The Correlation Between G3BP1 And Endocrine Therapy Resistance In Breast Cancer

Background and purpose:Endocrine therapy is the most effective treatment for ER positive breast cancer.However,endocrine therapy resistance can't be avoided.G3BP1is a specific binding protein with Ras GAP SH3 domain,which plays an important role in the occurrence and development of tumors.Some studies have found that G3BP1 is involved in the endocrine drug resistance pathway of breast cancer.The aim of this study was to investigate the correlation between G3BP1 and endocrine therapy resistanceMethods:1.Gene Expression Omnibus?GEO?database was retrieved to analyze the expression of G3BP1 m RNA in tamoxifen resistant cell lines.2. Tamoxifen resistant cell line T-47D^{Tam R}was established.3. G3BP1 protein expression in T-47D cells and T-47D^{Tam R}cells was detected.EGCG was used to down-regulate the expression of G3BP1 protein of T-47D^{Tam R}cells,and the sensitivity of T-47D^{Tam R}cells to TAM was observed.4. A total of 41 cases of tumor wax samples from breast cancer patients who received tamoxifen or aromatase inhibitor assisted endocrine therapy were collected.According to the recurrence time of the disease,they were divided into three groups:the primary drug resistance group,the secondary drug resistance group and the sensitive group.Immunohistochemical staining was carried out to analyze the expression of g3bp1protein in tumor samples of each group.Results:1.GEO database showed the expression of G3BP1 m RNA in tamoxifen resistant cell lines was higher than that in sensitive cell lines?P<0.01?.2.Compared with T-47D cells,G3BP1 protein expression in T-47D^{Tam R}cells was also significantly increased.After the expression level of G3BP1 in T-47D^{Tam R}cells was down-regulated,the sensitivity to TAM was increased?P<0.05?and RI value decreased.3.The expression of G3BP1 protein in primary endocrine resistance group was higher than that in secondary endocrine resistance group?84.62%vs 30%,P<0.01?and sensitive group?84.62%vs 28.6%,P<0.01?.Conclusion:G3BP1 is closely related to endocrine therapy resistance in breast cancer.