The Expression Of MAGL In Luminal Breast Cancer And Its Effect On The Proliferation And Apoptosis Of MCF-7 Cells

Objective:To explore the differences in the expression of Monoacylglycerol lipase（MAGL）in Luminal breast cancer tissues and paracancerous normal breast tissues,and to explore the relationship between its expression level and the clinical pathological characteristics and prognosis of patients with Luminal breast cancer,as well as its effect on the proliferation and apoptosis of MCF-7 cells in breast cancer and its mechanism.A preliminary study on the effects of MCF-7 on the growth and apoptosis of breast cancer cells and its mechanisms.Methods:1.Immunohistochemistry（IHC）was used to detect the expression of MAGL protein in 75 cases of Luminal breast cancer and 30 cases of paracancerous normal breast tissues,and to analyze whether there was any correlation between MAGL expression and age,blood lipids,menopause,body mass index（BMI）,tumor size,lymph node metastasis,histological grade,TNM stage and other clinicopathological characteristics as well as survival prognosis of patients with Luminal breast cancer.2.The MAGL expression in breast cancer MCF-7 cells was inhibited using the MAGL inhibitor JZL184.The effect of MAGL expression inhibition on the growth and proliferation ability of breast cancer MCF-7cells was detected using the CCK-8 method,Hoechst 33258 staining for fluoroscopic observation of cell morphology,and flow cytometry for detection of apoptosis rate.To further explore the role of MAGL in breast cancer MCF-7 cells,Western blot method was used to detect the expression levels of Bcl-2 and Bax in breast cancer MCF-7 cells after inhibition of MAGL expression.Results1.MAGL was significantly highly expressed in Luminal breast cancer tissues,with an expression rate of 77.3%,while it was low expressed in adjacent normal breast tissues,with an expression rate of 20.0%,with statistical significance（P<0.05）.2.In patients with Luminal type breast cancer,MAGL expression was positively correlated with increased lipids,BMI,lymph node metastasis and histological grade,and the difference was statistically significant（P<0.05）;it was not correlated with age,tumor size,whether menopause and TNM stage,and the difference was not statistically significant（P>0.05）.3.The Kaplan-Meier method was used to plot survival curves and log-ranked to compare the effects of MAGL positive and negative expression on overall survival（OS）and disease-free survival（DFS）in breast cancer patients.There was a trend towards shorter OS and DFS in patients with positive MAGL expression compared to those with negative expression,but neither reached a statistical difference（P>0.05）.4.CCK-8 results showed that the growth and proliferation of breast cancer MCF-7 cells were significantly inhibited after inhibition of MAGL expression,with a half-inhibitory concentration of（5.035±0.3）μmol·L^-1.The proliferative capacity of MCF-7 cells decreased with increasing JZL184concentration and showed a certain dose dependent effect.5.Hoechst 33258 staining showed that breast cancer MCF-7 cells showed typical apoptotic features under the microscope after inhibition of MAGL expression compared with the control group:the nuclei were solidified or fragmented into pieces and showed dense and intense blue fluorescence.The results of apoptosis detection by flow cytometry showed a statistically significant increase in the early apoptosis rate of breast cancer MCF-7 cells after inhibition of MAGL expression by JZL184 compared with the control group（P<0.05）.6.Western blot experiment showed that the expression level of antiapoptotic protein Bcl-2 decreased and the expression level of proapoptotic protein Bax increased significantly in breast cancer MCF-7cells after inhibiting the expression of MAGL,and apoptosis was induced in breast cancer MCF-7 cells,the discrepancy was statistically significant（P<0.05）.Conclusion:1.MAGL is highly expressed in Luminal type breast cancer tissues and lowly expressed in normal breast tissues adjacent to the cancer.2.The expression of MAGL in patients with Luminal type breast cancer was positively correlated with BMI,blood lipids,lymph node metastasis and histological grade.3.Inhibition of MAGL expression significantly inhibited the proliferation of breast cancer MCF-7 cells;induced apoptosis in breast cancer MCF-7 cells by down-regulating the expression level of anti-apoptotic protein Bcl-2 and up-regulating the expression level of pro-apoptotic protein Bax.