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COLON CELL DIFFERENTIATION--DCC ROLE IN MUC2 EXPRESSION

结肠细胞分化--DCC 在 MUC2 表达中的作用

基本信息

批准号：
6172806
负责人：
LEONARD H AUGENLICHT
金额：
$ 19.59万
依托单位：
MONTEFIORE MEDICAL CENTER (BRONX, NY)
依托单位国家：
美国
项目类别：
财政年份：
1996
资助国家：
美国
起止时间：
1996-06-01 至 2002-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/6172806
关键词：
cell differentiation colon neoplasms gene expression gene rearrangement genetic enhancer element genetic promoter element goblet cells human tissue laboratory mouse mucins neoplasm /cancer genetics phenotype point mutation protein biosynthesis tissue /cell culture transfection /expression vector tumor suppressor genes

项目摘要

The DCC gene is a potential tumor suppressor gene whose deletion or inactivation plays a role in colonic tumor progression. Recent evidence suggests that it plays a role in colonic goblet cell differentiation and mucin production, consistent with its less can also be effected by inducers which interact with metabolic processes and signal transduction pathways. Some of these inducers may be related to dietary components. We are in a unique position to dissect this link among DCC, mucin synthesis and cell differentiation since we have initiated detailed studies on the mechanisms of regulation of the MUC2 gene, the gene which encodes the principal colonic mucin peptide backbone. We have now cloned, mapped and partially sequenced approximately 90 kilobases of the locus on chromosome II encompassing the MUC2 gene and its promotor and enhancer, and have found this contig contains another mucin backbone gene, probably MUC5b, which is also expressed in colonic cells both in vivo and in vitro, that could be coordinately regulated with MUC2. We will investigate the interaction between DCC and MUC2 expression at the RNA and protein level, as well as the elaboration and secretion of mucus and growth parameters. Colonic carcinoma cell lines which have deleted at least one copy of DCC will be used as recipients of expression vectors which contain the entire wild-type DCC cDNA, or which encode specific extracellular and intracellular domains of the DCC protein, and the influence on constitutive and inducible MUC2 expression determined. The experiments will be extended to mucin synthesis and secretion, since we have demonstrated that expression of the gene does not necessarily lead to production and secretion of mature mucins. Further, different promotor constructs will be used to define the relationship between specific levels of DCC expression and cell and molecular phenotype. The promoter and enhancer for MUC2 will be dissected to delineate sequence elements and their boundaries necessary to establish responsiveness of MUC2 to DCC. Finally, we will investigate this relationship of mutations in the promotor of the MUC2 gene to the sub-class of colonic carcinomas having a mucinous phenotype. These experiments will provide detailed understanding of the interaction of a gene important in the differentiation and transformation of colonic epithelial cells with the principal hallmark of differentiation along one lineage. In addition, since mucinous colonic tumors in which MUC2 is deregulated exhibit a poorer prognosis than most common colorectal tumors, understanding this interaction may define prognostic factors which are not reflected in tumor histology or pathology.

DCC基因是一个潜在的抑癌基因，其缺失或缺失可能导致肿瘤细胞凋亡。失活在结肠肿瘤进展中起作用。最近的证据表明它在结肠杯状细胞分化中起作用，粘蛋白的产生，与其较少相一致，也可以受到诱导剂的影响其与代谢过程和信号转导途径相互作用。其中一些诱导物可能与膳食成分有关。我们处于一个独特的位置来剖析DCC，粘蛋白合成和细胞分化，因为我们已经开始详细研究， MUC2基因的调节机制，该基因编码主要结肠粘蛋白肽骨架。我们现在已经克隆，绘制和部分测序了染色体上基因座的约90个碱基 II包含MUC2基因及其启动子和增强子，并已发现该重叠群含有另一个粘蛋白骨架基因，可能是MUC5b，也在体内和体外的结肠细胞中表达，与MUC2协同调节。我们将研究DCC和MUC2表达之间的相互作用， RNA和蛋白质水平，以及粘液的加工和分泌生长参数。在大肠癌细胞系中，至少一个DCC拷贝将用作表达载体的受体其含有完整的野生型DCC cDNA，或其编码特异性的 DCC蛋白的细胞外和细胞内结构域，以及确定对组成型和诱导型MUC2表达影响。的实验将扩展到粘蛋白的合成和分泌，因为我们已经证明基因的表达并不一定导致成熟粘蛋白的产生和分泌。此外，不同的启动子结构将用于定义特定级别之间的关系 DCC表达与细胞和分子表型的关系。启动子和 MUC2的增强子将被解剖以描绘序列元件，它们的边界是建立MUC2对DCC的响应性所必需的。最后，我们将研究启动子中突变的这种关系 MUC2基因与结肠癌的亚类的关系，表型这些实验将提供详细的了解的相互作用，一个在结肠的分化和转化中重要的基因，上皮细胞，其主要标志是沿着一个沿着方向分化脉此外，由于其中MUC2被抑制的粘液性结肠肿瘤，失调的结肠直肠肿瘤比大多数常见的结肠直肠肿瘤表现出更差的预后，了解这种相互作用可能会定义预后因素，反映在肿瘤组织学或病理学中。