Down-regulation Of P-gap And CLC-3Expression By Curcumin Reverses Multidrug Resistance Of K562/ADM Cells

30%patients with leukemia occurs multidrug resistance, this has seriouslyblocked the treatment. So exploring the mechanism and making effective reversalhave become an urgent problem in the field of cancer research.Curcumin has become one of research hot spots in recent years, because it caninhibit the proliferation and reverse multidrug resistance of tumour cells. Althoughstudies have shown that the mechanism of reverse multidrug resistance of curcumin ismainly related to its inhibiton of P-gap, but its regulatory mechanism is not fullyunderstood. Studies suggest that the mechanism of multidrug resistance is related withhigh expression of CLC3(Chloride Channel3, CLC3) which participate in organnelleacidification.But whether CLC-3participate in multidrug resistance of leukemia cells? If so,whether the mechanism of curcumin reversing multidrug resistance has related withCLC-3? which has not been reported yet.1. ObjectiveIn this study, K562, K562/ADM cells were used as the object, the mechanism ofcur reverse multidrug were investigated on expression of P-gap and CLC-3.2. MethodDetection of the non-cytototic dose of curcumin and IC50of K562, K562/ADMcells by MTT, in order to assess the drug resistance and the reversal fold ofK562/ADM cells. Analysis of the morphological changes of K562/ADM cells aftertreated with noncytotic dose curcumin by means of inverted microscope observationand Wright,s-Giemsa stanining. RT-PCR and Western-blotting detected the mRNAand protein changes of P-gap and CLC-3in K562/ADM cells after treated withnon-cytototic dose curcumin.3. ResultThe MTT results showed that non-cytototic dose of curcumin was3ug/ml. 3ug/ml curcumin reverse multidrug resistance of K562/ADM cells by2.088folds.Inverted microscope observation and Wright,s-Giemsa stanining showed thatcurcumin promoted death and apoptosis of K562/ADM cells after treated with3ug/mlcurcumin. The RT-PCR results showed that the P-gap and CLC-3mRNA expressionof K562/ADM cells were significantly higher than K562cell,s, the P-gap mRNAexpression level was nearly zero,3ug/ml cur could reduce P-gap and CLC-3mRNAexpression and this effect of curcumin had time dependence. The Western-blottingresults showed that the P-gap and CLC-3protein expression of K562/ADM cells weresignificantly higher than K562cell,s, the P-gap protein expression level was nearlyzero,3ug/ml curcumin could reduce P-gap and CLC-3protein expression and thiseffect of curcumin had time dependence.4. Conclusioncurcumin can reverse multidrug resistance of K562/ADM cells. the multidrugresistance of K562/ADM cells is related with high expression of P-gap and CLC-3.curcumin can reverse multidrug resistance of K562/ADM cells by down-regulationP-gap and CLC-3expression.