Our previous work found that DMH1(4-[6-(4-isopropoxyphenyl)pyrazolo [1,5-a]pyrimidin-3-yl]quinoline) was a novel autophagy inhibitor. Here, we aimed to investigate the effects of DMH1 on chemotherapeutic drug-induced autophagy as well as the efficacy of chemotherapeutic drugs in different cancer cells. We found that DMH1 inhibited tamoxifen- and cispcis-diaminedichloroplatinum(II)(CDDP)-induced autophagy responses in MCF-7 and HeLa cells, and potentiated the anti-tumor activity of tamoxifen and CDDP for both cells. DMH1 inhibited 5-fluorouracil(5-FU)-induced autophagy responses in MCF-7 and HeLa cells, but did not affect the anti-tumor activity of 5-FU for these two cell lines. DMH1 itself did not induce cell death in MCF-7 and HeLa cells, but inhibited the proliferation of these cells. In conclusion, DMH1 inhibits chemotherapeutic drug-induced autophagy response and the enhancement of efficacy of chemotherapeutic drugs by DMH1 is dependent on the cell sensitivity to drugs.
Our previous work found that DMH1 (4[6-(4-isopropoxyphenyPpyrazolo [1,5-cdpyrimidin-3yllquinolinej was a novel autophagy inhibitor. Here, we aimed to investigate the effects of DMH1 on chemotherapeutic drug induced autophagy as well as the efficacy of chemotherapeutic drugs in different cancer cells. We found that DM H1 inhibited tamoxifen- and cispcis-diaminedichloroplatinum ( (CDDP)-induced autophagy responses in MCF-7 and HeLa cells, and potentiated the anti-tumor activity of nunoxifen and CDDP for both cells. DMH1 inhibited 5-11uorouracil (5-FU)-induced autophagy responses in MCF-7 and HeLa cells, but did not affect the anti -tumor activity of 5-FU for these two cell lines. DMH1 itself did not induce cell death in MCI -7 and HeLa cells, but inhibited the proliferation of these cells. In conclusion, DMH1 inhibits chemotherapeutic drug-induced autophagy response and the enhancement of efficacy of chemotherapeutic drugs by DMH I is dependent on the cell sensitivity to drugs. (C)2015 Chinese Pharmaceutical Association and Institute of Medica, Chinese Academy of Medical Sciences. Production and hosting by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).