Research On The Relationship Of14-3-3σ Promoter Methylation And Expression Of MDM2in Infiltrating Breast Cancer

ObjectiveDetecting the14-3-3σ gene methylation status and the14-3-3σ, MDM2protein expression in infiltrating breast cancer and adjacent breast tissue,analyzing the14-3-3σ of relationship between gene methylation and proteinexpression, to explore the role of the methylation of14-3-3σ gene in theoccurrence and development of infiltrating breast cancer.MethodApplication the DNA extraction kit to extract73fresh cases of infiltratingbreast cancer and12cases of breast cancer adjacent tissue genomic DNA. TheDNA samples was Processed using bisulfite, Using methylation specific PCRtechnique test the14-3-3σ gene methylation status in all samples;immunohistochchemical PV-9000two-step detect the expression of14-3-3σ,MDM2protein in all specimens.Results①The14-3-3σ gene methylation detection rate in73cases of infiltratingbreast cancer was54.79%(40/73), was obviously higher than12cases of breastcancer adjacent tissue16.67%（2/12）. The level of infiltrating breast cancerdetection rate of14-3-3σ gene methylation was connected with TNM staging,axillary lymph node metastasis and ER receptor(p<0,05).②In the40cases ofinfiltrating breast cancer14-3-3σ methylation specimens,35cases of14-3-3σprotein expression was negative,5cases were positive. The14-3-3σ genemethylation and14-3-3σ protein positive expression showed a negativecorrelation（r=－0.339, P<0.05）.③The14-3-3σ protein in infiltrating breast cancer of the positive expression rate was26.03%（19/73）, was clearly lowerthan breast cancer adjacent tissue83.33%（10/12）, and was correlated withTNM stage, axillary lymph node metastasis, HER-2receptor and ERreceptor(p<0,05); The MDM2protein positive expression rate of infiltrating breastcancer was61.64%（45/73）, was obviously higher than breast cancer adjacenttissue16.67%（2/12）. The positive expression rate of MDM2protein was onlyassociated with axillary lymph node metastasis.④The positive expression of14-3-3σ protein and MDM2protein in infiltrating breast cancer showed a negativecorrelation（r=－0.431, P<0.05）.Conclusions①14-3-3σ gene promoter high frequency methylation might be the keyfactor for the low expression of14-3-3σ protein in infiltrating breast cancerdevelopment.②The14-3-3σ protein and MDM2protein expression appeared anegative correlation in infiltrating breast cancer. The joint test for breast cancermay have found early and targeted therapy provides new molecular biologyindicators.