Exploiting POU2F3 addiction in the tuft cell variant of small cell lung cancer

项目摘要 小细胞肺癌(SCLC)是最具侵袭性的肺癌，与高度有丝分裂有关。 转移率、早期转移扩散和化疗耐药性的快速演变。我们最近发现了一本小说 一种类似于簇状细胞谱系的小细胞肺癌，可与经典的神经内分泌区分开来 通过POU2F3免疫组织化学染色确定本病的形态。重要的是，我们已经确定了几个 这种疾病变异形式所特有的分子脆弱性。在这项研究计划中，我们寻求 推进个性化治疗，利用小细胞肺癌簇状细胞变体中存在的独特谱系程序。 我们的创新功能基因组学策略已经发现了独一无二的可操作依赖关系 小细胞肺癌的簇状细胞变异体，如激酶IGF1R。此外，我们还发现了一种对丛生细胞的严重上瘾 小细胞肺癌变异为POU2F3。在这里，我们将研究POU2F3成瘾在小细胞肺癌中的分子基础， 明确的意图是开发干扰POU2F3功能的小分子。这样做的第一个目的是 提案将建立在我们在SCLC执行的广泛表观基因组分析的基础上，SCLC定义了 POU2F3在这种疾病中所维持的独特的增强剂景观。我们现在将雇用两名独立的 阐明小细胞肺癌细胞基因组中关键的POU2F3结合位点/增强子的功能方法， 它将被用来精确定位可能成为靶点的簇状细胞谱系回路的关键组件 从治疗上讲。第二个目标是评估POU2F3辅因子，我们已经通过一个 创新芯片-SICAP-MS分析内源性POU2F3结合位点。我们将表演 CRISPR外显子扫描和生化分析确定关键的POU2F3：辅因子 选择性地支持这种恶性肿瘤的相互作用。本提案的最终目标将采用功能 基因组学设计与IGF1R抑制剂linsitinib的药物组合是合理的，并开发合成的- 致命的基因交互作用。我们还将采用我们最新的CRISPR创新，同源共同瞄准CRISPR 筛查，以揭示与神经内分泌与簇状细胞变体相关的冗余激酶脆弱性 小细胞肺癌的研究。综上所述，我们估计大约18%的小细胞肺癌病例中存在簇状细胞样变异体。 相当于美国约5,000例新诊断的小细胞肺癌病例和约3,500例死亡 每年都只有一个州。因此，拟议的研究可能会产生持续的影响，影响到 迫切需要新药的患者群体。

Project Summary Small cell lung cancer (SCLC) is the most aggressive form of lung cancer, which is associated with a high mitotic rate, early metastatic spread, and a rapid evolution of chemotherapy resistance. We recently discovered a novel form of SCLC that resembles the tuft cell lineage, which can be distinguished from the classical neuroendocrine form of this disease through immunohistochemical staining of POU2F3. Importantly, we have identified several molecular vulnerabilities that are specific to the variant form of this disease. In this research proposal, we seek to advance personalized therapies that exploit the unique lineage program present in the tuft cell variant of SCLC. Our innovative functional genomics strategy has already uncovered actionable dependencies that are unique to tuft cell variant of SCLC, such as the kinase IGF1R. In addition, we discovered a profound addiction of tuft cell variant SCLC tumors to POU2F3. Here we will investigate the molecular basis of POU2F3 addiction in SCLC, with the explicit intent to develop small molecules that interfere with POU2F3 function. The first Aim of this proposal will build upon the extensive epigenomic analyses we have performed in SCLC, which has defined a unique enhancer landscape sustained by POU2F3 in this disease. We will now employ two independent functional approaches to elucidate the critical POU2F3 binding sites/enhancers in the genome of SCLC cells, which will be leveraged to pinpoint the critical components of the tuft cell lineage circuit that might be targeted therapeutically. The second Aim will evaluate POU2F3 cofactors, which we have already nominated via an innovative ChIP-SICAP-mass spectrometry analysis of endogenous POU2F3 binding sites. We will perform CRISPR exon scanning and biochemical analysis of each cofactor to define the critical POU2F3:cofactor interactions that selectively support this malignancy. The final Aim of this proposal will employ functional genomics to devise drug combinations with the IGF1R inhibitor linsitinib that are rational and exploit synthetic- lethal genetic interactions. We will also employ our latest CRISPR innovation, homolog co-targeting CRISPR screens, to expose redundant kinase vulnerabilities that are linked with neuroendocrine versus tuft cell variants of SCLC. In summary, we estimate that the tuft cell-like variant is present in ~18% of SCLC cases, which corresponds to approximately 5,000 newly diagnosed SCLC cases and approximately 3,500 deaths in the United States alone each year. Hence, the proposed research could lead to a sustained impact that affects a large patient population for which novel medicines are desperately needed.