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MSI-target gene-dependent alterations of cell surface glycosylation signatures in MSI colorectal cancer cell lines and primary tumors

MSI结直肠癌细胞系和原发性肿瘤中细胞表面糖基化特征的MSI靶基因依赖性改变

基本信息

批准号：
148215620
负责人：
Dr. Johannes F Gebert
金额：
--
依托单位：
Abteilung für Angewandte Tumorbiologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2014-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/148215620?language=en
关键词：
MSI target gene dependent alterations

项目摘要

Microsatellite unstable (MSI) tumors exhibit a variety of histoclinicopathological features including mucinous histology and improved prognosis when compared to their microsatellite stable (MSS) counterparts. Biallelic mutational inactivation of some MSI target genes is frequently observed and is generally believed to drive MSI tumorigenesis. Focussing on the pathogenetic mechanisms of these MSI tumors we recently uncovered a potential correlation between functional inactivation of specific MSI target genes and cell surface glycosylation pattern. The current proposal aims to explore MSI target gene-dependent alterations of cell surface glycosylation signatures in MSI colorectal cancer cell lines engineered to allow inducible expression of two of the most frequently mutated MSI target genes (ACVR2, TGFBR2). In a first general screening approach differential glycosylation profiles will be determined by Lectin-FACS analysis in target gene proficient (ACVR2+, TGFBR2+) and deficient (ACVR2-, TGFBR2-) MSI colorectal cancer cell lines and by lectin-histochemistry in primary MSI tumors, using a broad panel of different lectins. Based on these results the glycoproteins underlying the specific changes will be identified by lectin affinity chromatography, 2D-gel electrophoresis and mass spectrometry. From the resulting set of differentially glycosylated proteins two candidates (one ACVR2-dependent and one TGFBR2-dependent) will be characterized in detail with regard to the altered glycoepitope structures. Finally, we seek to demonstrate the MSI-tumor-specificity by comparing the abundance of the identified glycopeptides in MSI and MSS tumor cells. The results obtained from this study are of major clinical relevance because they will define and provide a novel source of MSI tumor-specific glycoprotein epitopes complementary to the known MSI-tumor specific frameshift peptide antigens enabling the development of new diagnostic and therapeutic strategies for MSI tumors.

与微卫星稳定(MSS)肿瘤相比，微卫星不稳定(MSI)肿瘤表现出包括粘液组织学在内的各种组织临床病理特征和改善的预后。一些MSI靶基因的双等位突变失活经常被观察到，并被普遍认为是导致MSI肿瘤发生的原因。着眼于这些MSI肿瘤的发病机制，我们最近发现了特定MSI靶基因的功能失活与细胞表面糖基化模式之间的潜在关联。目前的建议旨在探索MSI靶基因对MSI结直肠癌细胞系细胞表面糖基化特征的依赖变化，其工程设计允许诱导两个最频繁突变的MSI靶基因(ACVR2和TGFBR2)的表达。在第一种常规筛选方法中，将通过凝集素-流式细胞仪分析靶基因熟练(ACVR2+，TGFBR2+)和缺失(ACVR2-，TGFBR2-)MSI结直肠癌细胞株，并使用广泛的不同凝集素，在原发MSI肿瘤中通过凝集素组织化学来确定差异糖基化图谱。根据这些结果，将通过凝集素亲和层析、2D-凝胶电泳法和质谱法鉴定导致特异性变化的糖蛋白。从得到的一组差异糖基化蛋白中，将详细描述两个候选者(一个依赖ACVR2，一个依赖TGFBR2)改变的糖表位结构。最后，我们试图通过比较MSI和MSS肿瘤细胞中识别的糖肽的丰度来证明MSI肿瘤的特异性。这项研究的结果具有重要的临床意义，因为它们将定义并提供一种新的来源的MSI肿瘤特异性糖蛋白表位，补充已知的MSI肿瘤特异性移码多肽抗原，使开发新的MSI肿瘤诊断和治疗策略成为可能。