Quinolone-indolone Conjugate(QIC-1)induces Apoptosis By Inhibiting EGFR-STAT3-HK Ⅱpathway In Human Cancer Cells

Purpose:The epidermal growth factor receptor(EGFR) serves an important function in the proliferation of human tumors and is an effective target for the treatment of cancer. In this study,we want to screen the 20 quinolone-indolone conjugates targeting EGFR and to acquire a stronge st anti-tumor active compound, and further to investigate the potential mechanisms and the roles in resistant cancer cells. synthesized a new quinolone-indoloneconjugate QIC1(9-Fluoro-3,7-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-6-(2-oxo-1,2-dihydro-indol-3-ylidenemethyl)-7-oxo-2H-[1,4]oxazin o[2,3,4-ij]quinoline) targeting EGFR of the novel ompound QIC1.Methods:MTT(3-(4, 5-Dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide) assay was performed to determine the antitumor activity of 20 quinolone-indolone conjugates in varous human cancer cells and acquire the strongest anti-tumor active compound.Cell cycle was analyzed by Flow cytometry. Propidium iodide /Hoechst 33342 double staining assay was used to investigate the effect of strongest anti-tumor active compound on cancer cell apoptosis. Western blot was used to detect the expression level of the proteins related with cell proliferation and apoptosis.Results:1.We acquired a strongest anti-tumor active compound QIC1(9-Fluoro-3,7-dihydro-3-methyl-10-(4-methyl-1-piperazinyl)-6-(2-oxo-1,2-dihydro-indol-3-ylidenemethyl)-7-oxo-2H-[1,4]oxazino[2,3,4-ij]quinoline).2.The antiproliferative effect of QIC1 is stronger than the positive control Sunitinib in Hep G-2,MCF–7 and A549 cells.3.QIC1 arrested cell cycle at G2/M phase in Hep G-2 cells. QIC1 inhibited the synthesis ofDNA in A549 cells.4.QIC1 resulted in cell apoptosis and the increased expression of Bax and the reducedexpression of Bcl-2.5.Further analyses showed that QIC1 attenuated the activities of epidermal growth factorreceptor(EGFR) and the downstream STAT3-mediated HK Ⅱsignaling pathways.6.In addition, QIC1 showed anti-proliferative effects in MCF-7/DOX human doxorubicin-resistant breast cancer cells and enhanced anticancer activity of doxorubicin in the MCF-7/DOX cells.Conclusions:The reduced expression of phosphor-EGFR-phosphor-STAT3-HK Ⅱis chiefly responsible for all events of the new Quinolone-indolone conjugate QIC1 inhibiting proliferation and inducing apoptosis and QIC1 maybe process the activity of reversing the resistance of cancer cells.