The association of Phosphatase and tensin homolog (PTEN) deletion and prostate cancer risk: A meta-analysis

Biomedicine & Pharmacotherapy 83 (2016) 114–121

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The association of Phosphatase and tensin homolog (PTEN) deletion and prostate cancer risk: A meta-analysis Tianyi Gaoa,1, Yanping Meia,1, Huiling Sunb , Zhenlin Niea , Xiangxiang Liub , Shukui Wanga,b,* a b

Department of clinical Laboratory, Nanjing First Hospital, Nanjing Medical University, 68 Changle Road, Nanjing 210006, Jiangsu, China Central Laboratory, Nanjing First Hospital, Nanjing Medical University, 68 Changle Road, Nanjing 210006, Jiangsu, China

A R T I C L E I N F O

A B S T R A C T

Article history: Received 21 April 2016 Received in revised form 6 June 2016 Accepted 10 June 2016

Objective: Phosphatase and tensin homolog (PTEN) deleted on chromosome 10, a tumor suppressor that negatively regulates the phosphoinositide-3-kinase(PI3 K) which has been implicated in a number of human malignancies including prostate cancer. However the prognostic value of PTEN deletion in prostate cancer patient’s diagnosis and the mechanism of PTEN deletion in prostate cancer development still remain unclear. Method: A meta-analysis of 26 published studies including 8097 prostate cancer patients was performed. Results: Compared to PTEN normal patients, PTEN deletion patients showed a higher aggressive Gleason score(OR: 1.284, 95%CI = 1.145–1.439) and pathological stage(OR: 1.628, 95%CI = 1.270–2.087) which generally had a higher risk in prostate replace(HR: 1.738, 95%CI = 1.264–2.390). Significant association between PTEN deletion and ERG rearrangements in prostate cancer development was also proved that compared to PTEN normal patients, patients with PTEN deletion showed a higher risk in ERG rearrangements(OR: 1.345, 95%CI = 1.102–1.788). Conclusion: This study indicated that patients with PTEN deletion were associated with higher pathological stage or Gleason score and a higher risk in prostate cancer replace potentially represent a novel clinically relevant event to identify individuals at increased risk for the occurrence, progression and prognosis of prostate cancer. Prostate cancer patients with PTEN deletion usually had a higher risk in ERG rearrangements than other patients may be a potential new area for identifying poor prognosis patients and selecting patients for targeted therapies which required confirmation through adequately designed prospective studies. ã 2016 Published by Elsevier Masson SAS.

Keywords: PTEN deletion Prostate cancer ERG rearrangements Prognostic value

1. Introduction Prostate cancer (PCa) is a heterogeneous disease with a variable natural history [1]. It is estimated that only a small fraction of patients suffering from potential life-threatening disease requires aggressive treatment. Currently, the established prognostic factors (Gleason score, pathological stage and serum prostate-specific antigen (PSA)) can not precisely distinguish clinically aggressive PCa from clinically indolent ones [2]. Studies had also showed that though prostate cancer was diagnosed as organ-confined disease,

* Corresponding author at: Department of clinical Laboratory, Nanjing First Hospital, Nanjing Medical University, 68 Changle Road, Nanjing 210006, Jiangsu, China. E-mail address: [email protected] (S. Wang). 1 These authors contributed equally to this work. http://dx.doi.org/10.1016/j.biopha.2016.06.020 0753-3322/ã 2016 Published by Elsevier Masson SAS.

cancers with similar Gleason scores usually showed substantial interpatient heterogeneity and differential prostate cancer–specific mortality rates [3,4]. Patients with similar TNM stages, Gleason scores or pretreatment PSA values sometimes did not show the same prognosis which might due to the different tumor genomic progression [5]. Thus, novel prognostic biomarkers are urgently needed for PCa patient management to improve prostate cancer diagnosis and therapy. Phosphatase and tensin homolog (PTEN) deleted on chromosome 10, is a tumor suppressor that negatively regulates the phosphoinositide-3-kinase(PI3K)/AKT/mTOR pathway by catalyzing degradation of phosphatidylinositol-(3,4,5)-triphosphate (PIP3) generated by PI3K [6]. PIP3 activates the protein kinase AKT which then modulates a number of downstream targets with important roles in apoptosis and the cell-cycle progression, including BAD, CASP3 and CASP9, MDM2, mTOR, FKHR10 and

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FOXO3A, p27 and the JNK pathway [7]. Some studies have proven that the expression of PTEN can inhibit cell cycle progression, induce a G1 arrest, inhibit cell migration, and induce cell cycle arrest and apoptosis [8]. Loss or deletion of PTEN has been implicated in a number of human malignancies including prostate cancer which usually leads to constitutive activation of the PI3 K/Akt pathway which enhances cell proliferation and tumor angiogenesis and decreases apoptosis [9–11]. But the regulation of PTEN gene expression is complex and includes transcription factors, microRNAs, competitive endogenous RNAs, and DNA methylation. In addition, PTEN protein levels can be altered through aberrant phosphorylation, ubiquitination, and acetylation [12]. ERG(21q22.2) as a member of the ETS transcription factor family, has been described in several cohorts as being the most common gene rearrangements to occur in prostate cancer [13]. Recently, several studies showed that the ERG rearrangements were significantly associated with PTEN deletion in prostate cancer which may suggest a new mechanism of PTEN deletion in prostate cancer development [8,14]. However, in the study by King and colleagues, the association between them was not found [15]. Whether ERG rearrangements correlate to PTEN deletions still remains controversial. To date, deletion of PTEN has been proven in a number of individual studies. But the prognostic value of PTEN deletion in prostate cancer patient’s diagnosis and the relationship between PTEN deletion and ERG rearrangements in prostate cancer development still remain unclear. Therefore, a systematic review was performed of the literature with meta-analysis to obtain a more accurate evaluation of the role of PTEN genomic deletions in prostate cancer management and the association between PTEN deletion and ERG rearrangements. 2. Materials and methods 2.1. Ethics The study was conducted according to our institutional guidelines under the supervision of the Institutional Review Board of Nanjing First Hospital, Nanjing Medical University.

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treatment to the reappearance of PCa; 3)the subjects in every study comprised patients with PTEN deletion and patients without PTEN deletion; 4) when the same patient population reported in several publications, only the most recent report or the most complete one was included in this analysis to avoid overlapping between cohorts; 5) the number of patients in each study should be more than 5 respectively. Studies were excluded based on the following criteria: 1) duplicated studies, reviews, letters, unpublished data, and comments; 2) those published in language other than English; 3) lack of key information for further analysis; 4) non-human research. 2.4. Data collection Two investigators (TG, XL) independently evaluated and extracted data from each identified studies based on criteria of inclusion and exclusion, and the corresponding author was contacted to clarify missing or ambiguous data. OS was treated as a dominant outcome of interest, but RFS and DFS were set as the secondary outcomes. For each eligible study, we collected information regarding authors, year and source of publication, country of origin, inclusion criteria, exclusion criteria, pathological stage, Gleason score, PTEN deletion and ERG rearrangements frequencies in patients of prostate cancer and the HR and corresponding 95% CI for OS, RFS, or DFS as applicable. In studies defining PTEN deletion, there were two definitions: (1) complete PTEN loss; (2) PTEN loss and heterogeneity. Since it was hard to redefine PTEN deletion patients on a unified standard, we combined PTEN deletion patients in our meta-analysis according to their original group in each individual study. All included studies used patients without PTEN deletion as a control group. HR was firstly extracted from multivariate analysis where available. Otherwise, HR was extracted from univariate analysis. Of these studies, pathological stage < T2 was defined as lowstage, and pathological stage  T2 was defined as high-stage which were defined by clinical differentiation. Gleason score  7 was defined as high-GS and Gleason score  6 was defined as low-GS. 2.5. Meta-analysis and statistical analysis

2.2. Publication selection The published data searching was performed using a literature review system with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines [16]. Studies were identified via an electronic search of PubMed and Google Scholar using the following key words: prostate cancer; PCa; phosphatase and tensin homolog; PTEN; loss; deletion and prognosis or outcome. We also manually searched the references of these publications in order to retrieve additional studies. Only those published as full-text articles and in English were included as candidates. The search updated on 30; October; 2014. 2.3. Inclusion and exclusion criteria Studies were selected for analysis if they met the following criteria: 1) they were original epidemiological studies on the correlation between PTEN deletion and the prognosis of prostate cancer patients during this century; 2) availability of a hazard ratio (HR) and 95% confidence interval (CI) or a P value for overall survival (OS). For a secondary analysis, studies including an HR for disease-free survival (DFS), or recurrence-free survival (RFS) were also used to further analysis. OS was defined as the time from first being diagnosed as PCa to death, DFS was defined as the time from last treatment to disease recurrence or until the last follow-up date, and RFS was described as the time from PCa curative

The foremost analysis examined the differences in the frequency of ERG rearrangements between PTEN deletion prostate cancer patients and PTEN normal prostate cancer patients by odds ratio (OR) with the corresponding 95% CI. The strength of association between PTEN deletion and patients’ pathological stage and tumor Gleason score were also assessed by OR with the corresponding 95% CI. Hazard ratios with the corresponding 95% CIs were used to estimate the strength of the link between PTEN and clinical prognosis. To assess heterogeneity across the studies, the statistics analysis for heterogeneity was performed. If the studies were shown to be homogeneous with P >0. 05 for the Qstatistics, the summary of OR or pooled HRs was calculated by a fixed-effects model (the Mantel-Haenszel method) when between-study heterogeneity was absent [17]. Otherwise, a randomeffects model (the DerSimonian and Laird method) was selected [18]. Furthermore, a sensitivity analysis, by which a single study in the meta-analysis was deleted each time to determine the influence of the individual data set to the overall pooled OR, was performed to assess the stability of the results. The potential publication bias was examined visually in a funnel plot of log [OR] against its standard error (SE), and the degree of asymmetry was tested by Egger's test [19]. This meta-analysis was performed using the software STATA version 12. 0. All P-values were based on twosided tests and a P-value of less than 0. 05 was considered statistically significant.

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3. Results

3.2. Meta-analysis

3.1. Study characteristics

3.2.1. PTEN deletion in prostate cancer patients In general, studies evaluating OS in prostate cancer patients were tested in 6 reliable studies (Fig. 2a). The main results were summarized in Table 2. Under the random-effects model, the pooled HR of PTEN deletion in prostate cancer patients, compared to PTEN normal patients, was 1.379 with 95%CI = 0.975–1.993. The studies reported HR for RFS and DFS were also analyzed (Fig. 2b,c). Under the random-effects model, the pooled HR of DFS in PTEN deletion patients compared to PTEN normal patients, was 2.669 with 95%CI = 0.396–17.999. Then under the fixed-effects model, we found that the pooled HR of RFS in PTEN deletion patients was 1.738with 95%CI = 1.264–2.390, which showed significantly higher

According to our inclusion criteria, a total of 26 eligible studies [4,11,12,20–42] involving 8097 prostate cancer patients were included in the pooled analyses (Fig. 1). The characteristics of these studies are summarized in Table 1. Of these studies, three studies were conducted in Asia, eight were in Europe, and the rest were in USA and Canada. The PTEN deletion and ERG rearrangements were detected using fluorescence in situ hybridization analysis(FISH) or immunohistochemistry(IHC). Prostate cancer patients were confirmed pathologically in all the studies. There were 6 studies for OS, 4 for RFS, and 5 for DFS in the meta-analysis.

Fig. 1. Flow chart for selection of studies for inclusion in this meta-analysis.

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Table 1 Characteristics of studies included in this meta-analysis. First Author

Year

Location

N

Method

ERG (M/U)b

Pa (M/U)b c

+

GS (M/U)b d

HRe

Survival QSf

Low

High

Low

High

4/18 10/78 113/ 385 10/15

– 85/30 80/ 621 –

– 75/16 74/192

– 80/8 155/ 705 14/9

27 28 27

–

– 80/30 11/ 173 49/14

– – multivariate RFS multivariate RFS

IHC

24/24 15/44 51/ 470 3/20

multivariate RFS

26

77 224

IHC FISH

– 10/38

– 9/39

– 15/60

2/37 1/16

7/31 18/61

multivariate OS – –

27 28

2013 USA

77

FISH

23/18

17/16

– 13/ 136 23/23

18/13

4/8

36/29

–

–

27

2013 2013 2013 2013

USA USA USA Finland

101 90 125 268

IHC FISH IHC IHC

41/13 5/42 – 24/106

– 3/41 – 13/28

– 16/30 – 91/144

–

–

multivariate DFS multivariate OS

26 28 27 27

2013 2013 2013 2013 2013 2013 2012 2012

USA China China UK UK USA USA Germany

232 112 176 643 805 48 57 2266 47 322

3/3 37/85

6/35 19/167

– – – – – – 15/9 68/ 647 – 5/146

– – – – – – 20/12 351/ 1268 – 51/120

26 27 25 27 28 25 28 27

2011 Canada 2010 UK

– – – – – – 4/2 268/ 570 – 19/19

– multivariate – multivariate univariate multivariate multivariate multivariate

Shuhong Liu AHM Reid

FISH IHC FISH FISH IHC IHC IHC FISH(PTEN deletion)/IHC (ERG expression) FISH FISH

– – multivariate OS

26 27

Tarek A. Bismar

2010 USA

555

FISH

73/303

–

–

–

26

2009 2009 2008 2008

121 266 82 68

FISH FISH FISH IHC

3/61 22/130 14/24 –

– – – –

– – – –

160/ 48 – – – –

362/92

Jennifer C. King Bo Han Maisa Yoshimoto P McCall

71/ 108 14/43 30/84 23/21 –

– – – 26/ 161 – – – – – – 31/19 308/ 1034 – 20/ 131 –

– – – 16/74

Ritu Bhalla Fu-neng Jiang Mei Qi J Cuzick Ke Zu C M. Barnett ES.Antonarakis Antje Krohn

20/27 14/29 – 13/ 125 35/46 – 12/27 – – – 13/13 –

– – – –

– – multivariate multivariate

– – DFS DFS

25 25 26 26

Silvia Hernandez Xiaoyu Qu Thomas U.Ahearn

2016 Spain 2016 USA 2015 Sweden

70 160 1019

FISH FISH IHC

Jacqueline Fontugne Prabhakar Mithal Francesca Khani

2014 USA

86

2014 USA 2014 USA

Berrak Gumuskaya T L. Lotan Ray B. Nagle Wennuan Liu KA. Leinonen

USA USA Canada Denmark

33/118 – 7/130 – – – 22/8 –

– RFS – OS OS RFS OS RFS

FISH: fluorescence in situ hybridization analysis; IHC: immunohistochemistry; PCR-SSCP: PCR for the single-strand conformation polymorphism. OS, overall survival; RFS, recurrence-free survival; DFS, disease-free survival. a:P pathologic stage; b: patients with PTEN deletion versus patients with normal PTEN; c: pathological stage T2 was defined as low-stage and pathological stage T3 was defined as high-stage; d: Gleason score  6 was defined as low-GS and Gleason score  7 was defined as high-GS; e: hazard ratio; f: quality assessment.

Fig. 2. The forest plot of studies in PTEN deletion in prostate cancer patients. a: The forest plot of studies about the association between OS and PTEN deletion in prostate cancer patients; b: The forest plot of studies about the association between DFS and PTEN deletion in prostate cancer patients; c: The forest plot of studies about the association between RFS and PTEN deletion in prostate cancer patients; d: The forest plot of studies about the association between Gleason score and PTEN deletion in prostate cancer patients; e: The forest plot of studies about the association between pathological stage and PTEN deletion in prostate cancer patients; f: The forest plot of studies about the association between ERG arrangements and PTEN deletion in prostate cancer patients.

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Table 2 The heterogeneity and pooled analysis of studies included in this meta-analysis. Na

heterogeneity 2

Survival OS DFS RFS Gleason score Pathological stage ERG rearrangements

6 3 6 12 8 18

pooled analysis

X

df

p

HR/OR(95%CI)

p

I2

16.14 24.09 7.88 83.61 28.79 154.71

5 2 5 11 7 17

0.006 0.001 0.163 0.001 0.001 0.023

1.379(0.975–1.993) 2.669(0.396–17.999) 1.738(1.264–2.390) 1.284(1.145–1.439) 1.628(1.270–2.087) 1.345(1.043–1.736)

0.088 0.313 0.001 0.001 0.001 0.001

62.19% 91.7% 36.6% 86.8% 75.7% 89.0%

OS, overall survival; RFS, recurrence-free survival; DFS, disease-free survival.a: number of studies.

risk in prostate cancer recurrence compared to PTEN normal patients(p < 0.05, Table 2). The relationship between PTEN deletion and tumor Gleason score was also compared in 12 studies by random-effect model (Fig. 2d). The pooled OR of low-GS in PTEN deletion patients, compared to high-GS PTEN deletion patients was 1.284 (95% CI = 1.145–1.439, Table 2) which declared that PTEN deletion patients showed a higher aggressive Gleason score than PTEN normal patients(p < 0.05). In evaluating the association between PTEN deletion and pathological stage in prostate cancer, 8 studies by random-effect model was carried out in the study (Fig. 2e). The pooled OR of low-stage in PTEN deletion patients, compared to high-stage PTEN deletion patients was 1.628 (95%CI = 1.270–.087, Table 2) which demonstrated that patients with PTEN deletion had a higher tumor stage than PTEN normal patients(p < 0.05).

3.3. ERG rearrangements in PTEN deletion patients A total of 18 reliable studies was included in analyzing the association between PTEN deletion and ERG rearrangements in prostate cancer(Fig. 2f). Under the random-effect model, the pooled OR of patients with PTEN deletion compared to PTEN normal patients was 1.345(95%CI = 1.043–1.736, Table 2) which showed that prostate cancer patients with PTEN deletion showed a significant correlation to ERG rearrangements(p < 0.05). 3.4. Sensitivity analyses Sensitivity analysis of OS in prostate cancer patients compared to PTEN normal patients and the association between pathological stage/ERG rearrangements and PTEN deletion in prostate cancer

Fig. 3. Begg's funnel plot with pseudo 95% confidence limits of publication bias test for each study. a: Begg's funnel plot with pseudo 95% confidence limits of publication bias test of studies about the association between OS and PTEN deletion in prostate cancer patients; b: Begg's funnel plot with pseudo 95% confidence limits of publication bias test of studies about the association between DFS and PTEN deletion in prostate cancer patients; c: Begg's funnel plot with pseudo 95% confidence limits of publication bias test of studies about the association between RFS and PTEN deletion in prostate cancer patients; d: Begg's funnel plot with pseudo 95% confidence limits of publication bias test of studies about the association between Gleason score and PTEN deletion in prostate cancer patients; e: Begg's funnel plot with pseudo 95% confidence limits of publication bias test of studies about the association between pathological stage and PTEN deletion in prostate cancer patients; f: Begg's funnel plot with pseudo 95% confidence limits of publication bias test of studies about the association between ERG arrangements and PTEN deletion in prostate cancer patients.

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patients revealed that the results pattern were not significantly impacted by removing single study each time. But in the analysis of the association between Gleason score and PTEN deletion and the correlation between pathological stage and PTEN deletion in prostate cancer patients, the results showed that 11 and 7 studies were the main source of heterogeneity. Then the heterogeneity was decreased when Antje Krohn’s study was removed in each analysis. In addition, no other single study was found to impact the pooled OR as indicated by sensitivity analyses. 3.5. Publication bias As shown in Fig. 3, funnel plot and Egger’s test were performed to assess the publication bias in studies of association between PTEN deletion and overall survival/pathological stage/Gleason score/ERG rearrangements, The shape of the funnel plot indicated no evidence of obvious asymmetry and the Egger's test suggested the absence of publication bias (P > 0.05). 4. Discussion The results of our systematic review showed that PTEN deletion in prostate cancer was associated with increased risk for developing pathological stage or Gleason score of prostate cancer which showed a higher risk in prostate cancer recurrence in comparison between PTEN deletion prostate cancer patients and PTEN normal patients. Then we also found that prostate cancer patients with PTEN deletion usually accompanied with ERG rearrangements in tumor progression. PTEN is one of the most potent tumor suppressors known in human cancer [43]. First identified in human cancers as a frequent deletion on chromosome 10, previous clinical studies have shown that PTEN is a negative regulator of the PI3 K/AKT/mTOR pathway, the activation of which is implicated in 30–50% of human prostate cancer. PTEN deletion in rodents leads directly to the development of an aggressive prostate cancer with metastases and the development of castrate resistance after androgen deprivation therapy [44]. As a result, PTEN has been investigated increasingly in human prostate cancer tissue with studies having repeatedly shown that PTEN loss in the radical prostatectomy occurs at rates of 16–44% in clinically localized prostate cancer, and is associated with markers of aggressive prostate cancer including higher Gleason score, higher clinical stage, larger tumor size and so on [7,45]. However, the frequency and mode of PTEN deletion reported at various stages of clinical prostate cancer are variable. Shuhong Liu’s study suggested that PTEN deletion levels correlated with pathological tumor stage but not with Gleason score [35], and in Prabhakar Mithal’s study, deletion of PTEN was proven to correlate with tumor grade but not pathological stage [21]. While AHM Reid’s study demonstrated that PTEN deletion was correlated to not only pathological tumor stage but also Gleason score [36]. To resolve the conflicting results, we carried out a meta-analysis which support AHM Reid’s study that PTEN deletion in prostate cancer was associated with increased risk for developing pathological stage or Gleason score of prostate cancer. It is now recognized that PTEN has a function in the nucleus, and reports of PTEN nuclear localization have begun to multiply over the past few years in tumor and non-tumor cells [46]. Chung’s study have demonstrated that PTEN has dual nuclear localization signal-like sequences that mediate nuclear import, and have shown that nuclear PTEN is required for PTEN-mediated cell-cycle arrest and growth inhibition through the down-regulation of cyclin D1[47]. Reports from the literature also suggested that PTEN localizes to the nucleus during the G0-G1phase of cell cycle and mediates growth suppression through the inhibition of MAP kinase phosphorylation independent of Akt activation [48]. Now, PTEN is

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increasingly undergoing evaluation as a biomarker for identifying poor prognosis patients and selecting patients for targeted therapies, including the plethora of new agents targeting the PI3K/AKT pathway and DNA repair proteins [49]. Though in this meta-analysis, the OS and DFS were proven not to correlate to PTEN deletion which might due to the small number of studies. We still found that PTEN deletion was significantly associated with the RFS in prostate cancer. In vitro studies showed that ERG rearrangements by themselves are not capable of transforming normal epithelial cell lines (RWPE) but increase their invasion capabilities [50], whereas PTEN genomic deletions caused increased transformation and proliferation [51]. Using in vivo mouse models, it is evidenced that prostate cancer development requires the interaction between PTEN deletions and ERG rearrangements in that PTEN deletions causing AKT activation and HGPIN-like lesions followed by ERG rearrangements to allow for the establishment of prostate cancer [52]. However, the association and sequence incidence between those two genetic aberrations in human prostate cancer development and progression are not yet fully characterized. In the present study, we systematically analyzed the status of ERG rearrangements and PTEN deletions across meta-analysis which demonstrated that prostate cancer patients with PTEN deletion had a higher risk in ERG rearrangements than other patients. PTEN deletion cooperated with ERG rearrangements to promote prostate cancer progression, showing a potential new area for identifying poor prognosis patients and selecting patients for targeted therapies which required confirmation through adequately designed prospective studies. Some limitations in this study should be acknowledged. Firstly, only summarized data rather than individual patient data were used. Secondly, a part of studies, especially in subgroups analyses, was lightly relative. Thirdly, we only included studies reporting HR or survival curves, and consequently some publications reporting on the prognostic value of PTEN deletion were excluded. For example, only odds ratios were reported, so the selection bias might be appeared. In summary, our meta-analysis suggested that patients with PTEN deletion usually associated with higher pathological stage or Gleason score and a higher risk in prostate cancer recurrence, indicating that PTEN deletion is a potentially novel clinically event to identify individuals at increased risk for the occurrence, progression and prognosis of prostate cancer. Meanwhile, prostate cancer patients with PTEN deletion had a higher risk in ERG rearrangements, demonstrating that PTEN deletion might also be a potential new area for identifying poor prognosis patients and selecting patients for targeted therapies, which required confirmation through adequately designed prospective studies. Author contributions Conceived and designed the experiments: Shukui Wang and Tianyi Gao. Performed the experiments:Xiangxiang Liu, Zhenlin Nie and Yanping Mei. Analyzed the data: Tianyi Gao. Contributed reagents/materials/analysis tools: Yanping Mei and Huiling Sun. Wrote the manuscript: Shukui Wang and Tianyi Gao. Designed the software used in analysis: Tianyi Gao. Confict of interests We confirm that all the listed authors have participated actively in the study and approved the submitted manuscript. The authors do not have any possible conflicts of interest.

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Acknowledgments This project was supported by grants from The National Nature Science Foundation of China (nos. 81172141, 81200401, 81472027), Nanjing Science and Technology Committee Project (no. 201108025), Nanjing Medical Technology Development Project (no. ZKX11025), Nanjing Health Young Talent Project, Jiangsu Provincial Key Medical Talents to S.K.W., Nanjing Medical Science and Technique Development Foundation to Y.Q.P. (no. QRX11255) and B.S.H. (no. QRX11254).

[25]

[26]

[27]

[28]

References [1] M.M. Shen, C. Abate-Shen, Molecular genetics of prostate cancer: new prospects for old challenges, Genes Dev. 24 (2010) 1967–2000. [2] M.J. Barry, P.C. Albertsen, M.A. Bagshaw, M.L. Blute, R. Cox, R.G. Middleton, et al., Outcomes for men with clinically nonmetastatic prostate carcinoma managed with radical prostactectomy, external beam radiotherapy, or expectant management: a retrospective analysis, Cancer 91 (2001) 2302–2314. [3] A.V. D’Amico, et al., Cancer-specifi mortality after surgery or radiation for patients with clinically localized prostate cancer managed during the prostate-specific antigen era, J. Clin. Oncol. 21 (2003) 2163–2172. [4] M.K. Buyyounouski, T. Pickles, L.L. Kestin, R. Allison, S.G. Williams, Validating the interval to biochemical failure for the identifiation of potentially lethal prostate cancer, J. Clin. Oncol. 30 (2012) 1857–1863. [5] P.C. Boutros, M. Fraser, N.J. Harding, R. de Borja, D. Trudel, E. Lalonde, et al., Spatial genomic heterogeneity within localized multifocal prostate cancer, Nat. Genet. 47 (7) (2015) 736–745. [6] Cancer Genome Atlas Research Network. The Molecular Taxonomy of Primary Prostate Cancer. Cell. 163 4 1011-25, 2015. [7] M. Yoshimoto, A.M. Joshua, I.W. Cunha, R.A. Coudry, F.P. Fonseca, O. Ludkovski, et al., Absence of TMPRSS2:ERG fusions and PTEN losses in prostate cancer is associated with a favorable outcome, Mod. Pathol. 21 (12) (2008) 1451–1460. [8] G. Pourmand, A.A. Ziaee, A.R. Abedi, A. Mehrsai, H.A. Alavi, et al., Role of PTEN gene in progression of prostate cancer, Urol. J. 4 (2) (2007) 95–100. [9] I.U. Ali, L.M. Schriml, M. Dean, Mutational spectra of PTEN/MMAC1 gene: a tumor suppressor with lipid phosphatase activity, J. Natl. Cancer Inst. 91 (1999) 1922–1932. [10] I. Vivanco, C.L. Sawyers, The phosphatidylinositol 3-Kinase AKT pathway in human cancer, Nat. Rev. Cancer 2 (2002) 489–501. [11] M. Osaki, M. Oshimura, H. Ito, PI3K-Akt pathway: its functions and alterations in human cancer, Apoptosis 9 (2004) 667–676. [12] A. Carracedo, A. Alimonti, P.P. Pandolfi, PTEN level in tumor suppression: how much is too little? Cancer Res. 71 (2011) 629. [13] K.G. Hermans, J.L. Boormans, D. Gasi, G.J. van Leenders, G. Jenster, P.C. Verhagen, et al., Overexpression of prostate-specific TMPRSS2(exon 0)-ERG fusion transcripts corresponds with favorable prognosis of prostate cancer, Clin Cancer Res 15 (2009) 6398–6403. [14] P. McCall, C.J. Witton, S. Grimsley, K.V. Nielsen, J. Edwards, Is PTEN loss associated with clinical outcome measures in human prostate cancer? Br. J. Cancer 99 (8) (2008) 1296–1301. [15] J.C. King, J. Xu, J. Wongvipat, H. Hieronymus, B.S. Carver, D.H. Leung, et al., Cooperativity of TMPRSS2-ERG with PI3-kinase pathway activation in prostate oncogenesis, Nat. Genet. 41 (5) (2009) 524–526. [16] A. Liberati, D.G. Altman, J. Tetzlaff, C. Mulrow, P.C. Gøtzsche, J.P. Ioannidis, et al., The PRISMA statement for reporting systematic reviews and meta-analyses of studies that evaluate health care interventions: explanation and elaboration, PLoS Med. 6 (2009) (e1000100). [17] N. Mantel, W. Haenszel, Statistical aspects of the analysis of data from retrospective studies of disease, J. Natl. Cancer Inst. 22 (4) (1959) 719–748. [18] R. DerSimonian, N. Laird, Meta-analysis in clinical trials, Control. Clin. Trials 7 (3) (1986) 177–188. [19] F.N. Jiang, H.C. He, Y.Q. Zhang, D.L. Yang, J.H. Huang, Y.X. Zhu, et al., An integrative proteomics and interaction network-based classifier for prostate cancer diagnosis, PLoS One 8 (5) (2013) (e63941). [20] J. Fontugne, D. Lee, C. Cantaloni, C.E. Barbieri, O. Caffo, E. Hanspeter, et al., Recurrent prostate cancer genomic alterations predict response to brachytherapy treatment, Cancer Epidemiol. Biomarkers Prev. 23 (4) (2014) 594–600. [21] P. Mithal, E. Allott, L. Gerber, J. Reid, W. Welbourn, E. Tikishvili, et al., PTEN loss in biopsy tissue predicts poor clinical outcomes in prostate cancer, Int. J. Urol. (2014) (10.1111). [22] F. Khani, J.M. Mosquera, K. Park, M. Blattner, C. O'Reilly, T.Y. MacDonald, et al., Evidence for molecular differences in prostate cancer between african american and caucasian men, Clin. Cancer Res. 20 (18) (2014) 4925–4934. [23] B. Gumuskaya, B. Gurel, H. Fedor, H.L. Tan, C.A. Weier, J.L. Hicks, et al., Assessing the order of critical alterations in prostate cancer development and progression by IHC: further evidence that PTEN loss occurs subsequent to ERG gene fusion, Prostate Cancer Prostatic Dis. 16 (2) (2013) 209–215. [24] T.L. Lotan, B. Gumuskaya, H. Rahimi, J.L. Hicks, T. Iwata, B.D. Robinson, et al., Cytoplasmic PTEN protein loss distinguishes intraductal carcinoma of the

[29]

[30]

[31]

[32]

[33]

[34]

[35]

[36]

[37]

[38]

[39]

[40]

[41]

[42]

[43] [44] [45]

[46]

[47]

[48]

[49]

prostate from high-grade prostatic intraepithelial neoplasia, Mod. Pathol. 26 (4) (2013) 587–603. R.B. Nagle, A.M. Algotar, C.C. Cortez, K. Smith, C. Jones, U.G. Sathyanarayana, et al., ERG overexpression and PTEN status predict capsular penetration in prostate carcinoma, Prostate 73 (11) (2013) 1233–1240. W. Liu, C.C. Xie, C.Y. Thomas, S.T. Kim, J. Lindberg, L. Egevad, Z. Wang, et al., Genetic markers associated with early cancer-specific mortality following prostatectomy, Cancer 119 (13) (2013) 2405–2412. K.A. Leinonen, O.R. Saramäki, B. Furusato, T. Kimura, H. Takahashi, S. Egawa, et al., Loss of PTEN is associated with aggressive behavior in ERG-positive prostate cancer, Cancer Epidemiol. Biomarkers Prev. 22 (12) (2013) 2333–2344. R. Bhalla, L.P. Kunju, S.A. Tomlins, K. Christopherson, C. Cortez, S. Carskadon, et al., Novel dual-color immunohistochemical methods for detecting ERGPTEN and ERG-SPINK1 status in prostate carcinoma, Mod. Pathol. 26 (6) (2013) 835–848. M. Qi, X. Yang, F. Zhang, T. Lin, X. Sun, Y. Li, et al., ERG rearrangement is associated with prostate cancer-related death in Chinese prostate cancer patients, PLoS One 9 (2) (2014) e84959. J. Cuzick, Z.H. Yang, G. Fisher, E. Tikishvili, S. Stone, J.S. Lanchbury, et al., Prognostic value of PTEN loss in men with conservatively managed localised prostate cancer, Br. J. Cancer 108 (12) (2013) 2582–2589. K. Zu, N.E. Martin, M. Fiorentino, R. Flavin, R.T. Lis, J.A. Sinnott, et al., Protein expression of PTEN insulin-like growth factor I receptor (IGF-IR), and lethal prostate cancer: a prospective study, Cancer Epidemiol. Biomarkers Prev. 22 (11) (2013) 1984–1993. C.M. Barnett, M.C. Heinrich, J. Lim, D. Nelson, C. Beadling, A. Warrick, et al., Genetic profiling to determine risk of relapse-free survival in high-risk localized prostate cancer, Clin. Cancer Res. 20 (5) (2014) 1306–1312. E.S. Antonarakis, D. Keizman, Z. Zhang, B. Gurel, T.L. Lotan, J.L. Hicks, et al., An immunohistochemical signature comprising PTEN, MYC, and Ki67 predicts progression in prostate cancer patients receiving adjuvant docetaxel after prostatectomy, Cancer 118 (24) (2012) 6063–6071. A. Krohn, T. Diedler, L. Burkhardt, P.S. Mayer, C. De Silva, M. Meyer-Kornblum, et al., Genomic deletion of PTEN is associated with tumor progression and early PSA recurrence in ERG fusion-positive and fusion-negative prostate cancer, Am. J. Pathol. 181 (2) (2012) 401–412. S. Liu, M. Yoshimoto, K. Trpkov, Q. Duan, M. Firszt, J. Corcos, et al., Detection of ERG gene rearrangements and PTEN deletions in unsuspected prostate cancer of the transition zone, Cancer Biol. Ther. 11 (6) (2011) 562–566. A.H. Reid, G. Attard, L. Ambroisine, G. Fisher, G. Kovacs, D. Brewer, et al., Molecular characterisation of ERG: ETV1 and PTEN gene loci identifies patients at low and high risk of death from prostate cancer, Br. J. Cancer 102 (4) (2010) 678–684. T.A. Bismar, M. Yoshimoto, R.T. Vollmer, Q. Duan, M. Firszt, J. Corcos, et al., PTEN genomic deletion is an early event associated with ERG gene rearrangements in prostate cancer, BJU Int. 107 (3) (2011) 477–485. B. Han, R. Mehra, R.J. Lonigro, L. Wang, K. Suleman, A. Menon, et al., Fluorescence in situ hybridization study shows association of PTEN deletion with ERG rearrangement during prostate cancer progression, Mod. Pathol. 22 (8) (2009) 1083–1093. M. Yoshimoto, A.M. Joshua, I.W. Cunha, R.A. Coudry, F.P. Fonseca, O. Ludkovski, et al., Absence of TMPRSS2:ERG fusions and PTEN losses in prostate cancer is associated with a favorable outcome, Mod. Pathol. 21 (12) (2008) 1451–1460. X. Qu, C. Jeldres, L. Glaskova, C. Friedman, S. Schroeder, P.S. Nelson, et al., Identification of combinatorial genomic abnormalities associated with prostate cancer early recurrence, J. Mol. Diagn. 18 (2) (2016) 215–224. S. Hernandez, A. Font-Tello, N. Juanpere, S. de Muga, M. Lorenzo, M. Salido, et al., Concurrent TMPRSS2-ERG and SLC45A3-ERG rearrangements plus PTEN loss are not found in low grade prostate cancer and define an aggressive tumor subset, Prostate (2016) (Epub ahead of print). T.U. Ahearn, A. Pettersson, E.M. Ebot, T. Gerke, R.E. Graff, C.L. Morais, et al., A prospective investigation of PTEN loss and ERG expression in lethal prostate cancer, J. Natl. Cancer Inst. 108 (2) (2015). M.S. Song, L. Salmena, P.P. Pandolfi, The functions and regulation of the PTEN tumour suppressor, Nat. Rev. Mol. Cell Biol. 13 (2012) 283–296. M.A. De Velasco, H. Uemura, Preclinical remodeling of human prostate cancer through the PTEN/AKT pathway, Adv. Urol. 12 (2012) (Article ID 419348). O.J. Halvorsen, S.A. Haukaas, L.A. Akslen, Combined loss of PTEN and p27 expression is associated with tumor cell proliferation by Ki-67 and increased risk of recurrent disease in localized prostate cancer, Clin. Cancer Res. 9 (2003) 1474–1479. O. Gimm, A. Perren, L.P. Weng, D.J. Marsh, J.J. Yeh, U. Ziebold, et al., Differential nuclear and cytoplasmic expression of PTEN innormal thyroid tissue: and benign and malignant epithelial thyroidtumors, Am. J. Pathol. 156 (2000) 1693–1700. J.H. Chung, M.E. Ginn-Pease, C. Eng, Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) has nuclear localization signal-like sequences for nuclear import mediated by major vault protein, Cancer Res. 65 (2005) 4108–4116. J.H. Chung, M.C. Ostrowski, T. Romigh, T. Minaguchi, K.A. Waite, C. Eng, The ERK1/2 pathway modulates nuclear PTEN-mediated cell cycle arrest by cyclin D1 transcriptional regulation, Hum. Mol. Genet. 15 (2006) 2553–2559. K.J. Dedes, D. Wetterskog, A.M. Mendes-Pereira, R. Natrajan, M.B. Lambros, F.C. Geyer, et al., PTEN deficiency in endometrioid endometrial adenocarcinomas predicts sensitivity to PARP inhibitors, Sci. Transl. Med. 2 (2010) 53ra75.

T. Gao et al. / Biomedicine & Pharmacotherapy 83 (2016) 114–121 [50] S.A. Tomlins, D. Wetterskog, A.M. Mendes-Pereira, R. Natrajan, M.B. Lambros, F. C.et al. Geyer, Role of the TMPRSS2-ERG gene fusion in prostate cancer, Neoplasia 10 (2008) 177–188. [51] I. Sansal, W.R. Sellers, The biology and clinical relevance of the PTEN tumor suppressor pathway, J. Clin. Oncol. 22 (2004) 2954–2963.

121

[52] B.S. Carver, J. Tran, A. Gopalan, Z. Chen, S. Shaikh, A. Carracedo, et al., Aberrant ERG expression cooperates with loss of PTEN to promote cancer progression in the prostate, Nat. Genet. 41 (2009) 619–624.