ABSTRACT
This study is to evaluate the cytotoxicity of mitomycin C (MMC) and its analogue 5-(aziridin-1-yl)-3-hydroxymethyl-1-methylindole-4,7-dione (629) as well as the effect of transfection of constitutive androstane receptor (CAR) on their biological effects. HepG2 cells were transfected with the plasmids mCAR1/pCR3 mediated by liposome. Vector pCR3 was used as control. Transfected cells were screened by G418 resistance and limiting dilution. The expressions of plasmid mCAR1/pCR3 and CYP2B6 mRNA were detected by RT-PCR; Cytotoxicities of MMC and 629 in vitro were evaluated in g2car cells and HepG2 cells by MTT method under anaerobic and aerobic conditions. mRNA expression of CAR and CYP2B6 can not be detected in HepG2 cells and HepG2/pCR3 cells but can in g2car cells. It is shown that plasmid mCAR1/pCR3 was transfected into g2car cells successfully and target CYP2B6 was transactivated by CAR. To compare with aerobic and anaerobic, the cytotoxicities of MMC and 629 to HepG2 cells and g2car cells had significantly enhanced (P < 0.05), and transfect CAR gene can improve the cytotoxicity of MMC (P < 0.05), but not 629 (P > 0.05). Furthermore, CYP2B6 is one master enzyme for the metabolism of MMC and not 629. Transfection of CAR can increase expression of CYP2B6 mRNA in HepG2 cells, and can affect cytotoxicities of MMC and 629.