Liang Li1, Jing Tang1, Baohua Zhang2, Wen Yang1, Miyang LiuGao1, Ruoyu Wang3, Yexiong Tan1, Jianling Fan4, Yanxin Chang3, Jing Fu1, Feng Jiang3, Caiyang Chen3, Yingcheng Yang1, Jin Gu5, Dingming Wu5, Linna Guo1, Dan Cao1, Hengyu Li3, Guangwen Cao6, Mengchao Wu2, Michael Q Zhang5, Lei Chen1, Hongyang Wang7. 1. International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China. 2. Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, Shanghai, China. 3. International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China. 4. International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China Changzheng Hospital, Second Military Medical University, Shanghai, China. 5. Bioinformatics Division, TNLIST/Department of Automation, Tsinghua University, Beijing, China. 6. Department of Epidemiology, Second Military Medical University, Shanghai, China. 7. International Co-operation Laboratory on Signal Transduction, Eastern Hepatobiliary Surgery Institute, Second Military Medical University, Shanghai, China National Center for Liver Cancer, Shanghai, China National Laboratory for Oncogenes and Related Genes, Cancer Institute, Ruijing Hospital, Shanghai Jiao Tong University, Shanghai, China.
Abstract
OBJECTIVE: Liver tumour-initiating cells (T-ICs) are critical for hepatocarcinogenesis. However, the underlying mechanism regulating the function of liver T-ICs remains unclear. METHODS: Tissue microarrays containing 242 hepatocellular carcinoma (HCC) samples were used for prognostic analysis. Magnetically activated cell sorting was used to isolate epithelial cell adhesion molecule (EPCAM)-positive cells. The gene expressions affected by miR-429 were determined by arrays. Co-immunoprecipitation was used to study interactions among retinoblastoma protein (RB1), Rb binding protein 4 (RBBP4) and E2F transcription factor 1 (E2F1). The DNA methylation status in CpG islands was detected by quantitative methylation analysis. miRNAs in microvesicles were isolated by a syringe filter system. RESULTS: The significant prognosis factor miR-429 was upregulated in HCC tissues and also in primary liver T-ICs isolated from clinical samples. The enrichment of miR-429 in EPCAM+ T-ICs contributed to hepatocyte self-renewal, malignant proliferation, chemoresistance and tumorigenicity. A novel functional axis involving miR-429, RBBP4, E2F1 and POU class 5 homeobox 1 (POU5F1 or OCT4) governing the regulation of liver EPCAM+ T-ICs was established in vitro and in vivo. The molecular mechanism regulating miR-429 expression, involving four abnormal hypomethylated sites upstream of the miR-200b/miR-200a/miR-429 cluster, was first defined in both EPCAM+ liver T-ICs and very early-stage HCC tissues. miR-429 secreted by high-expressing cells has the potential to become a proactive signalling molecule to mediate intercellular communication. CONCLUSIONS: Epigenetic modification of miR-429 can manipulate liver T-ICs by targeting the RBBP4/E2F1/OCT4 axis. This miRNA might be targeted to inactivate T-ICs, thus providing a novel strategy for HCC prevention and treatment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
OBJECTIVE:Liver tumour-initiating cells (T-ICs) are critical for hepatocarcinogenesis. However, the underlying mechanism regulating the function of liver T-ICs remains unclear. METHODS: Tissue microarrays containing 242 hepatocellular carcinoma (HCC) samples were used for prognostic analysis. Magnetically activated cell sorting was used to isolate epithelial cell adhesion molecule (EPCAM)-positive cells. The gene expressions affected by miR-429 were determined by arrays. Co-immunoprecipitation was used to study interactions among retinoblastoma protein (RB1), Rb binding protein 4 (RBBP4) and E2F transcription factor 1 (E2F1). The DNA methylation status in CpG islands was detected by quantitative methylation analysis. miRNAs in microvesicles were isolated by a syringe filter system. RESULTS: The significant prognosis factor miR-429 was upregulated in HCC tissues and also in primary liver T-ICs isolated from clinical samples. The enrichment of miR-429 in EPCAM+ T-ICs contributed to hepatocyte self-renewal, malignant proliferation, chemoresistance and tumorigenicity. A novel functional axis involving miR-429, RBBP4, E2F1 and POU class 5 homeobox 1 (POU5F1 or OCT4) governing the regulation of liver EPCAM+ T-ICs was established in vitro and in vivo. The molecular mechanism regulating miR-429 expression, involving four abnormal hypomethylated sites upstream of the miR-200b/miR-200a/miR-429 cluster, was first defined in both EPCAM+ liver T-ICs and very early-stage HCC tissues. miR-429 secreted by high-expressing cells has the potential to become a proactive signalling molecule to mediate intercellular communication. CONCLUSIONS: Epigenetic modification of miR-429 can manipulate liver T-ICs by targeting the RBBP4/E2F1/OCT4 axis. This miRNA might be targeted to inactivate T-ICs, thus providing a novel strategy for HCC prevention and treatment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
Entities:
Keywords:
Hepatocellular Carcinoma; Signal Transduction; Stem Cells
Authors: Juan Sandoval; Angel Díaz-Lagares; Rocío Salgado; Octavio Servitje; Fina Climent; Pablo L Ortiz-Romero; Amparo Pérez-Ferriols; Maria P Garcia-Muret; Teresa Estrach; Mar Garcia; Lara Nonell; Manel Esteller; Ramon M Pujol; Blanca Espinet; Fernando Gallardo Journal: J Invest Dermatol Date: 2014-11-18 Impact factor: 8.551