AIM: To investigate the biological features of hepatitis B virus (HBV)-transfected HepG2. 2.15 cells.

METHODS: The cell ultrastructure, cell cycle and apoptosis, and the abilities of proliferation and invasion of HBV-transfected HepG2. 2.15 and the parent HepG2 cells were examined by electron microscopy, flow cytometry, 3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide and trans-well assay. Oncogenicity of the two cell lines was compared via subcutaneous injection and orthotopic injection or implantation in nude mice, and the pathological analysis of tumor formation was performed. Two cytoskeletal proteins were detected by Western blotting.

RESULTS: Compared with HepG2 cells, HepG2. 2.15 cells showed organelle degeneration and filopodia disappearance under electron microscope. HepG2. 2.15 cells proliferated and migrated slowly in vitro, and hardly formed tumor and lung metastasis in nude mice. Flow cytometry showed that the majority of HepG2. 2.15 cells were arrested in G1 phase, and apoptosis was minor in both cell lines. Furthermore, the levels of cytoskeletal proteins F-actin and Ezrin were decreased in HepG2. 2.15 cells.

CONCLUSION: HepG2. 2.15 cells demonstrated a lower proliferation and invasion ability than the HepG2 cells due to HBV transfection.