The fibroblast growth factor receptor 2-mediated extracellular signal-regulated kinase 1/2 signaling pathway plays is important in regulating excision repair cross-complementary gene 1 expression in hepatocellular carcinoma

Gang Chen; Hong Qiu; Shandong Ke; Shaoming Hu; Shiying Yu; Shengquan Zou

doi:10.3892/br.2013.96

The fibroblast growth factor receptor 2-mediated extracellular signal-regulated kinase 1/2 signaling pathway plays is important in regulating excision repair cross-complementary gene 1 expression in hepatocellular carcinoma

Biomed Rep. 2013 Jul;1(4):604-608. doi: 10.3892/br.2013.96. Epub 2013 Apr 19.

Authors

Gang Chen¹, Hong Qiu², Shandong Ke¹, Shaoming Hu¹, Shiying Yu², Shengquan Zou³

Affiliations

¹ Departments of Integrated Traditional Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.
² Oncology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.
³ Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, P.R. China.

Abstract

Excision repair cross-complementary gene 1 (ERCC1) is a downstream regulatory target of fibroblast growth factor receptor 2 (FGFR2); however, the mechanism of its action has not been elucidated. The cascades downstream of FGFR2 include the PKC, Ras/Raf/MEK/ERK, JAK/STAT and PI3K pathways. ERCC1 is considered to be a closely related downstream target gene of extracellular signal-regulated kinase (ERK)1/2, since ERCC1 mRNA and protein levels may be inhibited by the ERK inhibitor U0126. It was hypothesized that FGFR2, which specifically binds with fibroblast growth factor 7 (FGF7), may regulate ERCC1 gene expression through the ERK signaling pathway. The aim of the present study was to explore the association between the regulatory effect of FGFR2 on ERCC1 gene expression and the p-ERK1/2 signaling pathway in a drug-resistant hepatocellular carcinoma (HCC) cell line. The drug-resistant cell line HepG2/OXA and its parental cell line HepG2 were transfected with Bek shRNA in the logarithmic growth phase. Transfected and untransfected HepG2 and HepG2/OXA cells were then stimulated with FGF7 and changes in the protein expression of FGFR2, p-ERK1/2 and ERCC1 was detected with western blot analysis. Following transfection, HepG2/T and HepG2/OXA/T cells were observed to grow stably in a screening medium containing puromycin. The western blot analysis demonstrated a significant decrease in the protein expressions of FGFR2, p-ERK1/2 and ERCC1 in HepG2/T and HepG2/OXA/T cells as compared to untransfected cells. Expression of FGFR2, p-ERK1/2 and ERCC1 in HepG2/OXA cells was significantly increased compared to the parental HepG2 cells. Following stimulation with FGF7, the expression of FGFR2, p-ERK1/2 and ERCC1 was increased, with significant differences between HepG2 and HepG2/OXA cells in the expression of p-ERK1/2 and ERCC1. No differences were detected in the protein levels following Bek shRNA transfection in HepG2/T and HepG2/OXA/T cells. In conclusion, the FGFR2-mediated ERK1/2 signaling pathway in HCC cells plays an important role in the regulation of ERCC1 expression.

Keywords: excision repair cross-complementary gene 1; extracellular signal-regulated kinase; fibroblast growth factor receptor 2; hepatocellular carcinoma.