The Clinical Significance Of Immunoglobulin G In Ovarian Cancer And Study Of Restrain Expression Of Immunoglobulin G Gene By RNAi

Part â…  : The clinical significance of immunoglobulin G inovarian cancer [Objective]Immunoglobulin are found thus far only to be produced by differentiated B lymphocytes. By immunohistochemistry analysis, in situhybridization, RT-PCR, Western-Blot, Qiu Xiaoyan demonstrated that human cancers of epithelial origin, including carcinomas of breast, colon, liver,ovarian, lung tissues, also produce IgG. But there was no report about the relation of its expression with tumor cell differentiation and pathologic type. The objective of this study is to explore the clinical significance of immunoglobulin G in ovarian cancer by analyzing the relation of its expression with tumor cell differentiation and pathologic type in ovarian tissue. [Method]1. Fresh samples of ovarian cancer and ovarian benign tumor were collected from ShanDong University Qilu Hospital and tumor tissue suspension was prepared;2. In order to eliminate the pollution of lymphocytes in the cell suspension, lymphocytes were removed by gradient centrifugation in lymphocyte separation medium;3. After regulation of cell concentration, lysis buffer was added in cell suspension;4. IgG in ovarian tissue were measured by double antibody ELISA.[Result]1. IgG hadn't been measured in ovarian benign tumor and IgG had been exsited in ovarian cancer;2. IgG in epithelial ovarian cancer were significantly upper compared to the nonepithelial ovarian tumor control (PO.01) ;3. IgG in ovarian tissue of low differentiation were significantly upper compared to the ovarian tissue of medium and high differentiation control ( PO.05 ) ;[Conclusion]1. The expression of IgG in ovarian cancer has relation with pathologic type. IgG in epithelial ovarian cancer were significantly upper compared to the nonepithelial ovarian tumor.2. The expression of IgG in ovarian epithelial cancer tissue has negative correlation with cell differentiation of ovarian cancer;Part II: Study of restrain expression of immunoglobulin G geneby RNAi technique[objective]RNA interference is a newly-developed gene silence technique. The technique can not only be used in basic medical research but also be expected to become a new promising therapeutic toolt5]. Especially, small interfering RNAhas a great prospect in the treatment of tumor. The further search of Qiu Xiaoyan showed that blockade of tumor-derived IgG by either antisense DNA or antihuman IgG antibody increased programmed cell death and inhibited growth of cancer cells in vitro161. The purpose of this research is to study the inhibited effect of the expression of IgG induced by RNAi technique in SKOV3 cell lines. It is to explore the applying prospect of RNAi in the gene herapy of anti-tumors, the possibility of using IgG gene as a treating target of malignant.[Method]1. siRNAs had been designed according to siRNA principle and had been chemical synthesized by GenePharma company.2. Ovarian cancer cell line SKOV3 had been cultured.3. FAM-labeled siRNA had been transfected in ovarian cell line SKOV3 in order to observe the transfected effect.4. The special siRNA and the unspecial siRNA had been transfected in the ovarian cell line SKOV3.5. The mRNA of IgHV and the protein IgG had been measured after transfection by RT-PCR and Western-Blot. On the same time, the condition of apoptosis after RNAi were observed in the experiment.[Result]1. The results of RT-PCR showed that after transfection of specific siRNA the expression of IgHV mRNA were significantly suppressed;2. The results of Western-Blot showed that after transfection of specific siRNA the expression of IgG protein were effectively suppressed;3. Cell proliferation had been restrained and apoptosis had been reduced. [Conclusion]1. RNAi technique is effective tool to suppress the expression of IgG gene in ovarian cell line SKOV3.2. We have further demonstrated that tumor-derived IgG maybe has function of accelerate ovarian tumor growth and survival.