Study On Ad-VT Regmlating Autophagy Through Ampk Pathway And Reducing Drug Resistance Of MCF-7/ADR Cells

At the moment,the most common treatment for breast cancer is surgery combined with radiation and chemotherapy,but these treatments can have a lot of side effects,and the treatment of patients with metastatic disease is not ideal,and patients are more likely to relapse after treatment.At the same time,the use of effective resistance phenomena also rides the effect of chemotherapy in patients with metastatic disease is not ideal.The over expression of several ABC transporters in tumor cells is one of the main causes of multidrug resistance(MDR).Ad-VT(Ad-apoptin-h TERTp-E1A)is a recombinant adenovirus expressing VP3 protein of chicken anemia virus.Ad-VT(Ad-apoptinh TERTp-E1A)is a tumor-killing oncolytic adenovirus with twofold specificity.Our earlier research discovered that it may efficiently destroy breast cancer cells.And that the impact is enhanced when coupled with chemotherapy medications.Furthermore,it has not meant to establish if it can lower the resistance of breast cancer cells to chemotherapy medicines.In order to explore whether Ad-VT(Ad-apoptin-h TERTp-E1A)combined with adriamycin can reduce the drug resistance of breast cancer cells and its mechanism.CCK8,crystal violet staining,indirect immunofluorescence staining and flow cytometry were used to detect the changes of adriamycin resistance in MCF-7/ADR cells treated with Ad-VT.The changes of different drug resistance proteins in MCF-7/ADR cells infected by Ad-VT were analyzed by Western blot and q PCR.The tumorbearing model in nude mice was also established,and the anti-tumor effect and toxicity of different treatment groups were studied by measuring tumor diameter,body weight and immunohistochemical analysis.Thus,we can explore the effect of Ad-VT on adriamycin resistance of breast cancer in vitro and in vivo,and find out the ways to produce the effect,so as to provide a new theoretical basis for oncolytic adenovirus combined with chemotherapy in the treatment of breast cancer.The results showed that 500 n M doxorubicin combined with 60 MOI Ad-VT could significantly inhibit the growth of MCF-7/ADR cells,which was better than that of MCF-7/ADR cells treated with 60 MOI Ad-VT alone.The results of Western blot and q PCR confirmed that Ad-VT could reduce the resistance of MCF-7/ADR cells to adriamycin,which was related to the resistance protein MRP1.At the same time,flow cytometry showed that Ad-VT could induce stronger apoptosis in MCF-7/ADR cells.Further experiments show that stronger apoptosis and autophagy induced by Ad-VT in MCF-7/ADR cells are related to the reduction of drug resistance of MCF-7/ADR cells,and Ad-VT induces autophagy changes of MCF-7/ADR cells through AMPK pathway,thus reducing the resistance to doxorubicin.The tumor-bearing experiment in nude mice also showed that Ad-VT could also induce MCF-7/ADR cells to decrease the resistance to doxorubicin in vivo.To sum up,Ad-VT can not only kill MCF-7/ADR cells,but also regulate autophagy and reduce the resistance of MCF-7/ADR cells to adriamycin through AMPK pathway.It is suggested that oncolytic adenovirus Ad-VT can not only be used as a drug to kill breast cancer cells.But also play a very important role in the combined use of chemotherapeutic drugs.