Project description:Expression profiling was used to identify genes differentially expressed in MSS (microsatellite stable) and MSI (microsatellite unstable) colon cancer cell lines. Data submitted in support of manuscript entitled Villin expression is frequently lost in poorly differentiated colon cancer, Diego Arango, Sheren Al-Obaidi, David S. Williams, Jose Dopeso, Rocco Mazzolini, Georgia Corner, Do-Sun Byun, Carmel Murone, Lars Tögel, Nikolajs Zeps, Lauri A. Aaltonen, Barry Iacopetta and John M. Mariadason, American Journal of Pathology, 2012. 5 microsatellite stable (MSS) and 5 microsatellite unstable (MSI) colon cancer cell lines profiled. Each cell line grown and arrayed in duplicate, and the duplicates averaged for each cell line before calculating means for MSS and MSI lines.
Project description:Colorectal cancer, one of the most frequent types of malignancy in the Western world, develops through a multi-step process. The main pathways establishing transformation of normal mucosa to invasive carcinoma include chromosomal instability (CIN), microsatellite instability (MSI) or epigenetic silencing through the CpG Island Methylator Phenotype (CIMP). These pathways have distinct clinical, pathological and genetic characteristics. In general, altered cell surface glycosylation has been linked to colorectal cancer progression, however the impact of MSI-specific pathways on the glycosylation machinery of MSI colon cancer cells has not been investigated yet. In a recent study (Patsos et al., 2009) we have shown that MSI-specific mutations induce marked alterations in cell surface glycosylation, indicating specific changes in the expression of glyco-genes. Therefore the purpose of our experiment is to define these changes by glyco-gene chip analysis. Biallelic mutational inactivation of MSI target genes is believed to drive MSI tumorigenesis. TGFBR2, ACVR2 and AIM2 are among the most frequently mutated genes in MSI colorectal adenomas and carcinomas and functional studies indicate their contribution to MSI-carcinogenesis. A first general screening approach by lectin FACS analysis indicated a correlation between functional inactivation of these genes and cell surface glycosylation of the MSI colon cell line HCT116 (Patsos et al., 2009). For detailed analysis of the altered glycosylation pattern and the underlying molecular mechanisms we have established HCT116 double stable transfectants that allow doxycycline-inducible expression of the three MSI target genes TGFBR2, ACVR2 and AIM2 in a reversible manner. Thus we can experimentally control the expression of the MSI-genes and analyze short and long-term effects on different cell functions, including glycosylation. From the application of the glyco-gene chip for analysis of the transfectants we expect to gain seminal information on the influence of MSI-target genes on glycan expression and function in MSI tumor cells. Correlating loss-of-function of MSI target genes not yet linked with glycosylation to the regulation of the glycophenotype is a novel approach to investigate the glycobiology of tumor cells. In addition it is also suitable to detect new MSI-(glyco)markers for clinical applications, including diagnostic tumor markers and specific targets for immunotherapies.