HBx gene transfection affects the cycle of primary renal tubular epithelial cells through regulating cyclin expression

Hepatitis B virus X protein (HBx) has been previously demonstrated to be associated with the regulation of cell proliferation; however, the exact mechanisms underlying this effect remain unclear. The present study aimed to investigate the regulatory mechanism of HBx on the cycle progression of primary renal tubular epithelial cells. Primary renal tubular epithelial cells of Sprague Dawley (SD) rats were separated and cultured. The morphology of cultured cells was characterized by immunohistochemical analysis and the results demonstrated that primary renal tubular epithelial cells with the expected morphology and distribution were successfully separated and cultured from SD rats. HBx gene pcDNA3.1/myc vector and empty vector were constructed and transfected into cells as HBx and empty groups, respectively. Following transfection, the mRNA and protein levels of HBx, cyclin A, cyclin D1 and cyclin E in cells were determined by reverse transcription‑quantitative polymerase chain reaction and western blot analysis, respectively. The results demonstrated that following HBx gene transfection, the mRNA and protein levels of HBx, cyclin A, cyclin D1 and cyclin E in cells were significantly upregulated, compared with the empty control group (P