Expression of STAT3 gene in breast carcinoma and its clinical significance

Background and purpose: Few reports demonstrate the expression of STAT3 that has been found to be an oncogene in solid tumor.This study investigated mRNA and protein expression of STAT3 gene in breast carcinoma,to explore whether the expression of STAT3 gene is related to histological type,lymph node metastases,the level of ER、PR and CerbB-2 or not.Methods:The mRNA expression of STAT3 gene was detected in 32 cases of breast carcinoma and 10 cases of benign mammary lesions by fluorescent real-time RT-PCR,45 cases of paraffin-embedded specimens of breast carcinoma and 12 cases of tissues in carcinoma side were studied by immunohistochemical assay.Statistical analysis was carried out to analyze the correlation between STAT3 gene expression and clinical significance in these breast cancer patients.Results:The protein expression of pSTAT3 was detected in 45 cases of breast carcinoma and 12 cases of tissues in carcinoma side by immunohistochemical assay.The positive rate of pSTAT3 in breast carcinoma and carcinoma side were 16.7%(2/12)and 60%(27/45)(P0.05);in breast carcinoma with lymph node-negative and lymph node-positive were 48.1%(13/27)and 77.8%(14/18)(P0.05);in breast carcinoma with PR negative and PR positive were 37.5%(6/16) and 72.3%(21/29)(P0.05);The mRNA expressions of STAT3 gene were detected in 32 cases of breast carcinoma and 10 cases of benign mammary lesions by fluorescent real-time RT-Perth relative expression level of STAT3 mRNA in benign mammary lesions and breast carcinoma were 6×10-3±3×10-3 and 34×10-3±17×10-3(P0.05);in breast carcinoma with lymph node-negative and lymph node-positive were 26×10-3±13×10-3 and 39×10-3±18×10-3(P0.05);the relative expression level of STAT3 mRNA in breast carcinoma with PR negative and PR positive were 28×10-3±10×10-3 and 39×10-3±19×10-3(P0.05).Neither mRNA nor protein expression of STAT3 gene was correlated with age of patients,size of tumor,the level of ER and CerbB-2(P0.05).Conclusions:The expression of STAT3 gene may be related to the metastatic potential and the level of PR of breast carcinoma.