Background: Approximately 50% of hepatocellular carcinoma (HCC) arises due to the infection by hepatitis B virus X protein (HBx). Sorafenib, a unique targeted oral kinase inhibitor, is the therapeutic agent of choice for advanced HCC. The mechanism of HBx in drug resistance of sorafenib-resistant HCC cells was evaluated in this study.
Methods: Employing a stepwise increase of the sorafenib content, Hep3B and HepG2 cells were iteratively induced to establish drug-resistant cell lines (Hep3B/R and HepG2/R). The survival rate of Hep3B, Hep3B/R, HepG2, and HepG2/R cells was estimated using the cell counting kit-8 (CCK-8) assay. The IC50 values of sorafenib were calculated, exploring its effects under varying concentrations. The HBx content was quantified via quantitative reverse transcription PCR (RT-qPCR) and Western Blot. HBx overexpression and interfering virus vectors were constructed and transfected into Hep3B/R and HepG2/R cells. Cell viability and metastasis were assessed by colony formation, wound healing, and transwell assays. E-cadherin, N-cadherin, Vimentin, Slug, and Snail content was evaluated via Western Blot.
Results: HBx content was significantly elevated in Hep3B/R and HepG2/R subgroups compared to Hep3B and HepG2 subgroups. The proliferation, clonogenicity, invasiveness, and migratory abilities of Hep3B/R and HepG2/R cells in the HBx subgroup were markedly enhanced; E-cadherin content was significantly reduced, whereas the content of N-cadherin, Vimentin, Slug, and Snail was significantly elevated in the HBx subgroup. Conversely, in the sh-HBx subgroup, the proliferation, clonogenicity, invasion, and migration of Hep3B/R and HepG2/R cells were significantly reduced, E-cadherin content was markedly increased, and N-cadherin, Vimentin, Slug, and Snail content was significantly reduced, compared to the sh-negative control (NC) subgroup.
Conclusions: HBx knockout may affect the development of HCC by reducing the proliferation, invasion, and migration of Hep3B/R and HepG2/R cells through the inhibition of Epithelial-Mesenchymal Transition (EMT).
Keywords: drug resistance; hepatitis B virus X protein; hepatocellular carcinoma; sorafenib.