Restoring ciliogenesis as a novel approach to blocking breast cancer growth

项目总结 初级纤毛是大多数静止和分化的细胞表面的天线状结构，是 对于传递生长控制所需的信号至关重要，包括Hedgehog(HH)信号。因此， 纤毛的丧失改变了对细胞外暗示的反应。许多癌症，包括乳腺癌，表现出接近- 在致癌转化的早期阶段纤毛完全丧失。迫切需要新的战略 需要治疗最致命的亚型，三阴性乳腺癌(TNBC)。TNBC不成比例 在非裔美国人中观察到，因此代表着关键的健康差距。我们建议恢复 乳腺癌细胞的纤毛生成将恢复生长抑制信号，阻止肿瘤生长。 我们的初步数据表明：(1)癌细胞可以再生纤毛；(2)单基因或药物作用。 干预可以使癌细胞再生纤毛；(3)纤毛再生抑制增殖。我们会 在这些发现的基础上，进行创新的功能筛查，以确定限制 在乳腺癌细胞的纤毛生成，并测试恢复纤毛生成是否限制体内肿瘤的生长。 已确定的纤毛生成抑制剂将有助于解开癌细胞 抑制纤毛生成，确定纤毛如何抑制乳腺细胞增殖，并首次测试 逆转纤毛相关信号的丢失可以恢复转化的乳腺癌细胞的生长调节。 在目标1中，我们将进行一项新的全基因组筛查，以确定乳腺癌纤毛发生的抑制因素。 以前的筛查已经确定了促进纤毛生成的调节因子。相比之下，我们的屏幕将识别负面内容 纤毛组装的调节器。我们还将测试创新的假设，即结合纤毛修复 通过使用临床上相关的纤毛信号抑制剂，可以阻止肿瘤的生长。在目标2中，我们将测试如何 在动物模型中，恢复纤毛生成会影响乳腺癌的生长。总之，这些研究将揭示 癌细胞限制纤毛发生，这是癌细胞生物学中一个重要的、尚未解答的问题。成功者 恢复纤毛生成抑制肿瘤生长的证明将揭示一种新的治疗策略 针对乳腺癌，这可能适用于其他癌症类型。通过利用 戴纳赫特和赖特实验室优势互补，我们将创新地结合RNAi 筛查，最先进的纤毛分析，以及生物体癌症模型。虽然极具探索性，但在 遵循R21机制，发现促进纤毛发生和抑制乳腺癌的方法 生长将确定肿瘤避免生长控制的新方法，并可能建立一种新的范式 治疗乳腺癌。此外，为了解决癌症健康差距，我们将：(1)开始铺设 理解为什么TNBC不成比例地影响非裔美国人的机制基础和(2) 获取并鉴定原代TNBC样本，以确定肿瘤是否参与或表达 不同民族人群纤毛发生的调控因子不同。 好了！

PROJECT SUMMARY The primary cilium, an antenna-like structure on the surface of most quiescent and differentiated cells, is essential for transducing signals required for growth control, including Hedgehog (Hh) signals. Consequently, loss of cilia alters responsiveness to extracellular cues. Many cancers, including breast cancer, exhibit near- complete loss of cilia during the early stages of oncogenic transformation. Novel strategies are urgently needed to treat the most lethal sub-type, triple-negative breast cancer (TNBC). TNBC is disproportionately observed in African-Americans and thus represents a key health disparity. We propose that restoring ciliogenesis to breast cancer cells will restore growth suppressive signaling and block tumor growth. Our preliminary data indicate that (1) cancer cells can regrow cilia; (2) single gene or pharmacological intervention can cause cancer cells to regrow cilia; and (3) ciliary regrowth inhibits proliferation. We will build on these findings by conducting an innovative functional screen to identify the genes that restrict ciliogenesis in breast cancer cells, and test whether restoring ciliogenesis limits tumor growth in vivo. The identified ciliogenesis inhibitors will help unravel the molecular mechanisms by which cancer cells suppress ciliogenesis, identify how cilia inhibit breast cell proliferation, and test, for the first time, whether reversing the loss of cilium-associated signaling restores growth regulation to transformed breast cancer cells. In Aim 1, we will perform a novel genome-wide screen to identify inhibitors of ciliogenesis in breast cancer. Prior screens have identified regulators that promote ciliogenesis. In contrast, our screen will identify negative regulators of cilium assembly. We will also test the innovative hypothesis that restoration of cilia in combination with use of clinically relevant inhibitors of ciliary signaling can block tumor growth. In Aim 2, we will test how restoring ciliogenesis impacts breast cancer growth in animal models. Together, these studies will reveal how cancer cells restrict ciliogenesis, an important, unanswered question in cancer cell biology. The successful demonstration that restoring ciliogenesis inhibits tumor growth will reveal a novel strategy for targeting breast cancer, which may be applicable to other cancer types. By taking advantage of the complementary strengths of the Dynlacht and Reiter laboratories, we will innovatively combine RNAi screening, state-of-the-art ciliary analysis, and organismal cancer modeling. While highly exploratory, in keeping with the R21 mechanism, discovering the means to promote ciliogenesis and restrain breast cancer growth will identify novel ways that tumors avoid growth control and may establish a novel paradigm for treating breast cancer. Furthermore, to address cancer health disparities, we will: (1) begin to lay the mechanistic foundation for understanding why TNBC disproportionately affects African-Americans and (2) acquire and characterize primary TNBC samples to determine whether tumor ciliation or expression of regulators of ciliogenesis differs in different ethnic populations. !