The Effect Of Chloroxoquinoline In Breast Cancer And Its Related Mechanisms

Objective: Chloroxoquinoline is a new oral quinoline anti-tumor drug,which has been approved by the China Food and Drug Administration in recent years.It is often used as chemotherapy drug for advanced breast cancer and non-small cell lung cancer in clinic and mainly used alone.However,the lack of laboratory data about Chloroxoquinoline hinders its clinical application.This study intends to clarify the effect of Chloroxoquinoline in different types of breast cancer cells and its possible mechanism and to explore the effect of Chloroxoquinoline combined with Paclitaxel or Adriamycin in breast cancer cell lines.Methods: The breast cancer cell lines were treated with different concentrations of Chlroxoquinoline.Annexin V/PI(propidium iodide)staining was used to detect apoptosis and cell cycle by flow cytometry.Rhodamine-PHalloidin staining and immunofluorescent staining was used to observe the polymerization state of F-actin and the expression of ?-Tubulin in breast cancer cell lines,respectively.Wound healing and transwell assay was conducted to detect cell migration and invasion,respectively.Western Blot was used to detect the expression of apoptosis and cell cycle related proteins and the pHospHorylation level of key protein in Rho/Rho kinase signaling pathway.MTT and CCK-8 assay were used to observe the inhibition rate of cell proliferation.Results: Chloroxoquinoline can effectively inhibit the proliferation of three kinds of breast cancer cells,but its mechanism is different.For MDA-MB-231 cell line,it mainly promoted the apoptosis of tumor cells,while for Bcap-37 and MDA-MB-453 cell line,it mainly promoted the cell cycle arrest.Further study on the mechanism of effect showed that compared with the control cells,the breast cancer cell lines treated with Chloroxoquinoline showed dose-dependently changes in cell morpHology and decrease in cell body;the staining of F-actin and ?-Tubulin was dose-dependently irregular and clustered.Chloroxoquinoline treatment induced dose-dependently decrease in cell migration and invasion,and its effect is related to down regulating the pHospHorylation expression of Rho associated curl protein kinase 2(Rock2),pHospHorylated protein kinase(Limk)and actin depolymerizing factor Cofilin in Rho/Rho kinase signaling pathway(P<0.01).Furthermore,Compared with Chloroxoquinoline alone,Chloroxoquinoline combined with Paclitaxel or Doxorubicin capacities could dose-dependently inhibit the proliferation of breast cancer cells,and both of the combination of drugs had synergistic antitumor effect in vitro(the average CI value<1).Conclusion: Chloroxoquinoline could effectively inhibit the proliferation of breast cancer cell lines,mainly by promoting apoptosis or cell cycle arrest.Chlroxoquinoline could dose-dependently inhibit the polymerization state of F-actin and the expression of ?-Tubulin,the cytoskeleton aggregation of breast cancer cells lines,thus inhibit cell migration and lead to cell death.The preliminary results showed that this effect partially relates with down regulate in Rho/Rho kinase signaling pathway.Moreover,Chloroxoquinoline combined with Paclitaxel or Doxorubicin improved the antitumor capacities and had synergistic antitumor effect in breast cancer cell lines,which might be an effective therapeutic strategy to achieve synergistic antitumor effects.