RESUMO
@# Objective: To investigate the expression of galectin-3 protein in human breast cancer tissues and the effect of silencing galectin-3 gene on the migration, invasion and apoptosis of human breast cancer MCF-7 cells. Methods: The relative expression of galectin-3 protein in 15 cases of breast cancer tissues and corresponding para-cancerous tissues were detected by Western blotting; The expression of galectin-3 protein in paraffin sections of 100 cases of breast cancer tissues were detected by immunohistochemistry, and the correlation between galectin-3 expression and the clinicopathological characteristics of breast cancer patients was also analyzed. Galectin-3 siRNA were transfected into human breast cancer MCF-7 cells by liposome, then Real-time PCR and Western blotting were used to detect the mRNA and protein expression of galectin-3. The effect of galectin-3 gene silencing on cell migration and invasion ability of MCF-7 cells were detected by Transwell method. The effect of galectin-3 gene silencing on apoptosis of MCF-7 cells were detected by flow cytometry. Results: Western blotting detection showed that the relative expression of galectin-3 protein in breast cancer tissues were significantly higher than that in para-cancerous tissues (P<0.05); Immunohistochemistry detection showed that the positive expression rate of galectin-3 protein in breast cancer tissues was 67.00%, the positive expression rates in the lymph node metastasis, hormone receptor (ER, PR) negative groups were significantly higher (P<0.05), and the positive expression rate of galectin-3 protein were increased with the increase of TNM stage and histological grade (P<0.05); Galectin-3 siRNA transfection could significantly reduce the mRNAand protein expression of galectin-3 in MCF-7 cells (P<0.05), and reduce the invasion and migration ability but significantly improve the rate of apoptosis of MCF-7 cells (P<0.05). Conclusion: Galectin-3 is highly expressed in breast cancer tissues, and its silence can inhibit the invasion and metastasis of MCF-7 cells and induce apoptosis of MCF-7 cells. Galectin-3 can be used as a new target for biological therapy of breast cancer.