Okada H, Mizuno M, Ikeda N, Tomoda J, Tsuji T
First Department of Internal Medicine, Okayama University Medical School, Japan.
J Gastroenterol Hepatol. 1996 Jul;11(7):686-91. doi: 10.1111/j.1440-1746.1996.tb00315.x.
To define the significance of alterations in epithelial cell proliferation as a marker of high risk mucosa for colorectal cancer, we examined cell proliferative events in the colonic mucosa during chemical carcinogenesis using in vitro bromodeoxyuridine labelling and by analysing serial colonoscopic biopsy specimens from dimethylhydrazine (DMH)-treated rats. In both the rectum and flexure of the colon, an increased labelling index of colonic epithelial cells, an upward extension of the proliferating zone and an upward shift of the major area of DNA synthesis of epithelial cells were observed during DMH-induced colonic carcinogenesis in rats. These changes preceded the development of the colonic tumour and were observed in endoscopically normal rectal mucosa where the tumour was absent. We confirmed the altered cell proliferative events preceding the development of the tumour by examining serial colonoscopic biopsies. The results suggest that these alterations are features that identify premalignant colonic mucosa in DMH-treated rats.
为了确定上皮细胞增殖改变作为结直肠癌高风险黏膜标志物的意义，我们使用体外溴脱氧尿苷标记法，并通过分析二甲基肼（DMH）处理大鼠的系列结肠镜活检标本，研究了化学致癌过程中结肠黏膜的细胞增殖事件。在大鼠DMH诱导的结肠癌发生过程中，在结肠的直肠和弯曲处均观察到结肠上皮细胞标记指数增加、增殖区向上延伸以及上皮细胞DNA合成主要区域向上移位。这些变化先于结肠肿瘤的发生，并且在没有肿瘤的内镜检查正常的直肠黏膜中也观察到。通过检查系列结肠镜活检，我们证实了肿瘤发生之前细胞增殖事件的改变。结果表明，这些改变是识别DMH处理大鼠中癌前结肠黏膜的特征。
