Giaretti W, Rapallo A, Geido E, Sciutto A, Merlo F, Risio M, Rossini F P
Laboratory of Biophysics-Cytometry, National Institute for Cancer Research and Treatment, Candiolo, Genoa, Italy.
Am J Pathol. 1998 Oct;153(4):1201-9. doi: 10.1016/S0002-9440(10)65664-7.
Recent studies indicate that p21ras proteins mediate their multiple cell functions through interactions with multiple effectors and that the number of new effectors is growing. We recently reported that K-ras2 mutations in human colorectal adenomas were associated with chromosome instability and proliferation changes. In the present study, we extend these previous observations. Hereditary and multiple (n > or = 5) adenomas and adenomas with early cancer were excluded. Dysplasia was moderate in 91 cases and high in 25, and the median adenoma size was 1.5 cm. K-ras2 spectrum analysis was done by sequence-specific oligonucleotide hybridization using nuclear suspensions provided by analysis and sorting of multiparameter flow cytometry. In particular, tissue inflammatory cells were separated for DNA diploid tumors, whereas DNA aneuploid epithelial subclones were analyzed separately. K-ras2 mutations and DNA aneuploidy were both detected in 29 of 116 (25%) cases. DNA aneuploid index was in the near-diploid region in the majority of cases. DNA aneuploidy was strongly associated with G-->C/T transversions. An association was also found between low S-phase values and G-->A transitions. These findings were confirmed using multivariate logistic regression analysis to account for the effects of size, dysplasia, site, type, age, and sex. These data suggest that specific K-ras2 mutations in a subgroup of human sporadic colorectal adenomas play a role in chromosome instability and, contrary to expectations, are associated with inhibition of proliferation.
最近的研究表明，p21ras蛋白通过与多种效应器相互作用来介导其多种细胞功能，并且新效应器的数量正在增加。我们最近报道，人类结肠直肠腺瘤中的K-ras2突变与染色体不稳定性和增殖变化有关。在本研究中，我们扩展了这些先前的观察结果。排除了遗传性和多发性（n≥5）腺瘤以及伴有早期癌症的腺瘤。91例发育异常为中度，25例为高度，腺瘤的中位大小为1.5厘米。使用多参数流式细胞术分析和分选提供的核悬液，通过序列特异性寡核苷酸杂交进行K-ras2光谱分析。特别是，将组织炎症细胞分离出来用于DNA二倍体肿瘤，而DNA非整倍体上皮亚克隆则单独分析。116例中的29例（25%）同时检测到K-ras2突变和DNA非整倍体。在大多数情况下，DNA非整倍体指数处于近二倍体区域。DNA非整倍体与G→C/T颠换密切相关。在低S期值和G→A转换之间也发现了关联。使用多变量逻辑回归分析来考虑大小、发育异常、部位、类型、年龄和性别的影响，证实了这些发现。这些数据表明，人类散发性结肠直肠腺瘤亚组中的特定K-ras2突变在染色体不稳定性中起作用，并且与预期相反，与增殖抑制有关。
