Thorup I, Meyer O, Kristiansen E
Institute of Toxicology, National Food Agency, Søborg, Denmark.
Nutr Cancer. 1994;21(2):177-82. doi: 10.1080/01635589409514315.
Formation of aberrant crypt foci (ACF) in archived colon tissue from animals in a previous study was examined. The animals were fed a semisynthetic casein-based diet in which the carbohydrate pool was substituted with a dietary beet fiber (Fibeta) as the only source of fiber. Oral doses of dimethylhydrazine dihydrochloride (DMH-2HCl, 20 mg/kg body wt) once a week for 10 weeks were used as initiator. The rats were fed different levels of the fiber in a preinitiation period, during initiation, or in a postinitiation period. In general, the results showed a statistically significant inverse relation between duration of intake of high-fiber diet and number of animals with ACF, as well as the total number of ACF and number of small ACF (1-3 crypts) per affected animal. The previously reported data showed no protective effect of the dietary fiber at any stage of the colorectal carcinogenic process. The lack of correlation between the outcome of ACF and tumors could be related to the observation that statistically significant differences between groups were seen only in the total number of ACF and number of small ACF. The hypothesis that ACF are preneoplastic lesions needs to be supported by further experimental data. The present state of knowledge could indicate that ACF represent true preneoplastic lesions progressing into colon tumors or that ACF and colon tumors represent two parallel independent events as a consequence of the cancer initiation (i.e., the ACF not being preneoplastic lesions per se).
对先前一项研究中动物存档结肠组织中异常隐窝灶（ACF）的形成进行了检查。给动物喂食一种半合成的酪蛋白基饮食，其中碳水化合物库被膳食甜菜纤维（Fibeta）替代，作为唯一的纤维来源。每周口服一次二盐酸二甲肼（DMH - 2HCl，20 mg/kg体重），持续10周作为启动剂。在启动前、启动期间或启动后，给大鼠喂食不同水平的纤维。总体而言，结果显示高纤维饮食摄入持续时间与出现ACF的动物数量、ACF总数以及每只受影响动物的小ACF（1 - 3个隐窝）数量之间存在统计学上显著的负相关。先前报道的数据表明膳食纤维在结直肠癌致癌过程的任何阶段均无保护作用。ACF结果与肿瘤之间缺乏相关性可能与以下观察结果有关：仅在ACF总数和小ACF数量上观察到组间存在统计学上的显著差异。ACF是癌前病变这一假说需要进一步的实验数据支持。目前的知识状况可能表明，ACF代表真正进展为结肠肿瘤的癌前病变，或者ACF和结肠肿瘤代表癌症启动后的两个平行独立事件（即ACF本身不是癌前病变）。
