Locniskar M, Belury M A, Cumberland A G, Patrick K E, Fischer S M
Division of Nutrition, University of Texas, Austin 78712.
Nutr Cancer. 1991;16(1):1-11. doi: 10.1080/01635589109514135.
To investigate the effects of two levels of dietary corn oil on tumorigenesis, semipurified diets containing 5% or 10% corn oil were fed during the promotion stage of a mouse skin carcinogenesis model. Sencar mice were initiated with 10 nmol dimethylbenz[a]anthracene (DMBA) and promoted with either 1 microgram 12-O-tetradecanoylphorbol-13-acetate (TPA) or 40 mg benzoyl peroxide twice weekly for 24 or 52 weeks, respectively. No significant differences in kilocalories of food consumed or body weights were observed between the diet groups during the study. Fatty acid profiles of the epidermal phospholipids reflected dietary fat intake. For example, high levels of linoleate and low levels of arachidonate were found in the phosphatidylcholine fraction from mice fed the 10% corn oil diet compared with 5% corn oil. When the diets were fed during TPA promotion, the papilloma incidence after 11 weeks of treatment for the 5% corn oil group was 77% and 37% for the 10% corn oil group. By 15 weeks of TPA treatment, papilloma incidence between the diet groups was similar, and later, carcinoma incidence and yield were not different between the two groups. For the animals treated with benzoyl peroxide, there was only a slight but not significant difference in papilloma and carcinoma appearance. In parallel studies, ornithine decarboxylase activity, vascular permeability, hyperplasia, and prostaglandin E2 (PGE2) levels were elevated in the epidermis after promoter treatment, but only hyperplasia and PGE2 synthesis tended to reflect the dietary effects on tumor appearance. These data suggest that the quantity of dietary corn oil at the two levels tested, 5% and 10%, altered epidermal phospholipid fatty acid composition and PGE2 levels and had modest effects on the modulation of tumorigenesis in this skin model.
为研究两种水平的膳食玉米油对肿瘤发生的影响，在小鼠皮肤癌发生模型的促癌阶段，喂食含5%或10%玉米油的半纯化日粮。先用10 nmol二甲基苯并[a]蒽（DMBA）启动Sencar小鼠，然后分别用1微克12-O-十四酰佛波醇-13-乙酸酯（TPA）或40毫克过氧化苯甲酰每周两次进行促癌处理，持续24周或52周。在研究期间，各日粮组之间在食物摄入量千卡数或体重方面未观察到显著差异。表皮磷脂的脂肪酸谱反映了膳食脂肪摄入量。例如，与5%玉米油组相比，喂食10%玉米油日粮的小鼠磷脂酰胆碱部分中发现亚油酸水平高而花生四烯酸水平低。当在TPA促癌期间喂食日粮时，5%玉米油组在治疗11周后的乳头状瘤发生率为77%，10%玉米油组为37%。到TPA治疗15周时，各日粮组之间的乳头状瘤发生率相似，随后，两组之间的癌发生率和产率没有差异。对于用过氧化苯甲酰处理的动物，乳头状瘤和癌的出现仅存在轻微但不显著的差异。在平行研究中，启动子处理后表皮中的鸟氨酸脱羧酶活性、血管通透性、增生和前列腺素E2（PGE2）水平升高，但只有增生和PGE2合成倾向于反映膳食对肿瘤外观的影响。这些数据表明，在测试的5%和10%这两个水平的膳食玉米油改变了表皮磷脂脂肪酸组成和PGE2水平，并对该皮肤模型中肿瘤发生的调节有适度影响。
