title: miR-26b enhances radiosensitivity of hepatocellular carcinoma cells by targeting EphA2.
abstract: OBJECTIVE
  Although low-dose radiotherapy (RT) that involves low collateral damage is more suitable for hepatocellular carcinoma (HCC) than traditional high-dose RT, but to achieve satisfactory therapeutic effect with low-dose RT, it is necessary to sensitize HCC cells to irradiation. This study was aimed to determine whether radiosensitivity of HCC cells can be enhanced using miR-26b by targeting erythropoietin producing human hepatocelluar A2 (EphA2).
  
  
  METHODS
  The levels of miR-26b and EphA2 expression in multiple HCC cell lines were assessed by qPCR and western blotting, respectively, and compared with those in a hepatic cell line. HCC 97H cells were transfected with miR-26b mimics, EphA2-ShRNA or EphA2 over-expression vector before exposure to low-dose irradiation.
  
  
  RESULTS
  Different degrees of miR-26b down-regulation and EphA2 up-regulation were observed in all HCC cell lines, among which the HCC 97H cell line expressed the lowest level of miR-26b and highest level of EphA2. EphA2 was verified as the target of miR-26b by dual luciferase reporter assay. HCC 97H cells transfected with miR-26b mimics or EphA2-ShRNA reduced the expression of EphA2 protein, with significantly lower cell proliferation rate and cell invasion ability and higher apoptosis rate in response to low-dose irradiation than those in the non-transfected cells. These results were reversed after EphA2 was overexpressed by transfection with the EphA2 overexpression vector. Co-transfection with miR-26b mimics and EphA2 overexpression vector barely altered EphA2 expression level and cell response to low-dose irradiation.
  
  
  CONCLUSIONS
  These data suggest that miR-26b enhances radiosensitivity of HCC 97H cells by targeting EphA2 protein.
authors.affiliation: Department of Oncology, Third Xiangya Hospital, Central South University, NO.138, Tong Zi Po Road, Yue Lu District, Chang Sha, Hunan Province, China 410013.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Jin
authors.affiliation: Department of Oncology, Third Xiangya Hospital, Central South University, NO.138, Tong Zi Po Road, Yue Lu District, Chang Sha, Hunan Province, China 410013.
authors.forename: Xiang Jun
authors.initials: XJ
authors.lastname: Li
authors.affiliation: Department of Oncology, Third Xiangya Hospital, Central South University, NO.138, Tong Zi Po Road, Yue Lu District, Chang Sha, Hunan Province, China 410013.
authors.forename: Pei Guo
authors.initials: PG
authors.lastname: Cao
keywords: EphA2; HCC 97H cells; Hepatocellular carcinoma; Radiosensitivity; miR-26