Identifying Mitophagy Receptors as Targets in Ras-dysregulated Cells

胰腺导管腺癌（PDAC）的五年生存率约为5%， 美国最致命的癌症尽管90%以上的PDAC含有 激活编码GT3 KRas的基因内的突变， KRas抑制剂仅对G12C等位基因成功，占KRAS突变的3%， PDAC。因此，抑制KRas驱动的转化和肿瘤发生所必需的途径 可能为PDAC靶向治疗的发展提供更有前途的途径。其中一条途径 在致癌KRas表达的应答中上调包括一系列分解代谢过程 称为自噬。事实上，大量的指示性出版物表明，自噬可能代表了一种 某些侵袭性和难治性癌症的致命弱点，以及全面阻断自噬的抑制剂 在细胞培养和PDAC小鼠模型中显示出一些前景。然而，治疗浓度 这些自噬抑制剂导致毒性。进一步的转化进展受到了 缺乏特异性试剂：自噬实际上不是一个单一的过程，而是一个广泛的途径家族 不同的货物偏好和招募机制。最近，致癌KRasG12V表达， 占PDAC中KRAS突变的30%，已显示导致PDAC中KRAS突变的上调。 一种特殊形式的自噬，称为线粒体自噬，其中特定的线粒体自噬受体标记线粒体 用于降解。本提案的目的是确定线粒体自噬在KRasG12V转化中的作用 PDAC。我们的中心假设是KRas失调导致线粒体自噬上调， 促进肿瘤转化。为了验证这一假设，我们制定了两个具体目标。目标1将 确定KRasG12V转化所需的已知线粒体自噬受体。更以 在哺乳动物细胞中，这些途径中的许多是多余的，阻止了转化细胞中的容易分离。 AIM2将利用结构和遗传方法的新组合来鉴定新的线粒体自噬 受体和同源相互作用的合作伙伴，从而探讨线粒体自噬的机制，在Ras失调

The five year survival rate for pancreatic ductal adenocarcinomas (PDAC) is approximately 5% making it one of the most lethal cancers in the United States. Despite the fact that more than 90% of PDAC contain activating mutations within the gene encoding the GTPase KRas, the development of small-molecule inhibitors for KRas has only been successful for the G12C allele accounting for 3% of KRAS mutations in PDAC. As such, inhibiting pathways which are essential for KRas-driven transformation and tumorigenesis may provide a more promising avenue for the development of PDAC targeted therapies. One such pathway that is upregulated in response to oncogenic KRas expression encompasses a set of catabolic processes termed autophagy. Indeed, a wealth of indicative publications suggest that autophagy could represent an Achilles’ heel for certain aggressive and intractable cancers, and inhibitors that globally block autophagy have shown some promise in cell culture and mouse models of PDAC. However, therapeutic concentrations of these autophagy inhibitors resulted in toxicity. Further translational progress has been hampered by the lack of specific reagents: autophagy is actually not a single process but rather a broad family of pathways with distinct cargo preferences and mechanisms of recruitment. Recently, oncogenic KRasG12V expression, which accounts for 30% of KRAS mutations in PDAC, has been shown to result in the upregulation of a specialized form of autophagy, termed mitophagy, in which specific mitophagy receptors mark mitochondria for degradation. The goal of this proposal is to determine the role of mitophagy in KRasG12V transformation and PDAC. Our central hypothesis is that KRas dysregulation leads to the upregulation of mitophagy to promote neoplastic transformation. To test this hypothesis we have developed two specific aims. Aim 1 will determine which of the known mitophagy receptors are required for KRasG12V transformation. Furthermore, in mammalian cells, many of these pathways are redundant, preventing facile dissection in transformed cells. Aim 2 will leverage a novel combination of structural and genetic approaches to identify novel mitophagy receptors and cognate interaction partners and thus explore mechanisms of mitophagy in Ras-dysregulated