title: MicroRNA-497 regulates cell proliferation in hepatocellular carcinoma.
abstract: Hepatocellular carcinoma (HCC) is the most common primary cancer of the liver. MicroRNA-497 (miR-497) is known to be downregulated in several types of human cancer; however, the expression, function and underlying mechanisms of miR-497 in HCC remain unclear. Therefore, the present study investigated miR-497 expression in HCC samples and HCC-derived cell lines using reverse transcription-quantitative polymerase chain reaction. The protein expression of one of the predicted common targets of miR-497, insulin-like growth factor-1 receptor (IGF-1R), was assessed using western blot analyses and immunohistochemistry. The role of miR-497 in regulating the proliferation of HCC-derived cells was also investigatedin vitroandin vivo. Of 60 paired specimens from HCC patients, miR-497 was downregulated in 42 cancer specimens compared with adjacent non-cancer tissues. Western blotting and immunohistochemical analyses revealed that IGF-1R expression was significantly increased in HCC compared to control tissues. In addition, overexpression of miR-497 was observed to inhibit colony formation and tumor growth in MHCC-97H human HCC cells. Conversely, SMMC-7721 human HCC cells transfected with a miR-497 inhibitor exhibited enhanced colony formation and tumor growth. Finally, IGF-1R protein, phosphoinositide 3-kinase/Akt signaling pathway-associated proteins and cyclin pathway-associated proteins were differentially expressed between miR-497-overexpressing cells and miR-497-silenced cells. These results indicate that miR-497 may be a potentially effective gene therapy target.
authors.affiliation: Department of Hepatobiliary Surgery, Nanjing Medical University Affiliated Wuxi Second Hospital, Wuxi 214002, P.R. China.
authors.forename: Wen-Zhou
authors.initials: WZ
authors.lastname: Ding
authors.affiliation: Department of General Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu 226000, P.R. China.
authors.forename: Qing-Feng
authors.initials: QF
authors.lastname: Ni
authors.affiliation: Department of Hepatobiliary and Pancreatic Surgery, Ningbo Lihuili Hospital, Ningbo, Zhejiang 315200, P.R. China.
authors.forename: Ye-Ting
authors.initials: YT
authors.lastname: Lu
authors.affiliation: Department of Liver Transplantation Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Liang-Liang
authors.initials: LL
authors.lastname: Kong
authors.affiliation: Department of Liver Transplantation Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Jian-Jun
authors.initials: JJ
authors.lastname: Yu
authors.affiliation: Department of Liver Transplantation Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Long-Wei
authors.initials: LW
authors.lastname: Tan
authors.affiliation: Department of Liver Transplantation Center, The First Affiliated Hospital of Nanjing Medical University, Nanjing, Jiangsu 210029, P.R. China.
authors.forename: Lian-Bao
authors.initials: LB
authors.lastname: Kong
keywords: hepatocellular carcinoma; insulin-like growth factor-1 receptor; microRNA-497; phosphoinositide 3-kinase/Akt; proliferation