Expression Of Tip30 Protein In Breast Cancer And Function In Apoptotic Signal Transduction Pathway

Objective: Tip30 is a newly found tumor suppressing protein that has low level expression or deletion in many kinds of tumor cell lines, and it inhibits the growth of tumor cells of different orgin.To study was to investigate the expression of the tumor metastasis-suppressor gene Tip30 in breast cance(rbreast infiltrative ductal carcinoma and medullary of the breast)and breast benign lesion tissues(breast fibroadenoma and breast ductal hyperplasia). Its relationship with and clinical relevant factors and enhances apoptosis in human breast cancer. To study the expression of P53 and bax protein in breast cancer and breast benign lesion tissues, find the relationship of Tip30 with apoptosis-related gene P53 protein,bax protein in breast carcinoma and its significance.Methods: The expression of Tip30,P53 and bax protein were detected by immunohistochemical method(S-P) in breast carcinoma from 88 cases and compared with that in breast benign lesion tissues from 32 cases. Apoptosis were detected by TUNEL in 11 cases breast carcinoma.Results: (1) The peak age of femal breast cancer is 50-year-old in local area. (2)The positive expression rate of Tip30 protein in the 88 cases breast carcinoma and benign lesion tissues were 42%(37/88)and 75%(24/32), The positive expression rate of Tip30 protein in breast carcinoma was lower significantly than in benign tumor, respectively(P<0.05); Tip30 positive expression decreased with the breast tumor malignant dugree increased, in histological grade, the difference was ststistically significant after the test of X2 spssl(P<0.05), the positive expression rate of Tip30 protein in breast infiltrative ductal carcinoma and medullary breast carcinoma had no significant difference , and no correlation with age and lymph node metastasis(P<0.05). (3) The expression rate of P53 protein in breast carcinoma was 34.1%(30/88), significantly higher than that in benign lesion tissues(P<0.05); P53 positive expression increased with the breast tumor malignant dugree increased, the difference was ststistically significant after the test of X2 spssl(P<0.05); The positive expression rate of P53 was related to lymph node metastases(P<0.05), but there was no relationship with age,histological type.(4) The expression rate of bax protein in breast carcinoma significantly lower than that in benign lesion tissues, the difference was ststistically significant after the test of X2 spssl(P<0.05); the positive expression rate of bax in the tumors of Gradeâ…¢and Gradeâ… and Gradeâ…¡were 25%(4/16) and 68.1%(49/72); the positive expression rate of bax was related to lymph node metastases(P<0.05), but there was no relationship with age,histological type. (5) The expression of tip30 was not correlated with that of p53;There was position correlation between tip30 and bax; The expression of bax was not correlated with that of p53. (6)apoptosis cells were dectectde in 11 cases breast cance by TUNEL , 5 cases were positive expression. in 5 cases, positive expression of Tip30 and bax protein in 4 cases, negative expression of Tip30 in 1 case,in 4 cases, positive expression of p53 protein in 1 case.Tip30 gene can promote the apoptosis of cells with bax.Conclusion: 1. Tip30 is a tumor suppressing protein, the low expression rate of its may be one of factors of the occurrence and development of breast cancer, but it can not inhibit the metastases of lymph node 2. p53 was involved in the progression of breast cancer and the metastases of lymph node.3. Bax is a s proapoptosis gene ,it can be an inhibitor of breast cancer by promote cell apoptosis.4. Tip30 gene can enhence the apoptosis ,Tip30 and bax have coordinated pathogenic action, but the action of Tip30 was not correlated with that of p53. This result shows that the pathway of apoptosis induced by Tip30 not only through the changes of the expression of p53 (p53 dependent pathway), may be have other pathway (p53 independent pathway ).