[Effect of siRNA-Interfering ß-Catenin Expression on MDR of Human Multiple Myeloma Cell Line].

OBJECTIVE: To investigate the effecr of siRNA-interfering ß-catenin expression on drug-resistance of multiple myeloma cells. METHODS: The multiple myeloma cell line RPMI-8226 was cultured in vitro. The maphalan-resistant cell model was established by concentration gradient ascending of durg, then the drug-resistant cell line was instantaneously transfected with ß-catenin siRNA, the sensitivity of RPMI 8226 cells to maphalan was detected by CCK-8 meltod before and after the transfection with siRNA; the mRNA and protein expression of ß-catenin was detected by qRT-PCR and Western blot respectively, the apoptosis of cells was detected by flow cytometry. RESULTS: IC50 of maphalan decreased from (5.29±0.19) µmol/L to (1.88±0.64) µmol/L, suggesting that the deplation of ß-eatenin restored the sensitivity of drug-resistant cell line RPMI-8226 to malphalan. The Western blot showed that after the instaintaneous transfection with ß-catenin siRNA, the ß-catenin protein expression level obviously decreased, compared with level before transfection. After transfection, the maplalan-inducing apoptosis rate of cells increased from (35±0.5)% to (54±0.4)%, suggesting that the ß-catinin gene may correlated with drug-resistance of cells. Interfering the expression of ß-catenin gene could enhance the sensitivity of drug-resistant RPMI-8226 cells to maphalan. CONCLUSION: The ß-catenin siRNA interfereuce can inhisit the ß-catenin gene expression in Wnt/ß-catenin signaling pathway, suppress the cell proliferation, enhence the toxicity of maphalan on drug-resistant RPMI-8226 cells, thus result in increase of cell apoptosis.