Mechanism Of Endogenous Cannabinoid System On Invasion And Metastasis Of Breast Cancer Cells Under Chronic Intermittent Hypoxia

Objective:To investigate the role of endogenous cannabinoid system in the process of chronic intermittent hypoxia-promoting breast cancer cell metastasis by studying the proliferation,metastasis and signaling pathway of breast cancer cells under chronic intermittent hypoxia,in order to understand the molecular invasion and metastasis of OSAHS with breast cancer Mechanisms provide a basis for finding interventions and therapeutic targets for OSAHS with breast cancer.Methods:(1)Construction of chronic hypoxia(CH)and chronic intermittent hypoxia(CIH)breast cancer MCF-7 cell model,normal air cultured MCF-7 cells in the normoxic group(Normoxia),study chronic intermittent hypoxia on breast cancer cell proliferation And the effects of metastasis;MTT assay and Transwell assay were used to detect the growth and cell cycle of human breast cancer MCF-7 cells under chronic intermittent hypoxia;RT-PCR and Western blotting were used to detect chronic intermittent hypoxia-mediated breast cancer cells.Changes in the expression of cannabinoid receptors CB1 and CB2;(2)Construction of CB1 and CB2 interfering RNA(shRNA)fragment recombinant plasmids sh-CB1,sh-CB2,sh-CB1/CB2,transfected sh-CB1,sh-CB2,sh-CB1/CB2 recombinant plasmid into chronic intermittent hypoxia In MCF-7 cell model;IGF-1R,AKT,GSK-3β,pIGF-1R,pAKT,pGSK-3β,E-cadherin in MCF-7 cells after silencing silencing of cannabinoid receptors CB1 and CB2 by Western blotting,Vimentin,Snail1 expression.(3)Data were expressed as `x ± s.Differences between the two groups were compared using the t test,and one-way ANOVA was used for comparison between groups.Withα=0.05 as the test standard,P<0.05 indicated that the difference was significant.Result:(1)Compared with the Normoxia group,the proliferation and invasion ability of MCF-7 cells in CH group and CIH group increased,and the proliferation and invasion ability of MCF-7 cells in CIH group were stronger than that in CH group(p<0.05).(2)RT-PCR and Western results showed that the expression of CB1 and CB2 in MCF-7 cells of CH group and CIH group was higher than that of MCF-7 cells in Normoxia group,and CB1 and CB2 in MCF-7 cells of CIH group.The expression was significantly higher than that of the CH group(p<0.05);(3)RNA interference silencing CB1 and CB2 promoted cell cycle arrest of MCF-7cells in G0 phase under chronic intermittent hypoxia,significantly inhibited chronic intermittent hypoxia-mediated cell proliferation of MCF-7 cells,and inhibited chronic intermittent low Oxygen-mediated migration and invasion of MCF-7 cells(p<0.05);(4)RNA interference silencing CB1 and CB2 significantly reduced the ratio of p-IGF1R/IGF1 R,p-AKT/AKT and p-GSK3β/GSK3β in MCF-7 cells under chronic intermittent hypoxia,and decreased the expression of tumor metastasis-associated proteins vimentin and Snail1 At the same time,the expression of E-cadherin protein which mediates cell-to-cell adhesion was increased(p < 0.05).Conclusion:(1)CIH promotes proliferation and metastasis of breast cancer cells;(2)RNA interference silencing CB1 and CB2 in MCF-7 cells can inhibit the proliferation and metastasis of breast cancer cells under chronic intermittent hypoxia;(3)CIH may activate IGF-1R/AKT/GSK-3β signaling pathway by increasing the expression of cannabinoid receptors CB1 and CB2 in breast cancer cells,regulating the expression of proteins and promoting breast cancer cells proliferation and metastasis.