Expression Of COX-2 In Breast Cancer Tissues And MCF-7 Cells And The Effect Of COX-2 Inhibitor On MCF-7 Cells

Objective:To detecte the protein and mRNA expression of COX-2 in breast cancer tissues and MCF-7 cells,and expression of COX-2 protein and mRNA after selective COX-2 inhibitor of celecoxib had been used,observe the effect of celecoxib on the proliferation and apoptosis of MCF-7 cells.It provided experimental evidence for clinical treatment of breast cancer with celecoxib.Methods:1.Immunohistochemical staining was used to detect COX-2 protein expression in 72 breast cancer tissues;2.MCF-7 cells were grown in RPMI 1640 supplemented with 10%fetal bovine serum.Cells were maintainde at log phase at 37℃with 5%carbon dioxide;3.We used immuno-electronmicroscopy method to detect expression of COX-2 protein in MCF-7 cells;4.MCF-7 cells were cultured with celecoxib to detect COX-2 protein expression in immunohistochemical staining method;5.MCF-7 cells were cultured with celecoxib to detect COX-2 mRNA expression in situ hybridization method;6.MTT method was used to observe the effect ofcelecoxib on growth of MCF-7 cells.Results:1.Immunohistochemistry results showed that 39 cases in 72 breast cancer tissues could express COX-2 protein,the positive rate was 54.2%(39/72);2.Immuno-electronmicroscopy showed that COX-2 granules existed in endoplasmic reticulum,nuclear membrane and nuclear of MCF-7 cells; 3.Immunohistochemical results showed that MCF-7 cells could express COX-2 protein;and the expression of COX-2 protein decreased obviously after celecoxib was used;4.In situ hybridization results showed that MCF-7 cells could express COX-2 mRNA;and the expression of COX-2 mRNA decreased obviously after celecoxib was used;5.MTT results showed that celecoxib could inhibit MCF-7 cells growth significantly,in 24 hours after using celecoxib,cell inhibition rate changed from 13.5%to 42.3%;48 hours,cell inhibition rate changed from 17.0%to 57.7%;72 hours later,cell inhibition rate changed from 27.0%to 80.2%,with the increase of drug concentration and time,the number of apoptotic cells have a dose and time-dependent.Conclusion:1 It was confirmed that 54.2%of breast cancer and MCF-7 cells could express COX-2.2.Selective COX-2 inhibitor—celecoxib could significantly inhibit MCF-7 cells proliferation and induce apoptosis.It indicated that COX-2 inhibitor could be used as a new molecular target and provide an important theoretical basis for clinical application.