Immunohistochemical and molecular evaluation of TUSC2 expression in breast cancer.

Abstract

Tumor suppressor candidate 2 has shown to be deleted in lung, colon, and bladder cancer types. In the present study, we aimed to investigate the expression of TUSC2 in breast cancer. A total of thirty patients with breast cancer were included in the study. Normal and tumor tissue samples from fresh mastectomy materials were stored at -80C until the number of cases was completed for gene expression analysis. Histopathological examination was carried out with routine hematoxylin & eosin method. TUSC2 staining was performed for immunohistochemical analysis. The tumors of thirteen patients were Luminal A, fourteen patients were Luminal B, one patient was cerbB2(+), and tumors of two patients were triple-negative. Ki67 proliferation index was less than 14% in fifteen cases and tumor size was less than 2cm in seven cases. Lymphovascular invasion and lymph node metastasis were present in thirteen cases. Statistically, TUSC2 expression significantly decreased or was lost in breast tumor tissues compared to normal tissues (p < 0.0001). TUSC2 expression decreased as the Ki67 proliferation index increased (p = 0.0003), and TUSC2 expression decreased as tumor size increased (p = 0.0483). The loss or decrease in the TUSC2 expression was significant as the tumor grade increased (p = 0.3740). Gene expression analysis correlated with immunohistochemistry results. The results of the present study demonstrated a decrease or loss of TUSC2 expression in breast cancer tissue compared to normal tissue. A correlation was found between TUSC2 expression and Ki67 proliferation index and tumor size.