Molecular subtypes of colorectal cancers determined by PCR-based analysis.
Molecular subtypes of colorectal cancers determined by PCR-based analysis.
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DOI：
10.1111/cas.13164
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发表时间：
2017-03
期刊：
影响因子：
5.7
通讯作者：
Suzuki H
中科院分区：
文献类型：
--
作者：
Sugai T;Eizuka M;Takahashi Y;Fukagawa T;Habano W;Yamamoto E;Akasaka R;Otuska K;Matsumoto T;Suzuki H
肿瘤组织由异质细胞群组成。在孤立的肿瘤腺体中测定的等位基因失衡（AI）比率是肿瘤异质性的良好指标。然而，在大多数结直肠癌（CRC）病例中观察到的AI和微卫星不稳定性（MSI）发展模式与肿瘤进展之间的关联以前尚未报道。在这项研究中，我们研究了是否CRC的遗传谱分层的组合的AI比率和MSI促进分类的CRC，以及这些遗传谱是否与特定的分子改变在CRC。采用隐窝分离法从147例散发性CRC的肿瘤和正常腺体中分离DNA。使用基于PCR的微卫星分析确定AI和MSI状态，并根据AI比率和MSI状态进行分层。检查DNA甲基化状态（高甲基化、中等甲基化和低甲基化状态以及KRAS、BRAF和TP 53中的突变。此外，免疫染色粘蛋白标志物。根据这一分析，将四个亚组进行了分类。亚组1的特征是高MSI状态和BRAF突变;亚组2与高AI比率密切相关，其在结直肠癌发生的早期阶段积累，以及TP 53突变;亚组3与低AI比率相关，在结直肠癌发生的晚期阶段观察到，以及KRAS突变;亚组4被定义为次要亚组。这些结果证实了不同分子谱的分类为结直肠癌的发生提供了重要的见解。
Tumor tissue consists of a heterogeneous cell population. The allelic imbalance (AI) ratio, determined in isolated tumor glands, is a good index of tumor heterogeneity. However, associations of the patterns of AI and microsatellite instability (MSI) development, observed in most cases of colorectal cancer (CRC), with tumor progression have not been reported previously. In this study, we examined whether CRC genetic profiles stratified by a combination of the AI ratio and MSI facilitate categorization of CRC, and whether these genetic profiles are associated with specific molecular alterations in CRC. A crypt isolation method was used to isolate DNA from tumors and normal glands obtained from 147 sporadic CRCs. AI and MSI statuses were determined using PCR‐based microsatellite analysis and stratified based on AI ratio and MSI status. DNA methylation status (high methylation, intermediate methylation and low methylation status and mutations in KRAS,BRAF, and TP53 were examined. In addition, mucin markers were immunostained. Based on this analysis, four subgroups were categorized. Subgroup 1 was characterized by a high MSI status and BRAF mutation; subgroup 2 was closely associated with a high AI ratio, which accumulated during the early phases of colorectal carcinogenesis, and TP53 mutation; subgroup 3 was associated with a low AI ratio, seen during the later phases of colorectal carcinogenesis, and KRAS mutation; and subgroup 4 was defined as a minor subgroup. These results confirmed that classification of distinct molecular profiles provides important insights into colorectal carcinogenesis.