Background & objective: Multidrug resistance (MDR) is considered to be the major obstacle for chemotherapy. In order to reverse tumor MDR in vitro, we designed this study to establish human multidrug-resistant hepatocellular carcinoma cell line (HepG2/Adm) and to investigate its biological characteristics.
Methods: An adriamycin-resistant human hepatocellular carcinoma cell subline (HepG2/Adm) was established in vitro using gradually increased concentration of adriamycin (ADM) in culture. Cell growth was measured and multidrug resistance to multianticancer agents was evaluated by MTT assay. Flow cytometry (FCM) was performed to determine cell cycle,and to assess the expression of P-glycoprotein (P-gp), multidrug resistance-associated protein (MRP),lung-related protein (LRP),and glutathione S-transferase (GST), respectively. MDR mRNA expression related to these proteins were determined with reverse transcription polymerase chain reaction (RT-PCR).
Results: Compared to HepG2, HepG2/Adm had a prolonged doubling time of 30.1 hours. The number of cells in S-phase was significantly decreased (5.6+/-0.03)% in HepG2/Adm while those in G1 and G2-phase increased [(4.2+/-0.09)% and (1.5+/-0.08)%, respectively]. Furthermore, HepG2/Adm was resistant to many anti-tumor agents, and its IC(50) of ADM was 26 times higher than that of parent cell line HepG2. Significant overexpression of P-gp, MRP, and GST were detected. RT-PCR showed that mRNA expression of P-gp, MRP, LRP, and GST were significantly increased in HepG2/Adm.
Conclusion: HepG2/Adm is human multidrug-resistant, and its resistance may be closely related to the overexpression of P-gp, MRP, and GST.