[Nucleocytoplasmic translocation of ING5 protein in breast cancer and its correlation with poor clinicopathological characteristics of breast cancer].

Objective To investigate the nucleocytoplasmic translocation of inhibitor of growth family member 5 (ING5) gene in human breast cancer and the negative correlation between the nuclear high expression of ING5 protein and the clinicopathological characteristics of breast cancer. Methods We collected 260 cases of clinical primary breast cancer, 55 cases of metastatic cancer in lymph node, 61 cases of breast fibroadenoma, 110 cases of adenomatosis, and 91 cases of para-cancerous tissues. With the tissue microarrays, we detected ING5 expression in the nucleus and cytoplasm through immunohistochemistry, and statistically analyzed the correlations of nuclear and cytoplasmic ING5 expression with the clinicopathological characteristics of breast cancer. Results The expression of nuclear ING5 in the para-cancerous tissues was obviously higher than that in the fibroadenoma, adenomatosis and primary breast cancer; it was higher in the adenomatosis than in the primary breast cancer, and higher in the primary breast cancer than in the metastatic cancer in lymph node. The cytoplasmic ING5 expression in the para-carcinoma tissue was higher than that in the fibroadenoma, adenomatosis and primary breast cancer. These data suggested the nucleocytoplasmic translocation of ING5 protein in breast cancer. Moreover, nuclear ING5 high expression was negatively correlated with distant metastasis and positively with P53 expression, while cytoplasmic ING5 high expression was positively correlated with tumor size and estrogen receptor expression. The cytoplasm ING5 expression of triple-negative breast cancer was lower than that in the non-triple-negative breast cancer. Conclusion Nucleocytoplasmic translocation of ING5 protein occurs in breast cancer, and the high expression of nuclear ING5 is inversely related to some poor clinicopathological behaviors of breast cancer.