Mechanism study on miRNA- 18a and miRNA- 4802 suppressing drug resistance of lymphoma cells via inhibiting autophagy / 中国药房

ABSTRACT

OBJECTIVE To stud y the regulation mechanism of miRNA- 18a and miRNA-4802 on drug resistance of lymphoma cells via autophagy. METHODS Using human burkitt ’s lymphoma cell Daudi and human mantle cell lymphoma cell JeKo- 1 as the research objects ，adriamycin（ADR）and vincristine （VCR）as experimental drugs. After treatment of ADR and VCR ，relative cell viability was detected with CCK- 8 kit；the expression of apoptosis marker protein activated cleaved caspase- 9 and cleaved caspase-6 were detected by Western blot assay. The drug resistances of the two cells to ADR and VCR were investigated. The difference of autophagy activity between the two kinds of cells by expression detection of autophagy related proteins LC 3-Ⅱ and p62，autophagy flow experiment and transmission electron microscope observation. Fluorescence quantitative polymerase chain reaction was used to investigate the expression differences of miRNA- 18a and miRNA- 4802，ULK1 and ATG 7 mRNA in the two cells，and to detect the expression differences of ULK 1 and ATG 7 proteins. Taking JeKo- 1 cells as the research object ，the changes of autophagy activity and drug resistance were investigated after treatment with endogenous miRNAs （miRNA-18a mimics ， miRNA-4802 mimics）of two simulated organisms. RESULTS After ADR and VCR treatment ，compared with Daudi cells ，JeKo-1 cells had stronger drug resistance and autophagy activity. The expression of miRNA- 18a and miRNA- 4802 in JeKo- 1 cells were significantly lower than Daudi cells ，mRNA and protein expression of ULK 1 and ATG 7 were significantly higher than those of Daudi cells （P＜0.001）. After treatment of miRNA- 18a mimics and miRNA- 4802 mimics，the autophagy activities and drug resistances of JeKo- 1 cells were decreased significantly. CONCLUSIONS miRNA-18a and miRNA- 4802 can decrease drug resistances of lymphoma cells to ADR and VCR by reducing 2 the expression of autophagy-initiating genes ULK1 and ATG7， and inhibiting the autophagy activity of lymphoma cells.