Regulation Of SAHA Combined With CBI On Vascular Endothelial Cells In Breast Cancer Microenvironment

ObjectiveBreast cancer has surpassed lung cancer to become the largest cancer in the world,and its morbidity and mortality are rising year by year,which seriously harms women’s physical and mental health.The interaction between cancer cells and the tumor microenvironment plays a decisive role in the occurrence,development,metastasis,and response to drugs of breast cancer.Blood vessels are an important part of the microenvironment,which is considered a necessary condition for the growth and metastasis of breast cancer.In the angiogenesis of breast cancer,endothelial cells play a leading role in proliferating,migrating,and forming tubules under the action of a series of angiogenesis-promoting factors,forming new blood vessels.Therefore,inhibiting the proliferation and migration of vascular endothelial cells is very important for antiangiogenesis therapy.A large number of studies have shown that epigenetic modification plays an important role in regulating the tumor microenvironment.Suberoylanilide hydroxamic acid(SAHA),a new epigenetic regulation antineoplastic drug,belongs to the second-generation Histone deacetylase inhibitor(HDACI),which can improve the acetylation level of histone,up-regulate the expression of tumor suppressor genes,and promote the apoptosis and autophagy of cancer cells.Blocking the growth of tumor cells has a wide range of anti-tumor effects,but its clinical application is limited by its high concentration of cytotoxic side effects,rapid metabolism,and easy drug resistance.Many studies have shown that SAHA combined with other anticancer drugs can play a synergistic anti-tumor role.CA074 is a specific cathepsin B inhibitor(CBI),which can selectively inhibit the activity of cathepsin B(CTSB).Therefore,this study explored whether SAHA combined with CBI can regulate the microenvironment of breast cancer cells,inhibit the proliferation and migration of vascular endothelial cells,inhibit angiogenesis,and finally achieve the effect of inhibiting tumors.This study provides a theoretical basis for molecular targeted therapy of breast cancer and provides a new direction and idea for SAHA-combined therapy of breast cancer.MethodsA real-time cell analysis(RTCA)system was used to detect the effects of SAHA combined with CBI on the proliferation of breast cancer MCF-7 and MDA-MB-231 cells.The effects of breast cancer cell supernatant treated with combined drugs on the proliferation of human umbilical vein endothelial cells(HUVEC)were detected by RTCA and MTT experiments.A cell scratch test was used to detect the effect of breast cancer cell supernatant treated with combined drugs on HUVEC migration ability.Western Blot and qPCR were used to detect the effects of breast cancer cell supernatant after combined treatment on angiogenesis and autophagy-related factor expression in HUVEC.The effect of combined drugs on tumor growth in tumor-bearing mice was evaluated using a breast cancer xenograft model.The expression of angiogenesis-related proteins in tumor tissues of tumor-bearing mice was detected by an antibody chip experiment.Results1.The inhibitory effect of SAHA combined with CBI on the growth of breast cancer cells is time-dose dependent;the supernatant of breast cancer cells treated by SAHA combined with CBI significantly inhibited the proliferation and migration of HUVEC cells.2.The supernatant after SAHA combined with CBI significantly inhibited the expression of vascular endothelial growth factor(VEGF)and vascular endothelial growth factor receptor(VEGFR)in HUVEC cells and promoted the expression of autophagy-related factors in HUVEC cells.3.The experimental results of the breast cancer xenograft model showed that the combination of SAHA and CBI significantly inhibited the tumor growth of tumorbearing mice and could regulate the expression of angiogenesis-related proteins in tumor tissues of tumor-bearing mice.Conclusions1.SAHA combined with CBI-treated breast cancer cell supernatants may inhibit the proliferation and migration of HUVEC by down-regulating the expression of angiogenesis-related factors VEGF and VEGFR and up-regulating the expression of autophagy-related factors in HUVEC.2.SAHA combined with CBI inhibited tumor growth and regulated the expression of angiogenesis-related proteins in the tumor tissues of mice with breast cancer.