[Reversal of multidrug resistance in hepatocellular cell line HepG2R by mdr1-antisense RNA]

To investigate whether multidrug resistance gene 1(mdr1) could reverse multidrug resistance (MDR) in HepG2R cells.

An adenovirus vector, Adeno-asmdr, containing the antisense RNA driven by AFP promoter, was construct. Adeno-EGFP was transfected into HepG2, an AFP producing cell line, L02, a normal human liver cell line, and HeLa, a human cervical cancer cell line, the EGFP transcription level was detected by RT-PCR. Adeno-asmdr was transfected into HepG2R cells, the expression of P-gp170 was detected by western blotting, apoptosis was detected using TUNEL and flow cytometry, cell cycle was analyzed by flow cytometry.

EGFP was highly expressed in HepG2 cells, however, its expression in L02 or HeLa cells was very weak. Western blot showed that the P-gp170 was marked down-regulated 48h after transfection with Adeno-asmdr, and the expression of P-gp170 was detectable at least 7d post-transfection. Compared with control cells, Adeno-asmdr transfected HepG2R cells were more sensitive to different chemicals, as indicated by TUNEL staining and flow cytometry. Chemical treatment arrested the cells in S and G0/M phase.

The recombinant adenoviral vector, Adeno-asmdr, can block the expression of mdr1, and reverse MDR in HepG2R cells.