EVALUATION OF CHEMOPREVENTION AGENTS BY IN VITRO SCREENI

迫切需要能够抑制或延缓口腔黏膜癌变进程的化学预防药物。为了选择潜在的候选化学物质进行全动物和人体试验，需要进行体外筛选。正常口腔上皮细胞和永生化口腔上皮细胞系（发育不良的口腔上皮细胞）的培养被用于筛选潜在的化学预防药物。初始生长抑制或其他细胞毒性试验与测试化学预防剂的存在是用来选择适当的浓度范围，用于随后的转化抑制试验。在介质或溶剂（如二甲基亚砜）中，从1mm稀释5倍或最高可溶浓度，而无溶剂毒性。三个终点被用来测量暴露于潜在化学预防剂后的反应。三个终点是Ki-67、RAR-和细胞凋亡。五种无毒浓度（半对数稀释）应测量其调节每个终点的能力。适当的控制措施应同时进行测试。肯定答复和否定答复的标准应在提案中确定。ED50（50%有效剂量）应由标准方案确定的方法确定。适当的控件应使用。

Chemopreventive agents which inhibit or retard the cancer process in oral mucosa are urgently needed. In order to select potential chemical candidates for whole animal and human testing, in vitro screening is required. The culture of normal oral epithelial cells and immortalized oral epithelial cell lines (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. Five log dilutions from 1 mM or the highest soluble concentration in medium or in a solvent such as dimethylsulfoxide without solvent toxicity. Three endpoints are being used to measure response to exposure to potential chemopreventive agents. Three endpoints are Ki-67, RAR- , and apoptosis. Five nontoxic concentrations (at half-log dilutions) shall be measured for their ability to modulate each endpoint. Appropriate controls shall be simultaneously tested. The criteria for a positive and negative response shall be defined in the proposal. The ED50 (50% effective dose) shall be determined by a method determined by a standard protocol. The appropriate controls shall be used.