Role and mechanisms ofω-3 polyunsaturated fatty acids in inducing cell apoptosis and reversing drug resistance in multiple myeloma / 中国肿瘤临床

ABSTRACT

Objective:To explore the role and mechanisms ofω-3 polyunsaturated fatty acids (ω-3PUFAs) alone or in combination with dexamethasone (DEX) in inducing cell apoptosis and reversing drug resistance in multiple myeloma (MM). Methods:DEX-resistant MM cell line MM1R was treated with different concentrations of eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) alone or in combination with DEX for 24 or 48 h. Cel proliferation was detected by MTT assay. Cel cycle and apoptosis were measured by flow cytometry. Expression levels of apoptosis-related proteins were analyzed by Western blot. Two-tailed, unpaired Student's t-test was used to compare the two treatment groups. A value of P<0.05 was considered statistically significant. Results:MM1R proliferation was inhibited by different concentrations (10, 20, 50, and 100μM) of EPA or DHA alone or in combination with 10μM DEX in a dose-and time-dependent manner. The inhibition effect was significantly higher in combinative groups than in single EPA or DHA treatment group (P=0.014, P=0.032). The percentage of G0/G1 phase and cell apoptosis rate in MM1R treated with different concentrations of EPA or DHA alone increased in a dose-dependent manner. This percentage was also significantly higher in the combinative groups than in the single EPA or DHA treatment group (P=0.015, P=0.004). The expression levels of cleaved caspase-3 and Bax were upregulated, whereas those of pro-caspase-3 and BCL-2 were downregulated in a dose-dependent manner. Drug resistance gradually decreased in MM1R cells at different concentrations of EPA or DHA with the increase of drug concentration. The reversal fold also increased gradual y, whereas the cel s decreased in the two drug-combination groups compared with the single-drug group. Moreover, the drug-resistance reversal index increased significantly. Conclusion:ω-3PUFAs can inhibit DEX-resistant MM cell proliferation, arrest cell cycle, and induce cell apoptosis.ω-3PUFAs also exhibit a synergistic anti-resistanteffect in combination with DEX. Furthermore,ω-3PUFAs can serve as novel effective drugs for MM treatment.