Abstract:

Objective  To investigate the reversal effect on MDR1 gene-mediated multidrug resistance in human colon carcinoma LoVo/5-Fu cells by RNA interference. Methods  A eukaryotic expression plasmid of shRNA targeting on MDR1 was transiently transfected into human colon carcinoma LoVo/5-Fu cells. Expression of MDR1 mRNA was detected by real-time quantitative PCR. Drug sensitivity was measured by MTT. The apoptosis of cells was determined by flow cytometry assay. Results  After transfection with EASY-shRNA-MDR1，compared with the un-transfected group，expression of MDR1 mRNA in LoVo/5-Fu cells was reduced obviously(P<0.05); IC50 of 5-Fu and the resistance indexes were decreased obviously(P<0.05); the relative reverse rate of sensitivity of LoVo/5-Fu cells to 5-Fu was 74.7%; the apoptosis rate increased significantly (P<0.05). Conclusion  MDR1 shRNA effectively inhibited expression of MDR1，thus reuersed MDR1 genemediated multidrug resistance in human colon carcinoma LoVo/5-Fu cells.

Key words: Colon neoplasms； RNA interference； Multidrug resistance gene； Apoptosis； Gene therapy