Screen for inhibitors of STK-33 kinase activity

描述（由申请方提供）：小GTP酶RAS家族中的突变导致约30%的人类肿瘤。尽管在过去的25年中有强烈的活性，但RAS的直接抑制剂的鉴定已被证明具有挑战性，需要替代方法来调节RAS活性。一种这样的方法利用突变RAS依赖性细胞对非致癌细胞因子的明显依赖性。例如，丝氨酸/苏氨酸激酶STK 33最近已通过RNAi技术显示为突变型KRAS依赖性癌细胞而非KRAS非依赖性细胞的存活和增殖所需。这些结果表明突变体KRAS和STK 33之间的共依赖性，其导致STK 33抑制后的合成致死相互作用。该提案的总体目标是鉴定一组直接STK 33激酶活性抑制剂，其可以概括RNAi用于在突变KRAS依赖性细胞中诱导凋亡的基于细胞的特异性，而对KRAS非依赖性细胞没有可辨别的影响。该提案的具体目的是（1）在稳健、灵敏、先前验证的初步筛选中鉴定STK 33激酶活性抑制剂，（2）利用一组基于细胞的二级测定来选择特异性靶向突变KRAS依赖性细胞的STK 33抑制剂，以及（3）实施关键路径以促进探针优化和开发。这项研究计划的长期目标是利用这些STK 33特异性探针结合全面的蛋白质组学方法来阐明RAS依赖性调节和突变KRAS依赖性肿瘤发生的分子基础，目的是将这些知识转化为治疗机会。 公共卫生相关性：这项研究的总体目标是确定化学探针，以告知我们人类肿瘤中最常见的突变是如何导致癌症的。这种知识沿着这些化学探针作为先导结构，然后可以用于产生新的治疗机会。

DESCRIPTION (provided by applicant): Mutations in the RAS family of small GTPases are responsible for approximately 30% of human tumors. Despite intense activity over the last 25 years, the identification of direct inhibitors of RAS has proven challenging, necessitating alternative approaches to modulating RAS activity. One such approach takes advantage of the apparent dependency of mutant RAS-dependent cells on non-oncogenic cellular factors. For instance, the serine/threonine kinase, STK33, has recently been shown by RNAi techniques to be required for the survival and proliferation of mutant KRAS-dependent cancer cells, but not KRAS-independent cells. These results indicate a co-dependency between mutant KRAS and STK33 that results in a synthetic lethal interaction upon suppression of STK33. The overall goal of this proposal is to identify a set of direct STK33 kinase activity inhibitors that can recapitulate the exquisite cell-based specificity of RNAi for inducing apoptosis in mutant KRAS-dependent cells without discernable effects on KRAS-independent cells. The specific aims of this proposal are to (1) identify STK33 kinase activity inhibitors in a robust, sensitive, previously validated primary screen, (2) utilize a panel of secondary cell-based assays to select for those STK33 inhibitors that specifically target mutant KRAS-dependent cells, and (3) implement a critical path to facilitate probe optimization and development. The longer term objective of this research program is to utilize these STK33- specific probes in conjunction with a comprehensive proteomics approach to elucidate the molecular basis of RAS-dependent regulation and mutant KRAS-dependent tumorigenesis with the goal of translating this knowledge into a therapeutic opportunity. PUBLIC HEALTH RELEVANCE: The overall goal of this research is to identify chemical probes that will inform us about how the most common mutation occurring in human tumors causes cancer. This knowledge along with these chemical probes as lead structures can then be used to generate novel therapeutic opportunities.