association Studies. ⁎ Corresponding author at: Departamento de Patologia Clínica, Universidade Estadual de Campinas, Campinas 13083-877, São Paulo, Brazil. E-mail addresses: [email protected] (L. Labrador), [email protected] (K. Torres), [email protected] (M. Camargo), [email protected] (L. Santiago), [email protected] (E. Valderrama), [email protected] (M.A. Chiurillo).
http://dx.doi.org/10.1016/j.gene.2015.04.081 0378-1119/© 2015 Elsevier B.V. All rights reserved.
level that contribute to its initiation and progression. The most common histologic variant of gastric adenocarcinoma is the intestinal type (according to Lauren's classification), which arises of a progression from superficial non-atrophic gastritis, to chronic atrophic gastritis followed by intestinal metaplasia and dysplasia and finally, gastric adenocarcinoma (Correa, 1995). Usually this chronic inflammatory background is induced by Helicobacter pylori infection (McNamara and El-Omar, 2008). In recent years genome-wide association studies (GWAS) and highthroughput genetic analysis have identified several loci associated with gastric cancer mainly in Asian populations, including those at 1q22, 3q13.31, 5p13.1, 8q24, 10q23, and 20p13 (Sakamoto et al., 2008; Abnet et al., 2010; Shi et al., 2011; Saeki et al., 2013; Wadhwa et al., 2013). Particularly, the 8q24 chromosome region has been suspected to contain several cancer risk variants that lead to numerous cancer types, including breast, prostate, thyroid, colorectal and gastric cancer (Easton et al., 2007; Berndt et al., 2008; Ghoussaini et al., 2008; Wokołorczyk et al., 2008, 2009; Yeager et al., 2009; Turnbull et al., 2010; Von Holst et al., 2010; Guo et al., 2011; Lochhead et al., 2011; Neta et al., 2012; Ma et al., 2015). Several studies have evaluated the relationship between gene polymorphisms and gastric cancer susceptibility in Latin American
L. Labrador et al. / Gene 566 (2015) 120–124
populations (Chiurillo, 2014). However, there is no report of the relevance of chromosome 8q24 polymorphisms and gastric cancer in this region. Hence, we performed a case–control study to examine the possible link between three SNPs located at the chromosomal region 8q24 (rs1447295, rs4733616 and rs6983267) and gastric cancer in a Venezuelan population where the disease is the leading cause of cancer-related deaths (http://www.mpps.gob.ve/).
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1D Molecular Imaging Software (Eastman Kodak, Rochester, NY) was used for image analysis of ethidium bromide-stained agarose gels (3% w/v) and for allelic assignment of the PCR products and restriction fragments. To validate the RFLP–PCR tests we sequenced 10% of the amplified fragments. Also, the reproducibility of the three PCR–RFLP methods was assessed by repeating the genotyping of 25 samples on each group in independent experiments. The results were 100% concordant.
2. Methods 2.3. Statistical analysis 2.1. Patients and samples This study was approved by the Bioethics Committee of the School of Health Sciences, Universidad Centroccidental Lisandro Alvarado (UCLA), and all patients gave their written informed consent to participate in the study. The gastric cancer group consisted of 122 paraffinembedded samples from the archive of the Pathology Department Service of the Hospital Antonio María Pineda (HAMP), Barquisimeto, Venezuela. All gastric carcinoma samples included were identified as intestinal type (according to the Lauren's classification), and classified in degrees of differentiation depending on gland formation ranges: well, moderate and poorly differentiated tumors (Crawford, 1994). In the control group were included 129 patients diagnosed with chronic gastritis confirmed by histopathological analysis without evidence of gastric cancer. Patients with criteria for indication of endoscopy were referred to the Gastroenterology Service of the HAMP. The evaluation of chronic gastritis samples was performed according to the Sydney classification system in regard to the presence and degree of atrophic gastritis, granulocytic infiltration and lymphocytic infiltration. Two independent experts in pathology from the Department of Pathology (HAMP-UCLA) evaluated all biopsies. DNA from endoscopic and paraffin embedded biopsies was extracted by Wizard Genomic DNA Purification kit and MagneSil® Genomic Fixed Tissue System (Promega), respectively, according to the manufacturer's instructions. For PCR reactions 1–2 μl of genomic DNA was used. 2.2. Genotyping Table 1 summarizes primers and other details of the PCR–restriction fragment length polymorphism (PCR–RFLP) reactions used for rs1447295, rs4733616 and rs6983267 SNPs genotyping. We designed PCR primers to amplify DNA extracted from paraffin-embedded tissues efficiently. Primers for PCR were designed using software DNAMAN Version 7.212 (Lynnon Corporation). All amplification reactions were carried out on a GeneAmp® PCR System 9700 (Applied Biosystems) thermo cycler. Specific PCR reactions were performed in a final volume of 25 μl containing 1 × Green GoTaq® Flexi Buffer, 0.2 mM dNTPs, 1.5 mM MgCl2, 1.25 U of GoTaq DNA Polymerase (Promega). Kodak
The SPSS11.0 software (SPSS Inc., Chicago, IL, USA) was used for statistical analyses to compare the differences among groups. Multiple regression analysis was used to calculate the odd ratios (ORs) for dependent variable adjusted by age and sex. Analyses were carried out in three inheritance models regarding the known risk alleles: codominant, dominant and recessive. A P value of b0.05 was considered statistically significant. Hardy–Weinberg equilibrium was tested using the twosided χ2. Linkage disequilibrium was assessed for all possible combination of pairs of SNPs using Arlequin software version 3.5.1.2. The bestfitting models were determined by using Akaike information criterion (AIC). Statistic powers was post-hoc calculated using the G*Power software (version 3.1). 3. Results We genotyped 122 cases and 129 controls for each of the three variants of 8q24 included in this work. The mean age of subjects was 58.83 years (range, 40 to 88 years) for controls and 62.46 years (range, 35 to 94 years) for gastric cancer patients. There were 51.2% emales and 48.8% males and 27.9% females and 72.1% males among controls and cases, respectively. Gastric cancer tissues were classified as well-, moderately, and poorly differentiated carcinoma: 14 (11.5%), 56 (45.9%) and 52 (42.6%), respectively. For the subsequent analysis a single group was constituted with well and moderately differentiated gastric carcinoma samples (57.4%; 70/122). The genotype frequencies of rs1447295, rs4733616 and rs6983267 SNPs in controls and cases are shown in Table 1. Among the controls, the genotype distributions of the three SNPs were in Hardy–Weinberg equilibrium (P N 0.05) (Table 2). The 8q24 SNPs included in this study were not in linkage disequilibrium (D′ b 0.15; r2 b 0.01) with one another. The post-hoc power analyses (1-β) for all calculations are presented in Tables 2 and 3. There were no significant differences in genotype frequencies of rs1447295, rs4733616 and rs6983267 SNPs between gastric cancer and gastritis groups (Table 2). Interestingly, we observed that the rs4733616 homozygous TT genotype had a significantly increased risk for poorly differentiated gastric carcinoma according to codominant (OR = 3.59, 95% CI: 1.09–11.79, P = 0.035, 1-β = 0.997, AIC = 135.6) and recessive models (OR = 4.32, 95% CI: 1.35–13.83, P = 0.014, 1-
Table 1 Primers and PCR–RFLP parameters used in this work to genotype 8q24 polymorphisms. Polymorphism
Primer sequence (5′ → 3′) a
AT (°C)
SAF (bp)
RE
Genotype definition (bp)* GG: 22, 97 GT: 22, 97, 119 TT: 119 AA: 106 CA: 106, 70, 36 CC: 70, 36 CC: 72, 26 CT: 98, 72, 26 TT: 98
rs6983267 G/T
Forward : 5′-CCATAAAACAGAGGGACG-3′ Reversea: 5′-TTTCTTTGTACTTTTCTCAGGG-3′
57
119
HaeIII
rs1447295 C/A
Forwarda: 5′-CAATTGAGGAAGTGCCATTGG-3′ Reverseb: 5′-CAGAAATCCCTACCCCCACCAG-3′
59
106
HpyCH4IV
rs4733616 C/T
Forwarda: 5′-CTGAACTATTTGCAGGCTATAACTGC-3′ Reversea: 5′-AAGGCAGTGAAGCCACAGG-3′
59
98
MspI
AT = annealing temperature; SAF = size of amplified fragment; RE = restriction enzyme; * size of fragments of the indicated genotypes after digesting the PCR product with the respective restriction enzyme. Primers designed: a, this work; b, Wokołorczyk et al., 2009 Underlined nucleotides generate: HaeIII restriction site in the presence of rs6983267 G allele; MspI restriction site in the presence of rs4733616 C allele. For rs1447295, primers allow to amplify a 106 bp fragment containing this SNP, which in the presence of the C nucleotide generates a HpyCH4IV restriction site.
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Table 2 Association of rs1447295, rs4733616 and rs6983267 SNPs at 8q24 region with gastric cancer risk. SNP
Risk allele
HWE (control)
Inheritance model
Genotype
P value rs6983267
G
Dominant Recessive A
n
OR (95% CI)a
n
(%)
TT GT GG TT GG + GT GT + TT GG
27 56 46 27 102 83 46
(20.9) (43.4) (35.7) (20.9) (79.1) (64.3) (35.7)
26 47 49 26 96 73 49
(21.3) (38.5) (40.2) (21.3) (78.7) (59.8) (40.2)
1.00 0.97 (0.49–1.93) 1.29 (0.63–2.64) 1.00 1.14 (0.61–2.14) 1.00 1.25 (0.73–2.12)
CC CA AA CC CA + AA CC + CA AA
86 35 8 86 43 121 8
(66.7) (27.1) (6.2) (66.7) (33.3) (93.8) (6.2)
76 35 11 76 46 111 11
(62.3) (28.7) (9.0) (62.3) (37.7) (91.0) (9.0)
1.00 1.25 (0.70–2.23) 1.57 (0.58–4.27) 1.00 1.34 (0.78–2.29) 1.00 1.54 (0.58–4.10)
CC TC TT CC TC + TT CC + TC TT
69 47 13 69 60 116 13
(53.5) (36.4) (10.1) (53.5) (46.5) (89.9) (10.1)
74 32 16 74 48 106 16
(60.7) (26.2) (13.1) (60.7) (39.3) (86.9) (13.1)
1.00 0.64 (0.36–1.13) 1.00 (0.43–2.33) 1.00 0.72 (0.43–1.21) 1.00 1.18 (0.63–2.64)
P valuea
1-β
0.937 0.488
0.09415 0.07264
0.686
0.05279
0.419
0.31877
0.454 0.357
0.08299 0.27583
0.291
0.31561
0.389
0.45213
0.122 0.997
0.49440 0.07699
0.220
0.62819
0.682
0.35119
(%)
0.100 Codominant Dominant Recessive
rs4733616
Gastric cancer
0.201 Codominant
rs1447295
Control
T
0.246 Codominant Dominant Recessive
HWE: Hardy–Weinberg equilibrium; OR: odds ratio; CI: confidence interval; and n: number of subjects. Statistical power (1-β) was calculated for all observed P values. a Adjusted by age and gender.
β = 0.999, AIC = 125.5), adjusted by age and gender (Table 3). However, AIC score suggested recessive model as the best-fitting one. 4. Discussion Chromosome 8q24 is an established risk locus for carcinogenesis in various organs, including gastric cancer (Brisbin et al., 2011; Neta et al., 2012; Tarleton et al., 2014). Furthermore, recent studies revealed that copy number gains of genes located at 8q24 is an early event during
the multistage pathogenesis of gastric cancer (Kang, 2014), and is associated with poor survival patients with gastric cancer (Wang et al., 2015). In addition, the association of common polymorphisms located at chromosome 8q24 with the risk of prostate, breast, colorectal and thyroid follicular tumors has suggested a role for these variants in the formation of multiple adenomas (Berndt et al., 2008). The mechanism by which SNPs located in the gene-poor 8q24 region modify cancer risk is not completely understood. Among the proposed hypothesis it has been suggested that 8q24 region harbors cis-
Table 3 Distribution of rs1447295, rs4733616 and rs6983267 SNPs at 8q24 region according to the degree of histological differentiation of gastric cancer. SNP
Inheritance model
Genotype
OR (95% CI)a
Poor (N = 52)
W/M (N = 70)
n
n
n
(%)
TT GT GG TT GG + GT GT + TT GG
9 19 24 9 43 28 24
(17.3) (36.5) (46.1) (17.3) (82.7) (53.9) (46.1)
17 28 25 17 53 45 25
(24.3) (40.0) (35.7) (24.3) (75.7) (64.3) (35.7)
1.00 1.27 (0.44–3.61) 1.82 (0.67–4.90) 1.00 1.54 (0.61–3.85) 1.00 1.59 (0.75–3.35)
CC CA AA CC CA + AA CC + CA AA
32 16 4 32 20 48 4
(61.5) (30.8) (7.7) (61.5) (38.5) (92.3) (7.7)
44 19 7 44 26 63 7
(62.9) (27.1) (10.0) (62.9) (37.1) (90.0) (10.0)
1.00 1.16 (0.51–2.62) 0.69 (0.18–2.71) 1.00 1.02 (0.48–2.16) 1.00 0.68 (0.18–2.57)
CC TC TT CC TC + TT CC + TC TT
31 10 11 31 21 41 11
(59.6) (19.2) (21.2) (59.6) (40.4) (78.8) (21.2)
43 22 5 43 27 65 5
(61.4) (31.4) (7.2) (61.4) (38.6) (92.8) (7.2)
1.00 0.60 (0.24–1.49) 3.59 (1.09–11.79) 1.00 1.21 (0.53–2.36) 1.00 4.32 (1.35–13.83)
P valuea
1-β
0.664 0.238
0.18838 0.70323
0.360
0.43761
0.224
0.66918
0.729 0.596
0.09599 0.11974
0.955
0.06182
0.680
0.13532
0.272 0.035
0.45346 0.99774
0.764
0.06932
0.014
0.99997
rs6983267 Codominant Dominant Recessive rs1447295 Codominant Dominant Recessive rs4733616 Codominant Dominant Recessive
Poor: poorly differentiated; W/M: well and moderately differentiated gastric adenocarcinoma; OR: odds ratio; CI: confidence interval; and n: number of subjects. Statistical power (1-β) was calculated for all observed P values. Statistically significant results are shown in bold. a Adjusted by age and gender.
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regulatory enhancers for the nearby MYC proto-oncogene. Evidence indicating a functional link between 8q24 loci and MYC was provided by Tuupanen et al. (2009), which demonstrated that rs6983267 affects a binding site for the Wnt-regulated transcription factor 7-like 2 (TCF7L2), with the risk allele G showing stronger binding in vitro and in vivo. Moreover, evidence from Pomerantz et al. (2009) suggest that the rs6983267 variant is a transcriptional enhancer that cannot only differentially bind TCF7L2, but that the risk region physically interacts with MYC. Additional data support this interaction, for example, Ahmadiyeh et al. (2010) suggested that enhancer elements at 8q24 form a longrange chromatin loop with MYC in a tissue-specific manner, while Kim et al. (2014) found that the MYC enhancer region physically interacts with the active regulatory region of the long noncoding RNAs CARLo-5 promoter, thus regulating CARLo-5 expression, which is significantly correlated with the rs6983267 allele and increased cancer susceptibility. The association between variants on chromosome 8q24 and gastric cancer has been analyzed in recent reports (Park et al., 2008; Wokołorczyk et al., 2008; Guo et al., 2011; Lochhead et al., 2011; Tarleton et al., 2014; Ma et al., 2015). In this regard, Guo et al. (2011) found that the GT genotype of rs6983267 was associated with an increased risk of gastric cancer compared with GG genotype in Chinese population. Furthermore, the rs6983267 GT genotype increased the risk of gastric cancer of non-cardiac and intestinal type. However, in accordance with our results, other studies performed in Caucasian (Poland and USA) and Chinese populations did not find association of SNP rs6983267 with gastric cancer (Park et al., 2008; Wokołorczyk et al., 2008; Lochhead et al., 2011; Tarleton et al., 2014). Similar to studies conducted in Chinese populations (Park et al., 2008; Tarleton et al., 2014), our data also failed to show the existence of association between the 8q24 SNP rs1447295 and gastric cancer. This variant, previously identified as a prostate cancer-associated polymorphism (Severi et al., 2007; Wokołorczyk et al., 2010), was observed to be involved in an inverse (OR = 0.63; 95% CI, 0.41–0.97) and positive (OR = 7.43; 95% CI, 1.37–49.98) association with gastric cancer and esophageal squamous cell carcinoma risk, respectively in Caucasian (Lochhead et al., 2011). In our study, we did not observe difference on the genotype distribution of SNP rs4733616 between cases and controls. However, the homozygous TT genotype was associated with an increased risk of poorly differentiated gastric adenocarcinoma under the best-fitting recessive model of inheritance (OR = 4.32), but it was not associated with moderate/well-differentiated gastric cancer. The risk allele of rs4733616 (T) at chromosome 8q24 has been associated with the risk of papillary thyroid cancer (Neta et al., 2012), but its functional significance has not been clarified yet. The degree of differentiation of tumor cells has been shown to correlate with the aggressiveness and prognosis of gastric cancer, and should be evaluated in the management of this malignance (Adachi et al., 2000; Zu et al., 2014). Furthermore, genetic polymorphisms, mutations and epigenetic alterations have been related to the development of poorly differentiated type, but not with moderately or well-differentiated gastric cancer, suggesting that, in addition to the common molecular pathway of stomach carcinogenesis, the subtypes of gastric cancer result from different etiologic pathways or biological mechanisms (Yasui et al, 2006; Yu et al., 2010). Besides ethnical differences with populations previously analyzed, another explanation for the negative findings could be the inadequate statistical powers to detect potential associations (1-β b 0.80) observed for rs1447295 and rs6983267 in our study, probably due to the small sample size. Moreover, the post-hoc analysis indicates that there was enough statistical power (1-β N 0.80 at type I level of 0.05) to support the significant contribution observed for the TT genotype of rs4733616 to develop poorly differentiated gastric cancer. In summary, the present study is the first one to examine SNPs in the 8q24 chromosomal region related to risk of gastric cancer in a Latin American population. Unlike other types of cancer, the influence of
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rs1447295 and rs6983267 polymorphisms in gastric cancer susceptibility seems to be controversial. A limitation of our study is the relatively small sample size. Moreover, we cannot rule out the possibility that the observed significant association with rs4733616 TT genotype could be driven by the small number of well and moderately differentiated gastric carcinoma samples that presented this genotype. For that reason a larger number of samples to increase the statistical power is required to fully explore the role of the 8q24 chromosome region in the susceptibility of gastric cancer in our population. Other considered limitations were the difference in mean age and the unequal gender ratio between control and gastric cancer groups, which could originate confounding results. However, after adjustment for age and sex, we observed a significant association of rs4733616 variant with poorly differentiated gastric cancer. Further investigation is also needed in order to understand the potential use of rs4733616 polymorphism as a prognosis marker in the management of gastric cancer. Conflict of interest The authors declare no conflict of interest. Acknowledgments This study was supported by CDCHT-UCLA grant 001-CS-2013. We thank L. Mendoza for their technical assistance. We would also like to thank E. Armanie and N. Granda for endoscopic biopsy sampling. To Dr. N. Lander for revising the English of the manuscript. References Abnet, C.C., Freedman, N.D., Hu, N., Wang, Z., Yu, K., Shu, X.O., Yuan, J.M., Zheng, W., Dawsey, S.M., Dong, L.M., Lee, M.P., Ding, T., Qiao, Y.L., Gao, Y.T., Koh, W.P., Xiang, Y.B., Tang, Z.Z., Fan, J.H., Wang, C., Wheeler, W., Gail, M.H., Yeager, M., Yuenger, J., Hutchinson, A., Jacobs, K.B., Giffen, C.A., Burdett, L., Fraumeni Jr., J.F., Tucker, M.A., Chow, W.H., Goldstein, A.M., Chanock, S.J., Taylor, P.R., 2010. A shared susceptibility locus in PLCE1 at 10q23 for gastric adenocarcinoma and esophageal squamous cell carcinoma. Nat. Genet. 42, 764–767. Adachi, Y., Yasuda, K., Inomata, M., Sato, K., Shiraishi, N., Kitano, S., 2000. Pathology and prognosis of gastric carcinoma: well versus poorly differentiated type. Cancer 89, 1418–1424. Ahmadiyeh, N., Pomerantz, M.M., Grisanzio, C., Herman, P., Jia, L., Almendro, V., He, H.H., Brown, M., Liu, X.S., Davis, M., Caswell, J.L., Beckwith, C.A., Hills, A., Macconaill, L., Coetzee, G.A., Regan, M.M., Freedman, M.L., 2010. 8q24 prostate, breast, and colon cancer risk loci show tissue-specific long-range interaction with MYC. Proc. Natl. Acad. Sci. U. S. A. 107, 9742–9746. Berndt, S.I., Potter, J.D., Hazra, A., Yeager, M., Thomas, G., Makar, K.W., Welch, R., Cross, A.J., Huang, W.Y., Schoen, R.E., Giovannucci, E., Chan, A.T., Chanock, S.J., Peters, U., Hunter, D.J., Hayes, R.B., 2008. Pooled analysis of genetic variation at chromosome 8q24 and colorectal neoplasia risk. Hum. Mol. Genet. 17, 2665–2672. Brisbin, A.G., Asmann, Y.W., Song, H., Tsai, Y.Y., Aakre, J.A., Yang, P., Jenkins, R.B., Pharoah, P., Schumacher, F., Conti, D.V., Duggan, D.J., Jenkins, M., Hopper, J., Gallinger, S., Newcomb, P., Casey, G., Sellers, T.A., Fridley, B.L., 2011. Meta-analysis of 8q24 for seven cancers reveals a locus between NOV and ENPP2 associated with cancer development. BMC Med. Genet. 12, 156. Chiurillo, M.A., 2014. Role of gene polymorphisms in gastric cancer and its precursor lesions: current knowledge and perspectives in Latin American countries. World J. Gastroenterol. 20, 4503–4515. Correa, P., 1995. Helicobacter pylori and gastric carcinogenesis. Am. J. Surg. Pathol. 19, S37–S43. Crawford, J., 1994. The gastrointestinal tract. In: Robbins, S.L.C.R., Kumar, V., Schoen, F.J. (Eds.), Pathologic Basis of Disease. WB Saunders Co, Philadelphia, pp. 755–783. Easton, D.F., Pooley, K.A., Dunning, A.M., Pharoah, P.D., Thompson, D., Ballinger, D.G., Struewing, J.P., Morrison, J., Field, H., Luben, R., Wareham, N., Ahmed, S., Healey, C.S., Bowman, R., Meyer, K.B., Haiman, C.A., Kolonel, L.K., Henderson, B.E., Le Marchand, L., Brennan, P., Sangrajrang, S., Gaborieau, V., Odefrey, F., Shen, C.Y., Wu, P.E., Wang, H.C., Eccles, D., Evans, D.G., Peto, J., Fletcher, O., Johnson, N., Seal, S., Stratton, M.R., Rahman, N., Chenevix-Trench, G., Bojesen, S.E., Nordestgaard, B.G., Axelsson, C.K., Garcia-Closas, M., Brinton, L., Chanock, S., Lissowska, J., Peplonska, B., Nevanlinna, H., Fagerholm, R., Eerola, H., Kang, D., Yoo, K.Y., Noh, D.Y., Ahn, S.H., Hunter, D.J., Hankinson, S.E., Cox, D.G., Hall, P., Wedren, S., Liu, J., Low, Y.L., Bogdanova, N., Schürmann, P., Dörk, T., Tollenaar, R.A., Jacobi, C.E., Devilee, P., Klijn, J.G., Sigurdson, A.J., Doody, M.M., Alexander, B.H., Zhang, J., Cox, A., Brock, I.W., MacPherson, G., Reed, M.W., Couch, F.J., Goode, E.L., Olson, J.E., Meijers-Heijboer, H., van den Ouweland, A., Uitterlinden, A., Rivadeneira, F., Milne, R.L., Ribas, G., Gonzalez-Neira, A., Benitez, J., Hopper, J.L., McCredie, M., Southey, M., Giles, G.G., Schroen, C., Justenhoven, C., Brauch, H., Hamann, U., Ko, Y.D., Spurdle, A.B., Beesley, J., Chen, X., Mannermaa, A., Kosma, V.M., Kataja, V., Hartikainen, J., Day, N.E., Cox,
124
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D.R., Ponder, B.A., 2007. Genome-wide association study identifies novel breast cancer susceptibility loci. Nature 447, 1087–1093. Ferlay, J., Shin, H.R., Bray, F., Forman, D., Mathers, C., Parkin, D.M., 2010. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. Int. J. Cancer 127, 2893–2917. Ferlay, J., Soerjomataram, I., Ervik, M., Dikshit, R., Eser, S., Mathers, C., Rebelo, M., Parkin, D.M., Forman, D., Bray, F., 2013. GLOBOCAN 2012 v1.0, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 11 [Internet]. International Agency for Research on Cancer, Lyon, France Available from http://globocan.iarc.fr. Ghoussaini, M., Song, H., Koessler, T., Al Olama, A.A., Kote-Jarai, Z., Driver, K.E., Pooley, K.A., Ramus, S.J., Kjaer, S.K., Hogdall, E., Di Cioccio, R.A., Whittemore, A.S., Gayther, S.A., Giles, G.G., Guy, M., Edwards, S.M., Morrison, J., Donovan, J.L., Hamdy, F.C., Dearnaley, D.P., Ardern-Jones, A.T., Hall, A.L., O'Brien, L.T., Gehr-Swain, B.N., Wilkinson, R.A., Brown, P.M., Hopper, J.L., Neal, D.E., Pharoah, P.D., Ponder, B.A., Eeles, R.A., Easton, D.F., Dunning, A.M., 2008. Multiple loci with different cancer specificities within the 8q24 gene desert. J. Natl. Cancer Inst. 100, 962–966. Guo, Y., Fang, J., Liu, Y., Sheng, H.H., Zhang, X.Y., Chai, H.N., Jin, W., Zhang, K.H., Yang, C.Q., Gao, H.J., 2011. Association between polymorphism rs6983267 and gastric cancer risk in Chinese population. World J. Gastroenterol. 17, 1759–1765. Kang, J.U., 2014. Chromosome 8q as the most frequent target for amplification in early gastric carcinoma. Oncol. Lett. 7, 1139–1143. Kim, T., Cui, R., Jeon, Y.J., Lee, J.H., Lee, J.H., Sim, H., Park, J.K., Fadda, P., Tili, E., Nakanishi, H., Huh, M.I., Kim, S.H., Cho, J.H., Sung, B.H., Peng, Y., Lee, T.J., Luo, Z., Sun, H.L., Wei, H., Alder, H., Oh, J.S., Shim, K.S., Ko, S.B., Croce, C.M., 2014. Long-range interaction and correlation between MYC enhancer and oncogenic long noncoding RNA CARLo-5. Proc. Natl. Acad. Sci. U. S. A. 111, 4173–4178. Lochhead, P., Ng, M.T., Hold, G.L., Rabkin, C.S., Vaughan, T.L., Gammon, M.D., Risch, H.A., Lissowska, J., Mukhopadhya, I., Chow, W.H., El-Omar, E.M., 2011. Possible association between a genetic polymorphism at 8q24 and risk of upper gastrointestinal cancer. Eur. J. Cancer Prev. 20, 54–57. Ma, G., Gu, D., Lv, C., Chu, H., Xu, Z., Tong, N., Tag, C., Xu, Y., Zhang, B., Chen, J., 2015. Genetic variant in 8q24 is associated with prognosis in a Chinese population. J. Gastroenterol. Hepatol. 30, 689–695. McNamara, D., El-Omar, E., 2008. Helicobacter pylori infection and the pathogenesis of gastric cancer: a paradigm for host-bacterial interactions. Dig. Liver Dis. 40, 504–509. Neta, G., Yu, C.L., Brenner, A., Gu, F., Hutchinson, A., Pfeiffer, R., Sturgis, E.M., Xu, L., Linet, M.S., Alexander, B.H., Chanock, S., Sigurdson, A.J., 2012. Common genetic variants in the 8q24 region and risk of papillary thyroid cancer. Laryngoscope 122, 1040–1042. Park, S.L., Chang, S.C., Cai, L., Cordon-Cardo, C., Ding, B.G., Greenland, S., Hussain, S.K., Jiang, Q., Liu, S., Lu, M.L., Mao, J.T., Morgenstern, H., Mu, L.N., Ng, L.J., Pantuck, A., Rao, J., Reuter, V.E., Tashkin, D.P., You, N.C., Yu, C.Q., Yu, S.Z., Zhao, J.K., Belldegrun, A., Zhang, Z.F., 2008. Associations between variants of the 8q24 chromosome and nine smoking-related cancer sites. Cancer Epidemiol. Biomarkers Prev. 17, 3193–3202. Pomerantz, M.M., Ahmadiyeh, N., Jia, L., Herman, P., Verzi, M.P., Doddapaneni, H., Beckwith, C.A., Chan, J.A., Hills, A., Davis, M., Yao, K., Kehoe, S.M., Lenz, H.J., Haiman, C.A., Yan, C., Henderson, B.E., Frenkel, B., Barretina, J., Bass, A., Tabernero, J., Baselga, J., Regan, M.M., Manak, J.R., Shivdasani, R., Coetzee, G.A., Freedman, M.L., 2009. The 8q24 cancer risk variant rs6983267 shows long-range interaction with MYC in colorectal cancer. Nat. Genet. 41, 882–884. Saeki, N., Ono, H., Sakamoto, H., Yoshida, T., 2013. Genetic factors related to gastric cancer susceptibility identified using a genome-wide association study. Cancer Sci. 104, 1–8. Sakamoto, H., Yoshimura, K., Saeki, N., Katai, H., Shimoda, T., Matsuno, Y., Saito, D., Sugimura, H., Tanioka, F., Kato, S., Matsukura, N., Matsuda, N., Nakamura, T., Hyodo, I., Nishina, T., Yasui, W., Hirose, H., Hayashi, M., Toshiro, E., Ohnami, S., Sekine, A., Sato, Y., Totsuka, H., Ando, M., Takemura, R., Takahashi, Y., Ohdaira, M., Aoki, K., Honmyo, I., Chiku, S., Aoyagi, K., Sasaki, H., Ohnami, S., Yanagihara, K., Yoon, K.A., Kook, M.C., Lee, Y.S., Park, S.R., Kim, C.G., Choi, I.J., Yoshida, T., Nakamura, Y., Hirohashi, S., 2008. Genetic variation in PSCA is associated with susceptibility to diffuse-type gastric cancer. Nat. Genet. 40, 730–740. Severi, G., Hayes, V.M., Padilla, E.J., English, D.R., Southey, M.C., Sutherland, R.L., Hopper, J.L., Giles, G.G., 2007. The common variant rs1447295 on chromosome 8q24 and prostate cancer risk: results from an Australian population-based case–control study. Cancer Epidemiol. Biomarkers Prev. 16, 610–612. Shi, Y., Hu, Z., Wu, C., Dai, J., Li, H., Dong, J., Wang, M., Miao, X., Zhou, Y., Lu, F., Zhang, H., Hu, L., Jiang, Y., Li, Z., Chu, M., Ma, H., Chen, J., Jin, G., Tan, W., Wu, T., Zhang, Z., Lin, D.,
Shen, H., 2011. A genome-wide association study identifies new susceptibility loci for non-cardia gastric cancer at 3q13.31 and 5p13.1. Nat. Genet. 43, 1215–1218. Tarleton, H.P., Chang, S.C., Park, S.L., Cai, L., Ding, B., He, N., Hussain, S.K., Jiang, Q., Mu, L.N., Rao, J., Wang, H., You, N.C., Yu, S.Z., Zhao, J.K., Zhang, Z.F., 2014. Genetic variation at 8q24, family history of cancer, and upper gastrointestinal cancers in a Chinese population. Fam. Cancer 13, 45–56. Turnbull, C., Ahmed, S., Morrison, J., Pernet, D., Renwick, A., Maranian, M., Seal, S., Ghoussaini, M., Hines, S., Healey, C.S., Hughes, D., Warren-Perry, M., Tapper, W., Eccles, D., Evans, D.G., Hooning, M., Schutte, M., van den Ouweland, A., Houlston, R., Ross, G., Langford, C., Pharoah, P.D., Stratton, M.R., Dunning, A.M., Rahman, N., Easton, D.F., 2010. Genome-wide association study identifies five new breast cancer susceptibility loci. Nat. Genet. 42, 504–507. Tuupanen, S., Turunen, M., Lehtonen, R., Hallikas, O., Vanharanta, S., Kivioja, T., Björklund, M., Wei, G., Yan, J., Niittymäki, I., Mecklin, J.P., Järvinen, H., Ristimäki, A., Di-Bernardo, M., East, P., Carvajal-Carmona, L., Houlston, R.S., Tomlinson, I., Palin, K., Ukkonen, E., Karhu, A., Taipale, J., Aaltonen, L.A., 2009. The common colorectal cancer predisposition SNP rs6983267 at chromosome 8q24 confers potential to enhanced Wnt signaling. Nat. Genet. 41, 885–890. Von Holst, S., Picelli, S., Edler, D., Lenander, C., Dalén, J., Hjern, F., Lundqvist, N., Lindforss, U., Påhlman, L., Smedh, K., Törnqvist, A., Holm, J., Janson, M., Andersson, M., Ekelund, S., Olsson, L., Ghazi, S., Papadogiannakis, N., Tenesa, A., Farrington, S.M., Campbell, H., Dunlop, M.G., Lindblom, A., 2010. Association studies on 11 published colorectal cancer risk loci. Br. J. Cancer 103, 575–580. Wadhwa, R., Song, S., Lee, J.S., Yao, Y., Wei, Q., Ajani, J.A., 2013. Gastric cancer-molecular and clinical dimensions. Nat. Rev. Clin. Oncol. 10, 643–655. Wang, X., Liu, Y., Shao, D., Qian, Z., Dong, Z., Sun, Y., Xing, X., Cheng, X., Du, H., Hu, Y., Li, Y., Li, L., Dong, B., Li, Z., Wu, A., Wu, X., Bu, Z., Zong, X., Zhu, G., Ji, Q., Wen, X.Z., Zhang, L.H., Ji, J.F., 2015. Recurrent amplification of MYC and TNFRSF11B in 8q24 is associated with poor survival in patients with gastric cancer. Gastric Cancer http://dx.doi.org/ 10.1007/s10120-015-0467-2. Wokołorczyk, D., Gliniewicz, B., Sikorski, A., Zlowocka, E., Masojc, B., Debniak, T., Matyjasik, J., Mierzejewski, M., Medrek, K., Oszutowska, D., Suchy, J., Gronwald, J., Teodorczyk, U., Huzarski, T., Byrski, T., Jakubowska, A., Górski, B., van de Wetering, T., Walczak, S., Narod, S.A., Lubinski, J., Cybulski, C., 2008. A range of cancers is associated with the rs6983267 marker on chromosome 8. Cancer Res. 68, 9982–9986. Wokołorczyk, D., Lubiński, J., Narod, S.A., Cybulski, C., 2009. Genetic heterogeneity of 8q24 region in susceptibility to cancer. J. Natl. Cancer Inst. 101, 278–279. Wokołorczyk, D., Gliniewicz, B., Stojewski, M., Sikorski, A., Złowocka, E., Debniak, T., Jakubowska, A., Górski, B., van de Wetering, T., Narod, S.A., Lubiński, J., Cybulski, C., 2010. The rs1447295 and DG8S737 markers on chromosome 8q24 and cancer risk in the Polish population. Eur. J. Cancer Prev. 19, 167–171. Yasui, W., Sentani, K., Motoshita, J., Nakayama, H., 2006. Molecular pathobiology of gastric cancer. Scand. J. Surg. 95, 225–231. Yeager, M., Chatterjee, N., Ciampa, J., Jacobs, K.B., Gonzalez-Bosquet, J., Hayes, R.B., Kraft, P., Wacholder, S., Orr, N., Berndt, S., Yu, K., Hutchinson, A., Wang, Z., Amundadottir, L., Feigelson, H.S., Thun, M.J., Diver, W.R., Albanes, D., Virtamo, J., Weinstein, S., Schumacher, F.R., Cancel-Tassin, G., Cussenot, O., Valeri, A., Andriole, G.L., Crawford, E.D., Haiman, C.A., Henderson, B., Kolonel, L., Le, Marchand, L., Siddiq, A., Riboli, E., Key, T.J., Kaaks, R., Isaacs, W., Isaacs, S., Wiley, K.E., Gronberg, H., Wiklund, F., Stattin, P., Xu, J., Zheng, S.L., Sun, J., Vatten, L.J., Hveem, K., Kumle, M., Tucker, M., Gerhard, D.S., Hoover, R.N., Fraumeni Jr., J.F., Hunter, D.J., Thomas, G., Chanock, S.J., 2009. Identification of a new prostate cancer susceptibility locus on chromosome 8q24. Nat. Genet. 41, 1055–1057. Yu, J., Zeng, Z., Wang, S., Tian, L., Wu, J., Xue, L., Lee, C.W., Zhang, M., Goggins, W.B., Chen, M., Hu, P., Sung, J.J., 2010. IL-1B-511 polymorphism is associated with increased risk of certain subtypes of gastric cancer in Chinese: a case–control study. Am. J. Gastroenterol. 105, 557–564. Zu, H., Wang, H., Li, C., Xue, Y., 2014. Histologic type is important for estimating the tumor progression and outcomes of patients with gastric carcinoma. Int. J. Clin. Exp. Pathol. 7, 5692–5700.
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Short communication
Association of common variants on chromosome 8q24 with gastric cancer in Venezuelan patients Luis Labrador a, Keila Torres a, Maria Camargo a, Laskhmi Santiago a, Elvis Valderrama b, Miguel Angel Chiurillo a,⁎ a b
Laboratorio de Genética Molecular “Dr. Jorge Yunis-Turbay”, Decanato de Ciencias de la Salud, Universidad Centroccidental Lisandro Alvarado (UCLA), Barquisimeto 3001, Venezuela Departamento de Anatomía Patología, Hospital Antonio María Pineda-UCLA, Barquisimeto 3001, Venezuela
a r t i c l e
i n f o
Article history: Received 21 February 2015 Received in revised form 17 April 2015 Accepted 30 April 2015 Available online 2 May 2015 Keywords: Gastric cancer 8q24 SNPs Histologic differentiation Susceptibility
a b s t r a c t Gastric cancer remains one of the leading causes of death in the world, being Central and South America among the regions showing the highest incidence and mortality rates worldwide. Although several single nucleotide polymorphisms (SNPs) identified in the chromosomal region 8q24 by genome-wide association studies have been related with the risk of different kinds of cancers, their role in the susceptibility of gastric cancer in Latin American populations has not been evaluated yet. Hereby, we performed a case–control study to explore the associations between three SNPs at 8q24 and gastric cancer risk in Venezuelan patients. We analyzed rs1447295, rs4733616 and rs6983267 SNPs in 122 paraffin-embedded tumor samples from archival bank and 129 samples with chronic gastritis (obtained by upper endoscopy during the study) from the Central Hospital of Barquisimeto (Lara, Venezuela). Genotypes were determined by PCR–RFLP reactions designed in this study for efficient genotyping of formalin-fixed/paraffin-embedded tissues. No significant differences in genotype frequencies between case and control groups were found. However, carriers of the homozygous TT genotype of SNP rs4733616 had an increased risk of developing poorly differentiated gastric cancer according to the codominant (OR = 3.59, P = 0.035) and the recessive models (OR = 4.32, P = 0.014, best-fitting model of inheritance), adjusted by age and gender. Our study suggests that the SNP rs4733616 is associated with susceptibility to poorly differentiated gastric cancer in Venezuelans. Additional studies are needed to further interrogate the prognostic value of the rs4733616 marker in this high-risk population for gastric cancer. © 2015 Elsevier B.V. All rights reserved.
1. Introduction Gastric cancer incidence and mortality have been decreasing in most Western countries over the last few decades, however, it still remains the fifth most common cancer and the third leading cause of cancerrelated death in both sexes worldwide after lung and breast cancer (723,000 deaths in 2012) (Ferlay et al., 2010, 2013). Eastern Asia exhibits the highest estimated mortality rates in both sexes worldwide, followed by nations from Central and Eastern Europe and Central and South America (Ferlay et al., 2013). Gastric cancer is a complex disease resulting from the interaction between genetic and environmental risk factors at the stomach mucosa Abbreviations: SNP, Single Nucleotide Polymorphisms; PCR, Polymerase Chain Reaction; RFLP, Restriction Fragment Length Polymorphism; OR, Odds Ratio; GWAS, Genome-Wide Association Studies. ⁎ Corresponding author at: Departamento de Patologia Clínica, Universidade Estadual de Campinas, Campinas 13083-877, São Paulo, Brazil. E-mail addresses: [email protected] (L. Labrador), [email protected] (K. Torres), [email protected] (M. Camargo), [email protected] (L. Santiago), [email protected] (E. Valderrama), [email protected] (M.A. Chiurillo).
http://dx.doi.org/10.1016/j.gene.2015.04.081 0378-1119/© 2015 Elsevier B.V. All rights reserved.
level that contribute to its initiation and progression. The most common histologic variant of gastric adenocarcinoma is the intestinal type (according to Lauren's classification), which arises of a progression from superficial non-atrophic gastritis, to chronic atrophic gastritis followed by intestinal metaplasia and dysplasia and finally, gastric adenocarcinoma (Correa, 1995). Usually this chronic inflammatory background is induced by Helicobacter pylori infection (McNamara and El-Omar, 2008). In recent years genome-wide association studies (GWAS) and highthroughput genetic analysis have identified several loci associated with gastric cancer mainly in Asian populations, including those at 1q22, 3q13.31, 5p13.1, 8q24, 10q23, and 20p13 (Sakamoto et al., 2008; Abnet et al., 2010; Shi et al., 2011; Saeki et al., 2013; Wadhwa et al., 2013). Particularly, the 8q24 chromosome region has been suspected to contain several cancer risk variants that lead to numerous cancer types, including breast, prostate, thyroid, colorectal and gastric cancer (Easton et al., 2007; Berndt et al., 2008; Ghoussaini et al., 2008; Wokołorczyk et al., 2008, 2009; Yeager et al., 2009; Turnbull et al., 2010; Von Holst et al., 2010; Guo et al., 2011; Lochhead et al., 2011; Neta et al., 2012; Ma et al., 2015). Several studies have evaluated the relationship between gene polymorphisms and gastric cancer susceptibility in Latin American
L. Labrador et al. / Gene 566 (2015) 120–124
populations (Chiurillo, 2014). However, there is no report of the relevance of chromosome 8q24 polymorphisms and gastric cancer in this region. Hence, we performed a case–control study to examine the possible link between three SNPs located at the chromosomal region 8q24 (rs1447295, rs4733616 and rs6983267) and gastric cancer in a Venezuelan population where the disease is the leading cause of cancer-related deaths (http://www.mpps.gob.ve/).
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1D Molecular Imaging Software (Eastman Kodak, Rochester, NY) was used for image analysis of ethidium bromide-stained agarose gels (3% w/v) and for allelic assignment of the PCR products and restriction fragments. To validate the RFLP–PCR tests we sequenced 10% of the amplified fragments. Also, the reproducibility of the three PCR–RFLP methods was assessed by repeating the genotyping of 25 samples on each group in independent experiments. The results were 100% concordant.
2. Methods 2.3. Statistical analysis 2.1. Patients and samples This study was approved by the Bioethics Committee of the School of Health Sciences, Universidad Centroccidental Lisandro Alvarado (UCLA), and all patients gave their written informed consent to participate in the study. The gastric cancer group consisted of 122 paraffinembedded samples from the archive of the Pathology Department Service of the Hospital Antonio María Pineda (HAMP), Barquisimeto, Venezuela. All gastric carcinoma samples included were identified as intestinal type (according to the Lauren's classification), and classified in degrees of differentiation depending on gland formation ranges: well, moderate and poorly differentiated tumors (Crawford, 1994). In the control group were included 129 patients diagnosed with chronic gastritis confirmed by histopathological analysis without evidence of gastric cancer. Patients with criteria for indication of endoscopy were referred to the Gastroenterology Service of the HAMP. The evaluation of chronic gastritis samples was performed according to the Sydney classification system in regard to the presence and degree of atrophic gastritis, granulocytic infiltration and lymphocytic infiltration. Two independent experts in pathology from the Department of Pathology (HAMP-UCLA) evaluated all biopsies. DNA from endoscopic and paraffin embedded biopsies was extracted by Wizard Genomic DNA Purification kit and MagneSil® Genomic Fixed Tissue System (Promega), respectively, according to the manufacturer's instructions. For PCR reactions 1–2 μl of genomic DNA was used. 2.2. Genotyping Table 1 summarizes primers and other details of the PCR–restriction fragment length polymorphism (PCR–RFLP) reactions used for rs1447295, rs4733616 and rs6983267 SNPs genotyping. We designed PCR primers to amplify DNA extracted from paraffin-embedded tissues efficiently. Primers for PCR were designed using software DNAMAN Version 7.212 (Lynnon Corporation). All amplification reactions were carried out on a GeneAmp® PCR System 9700 (Applied Biosystems) thermo cycler. Specific PCR reactions were performed in a final volume of 25 μl containing 1 × Green GoTaq® Flexi Buffer, 0.2 mM dNTPs, 1.5 mM MgCl2, 1.25 U of GoTaq DNA Polymerase (Promega). Kodak
The SPSS11.0 software (SPSS Inc., Chicago, IL, USA) was used for statistical analyses to compare the differences among groups. Multiple regression analysis was used to calculate the odd ratios (ORs) for dependent variable adjusted by age and sex. Analyses were carried out in three inheritance models regarding the known risk alleles: codominant, dominant and recessive. A P value of b0.05 was considered statistically significant. Hardy–Weinberg equilibrium was tested using the twosided χ2. Linkage disequilibrium was assessed for all possible combination of pairs of SNPs using Arlequin software version 3.5.1.2. The bestfitting models were determined by using Akaike information criterion (AIC). Statistic powers was post-hoc calculated using the G*Power software (version 3.1). 3. Results We genotyped 122 cases and 129 controls for each of the three variants of 8q24 included in this work. The mean age of subjects was 58.83 years (range, 40 to 88 years) for controls and 62.46 years (range, 35 to 94 years) for gastric cancer patients. There were 51.2% emales and 48.8% males and 27.9% females and 72.1% males among controls and cases, respectively. Gastric cancer tissues were classified as well-, moderately, and poorly differentiated carcinoma: 14 (11.5%), 56 (45.9%) and 52 (42.6%), respectively. For the subsequent analysis a single group was constituted with well and moderately differentiated gastric carcinoma samples (57.4%; 70/122). The genotype frequencies of rs1447295, rs4733616 and rs6983267 SNPs in controls and cases are shown in Table 1. Among the controls, the genotype distributions of the three SNPs were in Hardy–Weinberg equilibrium (P N 0.05) (Table 2). The 8q24 SNPs included in this study were not in linkage disequilibrium (D′ b 0.15; r2 b 0.01) with one another. The post-hoc power analyses (1-β) for all calculations are presented in Tables 2 and 3. There were no significant differences in genotype frequencies of rs1447295, rs4733616 and rs6983267 SNPs between gastric cancer and gastritis groups (Table 2). Interestingly, we observed that the rs4733616 homozygous TT genotype had a significantly increased risk for poorly differentiated gastric carcinoma according to codominant (OR = 3.59, 95% CI: 1.09–11.79, P = 0.035, 1-β = 0.997, AIC = 135.6) and recessive models (OR = 4.32, 95% CI: 1.35–13.83, P = 0.014, 1-
Table 1 Primers and PCR–RFLP parameters used in this work to genotype 8q24 polymorphisms. Polymorphism
Primer sequence (5′ → 3′) a
AT (°C)
SAF (bp)
RE
Genotype definition (bp)* GG: 22, 97 GT: 22, 97, 119 TT: 119 AA: 106 CA: 106, 70, 36 CC: 70, 36 CC: 72, 26 CT: 98, 72, 26 TT: 98
rs6983267 G/T
Forward : 5′-CCATAAAACAGAGGGACG-3′ Reversea: 5′-TTTCTTTGTACTTTTCTCAGGG-3′
57
119
HaeIII
rs1447295 C/A
Forwarda: 5′-CAATTGAGGAAGTGCCATTGG-3′ Reverseb: 5′-CAGAAATCCCTACCCCCACCAG-3′
59
106
HpyCH4IV
rs4733616 C/T
Forwarda: 5′-CTGAACTATTTGCAGGCTATAACTGC-3′ Reversea: 5′-AAGGCAGTGAAGCCACAGG-3′
59
98
MspI
AT = annealing temperature; SAF = size of amplified fragment; RE = restriction enzyme; * size of fragments of the indicated genotypes after digesting the PCR product with the respective restriction enzyme. Primers designed: a, this work; b, Wokołorczyk et al., 2009 Underlined nucleotides generate: HaeIII restriction site in the presence of rs6983267 G allele; MspI restriction site in the presence of rs4733616 C allele. For rs1447295, primers allow to amplify a 106 bp fragment containing this SNP, which in the presence of the C nucleotide generates a HpyCH4IV restriction site.
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Table 2 Association of rs1447295, rs4733616 and rs6983267 SNPs at 8q24 region with gastric cancer risk. SNP
Risk allele
HWE (control)
Inheritance model
Genotype
P value rs6983267
G
Dominant Recessive A
n
OR (95% CI)a
n
(%)
TT GT GG TT GG + GT GT + TT GG
27 56 46 27 102 83 46
(20.9) (43.4) (35.7) (20.9) (79.1) (64.3) (35.7)
26 47 49 26 96 73 49
(21.3) (38.5) (40.2) (21.3) (78.7) (59.8) (40.2)
1.00 0.97 (0.49–1.93) 1.29 (0.63–2.64) 1.00 1.14 (0.61–2.14) 1.00 1.25 (0.73–2.12)
CC CA AA CC CA + AA CC + CA AA
86 35 8 86 43 121 8
(66.7) (27.1) (6.2) (66.7) (33.3) (93.8) (6.2)
76 35 11 76 46 111 11
(62.3) (28.7) (9.0) (62.3) (37.7) (91.0) (9.0)
1.00 1.25 (0.70–2.23) 1.57 (0.58–4.27) 1.00 1.34 (0.78–2.29) 1.00 1.54 (0.58–4.10)
CC TC TT CC TC + TT CC + TC TT
69 47 13 69 60 116 13
(53.5) (36.4) (10.1) (53.5) (46.5) (89.9) (10.1)
74 32 16 74 48 106 16
(60.7) (26.2) (13.1) (60.7) (39.3) (86.9) (13.1)
1.00 0.64 (0.36–1.13) 1.00 (0.43–2.33) 1.00 0.72 (0.43–1.21) 1.00 1.18 (0.63–2.64)
P valuea
1-β
0.937 0.488
0.09415 0.07264
0.686
0.05279
0.419
0.31877
0.454 0.357
0.08299 0.27583
0.291
0.31561
0.389
0.45213
0.122 0.997
0.49440 0.07699
0.220
0.62819
0.682
0.35119
(%)
0.100 Codominant Dominant Recessive
rs4733616
Gastric cancer
0.201 Codominant
rs1447295
Control
T
0.246 Codominant Dominant Recessive
HWE: Hardy–Weinberg equilibrium; OR: odds ratio; CI: confidence interval; and n: number of subjects. Statistical power (1-β) was calculated for all observed P values. a Adjusted by age and gender.
β = 0.999, AIC = 125.5), adjusted by age and gender (Table 3). However, AIC score suggested recessive model as the best-fitting one. 4. Discussion Chromosome 8q24 is an established risk locus for carcinogenesis in various organs, including gastric cancer (Brisbin et al., 2011; Neta et al., 2012; Tarleton et al., 2014). Furthermore, recent studies revealed that copy number gains of genes located at 8q24 is an early event during
the multistage pathogenesis of gastric cancer (Kang, 2014), and is associated with poor survival patients with gastric cancer (Wang et al., 2015). In addition, the association of common polymorphisms located at chromosome 8q24 with the risk of prostate, breast, colorectal and thyroid follicular tumors has suggested a role for these variants in the formation of multiple adenomas (Berndt et al., 2008). The mechanism by which SNPs located in the gene-poor 8q24 region modify cancer risk is not completely understood. Among the proposed hypothesis it has been suggested that 8q24 region harbors cis-
Table 3 Distribution of rs1447295, rs4733616 and rs6983267 SNPs at 8q24 region according to the degree of histological differentiation of gastric cancer. SNP
Inheritance model
Genotype
OR (95% CI)a
Poor (N = 52)
W/M (N = 70)
n
n
n
(%)
TT GT GG TT GG + GT GT + TT GG
9 19 24 9 43 28 24
(17.3) (36.5) (46.1) (17.3) (82.7) (53.9) (46.1)
17 28 25 17 53 45 25
(24.3) (40.0) (35.7) (24.3) (75.7) (64.3) (35.7)
1.00 1.27 (0.44–3.61) 1.82 (0.67–4.90) 1.00 1.54 (0.61–3.85) 1.00 1.59 (0.75–3.35)
CC CA AA CC CA + AA CC + CA AA
32 16 4 32 20 48 4
(61.5) (30.8) (7.7) (61.5) (38.5) (92.3) (7.7)
44 19 7 44 26 63 7
(62.9) (27.1) (10.0) (62.9) (37.1) (90.0) (10.0)
1.00 1.16 (0.51–2.62) 0.69 (0.18–2.71) 1.00 1.02 (0.48–2.16) 1.00 0.68 (0.18–2.57)
CC TC TT CC TC + TT CC + TC TT
31 10 11 31 21 41 11
(59.6) (19.2) (21.2) (59.6) (40.4) (78.8) (21.2)
43 22 5 43 27 65 5
(61.4) (31.4) (7.2) (61.4) (38.6) (92.8) (7.2)
1.00 0.60 (0.24–1.49) 3.59 (1.09–11.79) 1.00 1.21 (0.53–2.36) 1.00 4.32 (1.35–13.83)
P valuea
1-β
0.664 0.238
0.18838 0.70323
0.360
0.43761
0.224
0.66918
0.729 0.596
0.09599 0.11974
0.955
0.06182
0.680
0.13532
0.272 0.035
0.45346 0.99774
0.764
0.06932
0.014
0.99997
rs6983267 Codominant Dominant Recessive rs1447295 Codominant Dominant Recessive rs4733616 Codominant Dominant Recessive
Poor: poorly differentiated; W/M: well and moderately differentiated gastric adenocarcinoma; OR: odds ratio; CI: confidence interval; and n: number of subjects. Statistical power (1-β) was calculated for all observed P values. Statistically significant results are shown in bold. a Adjusted by age and gender.
L. Labrador et al. / Gene 566 (2015) 120–124
regulatory enhancers for the nearby MYC proto-oncogene. Evidence indicating a functional link between 8q24 loci and MYC was provided by Tuupanen et al. (2009), which demonstrated that rs6983267 affects a binding site for the Wnt-regulated transcription factor 7-like 2 (TCF7L2), with the risk allele G showing stronger binding in vitro and in vivo. Moreover, evidence from Pomerantz et al. (2009) suggest that the rs6983267 variant is a transcriptional enhancer that cannot only differentially bind TCF7L2, but that the risk region physically interacts with MYC. Additional data support this interaction, for example, Ahmadiyeh et al. (2010) suggested that enhancer elements at 8q24 form a longrange chromatin loop with MYC in a tissue-specific manner, while Kim et al. (2014) found that the MYC enhancer region physically interacts with the active regulatory region of the long noncoding RNAs CARLo-5 promoter, thus regulating CARLo-5 expression, which is significantly correlated with the rs6983267 allele and increased cancer susceptibility. The association between variants on chromosome 8q24 and gastric cancer has been analyzed in recent reports (Park et al., 2008; Wokołorczyk et al., 2008; Guo et al., 2011; Lochhead et al., 2011; Tarleton et al., 2014; Ma et al., 2015). In this regard, Guo et al. (2011) found that the GT genotype of rs6983267 was associated with an increased risk of gastric cancer compared with GG genotype in Chinese population. Furthermore, the rs6983267 GT genotype increased the risk of gastric cancer of non-cardiac and intestinal type. However, in accordance with our results, other studies performed in Caucasian (Poland and USA) and Chinese populations did not find association of SNP rs6983267 with gastric cancer (Park et al., 2008; Wokołorczyk et al., 2008; Lochhead et al., 2011; Tarleton et al., 2014). Similar to studies conducted in Chinese populations (Park et al., 2008; Tarleton et al., 2014), our data also failed to show the existence of association between the 8q24 SNP rs1447295 and gastric cancer. This variant, previously identified as a prostate cancer-associated polymorphism (Severi et al., 2007; Wokołorczyk et al., 2010), was observed to be involved in an inverse (OR = 0.63; 95% CI, 0.41–0.97) and positive (OR = 7.43; 95% CI, 1.37–49.98) association with gastric cancer and esophageal squamous cell carcinoma risk, respectively in Caucasian (Lochhead et al., 2011). In our study, we did not observe difference on the genotype distribution of SNP rs4733616 between cases and controls. However, the homozygous TT genotype was associated with an increased risk of poorly differentiated gastric adenocarcinoma under the best-fitting recessive model of inheritance (OR = 4.32), but it was not associated with moderate/well-differentiated gastric cancer. The risk allele of rs4733616 (T) at chromosome 8q24 has been associated with the risk of papillary thyroid cancer (Neta et al., 2012), but its functional significance has not been clarified yet. The degree of differentiation of tumor cells has been shown to correlate with the aggressiveness and prognosis of gastric cancer, and should be evaluated in the management of this malignance (Adachi et al., 2000; Zu et al., 2014). Furthermore, genetic polymorphisms, mutations and epigenetic alterations have been related to the development of poorly differentiated type, but not with moderately or well-differentiated gastric cancer, suggesting that, in addition to the common molecular pathway of stomach carcinogenesis, the subtypes of gastric cancer result from different etiologic pathways or biological mechanisms (Yasui et al, 2006; Yu et al., 2010). Besides ethnical differences with populations previously analyzed, another explanation for the negative findings could be the inadequate statistical powers to detect potential associations (1-β b 0.80) observed for rs1447295 and rs6983267 in our study, probably due to the small sample size. Moreover, the post-hoc analysis indicates that there was enough statistical power (1-β N 0.80 at type I level of 0.05) to support the significant contribution observed for the TT genotype of rs4733616 to develop poorly differentiated gastric cancer. In summary, the present study is the first one to examine SNPs in the 8q24 chromosomal region related to risk of gastric cancer in a Latin American population. Unlike other types of cancer, the influence of
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rs1447295 and rs6983267 polymorphisms in gastric cancer susceptibility seems to be controversial. A limitation of our study is the relatively small sample size. Moreover, we cannot rule out the possibility that the observed significant association with rs4733616 TT genotype could be driven by the small number of well and moderately differentiated gastric carcinoma samples that presented this genotype. For that reason a larger number of samples to increase the statistical power is required to fully explore the role of the 8q24 chromosome region in the susceptibility of gastric cancer in our population. Other considered limitations were the difference in mean age and the unequal gender ratio between control and gastric cancer groups, which could originate confounding results. However, after adjustment for age and sex, we observed a significant association of rs4733616 variant with poorly differentiated gastric cancer. Further investigation is also needed in order to understand the potential use of rs4733616 polymorphism as a prognosis marker in the management of gastric cancer. Conflict of interest The authors declare no conflict of interest. Acknowledgments This study was supported by CDCHT-UCLA grant 001-CS-2013. We thank L. Mendoza for their technical assistance. We would also like to thank E. Armanie and N. Granda for endoscopic biopsy sampling. To Dr. N. Lander for revising the English of the manuscript. References Abnet, C.C., Freedman, N.D., Hu, N., Wang, Z., Yu, K., Shu, X.O., Yuan, J.M., Zheng, W., Dawsey, S.M., Dong, L.M., Lee, M.P., Ding, T., Qiao, Y.L., Gao, Y.T., Koh, W.P., Xiang, Y.B., Tang, Z.Z., Fan, J.H., Wang, C., Wheeler, W., Gail, M.H., Yeager, M., Yuenger, J., Hutchinson, A., Jacobs, K.B., Giffen, C.A., Burdett, L., Fraumeni Jr., J.F., Tucker, M.A., Chow, W.H., Goldstein, A.M., Chanock, S.J., Taylor, P.R., 2010. A shared susceptibility locus in PLCE1 at 10q23 for gastric adenocarcinoma and esophageal squamous cell carcinoma. Nat. Genet. 42, 764–767. Adachi, Y., Yasuda, K., Inomata, M., Sato, K., Shiraishi, N., Kitano, S., 2000. Pathology and prognosis of gastric carcinoma: well versus poorly differentiated type. Cancer 89, 1418–1424. Ahmadiyeh, N., Pomerantz, M.M., Grisanzio, C., Herman, P., Jia, L., Almendro, V., He, H.H., Brown, M., Liu, X.S., Davis, M., Caswell, J.L., Beckwith, C.A., Hills, A., Macconaill, L., Coetzee, G.A., Regan, M.M., Freedman, M.L., 2010. 8q24 prostate, breast, and colon cancer risk loci show tissue-specific long-range interaction with MYC. Proc. Natl. Acad. Sci. U. S. A. 107, 9742–9746. Berndt, S.I., Potter, J.D., Hazra, A., Yeager, M., Thomas, G., Makar, K.W., Welch, R., Cross, A.J., Huang, W.Y., Schoen, R.E., Giovannucci, E., Chan, A.T., Chanock, S.J., Peters, U., Hunter, D.J., Hayes, R.B., 2008. Pooled analysis of genetic variation at chromosome 8q24 and colorectal neoplasia risk. Hum. Mol. Genet. 17, 2665–2672. Brisbin, A.G., Asmann, Y.W., Song, H., Tsai, Y.Y., Aakre, J.A., Yang, P., Jenkins, R.B., Pharoah, P., Schumacher, F., Conti, D.V., Duggan, D.J., Jenkins, M., Hopper, J., Gallinger, S., Newcomb, P., Casey, G., Sellers, T.A., Fridley, B.L., 2011. Meta-analysis of 8q24 for seven cancers reveals a locus between NOV and ENPP2 associated with cancer development. BMC Med. Genet. 12, 156. Chiurillo, M.A., 2014. Role of gene polymorphisms in gastric cancer and its precursor lesions: current knowledge and perspectives in Latin American countries. World J. Gastroenterol. 20, 4503–4515. Correa, P., 1995. Helicobacter pylori and gastric carcinogenesis. Am. J. Surg. Pathol. 19, S37–S43. Crawford, J., 1994. The gastrointestinal tract. In: Robbins, S.L.C.R., Kumar, V., Schoen, F.J. (Eds.), Pathologic Basis of Disease. WB Saunders Co, Philadelphia, pp. 755–783. Easton, D.F., Pooley, K.A., Dunning, A.M., Pharoah, P.D., Thompson, D., Ballinger, D.G., Struewing, J.P., Morrison, J., Field, H., Luben, R., Wareham, N., Ahmed, S., Healey, C.S., Bowman, R., Meyer, K.B., Haiman, C.A., Kolonel, L.K., Henderson, B.E., Le Marchand, L., Brennan, P., Sangrajrang, S., Gaborieau, V., Odefrey, F., Shen, C.Y., Wu, P.E., Wang, H.C., Eccles, D., Evans, D.G., Peto, J., Fletcher, O., Johnson, N., Seal, S., Stratton, M.R., Rahman, N., Chenevix-Trench, G., Bojesen, S.E., Nordestgaard, B.G., Axelsson, C.K., Garcia-Closas, M., Brinton, L., Chanock, S., Lissowska, J., Peplonska, B., Nevanlinna, H., Fagerholm, R., Eerola, H., Kang, D., Yoo, K.Y., Noh, D.Y., Ahn, S.H., Hunter, D.J., Hankinson, S.E., Cox, D.G., Hall, P., Wedren, S., Liu, J., Low, Y.L., Bogdanova, N., Schürmann, P., Dörk, T., Tollenaar, R.A., Jacobi, C.E., Devilee, P., Klijn, J.G., Sigurdson, A.J., Doody, M.M., Alexander, B.H., Zhang, J., Cox, A., Brock, I.W., MacPherson, G., Reed, M.W., Couch, F.J., Goode, E.L., Olson, J.E., Meijers-Heijboer, H., van den Ouweland, A., Uitterlinden, A., Rivadeneira, F., Milne, R.L., Ribas, G., Gonzalez-Neira, A., Benitez, J., Hopper, J.L., McCredie, M., Southey, M., Giles, G.G., Schroen, C., Justenhoven, C., Brauch, H., Hamann, U., Ko, Y.D., Spurdle, A.B., Beesley, J., Chen, X., Mannermaa, A., Kosma, V.M., Kataja, V., Hartikainen, J., Day, N.E., Cox,
124
L. Labrador et al. / Gene 566 (2015) 120–124
D.R., Ponder, B.A., 2007. Genome-wide association study identifies novel breast cancer susceptibility loci. Nature 447, 1087–1093. Ferlay, J., Shin, H.R., Bray, F., Forman, D., Mathers, C., Parkin, D.M., 2010. Estimates of worldwide burden of cancer in 2008: GLOBOCAN 2008. Int. J. Cancer 127, 2893–2917. Ferlay, J., Soerjomataram, I., Ervik, M., Dikshit, R., Eser, S., Mathers, C., Rebelo, M., Parkin, D.M., Forman, D., Bray, F., 2013. GLOBOCAN 2012 v1.0, Cancer Incidence and Mortality Worldwide: IARC CancerBase No. 11 [Internet]. International Agency for Research on Cancer, Lyon, France Available from http://globocan.iarc.fr. Ghoussaini, M., Song, H., Koessler, T., Al Olama, A.A., Kote-Jarai, Z., Driver, K.E., Pooley, K.A., Ramus, S.J., Kjaer, S.K., Hogdall, E., Di Cioccio, R.A., Whittemore, A.S., Gayther, S.A., Giles, G.G., Guy, M., Edwards, S.M., Morrison, J., Donovan, J.L., Hamdy, F.C., Dearnaley, D.P., Ardern-Jones, A.T., Hall, A.L., O'Brien, L.T., Gehr-Swain, B.N., Wilkinson, R.A., Brown, P.M., Hopper, J.L., Neal, D.E., Pharoah, P.D., Ponder, B.A., Eeles, R.A., Easton, D.F., Dunning, A.M., 2008. Multiple loci with different cancer specificities within the 8q24 gene desert. J. Natl. Cancer Inst. 100, 962–966. Guo, Y., Fang, J., Liu, Y., Sheng, H.H., Zhang, X.Y., Chai, H.N., Jin, W., Zhang, K.H., Yang, C.Q., Gao, H.J., 2011. Association between polymorphism rs6983267 and gastric cancer risk in Chinese population. World J. Gastroenterol. 17, 1759–1765. Kang, J.U., 2014. Chromosome 8q as the most frequent target for amplification in early gastric carcinoma. Oncol. Lett. 7, 1139–1143. Kim, T., Cui, R., Jeon, Y.J., Lee, J.H., Lee, J.H., Sim, H., Park, J.K., Fadda, P., Tili, E., Nakanishi, H., Huh, M.I., Kim, S.H., Cho, J.H., Sung, B.H., Peng, Y., Lee, T.J., Luo, Z., Sun, H.L., Wei, H., Alder, H., Oh, J.S., Shim, K.S., Ko, S.B., Croce, C.M., 2014. Long-range interaction and correlation between MYC enhancer and oncogenic long noncoding RNA CARLo-5. Proc. Natl. Acad. Sci. U. S. A. 111, 4173–4178. Lochhead, P., Ng, M.T., Hold, G.L., Rabkin, C.S., Vaughan, T.L., Gammon, M.D., Risch, H.A., Lissowska, J., Mukhopadhya, I., Chow, W.H., El-Omar, E.M., 2011. Possible association between a genetic polymorphism at 8q24 and risk of upper gastrointestinal cancer. Eur. J. Cancer Prev. 20, 54–57. Ma, G., Gu, D., Lv, C., Chu, H., Xu, Z., Tong, N., Tag, C., Xu, Y., Zhang, B., Chen, J., 2015. Genetic variant in 8q24 is associated with prognosis in a Chinese population. J. Gastroenterol. Hepatol. 30, 689–695. McNamara, D., El-Omar, E., 2008. Helicobacter pylori infection and the pathogenesis of gastric cancer: a paradigm for host-bacterial interactions. Dig. Liver Dis. 40, 504–509. Neta, G., Yu, C.L., Brenner, A., Gu, F., Hutchinson, A., Pfeiffer, R., Sturgis, E.M., Xu, L., Linet, M.S., Alexander, B.H., Chanock, S., Sigurdson, A.J., 2012. Common genetic variants in the 8q24 region and risk of papillary thyroid cancer. Laryngoscope 122, 1040–1042. Park, S.L., Chang, S.C., Cai, L., Cordon-Cardo, C., Ding, B.G., Greenland, S., Hussain, S.K., Jiang, Q., Liu, S., Lu, M.L., Mao, J.T., Morgenstern, H., Mu, L.N., Ng, L.J., Pantuck, A., Rao, J., Reuter, V.E., Tashkin, D.P., You, N.C., Yu, C.Q., Yu, S.Z., Zhao, J.K., Belldegrun, A., Zhang, Z.F., 2008. Associations between variants of the 8q24 chromosome and nine smoking-related cancer sites. Cancer Epidemiol. Biomarkers Prev. 17, 3193–3202. Pomerantz, M.M., Ahmadiyeh, N., Jia, L., Herman, P., Verzi, M.P., Doddapaneni, H., Beckwith, C.A., Chan, J.A., Hills, A., Davis, M., Yao, K., Kehoe, S.M., Lenz, H.J., Haiman, C.A., Yan, C., Henderson, B.E., Frenkel, B., Barretina, J., Bass, A., Tabernero, J., Baselga, J., Regan, M.M., Manak, J.R., Shivdasani, R., Coetzee, G.A., Freedman, M.L., 2009. The 8q24 cancer risk variant rs6983267 shows long-range interaction with MYC in colorectal cancer. Nat. Genet. 41, 882–884. Saeki, N., Ono, H., Sakamoto, H., Yoshida, T., 2013. Genetic factors related to gastric cancer susceptibility identified using a genome-wide association study. Cancer Sci. 104, 1–8. Sakamoto, H., Yoshimura, K., Saeki, N., Katai, H., Shimoda, T., Matsuno, Y., Saito, D., Sugimura, H., Tanioka, F., Kato, S., Matsukura, N., Matsuda, N., Nakamura, T., Hyodo, I., Nishina, T., Yasui, W., Hirose, H., Hayashi, M., Toshiro, E., Ohnami, S., Sekine, A., Sato, Y., Totsuka, H., Ando, M., Takemura, R., Takahashi, Y., Ohdaira, M., Aoki, K., Honmyo, I., Chiku, S., Aoyagi, K., Sasaki, H., Ohnami, S., Yanagihara, K., Yoon, K.A., Kook, M.C., Lee, Y.S., Park, S.R., Kim, C.G., Choi, I.J., Yoshida, T., Nakamura, Y., Hirohashi, S., 2008. Genetic variation in PSCA is associated with susceptibility to diffuse-type gastric cancer. Nat. Genet. 40, 730–740. Severi, G., Hayes, V.M., Padilla, E.J., English, D.R., Southey, M.C., Sutherland, R.L., Hopper, J.L., Giles, G.G., 2007. The common variant rs1447295 on chromosome 8q24 and prostate cancer risk: results from an Australian population-based case–control study. Cancer Epidemiol. Biomarkers Prev. 16, 610–612. Shi, Y., Hu, Z., Wu, C., Dai, J., Li, H., Dong, J., Wang, M., Miao, X., Zhou, Y., Lu, F., Zhang, H., Hu, L., Jiang, Y., Li, Z., Chu, M., Ma, H., Chen, J., Jin, G., Tan, W., Wu, T., Zhang, Z., Lin, D.,
Shen, H., 2011. A genome-wide association study identifies new susceptibility loci for non-cardia gastric cancer at 3q13.31 and 5p13.1. Nat. Genet. 43, 1215–1218. Tarleton, H.P., Chang, S.C., Park, S.L., Cai, L., Ding, B., He, N., Hussain, S.K., Jiang, Q., Mu, L.N., Rao, J., Wang, H., You, N.C., Yu, S.Z., Zhao, J.K., Zhang, Z.F., 2014. Genetic variation at 8q24, family history of cancer, and upper gastrointestinal cancers in a Chinese population. Fam. Cancer 13, 45–56. Turnbull, C., Ahmed, S., Morrison, J., Pernet, D., Renwick, A., Maranian, M., Seal, S., Ghoussaini, M., Hines, S., Healey, C.S., Hughes, D., Warren-Perry, M., Tapper, W., Eccles, D., Evans, D.G., Hooning, M., Schutte, M., van den Ouweland, A., Houlston, R., Ross, G., Langford, C., Pharoah, P.D., Stratton, M.R., Dunning, A.M., Rahman, N., Easton, D.F., 2010. Genome-wide association study identifies five new breast cancer susceptibility loci. Nat. Genet. 42, 504–507. Tuupanen, S., Turunen, M., Lehtonen, R., Hallikas, O., Vanharanta, S., Kivioja, T., Björklund, M., Wei, G., Yan, J., Niittymäki, I., Mecklin, J.P., Järvinen, H., Ristimäki, A., Di-Bernardo, M., East, P., Carvajal-Carmona, L., Houlston, R.S., Tomlinson, I., Palin, K., Ukkonen, E., Karhu, A., Taipale, J., Aaltonen, L.A., 2009. The common colorectal cancer predisposition SNP rs6983267 at chromosome 8q24 confers potential to enhanced Wnt signaling. Nat. Genet. 41, 885–890. Von Holst, S., Picelli, S., Edler, D., Lenander, C., Dalén, J., Hjern, F., Lundqvist, N., Lindforss, U., Påhlman, L., Smedh, K., Törnqvist, A., Holm, J., Janson, M., Andersson, M., Ekelund, S., Olsson, L., Ghazi, S., Papadogiannakis, N., Tenesa, A., Farrington, S.M., Campbell, H., Dunlop, M.G., Lindblom, A., 2010. Association studies on 11 published colorectal cancer risk loci. Br. J. Cancer 103, 575–580. Wadhwa, R., Song, S., Lee, J.S., Yao, Y., Wei, Q., Ajani, J.A., 2013. Gastric cancer-molecular and clinical dimensions. Nat. Rev. Clin. Oncol. 10, 643–655. Wang, X., Liu, Y., Shao, D., Qian, Z., Dong, Z., Sun, Y., Xing, X., Cheng, X., Du, H., Hu, Y., Li, Y., Li, L., Dong, B., Li, Z., Wu, A., Wu, X., Bu, Z., Zong, X., Zhu, G., Ji, Q., Wen, X.Z., Zhang, L.H., Ji, J.F., 2015. Recurrent amplification of MYC and TNFRSF11B in 8q24 is associated with poor survival in patients with gastric cancer. Gastric Cancer http://dx.doi.org/ 10.1007/s10120-015-0467-2. Wokołorczyk, D., Gliniewicz, B., Sikorski, A., Zlowocka, E., Masojc, B., Debniak, T., Matyjasik, J., Mierzejewski, M., Medrek, K., Oszutowska, D., Suchy, J., Gronwald, J., Teodorczyk, U., Huzarski, T., Byrski, T., Jakubowska, A., Górski, B., van de Wetering, T., Walczak, S., Narod, S.A., Lubinski, J., Cybulski, C., 2008. A range of cancers is associated with the rs6983267 marker on chromosome 8. Cancer Res. 68, 9982–9986. Wokołorczyk, D., Lubiński, J., Narod, S.A., Cybulski, C., 2009. Genetic heterogeneity of 8q24 region in susceptibility to cancer. J. Natl. Cancer Inst. 101, 278–279. Wokołorczyk, D., Gliniewicz, B., Stojewski, M., Sikorski, A., Złowocka, E., Debniak, T., Jakubowska, A., Górski, B., van de Wetering, T., Narod, S.A., Lubiński, J., Cybulski, C., 2010. The rs1447295 and DG8S737 markers on chromosome 8q24 and cancer risk in the Polish population. Eur. J. Cancer Prev. 19, 167–171. Yasui, W., Sentani, K., Motoshita, J., Nakayama, H., 2006. Molecular pathobiology of gastric cancer. Scand. J. Surg. 95, 225–231. Yeager, M., Chatterjee, N., Ciampa, J., Jacobs, K.B., Gonzalez-Bosquet, J., Hayes, R.B., Kraft, P., Wacholder, S., Orr, N., Berndt, S., Yu, K., Hutchinson, A., Wang, Z., Amundadottir, L., Feigelson, H.S., Thun, M.J., Diver, W.R., Albanes, D., Virtamo, J., Weinstein, S., Schumacher, F.R., Cancel-Tassin, G., Cussenot, O., Valeri, A., Andriole, G.L., Crawford, E.D., Haiman, C.A., Henderson, B., Kolonel, L., Le, Marchand, L., Siddiq, A., Riboli, E., Key, T.J., Kaaks, R., Isaacs, W., Isaacs, S., Wiley, K.E., Gronberg, H., Wiklund, F., Stattin, P., Xu, J., Zheng, S.L., Sun, J., Vatten, L.J., Hveem, K., Kumle, M., Tucker, M., Gerhard, D.S., Hoover, R.N., Fraumeni Jr., J.F., Hunter, D.J., Thomas, G., Chanock, S.J., 2009. Identification of a new prostate cancer susceptibility locus on chromosome 8q24. Nat. Genet. 41, 1055–1057. Yu, J., Zeng, Z., Wang, S., Tian, L., Wu, J., Xue, L., Lee, C.W., Zhang, M., Goggins, W.B., Chen, M., Hu, P., Sung, J.J., 2010. IL-1B-511 polymorphism is associated with increased risk of certain subtypes of gastric cancer in Chinese: a case–control study. Am. J. Gastroenterol. 105, 557–564. Zu, H., Wang, H., Li, C., Xue, Y., 2014. Histologic type is important for estimating the tumor progression and outcomes of patients with gastric carcinoma. Int. J. Clin. Exp. Pathol. 7, 5692–5700.