Ratto C, Flamini G, Sofo L, Nucera P, Ippoliti M, Curigliano G, Ferretti G, Sgambato A, Merico M, Doglietto G B, Cittadini A, Crucitti F
Catholic University-Policlinico A. Gemelli, Department of Clinica Chirurgica, Rome, Italy.
Dis Colon Rectum. 1996 Nov;39(11):1238-44. doi: 10.1007/BF02055116.
Best chances of a cure from colorectal cancer are obtained before metastatic spread. Lack of specific tests allowing early diagnosis of the tumor accounts for investigation of gene alterations involved in carcinogenesis by a noninvasive method. In the present study, K-ras codons 12 and 13 mutations were studied in neoplastic cells shed from the bowel into the stool and those contained in the tumor and normal mucosa. Moreover, healthy patients and a few others with precancerous conditions were examined.
Stool, tumor, and mucosa samples were taken from 25 patients with colorectal adenocarcinoma. Stool and mucosa samples were obtained from 11 healthy patients, and stool, pathologic bowel tissue, and normal mucosa samples were obtained from 3 patients with adenoma (1) or ulcerative colitis (2). Polymerase chain reaction amplification and restriction enzyme analysis were performed.
K-ras codon 12 mutations were detected in both tumor and stool samples of 10 cancer patients, and no gene alterations were observed in 14 patients. In one patient with a tumor, a mutation was shown in only the tumor tissue. The agreement rate in tumor and stool analysis was 96 percent. A normal pattern of K-ras codons 12 and 13 was observed in the bowel mucosa. All stool and mucosa samples from healthy patients were not altered in K-ras. Agreement was registered between samples taken from patients with preneoplastic lesions.
These preliminary findings show a high rate of accuracy in the investigation of K-ras alterations in the colorectal cells shed into the feces, suggesting that such an approach could be used to study other gene alterations and, prospectively, to identify early colorectal cancers.
在结直肠癌发生转移之前进行治疗，治愈的机会最大。由于缺乏能够早期诊断肿瘤的特异性检测方法，因此需要通过非侵入性方法研究参与致癌过程的基因改变。在本研究中，对从肠道排入粪便的肿瘤细胞以及肿瘤和正常黏膜中所含的细胞进行了K-ras密码子12和13突变的研究。此外，还对健康患者和其他一些患有癌前病变的患者进行了检查。
从25例结直肠腺癌患者中采集粪便、肿瘤和黏膜样本。从11例健康患者中获取粪便和黏膜样本，从3例患有腺瘤（1例）或溃疡性结肠炎（2例）的患者中获取粪便、病理肠道组织和正常黏膜样本。进行聚合酶链反应扩增和限制性酶切分析。
在10例癌症患者的肿瘤和粪便样本中均检测到K-ras密码子12突变，14例患者未观察到基因改变。在1例肿瘤患者中，仅在肿瘤组织中发现了突变。肿瘤和粪便分析的一致率为96%。在肠道黏膜中观察到K-ras密码子12和13的正常模式。健康患者的所有粪便和黏膜样本的K-ras均未改变。癌前病变患者的样本之间存在一致性。
这些初步研究结果表明，对排入粪便中的结直肠细胞进行K-ras改变的研究具有很高的准确性，这表明这种方法可用于研究其他基因改变，并有望用于早期结直肠癌的识别。
