- Email: [email protected]
P63 SMAD4-DEPENDENT REGULATION OF HEPATOCELLULAR CARCINOMA GROWTH AND PROGRESSION
POSTERS Conclusions: The interaction of the HCC tumour-microenvironment with DC can induce a subset of CD8+ Treg which mediate CD39 dependent suppression of effector T-cells. This novel pathway of CD8+ Treg induction and suppression may offer potential for future immunotherapeutic modulation in HCC. P61 avb6 INTEGRIN ANTAGONISM IMPEDES SPHEROID FORMATION OF TUMOR CELLS IN VITRO AND CHOLANGIOCARCINOMA PROGRESSION IN VIVO E. Patsenker, V. Schneider, M. Ledermann, H. Saegesser, A. Keogh, F. Stickel. Department of Clinical Pharmacology and Visceral Research, University of Bern, Bern, Switzerland E-mail: [email protected] Background and Aims: avb6 integrin is markedly upregulated in liver fibrosis and human cholangiocarcinoma (CC), and its genetic and pharmaceutical inhibition revealed potent antifibrotic activity in experimental liver fibrosis. Whether avb6 integrin inhibition may interfere with cholangiocarcinogenesis is unknown. Methods: To induce experimental CC, male Sprague-Dawley rats were treated with thioacetamide (TAA) for 22 weeks, followed by specific non-peptidic avb6 integrin inhibitor EMD527040 at 60 mg/kg/day i.p. after 9 weeks of TAA. Besides mortality and tumor incidence, expression of avb6 integrin was evaluated by immunohistochemistry and RT-PCR. In vitro, 3D culture cell invasion assay was used to evaluate cholangiocarcinoma TFK-1 cells spheroid formation and invasive capacities. Human liver specimens of patients with cirrhosis, cholangiocarcinoma and normal liver tissues were analyzed by EMT RT2 Profiler™ PCR Array (Qiagen). Results: TAA administration in rats induced CC in 80% of animals with no mortality, and an upregulation of avb6 integrin by 15-fold. Treatment with EMD527040 reduced the incidence of CC by 50%, and caused a significant down-regulation of avb6 mRNA expression. In vitro, 10mM EMD527040 completely prevented spheroid formation of cholangiocarcinoma cells TFK-1 in 3D system cultivation, whereas no matrix invasion with this cell type was observed. Microarrays in human CC samples detected a significant upregulation of 4 genes related to EMT: COL1A2, COL3A1, KRT19 and VCAN (p < 0.05), while there was a significant 5-fold downregulation of the EGFR, ESR1, F11R, IL1RN, NUDT13, PPPDE2 and WNT11 genes. Conclusions: Pharmaceutical targeting of avb6 integrin reduces tumor burden in an experimental model of CC, possibly by inhibiting tumor dissemination. P62 MMP10 EXPRESSION PROTECTS FROM ACUTE LIVER INJURY BUT CONTRIBUTES TO HEPATOCELLULAR CARCINOMA PROGRESSION O. Garcia-Irigoyen1 , S. Carotti2 , M.U. Latasa1 , I. Uriarte1,3 , S. Morini2 , G. Perrone4 , U. Vespasiani-Gentilucci5 , M. Elizalde1 , R. Urtasun1 , J.A. Rodriguez6 , J. Orbe6 , J.A. Paramo6 , J. Prieto1,3 , C. Berasain1,3 , M.A. Avila1,3 . 1 Hepatology and Gene Therapy, Cima. University of Navarra, Pamplona, Spain; 2 Universita Campus Bio-Medico/Ultrastructural Anatomy, Roma, Italy; 3 Ciber de Enfermedades Hepaticas y Digestivas (Ciberehd), Pamplona, Spain; 4 Universita Campus Bio-Medico/Anatomical Pathology, 5 Universita Campus Bio-Medico/Liver Unit, Roma, Italy; 6 Cardiovascular Biology, Cima. University of Navarra, Pamplona, Spain E-mail: [email protected] Background and Aims: Extracellular matrix (ECM) remodeling is an essential process in liver wound healing. However, this response is also involved in hepatocellular carcinoma (HCC) progression. ECM turnover is carried out by proteases including matrix metalloproteases (MMPs). We have addressed the expression and function of MMP10 (stromelysin-2) in acute liver injury and hepatocarcinogenesis.
Methods: MMP10 was detected by immunohistochemistry in cirrhotic human liver and HCC tissues. Hepatic MMP10 expression was examined in two murine models: CCl4induced acute liver injury and diethylnitrosamine (DEN)-induced hepatocarcinogenesis. MMP10 was detected by qPCR, western blotting and immunohistochemistry. The role of MMP10 was evaluated in CCl4 and DEN-treated Mmp10+/+ and Mmp10−/− mice. Vascular endothelial growth factor (VEGF) and hypoxia influence on MMP10 expression were studied in HCC cells. HCC cell lines overexpressing MMP-10 were generated and characterized. Results: In human tissues MMP10 expression was increased in macrophages, biliary cells and hepatocytes in cirrhotic livers, and markedly elevated in HCC cells. Acute CCl4 treatment increased MMP10 expression, and MMP10 was progressively induced in liver carcinogenesis. Mmp10−/− mice showed increased CCl4-induced liver injury, impaired ECM turnover and delayed resolution of necrotic areas. Conversely, Mmp10−/− mice showed less HCC incidence, smaller tumors, smaller histological neoplastic lesions and much fewer HCC lung metastases. MMP10 expression was induced by hypoxia and VEGF in HCC cells. HCC cells expressing MMP10 showed enhanced migration. Conclusions: MMP10 plays an important role in the hepatic wound healing response during acute injury. However, chronic upregulation of MMP10 expression can contribute to HCC progression and metastasis. P63 SMAD4-DEPENDENT REGULATION OF HEPATOCELLULAR CARCINOMA GROWTH AND PROGRESSION P.Y. Hernanda1 , C. Kan1 , A.M. Das2 , K. Sideras1 , S.J.A. Bots1 , H.L.A. Janssen1,3 , L.L. Kodach4 , H.J. Metselaar1 , J. Kwekkeboom1 , D. Sprengers1 , M.J. Bruno1 , T.L.M. ten Hagen2 , M.P. Peppelenbosch1 , Q. Pan1 . 1 Department of Gastroenterology and Hepatology, 2 Laboratory of Experimental Surgical Oncology, Section Surgical Oncology, Department of Surgery, Erasmus MC University Medical Center, Rotterdam, Netherlands; 3 Division of Gastroenterology, University Health Network, Toronto, ON, Canada; 4 Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, Netherlands E-mail: [email protected] Background and Aims: SMAD4 is recognized as a central mediator of Transforming Growth Factor Beta (TGF-b) and Bone Morphogenetic Protein (BMP) signaling pathways which are involved in regulating tumor progression. In general, SMAD4 is considered a tumor suppressor. Here we investigated the role of SMAD4 in hepatocellular carcinoma (HCC). Methods: Immunohistochemical stainings were performed in paraffin embedded-tissue microarray patient HCC (n = 42). Three HCC cell lines were used for functional assay in vitro and in immune-deficient mice. Results: SMAD4 protein level was significantly higher in human HCC tissue compared with adjacent liver tissue (n = 42, P < 0.05). High SMAD4 levels were significantly associated with higher recurrence rate (p = 0.05), shorter time to recurrence (p < 0.05) and more tumor lesion (p < 0.01). Interestingly, high SMAD4 levels were associated with low p-SMAD 1/5/8 (a downstream target of BMP signaling) expression, both in patients and HCC cell lines. Knockdown of SMAD4 in HCC cell lines showed a significant decrease of migratory and colony formation capacity, whereas ectopic overexpression of SMAD4 resulted in increased migration activity demonstrated by the ring-barrier migration assay. However, knockdown of SMAD4 conferred resistance to the anti-growth effects of BMP4, TGF-b and Activin in HCC cell lines. Interim analysis (at day 12) of xenograft experiment showed that Smad4 knockdown appears to delay tumor initiation of HCC cells in nude mice. Conclusions: Basal SMAD4 expression is required for the antitumor function of BMP signaling in HCC. Elevated Smad4 expression
Journal of Hepatology 2014 vol. 60 | S67–S214
S87
POSTERS correlates with poor outcome in HCC patients and more aggressive phenotype and function of HCC cells. P64 THE ULTRACONSERVED NON CODING RNA UC.158 IS DOWNSTREAM OF THE WNT/b-CATENIN PATHWAY IN LIVER CANCERS V. Paulus-Hock1 , A. Lampis2 , G. Ferrari1 , L. Boulton3 , R. Guest3 , D. Athineos4 , T. Jamieson4 , A. Veronese5 , R. Visone5 , R. Evans1 , G.J. Feng6 , T. Dale6 , M. Negrini7 , S. Forbes3 , T. Patel8 , O. Sansom4 , N. Valeri2 , C. Braconi1,9 . 1 Institute of Cancer Sciences, University of Glasgow, Glasgow, 2 Division of Molecular Pathology, Institute of Cancer Research, London, 3 Scottish Centre for Regenerative Medicine, MRC Centre for Regenerative Medicine, Edinburgh, 4 Beatson Institute for Cancer Research, Glasgow, United Kingdom; 5 Aging Research Center, University of Chieti, Chieti, Italy; 6 School of Biosciences, University of Cardiff, Cardiff, United Kingdom; 7 University of Ferrara, Ferrara, Italy; 8 Mayo Clinc, Jacksonville, FL, United States; 9 Division of Cancer Therapeutics, Institute of Cancer Research, London, United Kingdom E-mail: [email protected] Background and Aims: We aimed at investigating the effect of the Wnt/b-catenin signalling on Transcribed-Ultraconserved-Regions (T-UCR), a class of 481 non-coding-RNAs, which are identical across the genome of human mouse and rat and play a role in carcinogenesis. These may be explored as therapeutic targets. Methods: APCfl/fl mice develop Wnt/b-catenin dependent HCC. Expression of T-UCR was assessed by microarray-analysis with sense and antisense probes, and by specific real-time-PCR. Results: Twenty-two T-UCRs were aberrantly expressed, with 4 up- and 18 down-regulated >2 fold in tumour tissues from APCfl/fl compared to normal liver from WT. Over-expression of uc.158 could differentiate APCfl/fl -HCC from DEN-induced-HCC. uc.158 is overexpressed in HepG2 vs Huh7 and in HSC vs normal hepatocytes, in line with the activation of the Wnt pathway. Treatment with Lithium-Chloride that increased nuclear localization of b-catenin increased uc.158 in Huh-7 cells. Uc.158 was reduced after inhibition of b-catenin by siRNA or ICG-001 in HepG2. Uc.158 expression was not increased in PLC/PRF-5 cells (AXIN1-mutated), as well as no differences were observed between the liver of AXIN1−/− and WT mice, in line with the absence of b-catenin activation in these tumours. Recent findings suggest that Wnt/b-cat pathway is activated in cholangiocarcinoma (CCA). We found increased expression of uc.158 in human CCA. Tumour tissue from rat model of thioacetamide-induced CCA expressed uc.158, which was reduced after in vivo treatment with ICG-001 or C59 (Wnt/b-catenin inhibitors). Conclusions: uc.158 is activated by Wnt/b-catenin pathway in primary liver cancers across three species and may represent a promising target for developing novel therapeutics in a subset of cancers. P65 MUTATION SPECTRUM ASSOCIATED WITH THE PROGRESSION OF HBV-RELATED HEPATOCELLULAR CARCINOMA H.G. Woo1 , S.S. Kim2 , H.W. Cho1,3 , S.M. Kwon1,3 , H.J. Cho2 , S.J. Ahn2 , S.W. Cho2 , J.Y. Cheong2 . 1 Department of Physiology, 2 Department of Gastroenterology, 3 Graduate School of Biomedical Science, Ajou University School of Medicine, Suwon, Korea, Republic of E-mail: [email protected]
and paired non-tumoral adjacent liver tissues with heterogeneous differentiation status. Tumor-specific variations (TSV) and 535 nontumor-specific variations (NSV) were profiled in the early and advanced HCC, respectively. Results: Enriched cancer-specific mutations at chromosome 1q were observed in the advanced HCC compared to those in the early HCC. Functional difference of the mutation spectrum was also identified between early and advanced HCC. The early HCCs were frequently mutated in the genes related to immune-related and protein transport functions, while the advanced HCC had mutations in proliferation-related genes. Conclusions: This suggests the differential mutations in gene functions may contribute to the heterogeneous progression of HCC. Our whole-exome sequencing analysis revealed mutation profiles which might be associated with the heterogeneous progression of HCC. P66 IMPDH2-TARGETED CONSTRAINT OF CELL GROWTH IN HEPATOCELLULAR CARCINOMA BY MYCOPHENOLIC ACID K. Chen1,2 , K. Man3 , H.J. Metselaar1 , H.L.A. Janssen1,4 , J. Kwekkeboom1 , D. Sprengers1 , M.J. Bruno1 , M.P. Peppelenbosch1 , Q. Pan1 . 1 Department of Gastroenterology & Hepatology, Erasmus MC-University Medical Center, Rotterdam, Netherlands; 2 Zhejiang Sci-tech University, Hangzhou, 3 Department of Surgery, Hong Kong University, Hong Kong, China; 4 Division of Gastroenterology, University Health Network, Toronto, ON, Canada E-mail: [email protected] Background and Aims: Immunosuppressants have significant impact on hepatocellular carcinoma (HCC) recurrence after liver transplantation. This study evaluated the effects and mechanismof-action of mycophenolic acid (MPA), an immunosuppressant commonly used after liver transplantation, in experimental HCC models. Methods: Five HCC cell lines and nude mice with partial immunodeficiency were used. Results: With clinically achievable concentrations, MPA potently inhibited cell proliferation in five HCC cell lines determined by the MTT assay. Flowcytometric analysis showed induction of apoptosis in 54%±2.8 (n = 3) cells after treatment with 20 mg/ml MPA for 5 days. In colony formation assays, MPA profoundly suppressed the number and size of formed colonies by treatment with only 1 mg/ml MPA, whereas colony formation was completely prevented by higher concentrations. Cell cycle analysis demonstrated that MPA arrested a considerable portion (22%±3, at 5 mg/ml) of HCC cells in the G0/G1 phase. Ectopic over-expression of IMPDH2 that lacks the binding site of MPA but retains its enzyme activity resulted in complete resistance to MPA. In nude mice subcutaneously engrafted with a HCC cell line, MPA significantly delayed tumor formation. Low dose (60 mg/kg) of MPA slightly promoted tumor growth (conceivably due to immunosuppression) but a high dose (250 mg/kg) constrained tumor growth, compared with PBS treated mice. Conclusions: MPA can specifically inhibit HCC cell growth by targeting IMPDH2. Besides immunosuppression-mediated tumor promotion which is observed with virtually all types of immunosuppressants, MPA can on the other hand specifically constrain HCC growth in mice. Clinical studies are encouraged to further validate in patients.
Background and Aims: Recent advance of sequencing technology has revealed genome-wide mutation profiles in numerous cancer types. However, its heterogeneous landscape of somatic mutations associated with the progression of liver cancer is not fully understood. Methods: We profiled mutation spectrum of whole-exome in 12 cases of Hepatitis B-related hepatocellular carcinoma (HCC) S88
Journal of Hepatology 2014 vol. 60 | S67–S214
Methods: MMP10 was detected by immunohistochemistry in cirrhotic human liver and HCC tissues. Hepatic MMP10 expression was examined in two murine models: CCl4induced acute liver injury and diethylnitrosamine (DEN)-induced hepatocarcinogenesis. MMP10 was detected by qPCR, western blotting and immunohistochemistry. The role of MMP10 was evaluated in CCl4 and DEN-treated Mmp10+/+ and Mmp10−/− mice. Vascular endothelial growth factor (VEGF) and hypoxia influence on MMP10 expression were studied in HCC cells. HCC cell lines overexpressing MMP-10 were generated and characterized. Results: In human tissues MMP10 expression was increased in macrophages, biliary cells and hepatocytes in cirrhotic livers, and markedly elevated in HCC cells. Acute CCl4 treatment increased MMP10 expression, and MMP10 was progressively induced in liver carcinogenesis. Mmp10−/− mice showed increased CCl4-induced liver injury, impaired ECM turnover and delayed resolution of necrotic areas. Conversely, Mmp10−/− mice showed less HCC incidence, smaller tumors, smaller histological neoplastic lesions and much fewer HCC lung metastases. MMP10 expression was induced by hypoxia and VEGF in HCC cells. HCC cells expressing MMP10 showed enhanced migration. Conclusions: MMP10 plays an important role in the hepatic wound healing response during acute injury. However, chronic upregulation of MMP10 expression can contribute to HCC progression and metastasis. P63 SMAD4-DEPENDENT REGULATION OF HEPATOCELLULAR CARCINOMA GROWTH AND PROGRESSION P.Y. Hernanda1 , C. Kan1 , A.M. Das2 , K. Sideras1 , S.J.A. Bots1 , H.L.A. Janssen1,3 , L.L. Kodach4 , H.J. Metselaar1 , J. Kwekkeboom1 , D. Sprengers1 , M.J. Bruno1 , T.L.M. ten Hagen2 , M.P. Peppelenbosch1 , Q. Pan1 . 1 Department of Gastroenterology and Hepatology, 2 Laboratory of Experimental Surgical Oncology, Section Surgical Oncology, Department of Surgery, Erasmus MC University Medical Center, Rotterdam, Netherlands; 3 Division of Gastroenterology, University Health Network, Toronto, ON, Canada; 4 Department of Gastroenterology and Hepatology, Leiden University Medical Center, Leiden, Netherlands E-mail: [email protected] Background and Aims: SMAD4 is recognized as a central mediator of Transforming Growth Factor Beta (TGF-b) and Bone Morphogenetic Protein (BMP) signaling pathways which are involved in regulating tumor progression. In general, SMAD4 is considered a tumor suppressor. Here we investigated the role of SMAD4 in hepatocellular carcinoma (HCC). Methods: Immunohistochemical stainings were performed in paraffin embedded-tissue microarray patient HCC (n = 42). Three HCC cell lines were used for functional assay in vitro and in immune-deficient mice. Results: SMAD4 protein level was significantly higher in human HCC tissue compared with adjacent liver tissue (n = 42, P < 0.05). High SMAD4 levels were significantly associated with higher recurrence rate (p = 0.05), shorter time to recurrence (p < 0.05) and more tumor lesion (p < 0.01). Interestingly, high SMAD4 levels were associated with low p-SMAD 1/5/8 (a downstream target of BMP signaling) expression, both in patients and HCC cell lines. Knockdown of SMAD4 in HCC cell lines showed a significant decrease of migratory and colony formation capacity, whereas ectopic overexpression of SMAD4 resulted in increased migration activity demonstrated by the ring-barrier migration assay. However, knockdown of SMAD4 conferred resistance to the anti-growth effects of BMP4, TGF-b and Activin in HCC cell lines. Interim analysis (at day 12) of xenograft experiment showed that Smad4 knockdown appears to delay tumor initiation of HCC cells in nude mice. Conclusions: Basal SMAD4 expression is required for the antitumor function of BMP signaling in HCC. Elevated Smad4 expression
Journal of Hepatology 2014 vol. 60 | S67–S214
S87
POSTERS correlates with poor outcome in HCC patients and more aggressive phenotype and function of HCC cells. P64 THE ULTRACONSERVED NON CODING RNA UC.158 IS DOWNSTREAM OF THE WNT/b-CATENIN PATHWAY IN LIVER CANCERS V. Paulus-Hock1 , A. Lampis2 , G. Ferrari1 , L. Boulton3 , R. Guest3 , D. Athineos4 , T. Jamieson4 , A. Veronese5 , R. Visone5 , R. Evans1 , G.J. Feng6 , T. Dale6 , M. Negrini7 , S. Forbes3 , T. Patel8 , O. Sansom4 , N. Valeri2 , C. Braconi1,9 . 1 Institute of Cancer Sciences, University of Glasgow, Glasgow, 2 Division of Molecular Pathology, Institute of Cancer Research, London, 3 Scottish Centre for Regenerative Medicine, MRC Centre for Regenerative Medicine, Edinburgh, 4 Beatson Institute for Cancer Research, Glasgow, United Kingdom; 5 Aging Research Center, University of Chieti, Chieti, Italy; 6 School of Biosciences, University of Cardiff, Cardiff, United Kingdom; 7 University of Ferrara, Ferrara, Italy; 8 Mayo Clinc, Jacksonville, FL, United States; 9 Division of Cancer Therapeutics, Institute of Cancer Research, London, United Kingdom E-mail: [email protected] Background and Aims: We aimed at investigating the effect of the Wnt/b-catenin signalling on Transcribed-Ultraconserved-Regions (T-UCR), a class of 481 non-coding-RNAs, which are identical across the genome of human mouse and rat and play a role in carcinogenesis. These may be explored as therapeutic targets. Methods: APCfl/fl mice develop Wnt/b-catenin dependent HCC. Expression of T-UCR was assessed by microarray-analysis with sense and antisense probes, and by specific real-time-PCR. Results: Twenty-two T-UCRs were aberrantly expressed, with 4 up- and 18 down-regulated >2 fold in tumour tissues from APCfl/fl compared to normal liver from WT. Over-expression of uc.158 could differentiate APCfl/fl -HCC from DEN-induced-HCC. uc.158 is overexpressed in HepG2 vs Huh7 and in HSC vs normal hepatocytes, in line with the activation of the Wnt pathway. Treatment with Lithium-Chloride that increased nuclear localization of b-catenin increased uc.158 in Huh-7 cells. Uc.158 was reduced after inhibition of b-catenin by siRNA or ICG-001 in HepG2. Uc.158 expression was not increased in PLC/PRF-5 cells (AXIN1-mutated), as well as no differences were observed between the liver of AXIN1−/− and WT mice, in line with the absence of b-catenin activation in these tumours. Recent findings suggest that Wnt/b-cat pathway is activated in cholangiocarcinoma (CCA). We found increased expression of uc.158 in human CCA. Tumour tissue from rat model of thioacetamide-induced CCA expressed uc.158, which was reduced after in vivo treatment with ICG-001 or C59 (Wnt/b-catenin inhibitors). Conclusions: uc.158 is activated by Wnt/b-catenin pathway in primary liver cancers across three species and may represent a promising target for developing novel therapeutics in a subset of cancers. P65 MUTATION SPECTRUM ASSOCIATED WITH THE PROGRESSION OF HBV-RELATED HEPATOCELLULAR CARCINOMA H.G. Woo1 , S.S. Kim2 , H.W. Cho1,3 , S.M. Kwon1,3 , H.J. Cho2 , S.J. Ahn2 , S.W. Cho2 , J.Y. Cheong2 . 1 Department of Physiology, 2 Department of Gastroenterology, 3 Graduate School of Biomedical Science, Ajou University School of Medicine, Suwon, Korea, Republic of E-mail: [email protected]
and paired non-tumoral adjacent liver tissues with heterogeneous differentiation status. Tumor-specific variations (TSV) and 535 nontumor-specific variations (NSV) were profiled in the early and advanced HCC, respectively. Results: Enriched cancer-specific mutations at chromosome 1q were observed in the advanced HCC compared to those in the early HCC. Functional difference of the mutation spectrum was also identified between early and advanced HCC. The early HCCs were frequently mutated in the genes related to immune-related and protein transport functions, while the advanced HCC had mutations in proliferation-related genes. Conclusions: This suggests the differential mutations in gene functions may contribute to the heterogeneous progression of HCC. Our whole-exome sequencing analysis revealed mutation profiles which might be associated with the heterogeneous progression of HCC. P66 IMPDH2-TARGETED CONSTRAINT OF CELL GROWTH IN HEPATOCELLULAR CARCINOMA BY MYCOPHENOLIC ACID K. Chen1,2 , K. Man3 , H.J. Metselaar1 , H.L.A. Janssen1,4 , J. Kwekkeboom1 , D. Sprengers1 , M.J. Bruno1 , M.P. Peppelenbosch1 , Q. Pan1 . 1 Department of Gastroenterology & Hepatology, Erasmus MC-University Medical Center, Rotterdam, Netherlands; 2 Zhejiang Sci-tech University, Hangzhou, 3 Department of Surgery, Hong Kong University, Hong Kong, China; 4 Division of Gastroenterology, University Health Network, Toronto, ON, Canada E-mail: [email protected] Background and Aims: Immunosuppressants have significant impact on hepatocellular carcinoma (HCC) recurrence after liver transplantation. This study evaluated the effects and mechanismof-action of mycophenolic acid (MPA), an immunosuppressant commonly used after liver transplantation, in experimental HCC models. Methods: Five HCC cell lines and nude mice with partial immunodeficiency were used. Results: With clinically achievable concentrations, MPA potently inhibited cell proliferation in five HCC cell lines determined by the MTT assay. Flowcytometric analysis showed induction of apoptosis in 54%±2.8 (n = 3) cells after treatment with 20 mg/ml MPA for 5 days. In colony formation assays, MPA profoundly suppressed the number and size of formed colonies by treatment with only 1 mg/ml MPA, whereas colony formation was completely prevented by higher concentrations. Cell cycle analysis demonstrated that MPA arrested a considerable portion (22%±3, at 5 mg/ml) of HCC cells in the G0/G1 phase. Ectopic over-expression of IMPDH2 that lacks the binding site of MPA but retains its enzyme activity resulted in complete resistance to MPA. In nude mice subcutaneously engrafted with a HCC cell line, MPA significantly delayed tumor formation. Low dose (60 mg/kg) of MPA slightly promoted tumor growth (conceivably due to immunosuppression) but a high dose (250 mg/kg) constrained tumor growth, compared with PBS treated mice. Conclusions: MPA can specifically inhibit HCC cell growth by targeting IMPDH2. Besides immunosuppression-mediated tumor promotion which is observed with virtually all types of immunosuppressants, MPA can on the other hand specifically constrain HCC growth in mice. Clinical studies are encouraged to further validate in patients.
Background and Aims: Recent advance of sequencing technology has revealed genome-wide mutation profiles in numerous cancer types. However, its heterogeneous landscape of somatic mutations associated with the progression of liver cancer is not fully understood. Methods: We profiled mutation spectrum of whole-exome in 12 cases of Hepatitis B-related hepatocellular carcinoma (HCC) S88
Journal of Hepatology 2014 vol. 60 | S67–S214