The Study On XIAP Expression In Epithelial Ovarian Carcinoma

As one of the most malignant gynecologic tumors, ovarian carcinoma's incidence rate is 5-7/100k.Since the early symptoms of ovarian carcinoma are obscure and secret, about 60～70 % of patients present with already advanced disease, requiring major surgery and intensive and usually complex additional therapies. The survival rate in 5 years is always 30%. Ovarian carcinoma has become the most fearful carcinoma endangering the femal. Besides, epithelial ovarian carcinoma has a higher mortality rate of all gynecologic malignancies. The development of metastasis is the main cause of death of this cancer. Therefore, one of the aim in cancer research is to define molecular mechanisms leading to the metastasis of tumor cells.In 1996,Liston et al. identified a new gene of inhibitor of apoptosis proteins family (IAPs) by southern hybridization & PCR. This new gene was named XIAP(X-linked inhibitor of apoptosis protein),located at Xq25.As a new member of IAPs, XIAP's ability of inhibiting apoptosis has been certified among many kinds of carcinomas. It has been manifested in a lot of research, XIAP's overexpression plays a great role in progression and prognosis of carcinomas. In the present studies, we want to investigate:1, Whether altered expression of XIAP gene occurs in epithelial ovarian carcinoma(EOC) by using RT-PCR method. In addition, whether expression levels of XIAP are associated with specific clinicopathologic characteristics of EOC patients was determined. By statistic analysis, we want to find out the risk factors of EOC metastasis, and to provide theoretical support for therapy, follow-up and prognosis.2, To investigate the expression of XIAP in 3AO,SKOV3 cell lines before and after being treated by Taxol, Cisplatinum(cDDP),we can provide theoretical basement for clinical therapy and further experimental research of EOC's metastasis and invasion.Part IThe Clinicopathologic Significance Of XIAP ExpressionIn Human Epithelial Ovarian CarcinomaObjective: To investigate the expression of XIAP mRNA in different age,stage,grading,histologictype,lymphnode metastasis (or distant metastasis) and cancerous ascites of human EOC. To explore whether the expression of XIAP gene is associated with its clinicopathologic characters.Methods: By reverse transcription-polymerase chain reaction (RT-PCR) the XIAP mRNA was examined in 50 EOC tissues and 12 normal ovarian tissues,and semi-quantification of band densities was also performed. Comparisons were made between expression patterns in normal ovary and EOC tissues by x~2 analyses.The relationship between the mRNA level of XIAP and the EOC's clinicopathologic characters was analysed by one-factor analysis of variance.Results: 1, Percentage of XIAP enhanced expression was 13.3% in normal ovarian tissue, 74% in ovarian carcinoma. The difference was significant(P<0.01). 2, Among ovarian carcinoma ,the enhanced expression of XIAP mRNA was associated with the staging.( P <0.05) 3, The expression of XIAP was nearly all positive in EOC with cancerous ascites. The expression of XIAP in EOC with ascites was higher than that in EOC without ascites. (p<0.01) 4, There was no diference between well-differentiated tissues and poorly differentiated ones. (P>0.05)Conclusion: 1, The expression level of XIAP mRNA is higher in ovarian carcinoma than in normal ovarian tissues. 2% The overexpression of XIAP is significantly associated with clinical stage, cancerous ascites of EOC. 3, D etecting the expression of XIAP may play a important role in the early diagnosis and predicting pronosis of EOC.Part IIEffect of Taxol combined with cDDP on the expressionof XIAP in human ovarian cancer cell line SK0V3/3A0Objective: To investigate the growth suppressive effect of Taxol and cDDP on human ovarian cancer cell line SKOV3/3AO. The expression of XIAP was also detected in the cell lines before and after they're treated by the drugs.Methods: The condition of SKOV3/3AO cells was visualized morphologically by phase contrast microscopy. A wide range of taxol concentration(from 1μg/ml-100μg/ml) and cDDP(1μg/ml-100μg/ml) were tested using the MTT assay. The expression level of XIAP gene in SKOV3/3AO cell lines were measured by RT-PCR and immunocytochemistry (ICC).Results: 1, The expression of XIAP mRNA and protein in SKOV3 cell line was higher than 3AO.( P < 0.05)After treated by the same drugs with the same concentration,the survival rate of SKOV3 was higher than 3AO. ( P < 0.05) cDDP( 1μg/ml) hardly had effect on cell lines. Taxol was more powerful than cDDP at the same concentration. ( P < 0.05) The expression of XIAP mRNA and protein was decreasing and the survival rate was gradually decreasing while the concentration was increasing. There are linear regression and correlation between the expression of XIAP and the cell survival rate. (P< 0.05) 2, MTT assay demonstrated that high-dose taxol, cDDP and the combined groups could patially inhibit the growth of SKOV3/3AO cells, which showed does-dependent tendency. Furthermore, the inhibiting effects were significantly different among the cells treated with medicine of different concentration(P<0.05).Conclusion: 1, Taxol combined with cDDP have a significant inhibitory effect on the growth of human ovarian cancer cell line in a dose-dependent manner, which provide us a powerful evidence of clinical chemotherapy of EOC. 2, Results showed that Taxol and cDDP could effectively decrease XIAP expression in human ovarian carcinoma cell lines. Chemotherapy has much better effect on tumor metastasis , which provide us an experimental evidence for advanced research. 3, The expression of XIAP could correlate with the anti-apoptosis ability on stressful surrounding.