IN VITRO SCREENING OF POTENTIAL CHEMOPREVENTIVE AGENTS

正常口腔黏膜上皮细胞和永生化口腔黏膜上皮细胞的培养 已经公开了上皮细胞系（例如参见Xu等， 细胞科学方法18：31-39，1996年和Sacks，癌症和 Metastasis Review，15：27-51，1996）。 这些培养物或优选地 发育异常的口腔上皮细胞被用来筛选潜在的 化学预防剂初始生长抑制或其他 存在测试化学预防剂的细胞毒性测定是 用于选择合适的浓度范围， 随后的转化抑制测定。 归纳的层次 与抑制、逆转或 延缓癌症进程，以应对暴露于潜在的 正在研究化学预防剂。正常口腔上皮 细胞和永生化口腔上皮细胞系（发育异常的口腔上皮细胞系）， 上皮细胞）被用来筛选潜在的化学预防性 剂. 选择的终点可用于定量 反应应测量至少三个终点，以确定对 化学预防剂终点包括：细胞阻滞 周期，谷胱甘肽含量增加，诱导细胞凋亡， 倍性、增殖指数（PCNA，BrdU）、Ki-67、MiB-1、 p53、KS-5、核多形性指数、RAR-β、TGF-β和 微核正在同时测试适当的控制措施。 ED 50（50%有效剂量）通过以下方法测定： 由标准协议确定。

The culture of normal oral epithelial cells and immortalized oral epithelial cell lines has been published (for example see Xu et al., Methods in Cell Science 18:31-39, 1996 and Sacks, Cancer and Metastasis Review, 15:27-51, 1996). Such cultures or preferably dysplastic oral epithelial cells are being used to screen potential chemopreventive agents. Initial growth inhibition or other cytotoxicity assays with the test chemopreventive agent present are being used to select appropriate concentration ranges for use in the subsequent transformation-inhibition assays. The levels of induction of three endpoints associated with inhibiting, reversing, or retarding the cancer process in response to exposure to potential chemopreventive agents are being explored. Normal oral epithelial cells and immortalized oral epithelial cell lines (dysplastic oral epithelial cells) are being used to screen potential chemopreventive agents. The endpoints chosen are amenable to quantitation of response. At least three endpoints shall be measured for response to chemopreventive agents. The endpoints include: retardation of cell cycle, increased glutathione content, and induction of apoptosis, changes in ploidy, proliferative index (PCNA, BrdU), Ki-67, MiB-1, p53, KS-5, nuclear pleomorphism index, RAR-beta, TGF-beta, and micronuclei. Appropriate controls are being simultaneously tested. The ED50 (50% effective dose) are being determined by a method determined by a standard protocol.