NUTRITIONAL REGULATION OF CARCINOGENS IN PLACENTA-RELATED CELLS

质膜糖蛋白170（P-gp）是导致 多药耐药性也可能是一种化学致癌物 外排泵，可以通过饮食和营养素调节。 发现P-gp 主要存在于各种血管的管腔内的细胞中， 组织，包括胎盘和妊娠子宫的子宫内膜， P-gp在正常组织中的功能作用尚未被证实。 测定 胎盘营养素对MDR表达的调控 将研究相关细胞系。 我们将检测MDR 1的表达， 和MDR 3在体外模型中，如新转化的来源缺陷型 SV 40突变型羊膜上皮细胞系，HAA 580 D-8 C;转化的 胎盘滋养层细胞系;胎盘成纤维细胞系;和 绒毛膜癌细胞系JEG-3。 杂交实验与新 针对MDR 1和MDR 3的MDR探针将很快被开发出来， 以确定这些细胞系作为MDR模型的可行性 表情 监管机构，如已知的MDR竞争对手， 孕酮、MDR增强剂、雌二醇和营养素如维甲酸 酸，地塞米松和二丁酰cAMP将被检查其 在MDR表达中的调节作用和对MDR的预防作用 致癌作用

The plasma membrane glycoprotein 170 (P-gp) that is responsible for multidrug resistance, MDR, also may function as a chemical carcinogen efflux pump that can be regulated by diet and nutrients. P-gp is found predominantly in the cells lining the luminal space of a variety of tissues, including the placenta and the endometrium of the gravid uterus of the mouse, but the functional role of P-gp in normal tissues has not been determined. The regulation of expression of MDR by nutrients in placenta- related cell lines will be studied. We will examine the expression of MDR1 and MDR3 in in vitro models, such as a newly transformed origin-defective SV40-mutant amnion epithelial cell line, HAA580D-8C; a transformed placental trophoblast cell line; a placental fibroblast cell line; and a choriocarcinoma cell line, JEG-3. Hybridization experiments with newly developed MDR probes which are specific for MDR1 and MDR3 will soon be conducted to determine the feasibility of these cell lines as models of MDR expression. Regulatory agents such as the known MDR competitor, progesterone, the MDR enhancer, estradiol, and nutrients such as retinoic acid, dexamethasone, and dibutyrl cAMP will be examined for their regulatory roles in the expression of MDR and the prevention of carcinogenesis.