Role of SIRT1 in Regulation of Epithelial-to-mesenchymal Transition in Breast Cancer Lymph Nodes Metastasis

Luminal A breast cancer is a kind of breast cancer with low rate lymph node metastasis and good survival. But in clinical practice, Luminal A breast cancer can present with early, unexpected lymph node metastasis some time, indicates poor survival. Silent information regulator 2 homolog 1 (SIRT1) plays a different role in breast cancer with different molecular typing. Previous study supports a role of SIRT1 protein as tumor suppressor in Luminal A breast cancer, in association with apoptosis-related proteins. The epithelial-to-mesenchymal transition(EMT) process results in loss of cell-cell adhesion, increased cell mobility, and is crucial for enabling the metastasis of cancer cells. But no similar study in Luminal A breast cancer. Hence, this study will 1) investigate the expression pattern of SIRT1 in primary tumor and lymph node metastasis; 2) investigate the different expression pattern of SIRT1 in T2/T3 , lymph node negative tumor and T1, lymph node positive tumor; 3) investigate potential role of SIRT1 enzyme in regulating cell migration and invasion in Luminal A breast cancer cells.