INTERACTIONS OF TUMOR PROMOTERS WITH RECEPTORS

佛波酯促肿瘤作用的分子机制 将通过确定正常的生理功能来研究 细胞内佛波酯受体蛋白与肿瘤的作用 受体功能的启动子。佛波醇酯引发了许多变化 细胞形态、生长和分化。这通常是 假定是通过可逆结合和高亲和力发生的 一种具有蛋白激酶的细胞受体蛋白的特异性 与之密切相关的活动。膜既结合又可溶 胞浆受体存在于细胞中，尽管后者需要钙和 磷脂起作用。这一数据和其他数据表明，作为其 细胞的正常功能与可溶性胞浆受体相关 与细胞膜和佛波酯可能直接影响这方面 它的功能。研究计划包括分析 佛波醇定量检测刺激细胞内受体的定位 细胞的酯结合活性、紫外光显微镜观察 用最近标记的受体特异性抗体进行染色，并观察 共价结合的受体特异性抗体染色的细胞 用透射电子显微镜观察铁蛋白。抗体将会是 由以抗原受体为抗原受体的单抗杂交瘤方法产生 从小鼠脑中提纯的蛋白质。最初的生化实验将 以凝集素刺激的原代小鼠脾细胞为模型系统， 佛波酯和淋巴因子。这些结果将应用于一项研究 原代小鼠表皮角质形成细胞和C3H10T-1/2成纤维细胞在 它们的生长和形态控制会受到钙的影响， 多肽生长因子和佛波酯。归根结底 研究将扩展到小鼠的表皮，在活体内，以便 已知的影响癌症发生过程的体内治疗的效果 表皮可以与培养细胞的结果相比较。 这些研究以及对细菌相互作用的生化研究 受体与其他细胞蛋白一起会导致一种 可观察到佛波醇酯作用的无细胞体系。 这些研究将有助于确定佛波醇的生物学作用。 酯和有助于了解促进肿瘤的生物学过程 和化学致癌。

The molecular mechanism of action of the tumor promoting phorbol esters will be investigated by determining the normal physiological function of the phorbol ester receptor protein in cells and the effect of tumor promoters on receptor function. Phorbol esters elicit numerous changes in cellular morphology, growth, and differentiation. This is generally assumed to occur via binding reversibly and with high affinity and specificity to a cellular receptor protein which has protein kinase activity tightly associated with it. Both membrane bound and soluble cytosolic receptors exist in cells although the latter requires calcium and phospholipid to function. This and other data suggest that as part of its normal function in cells the soluble cytosolic receptor becomes associated with cell membranes and that phorbol esters may directly affect this aspect of its function. The research plan involves analysis of changes in the localization of the receptor in stimulated cells by quantitation of phorbol ester binding activity, ultraviolet light microscopic observation of cells stained with fluorecently labeled receptor specific antibodies, and viewing of cells stained with receptor specific antibodies covalently bound to ferritin using a trasmission electron microscope. The antibodies will be produced by the monoclonal hybridoma method using as antigen receptor protein purified from mouse brain. Initial biochemical experiments will use as a model system primary mouse spleen cells stimulated with lectins, phorbol esters, and lymphokines. These results will be applied to a study of primary mouse epidermal keratinocytes and C3H 10T-1/2 fibroblasts in which growth and morphological controls are affected by calcium, polypeptide growth factors, and phorbol esters. Ultimately the investigation will be extended to mouse epidermis, in vivo, so that the effects of in vivo treatments known to affect the carcinogenic process in epidermis can be compared to the results obtained with cells in culture. These studies as well as a biochemical investigation of interactions of the receptor with other cellular proteins will lead to the development of a cell free system in which the actions of phorbol esters can be observed. These studies will help characterize the biological action of phorbol esters and aid in understanding the biological processes of tumor promotion and chemical carcinogenesis.