Functional impact of Galectin-3 and TRAIL expression in breast cancer cells.

OBJECTIVE

To examine the expression of Galectin-3 and TRAIL in breast cancer tissue and their effects on the proliferation and apoptosis of breast cancer cells.

PATIENTS AND METHODS

Breast cancer and normal adjacent tissue were collected from 120 patients pathologically diagnosed with breast cancer who underwent a modified radical mastectomy. SP method of immunohistochemistry was used to detect the expression levels of Galectin-3 and TRAIL in breast cancer tissues and normal adjacent tissues. The correlation between the expressions of Galectin-3 and TRAIL, and clinical prognosis of breast cancer were analyzed. Breast cancer cells were transfected with Galectin-3 siRNA and TRAIL overexpression constructs. Cell proliferation was measured by XTT method, and apoptosis was detected by flow cytometry.

RESULTS

Higher Galectin-3 level and lower TRAIL level were found in breast cancer tissues compared with those in normal adjacent tissues (p < 0.001). High expression level of Galectin-3 and low expression level of TRAIL were found to be positively correlated with the shorter median survival time and overall survival time. Galectin-3 silencing by siRNA interference and TRAIL overexpression significantly decreased cell viability of MDA-MB-231 and increased the number of apoptotic cells.

CONCLUSIONS

The expression level of Galectin-3 in breast cancer tissues was significantly increased compared with that in normal tissues, while the level of TRAIL protein was significantly decreased in cancer tissue. The biological role of these two proteins seems to be synergistic in inhibiting apoptosis of cancer cells. Therefore, the evaluation method that combined both Galectin-3 and TRAIL is of great clinical value in the evaluation of clinical prognosis of patients with breast cancer.