The Expression And Significance Of STIM1 And ERα In Breast Cancer Tissue

Objective:Breast cancer is one of the most common malignant tumor in women. Recently the treatment of breast cancer has gone into multidisciplinary comprehensive modle,and the prognosis has improved. There are still 20% ~ 30% positive lymph node and75% negative of patients with early breast cancer recurrence and metastasis in different period of postoperative. Ca2+, as the second messenger, is one of hot moleculers in the development of cancer. SOCE which channel called SOCs is the major mechanism of Ca2+ entry in non-excitable cells such as epithelial cell. Recent studies have identified two important molecules responsible for SOCE activation:STIM1(stromal interaction molecule 1) and Orai1. STIM1 serves as a Ca2+ sensor and plays an important role in the occurrence or development of breast cancer.Therefore, this study want to explore the expression and significance of STIM1 in breast cancer tissue and find a new sight for diagnosis and treatment in breast cancer.Methods:We selected 165 cases of invasive ductal carcinoma of breast from January 2007 to December 2009, and 40 cases of breast IDC with matching of normal breast tissue ajacent to carcinoma in the cancer hospital of tianjin medical university. En Vision immunohistochemistry method was used to assess the expression of STIM1 and ERαin breast cancer tissues. To explore the association of its expression with clinicopathological characteristics and prognosis of breast cancer patients,including tumor size, Lymph node and distant metastasis, subtype and r prognosis.Results:1. Immunohistochemical staining results revealed that the positive expression of STIM1 showed cytoplasm staining, ERα showed nucleu staining.The expression of STIM1 in IDC and in tumor-ajacent normal tissues was 90.0% and 72.5%.2. The association between the expression of STIM1 and clinicopathological characteristics in IDC of breast.The expression of STIM1 was correlated with tumor size, lymph node metastasis and expression of estrogen receptor α(ERα) in IDC. Compared with the T≤2cmgroup, LN(-) group and ERα(+) group, the expression of STIM1 in the T>2cm group, LN(+) group and ERα(-) group was significantly higher. But was not correlated with HER-2,Ki-67 and p53.3. The association between the expression of STIM1 and prognosis in IDC of breast.The Log-rank test showed that tumor size, lymph node metastasis, ERα, STIM1 levels and chemotherapy affect patients DFS and OS.The COX Multi-factor analysis showed that the expression level of STIM1 and the prognosis of patients with breast cancer have no statistical significance.Conclusion:1. The high expression of STIM1 was detected in IDC of breast, which may play important roles in the development of breast cancer.2. The expression of STIM1 was correlated with tumor size, lymph node metastasis,expression of estrogen receptor α(ERα) in IDC of breast, which suggests us STIM1 may be involved in cell proliferation and metastasis process in breast cancer.3. The expression of STIM1 affect patients DFS and OS, the patients of higher expression have poorer prognosis. So the expression of STIM1 may be correlated with poor prognosis in IDC of breast.