CELL CYCLE REGULATION AND CHEMOSENSITIVITY

我们的研究小组正在利用使能技术 参与进化的分子事件的新知识 既能破译化学敏感性的分子基础， 发现新的更有选择性的化疗药物。电流 重点放在（1）发展同基因模型系统 从正常的人体细胞中提取，研究生物学和 在人类癌症中通常改变的基因的药理学影响和（2） 抗癌细胞周期调控元件研究进展 药物发现。我们目前的研究组合部分是由 我们对p53肿瘤抑制因子在化疗敏感性中的作用的研究 （奥康纳等人，癌症研究所，53：4776，1993; Fan等人，癌症研究所， 54：5824，1994; Fan等人，癌症研究所，55：1649，1995; Fan等人， Oncogene，14：2127，1997）。这些研究最近已扩展到 NCI抗癌药物筛选的60个细胞系（OConnor等， 癌症研究所，57：4285，1997; Weinstein等人，Science，275：343，1997） 以及在该测定中鉴定的可能利用缺陷型p53的试剂 目前正在对其活动进行分析。我们现在 专注于基于正常的体外模型系统的生成， 缺乏p53功能的人乳腺上皮细胞和衍生物， 涉及逆转录病毒递送的显性阴性突变p53转基因。 这些研究作为一个起点，以评估其他的影响， 在生物学上，人类乳腺癌中常见的遗传变异 和药理学。我们还发现，药物，如 与戊巴比妥钠和UCN-01一样，优先消除G2检查点 在p53缺陷型癌细胞中（Fan等，癌症研究，55：1649， 1995年：Wang等人，JNCI，88：956，1996）。我们发现UCN-01 通过Cdc 2依赖性途径，通过缓解Cdc 2- 抑制性磷酸化。我们已经排除了Wee 1激酶作为 UCN-01行动的直接目标目前的调查包括 偶联UCN-01分子的构效关系研究 体外评估G2/M调节的其他靶点 机械.正在使用的技术包括逆转录病毒基因 递送，微网格cDNA阵列，基于多孔的药物分析工具 和高通量生化分析。

Our research group is utilizing enabling technologies to exploit emerging knowledge of molecular events that participate in the evolution of cancer to both decipher the molecular basis of chemosensitivity and to discover new and more selective chemotherapeutic agents. Current emphasis is placed on the (1) development of isogenic model systems derived from normal human cells to study the biological and pharmacological impact of genes commonly altered in human cancer and (2) investigation of control elements in cell cycle pathways for anticancer drug discovery. Our current research portfolio was shaped, in part, by our studies on the role of the p53 tumor suppressor in chemosensitivity (OConnor et al., Cancer Res., 53: 4776, 1993; Fan et al., Cancer Res., 54:5824, 1994; Fan et al., Cancer Res., 55:1649, 1995; Fan et al., Oncogene, 14: 2127, 1997). These studies have recently been extended to the 60 cell lines of the NCI anticancer drug screen (OConnor et al., Cancer Res., 57:4285, 1997; Weinstein et al., Science, 275:343, 1997) and agents identified in this assay that might exploit defective-p53 function for their activity are presently being analyzed. We are now focused on the generation of in vitro model systems based on normal human mammary epithelial cells and derivatives lacking p53 function due to a retrovirally-delivered dominant-negative mutant p53 transgene. These studies act as a starting point to assess the influence of other common genetic alterations seen in human breast cancer on the biology and pharmacology of normal cells. We have also found that drugs, such as pentoxifylline and UCN-01, preferentially abrogated the G2 checkpoint in p53-defective cancer cells (Fan et al., Cancer Research, 55:1649, 1995: Wang et al., JNCI, 88:956, 1996). We have found that UCN-01 abrogates G2 arrest through a Cdc2-dependent pathway by relieving Cdc2- inhibitory phosphorylations. We have excluded the Wee1 kinase as a direct target of UCN-01 action. Current investigations include a structure-activity relationship study of the UCN-01 molecule coupled with in vitro assessment of other targets of the G2/M regulatory machinery. Enabling technologies being used include retroviral gene delivery, microgridded cDNA arrays, multiwell-based drug analysis tools and high-throughput biochemical analysis.