The Molecular Genetics of MUC16

CA 125抗原是卵巢上皮性癌的一种良好的血清标志物，临床上用于监测对治疗的反应和这种恶性肿瘤的复发。最近的鉴定和克隆的cDNA分子编码的核心肽的CA 125抗原揭示了相当大的同源性的膜相关粘蛋白家族，和CA 125编码基因被命名为MUC 16。MUC 16的克隆和鉴定为基于分子遗传学的机制评价该分子在卵巢肿瘤中的作用提供了多种新的机会。该项目的长期目标是测试MUC 16在细胞的发展和/或维持中起关键作用的假设。 卵巢癌的恶性表型这一目标将通过广泛的实验方法来实现，这些方法旨在深入了解MUC 16在正常发育和细胞生物学中的功能，以及在卵巢上皮细胞的肿瘤转化中的功能。本研究的具体目标是：1）对MUC 16和Muc 16基因的基因组结构进行注释，并分析其启动子。外显子-内含子边界、编码区、非翻译区和转录因子结合位点将在物理和功能上进行表征。2)Muc 16在体内的功能。蛋白质表达在胚胎发育过程中，在新生和成年小鼠，并在小鼠卵巢癌将是 确定，将Muc 16的转基因敲低的影响，在时间和组织特异性的方式时，与转基因小鼠杂交倾向于浸润性卵巢癌。3)利用已有的MUC 16表达调控的数据，将其分子通路与启动子结构联系起来，验证MUC 16翻译后加工导致CA 125分泌的假说，并探讨MUC 16翻译后加工的机制。4)确定人卵巢上皮细胞中MUC 16表达的减少是否 癌细胞影响肿瘤表型。RNA干扰方法将用于确定人卵巢癌细胞中MUC 16 mRNA水平的降低是否影响细胞增殖、分化、锚定非依赖性生长或体内致瘤性。预计MUC 16在多种生物学背景下的功能研究将证明最终阐明该分子在卵巢肿瘤发生中的作用是最有效的。

The CA125 antigen is a well-characterized serum marker for epithelial ovarian carcinoma and is utilized clinically to monitor response to therapy and recurrence of this malignancy. Recent identification and cloning of a cDNA molecule encoding the core peptide of the CA125 antigen revealed considerable homology to a family of membrane-associated mucins, and the CA125-encoding gene was designated MUC16. The cloning and characterization of MUC16 provides multiple new opportunities for a molecular genetic-based, mechanistic evaluation of the role of this molecule in ovarian neoplasia. The long-term goal of this project is to test the hypothesis that MUC16 plays a critical role in the development and/or maintenance of the malignant phenotype in ovarian carcinoma. This goal will be accomplished through a broad range of experimental approaches designed to gain insight into the function of MUC16 in normal development and cell biology, as well as in the neoplastic transformation of ovarian epithelial cells. The specific aims of this project are to: 1) Annotate the genomic structures and analyze promoters of the MUC16 and Muc16 genes. Exon-intron boundaries, coding regions, untranslated regions and transcription factor binding sites will be characterized physically and functionally. 2) Characterize the function of Muc16 in vivo. Protein expression during embryonic development and in the neonatal and adult mouse and in murine ovarian cancers will be determined, as will the effects of transgenic knockdown of Muc16 in a temporal- and tissue-specific manner when crossed with transgenic mice prone to invasive ovarian carcinoma. 3) Using previously generate data on the regulation of MUC16 expression, correlate implied molecular pathways with promoter structure, and test the hypothesis that CA125 secretion results from post-translational processing of MUC16, exploring the mechanism of this processing. 4) Determine whether a reduction in MUC16 expression in human ovarian carcinoma cells affects the neoplastic phenotype. An RNA interference approach will be used to determine whether reduction of MUC16 mRNA levels in human ovarian carcinoma cells affects cell proliferation, differentiation, anchorage-independent growth or tumorigenicity in vivo. It is anticipated that studies of the function of MUC16 in multiple biological contexts will prove most effective in ultimately elucidating the role of this molecule in ovarian tumorigenesis.