A Study On Expression Of AIB1 Protein In Epithelial Ovarian Cancer And Relation To Apoptosis

Objective To investigate the expression of AIB1(amplified in breast cancer 1) protein in epithelial ovarian cancers and to analyze the relationship between AIB1 protein and estrogen receptor(ER),progesterone receptor(PR),P53 protein,Bcl-2 protein.Methods By immunohistochemical method SP, We examined AIB1,P53,Bcl-2 protein expression levels in 24 normal ovaries,24 benign ovarian tumors,18 borderline ovarian tumors as well as 69 epithelial ovarian cancers. We also examined ER,PR expressions in ovarian cancers at the same time. The relations of AIB1 expression to clinico-pathological features and ER,PR,P53,Bcl-2 protein expressions in ovarian cancers were analyzed by SPSS 11.0 statistic software.Results(1) The AIB1 protein is located in the cytoplasm of normal ovaries while benign ovarian tumors, borderline ovarian tumors and ovarian cancers also show nuclear expressions besides cytoplasmic expressions. (2) The expression rate of AIB1 protein in ovarian cancers was 65.22ï¼…, which was higher than that in normal ovaries(8.33ï¼…),benign ovarian tumors(25ï¼…) and borderline ovarian tumors(38.89ï¼…). The positive AIB1 expression rate in the nucleus of benign ovarian tumors, borderline ovarian tumors, ovarian cancers were 4.17ï¼…,16.67ï¼…,30.43ï¼…respectively. (3) AIB1 expression levels in ovarian cancers were inversely correlated with histological differentiation. Poorly-differentiated cancers showed higher expression rate(81.82ï¼…) compared with well-differentiated(37.5ï¼…) and moderately-differentiated cancers(53.57ï¼…) (P=0.022, P=0.018). The expression of AIB1 protein in late clinical stage(stageâ…¢-â…£) was 80.39ï¼…(41/51), which was higher than that in early stage [stageâ… -â…¡, 22.22ï¼…(4/18)](P=0.000). The relationship of AIB1 protein with lymph node involvement was significant(P=0.007). AIB1 expression in different histological groups was not significant.(4) In ovarian cancers, the positive rates of ER, PR were 31.88ï¼…,26.09ï¼…respectively which were not related to AIB1 expression.(5) The positive expression rates of P53, Bcl-2 protein in ovarian cancers were 0ï¼…,4.17ï¼…,27.78ï¼…,56.52ï¼…; 4.17ï¼…,12.5ï¼…,44.44ï¼…,62.32ï¼…respectively. Significant positive correlations of AIB1 expression with p53 and Bcl-2 protein were observed in these ovarian cancers(r=0.342, P=0.004; r=0.311, P=0.009).Conclusion In ovarian cancers, AIB1 protein expression is increased and shows positive correlation with P53,Bcl-2 protein. AIB1 abnormal expression maybe associated with higher malignant biological behavior. The overexpression of AIB1 may be involved in the carcinogenesis and development of epithelial ovarian cancers through non-hormone dependent pathway. Our findings suggest possible correlations of AIB1 with apoptosis modulated genes such as P53 and Bcl-2.