The expression of topoisomeraseⅡα and p53 gene in breast cancer and their roles in resistance to chemotherapy
Lü Zhengmei 1, Wang Baotai 2,Wu Qiang 2 ( 1Dept of Histology and Embryology, 2Dept of Pathology,Anhui Medical University,Hefei 230032)
Objective To investigate the expression patterns of topoisomerase Ⅱα(TOPOⅡα)and p53 gene in patients with breast cancer and their roles in chemotherapeutic resistance. Methods By using immunohistochemical S P method,the expression of topoisomeraseⅡ α and p53 were determined in 91 cases of untreate d primary breast cancer and 18 cases of relapsed or metastatic breast cancer after chemotherapy. Results (1)Positive expressions of TOPOⅡα were 42% in 91 cases of untreated primary breast cancer. Significant difference for the expression was shown in relation to the histological type( P 0 05),tumor size( P 0 05), histological grade( P 0 01),and clinical stage( P 0 05).(2)Positive expressions of TOPOⅡα were 17% in 18 cases of relapsed or metastatic breast cancer,and the difference was statistically significant in comparison to th at in untreated primary breast cancer( P 0 05).(3)The difference of posi tive expressions of p53 was not significant between untreated primary breast ca ncer and relapsed or metastatic breast cancer ( P 0 05).(4)No significant r elationship existed between expressions of p53 and TOPOⅡα. Conclusion The expression of TOPOⅡα is related to poor prognostic factors in untre ated primary breast cancer. TOPOⅡα may be implicated in the development of res istance to cytotoxic drugs.Immunohistochemical assessment of TOPOⅡα expression in breast cancer may be useful for tailoring chemotherapy with TOPOⅡ inhibitor s.