TUMOR PROMOTER INDUCED PROTEIN PHOSPHORYLATION

人结肠上皮细胞的转化对它们的影响 对新的有丝分裂信号的敏感性。粪二甘油酯(DGs)，组成 在体内发现油酸、肉豆蔻酸或棕榈酸残留物 MM浓度(癌症研究49：544-548,1989)，并可能源自 来自膳食脂肪。当DGs被加入体外培养的结肠细胞中时 洗涤剂-胶束在生理浓度下，他们诱导 癌前结肠细胞、某些癌细胞的增殖，但不是 正常结肠细胞(同上)。DGS还增加了尿激酶的分泌 癌细胞。与这种对肿瘤的选择性生物活性平行 细胞，粪二甘油三酯诱导酪氨酸残基的磷酸化 在癌细胞和腺瘤细胞中有一个63kd的膜蛋白，但不正常 细胞，抗酪氨酸磷酸单抗免疫印迹显示 抗体。我们建议继续研究信号的机制 DGs通过酪氨酸激酶在结肠细胞中的转导作用 底物pp63。

Transformation of human colonic epithelial cells confers on them sensitivity to new mitogenic signals. Fecal diglycerides (DGs), composed of oleic, myristic, or palmitic acid residues, were found in vivo at uM to mM concentrations (Cancer Res.49 :544-548, 1989), and were probably derived from dietary fat. When DGs were added to colon cells in vitro in detergent-micelles at physiological concentrations, they induced proliferation of premalignant colonocytes, some carcinoma cells, but not normal colonocytes (ibid). DGs also increased urokinase secretion from carcinoma cells. Parallel to this selective biological activity on tumor cells, fecal diglycerides induced the phosphorylation on tyrosine residues of a 63 kd membrane protein in carcinoma and adenoma cells but not normal cells, as shown by immunoblotting with antiphosphotyrosine monoclonal antibody. We propose to continue to study the mechanism of signal transduction initiated by DGs in colon cells through the tyrosine kinase substrate pp63.