Pryme I F, Bardocz S, Pusztai A, Ewen S W
Department of Biochemistry and Molecular Biology, University of Bergen, Norway.
Cancer Lett. 1999 Nov 1;146(1):87-91. doi: 10.1016/s0304-3835(99)00242-6.
The growth of a non-Hodgkin lymphoma, developing subcutaneously as a solid tumour in NMRI mice, is markedly diminished by including phytohaemagglutinin (PHA), a lectin present in raw kidney bean (Phaseolus vulgaris), in the diet. In the experiment described in this communication the effect of first allowing tumours to develop for 5 days before switching the mice to a diet containing PHA at different concentrations was tested to establish whether or not feeding the lectin at late times also resulted in reducing tumour growth. This switch of diet indeed proved to be effective in slowing down growth of the lymphoma tumour. The reduced rate of growth occurs in a dose-dependent manner. We have suggested that a competition between the gut epithelium undergoing PHA-stimulated hyperplasia and the developing tumour may occur for polyamines and other nutrients from a common body pool and this could be an important contributory factor with regard to the observed low level of tumour growth following the feeding of PHA-containing diet. Recent data which showed that the level of hyperplasia of the small bowel in response to feeding the PHA diets was higher in non-injected mice compared to those which had been injected with tumour cells substantiated the concept of competition between gut and tumour for nutrients and other requirements for growth.
在NMRI小鼠皮下形成实体瘤的非霍奇金淋巴瘤的生长，通过在饮食中添加植物血凝素（PHA）（一种存在于生芸豆（菜豆）中的凝集素）而显著减缓。在本通讯所述的实验中，测试了先让肿瘤生长5天，然后将小鼠转换为含有不同浓度PHA的饮食的效果，以确定在后期喂食凝集素是否也会导致肿瘤生长减缓。这种饮食转换确实被证明对减缓淋巴瘤肿瘤的生长有效。生长速率的降低呈剂量依赖性。我们认为，经历PHA刺激增生的肠道上皮与发育中的肿瘤之间可能会竞争来自共同体内库的多胺和其他营养物质，这可能是喂食含PHA饮食后观察到肿瘤生长水平较低的一个重要促成因素。最近的数据表明，与注射了肿瘤细胞的小鼠相比，未注射小鼠对PHA饮食的小肠增生水平更高，这证实了肠道与肿瘤之间对营养物质和其他生长需求存在竞争的概念。
