The Clinical And Experimental Study On Metastasis Suppressor Gene KAI1/CD82 Expression In Epithelial Ovarian Carcinoma

Of all gynecologic cancers, ovarian malignancies reprsent the greatest clinical challenge, since the early symptoms of ovarian cancer is obscure and secretly, and 60-70 % of patients present with already advanced disease, requiring major surgery and intensive and often complex additional therapies. Ovarian cancer has the highest 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 metastatic spread of tumor cells.In 1995, a metastasis suppressor gene, KAI1, was identified from mouse cell line AT6.1 of human chromosome 11 in prostatic cancer by Dong. KAI1 specifies a protein of 267 amino acides, which belong to a structurally distinct family of cell surface glycoproteins.i.e., the transmembrane 4 superfamily (TM4SF). Metastasis suppressor gene KAI1/CD82 is a member of TM4SF, which is involved in tumor cells growth, adhesion and motility. In addition to prostate cancer, the potential importance of KAI1 as ametastasis suppresor gene has been implicated in many other human tumors. Downregulation of KAI1/CD82 was reported to be associated with an increased rate of metastasis, a more aggressive clinical behavior of the tumor, a shorter survival time and a dismal prognosis in malignant carcinomas. In the present study, we investigated 1 , whether altered expression of KAI1/CD82 occurred in epithelial ovarian carcinoma(EOC) by using immunohistochemistry (IHC) methods. In addition, whether expression levels of KAI1 are associated with specificclinicopathologic characteristics of EOC patients was determined. By multivariant analyses, we want to find out the risk factors of EOC metastasis, and to determine the prognostic significance of the expression of KAI1 in EOC. 2-* To investigate the growth suppressive effect of Etoposide ( VP 16) and Cisplatinum (cDDP) on human ovarian cancer cell line 3 AO. The effect on the expression of metastasis suppressor gene KAI1 was also detected in the cell lines.Part I The Clinicopathologic significance of metastasis suppressor gene KAI1/CD82 expression in Epithelial Ovarian CarcinomaObjective: We perform this study, aiming to investigate the potential role of KAI1/CD82 expression in different age> stage ^ grading n histologictype^ lymph node metastasis (or distan metastasis) and cancerous ascites in EOC. To help determine whether the expression of the KAI1/CD82 gene is associated with EOC progression and metastasis.Methods: Immunohistochemistry SP method was performed to examine the expression level of KAI1/CD82 in normal ovary and various grades of primary and metastatic EOC. Comparisons were made between expression patterns in normal ovary and EOC. The expression of KAI1 among groups were initially compared by x 2 analyses. Odds ratios(OR) and 95% confidence interval(95%CI) were calculated by binary logistic regression.Results: 1 -. The study revealed a close relationship between tumor phenotype and KAI1/CD82 expression levels, characterized by high expression(12/12) in normal ovary , while low expression(38/66) in primary invasive and metastatic tumors. Statistically significant differences were noted between normal ovary and EOC (PO.05). 2, The statistical evaluation showed that decrease of KAI1/CD82 expression was associated with the advanced stage of EOC (P<0.05). 3^ It also revealed an inverse relationship between histological grade and KAI1/CD82 expression (P<0.05). 4^ The statistical evaluation also showed that the expression of KAI1/CD82 had a correlation with lymph node metastasis(or distant metastasis)(PO.05). 5> Statistically significance showed that the patients without cancerous ascites have higher KAI1/CD82 expression levels than that who have cancerous ascites (PO.05). 6 â– > There is no significant relationship among KAI1/CD82 expression and age and tumor histologictype (P>0.05). 7, Binary logistic regression revealed that KAI1/CD82 expression, tumor grading and cancerous ascites are the risk factors of EOC metastasis (OR 2.143 > 2.163 and 3.164). There were no significant result were founded in the analyses combined with age and tumor histologictype (OR 1.031 and 0.716).Conclusion: 1, KAI1/CD82 protein expression is closely correlated with the maligment progression and metastasis of EOC. It may be an early event in the progression of this tumor. Detecting the expression of KAI1/CD82 probably possesses clinical significance in evaluating the differentiation, tumor progression and predicting the prognosis of EOC. 2, KAIl expression, tumor grading and cancerous ascites are the risk factors of EOC metastasis. Monitoring the expression of KAI1/CD82 will help to distinguish the High Risk people and to direct clinical follow-up and treatment. Age and tumor histologictyp is not associated with metastasis of EOC.Part II Effect of VP16 combined with cDDP on the expression of metastasis suppressor gene KAI1/CD82 in human ovarian cancer cell line 3AOObjective: To investigate the growth suppressive effect of VP16 and cDDP on human ovarian cancer cell line 3AO. The effect on metastasis suppressor gene KAI1/CD82 expression was also detected in the cell lines.Methods: The condition of 3AO cells was visualized morphologically by phase contrast microscopy. A wide range of VP16 concentration(from 10 u g/ml-30u g/ml) and cDDP(l u g/ml-9 u g/ml) were tested using the MTT assay. The expression level of KAIl gene in 3AO cell lines were measured by RT-PCRand immunocytochemistry(ICH).Results: 1 > In quiescent condition, no significant difference in morphic was observed in different cell groups with low-dose VP16. The ovarian cancer cells treated by high-does VP16 and all concentration of cDDP become round, in which toxic granulars and apoptosis bodies appeard. In combined groups, changes of apoptosis in morphology were visualized obviously. 2^ MTT assay demonstrated that high-does VP^ cDDP and the combined groups could patially inhibit the growth of 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). 3n The KAI1/CD82 protein expression in different 3AO cells treated with VP16> cDDP and combined groups of different final concentration were significantly up-regulated compared with the control(P<0.05). Among these groups, the combined groups showed the strongest expression of KAI1/CD82 even in apoptosis bodies. In addition, the effect of both VP16 and cDDP on inducing KAI1/CD82 expression was does-dependent. 4> Result also showed the same significant up-regulation of KAIlmRNA in 30 u g/ml VP16 and 3 U g/ml cDDP by RT-PCR (PO.05).Conclusion: 1 -. VP16 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 VP16 and cDDP could effectively induced KAI1 expression in human ovarian cancer cell lines. Chemotherapy has much better effect on tumor metastasis , which provide us an experimental evidence for advanced research.