The role of PARP10 in alleviating replication stress and promoting cellular proliferation and tumorigenesis

项目摘要 比较癌细胞优先使用和依赖的分子途径的鉴定 对正常细胞的作用是设计新的个性化癌症疗法的关键。PARP10是一种特征不佳的 PARP家族的成员。我们先前表明，PARP10促进跨病变合成(TLS)- 在DNA复制过程中介导DNA损伤的旁路，从而减轻复制压力。最近， 我们还发现PARP10是一个新的癌基因。我们发现PARP10基因被扩增和/或 在包括乳腺和卵巢在内的大量肿瘤中过表达，很少观察到发生 监管下调或亏损的可能性。我们发现PARP10基因在大量的 包括乳腺癌和卵巢在内的人类肿瘤的比例，几乎没有发生下调或 损失。此外，我们发现PARP10在未转化的人上皮RPE1细胞中过表达 结果促进了增殖，抵抗了复制压力，并增加了移植瘤的形成 免疫功能低下的小鼠。在HeLa癌症细胞中发现PARP10基因敲除后发现了相反的表型 细胞。这些发现表明PARP10是一个可能的癌基因，它的表达促进肿瘤的发生 形成和生长。诱变的TLS之前曾被提出用来促进这两种基因的转化 允许超增殖并导致基因组不稳定。因此，我们假设PARP10表达式 通过TLS介导的复制抑制结构的旁路来抑制复制应激，从而 允许癌细胞过度增殖。我们建议在这里直接测试这一点，具体有三个目标 在三个不同的层面上解决假设：目标1将调查PARP10使用的机制，以 通过生化和细胞定位在分子水平上调节依赖于增殖细胞核抗原的TLS 相互作用分析。目标2将从功能上测试这种细胞过程机制的影响，包括 基因组稳定性和DNA复制。目标3将使用小鼠遗传模型来明确地研究 Parp10的表达是否诱导肿瘤的形成或促进肿瘤的生长。使用最先进的蜂窝网络， 分子和基因组工具(包括：CRISPR/Cas9介导的基因组编辑；分子DNA纤维 结合测量叉子的稳定性；下一代测序方法测量突变和 突变负担)我们将在这里研究这种新的致癌功能背后的分子机制 PARP10。这可能最终导致癌症治疗的新靶点得到验证。

Project Summary Identification of molecular pathways that are preferentially employed and relied upon by cancer cells compared to normal cells is key to designing novel personalized cancer therapies. PARP10 is a poorly characterized member of the PARP family. We previously showed that PARP10 promotes translesion synthesis (TLS)- mediated bypass of DNA lesions during DNA replication, thereby alleviating replication stress. More recently, we also showed that PARP10 is a novel oncogene. We found that the PARP10 gene is amplified and/or overexpressed in a large number of tumors including breast and ovarian, with very few observed occurrences of downregulation or loss. We found that the PARP10 gene is amplified and/or overexpressed in a large proportion of human tumors including breast and ovarian, with almost no occurrences of downregulation or loss. Moreover, we found that PARP10 overexpression in, non-transformed human epithelial RPE1 cells results in enhanced proliferation, resistance to replication stress, and increased xenograft tumor formation in immunocompromised mice. The opposing phenotypes were found upon knockout of PARP10 in cancer HeLa cells. These findings suggest that PARP10 is a putative oncogene and its expression promotes tumor formation and growth. Mutagenic TLS has been previously proposed to promote transformation by both allowing hyper-proliferation and inducing genomic instability. Thus, we hypothesize that PARP10 expression suppresses replication stress through TLS-mediated bypass of replication arresting structures, thereby allowing hyper-proliferation of cancer cells. We propose here to directly test this, in three specific aims which address the hypothesis at three different levels: Aim 1 will investigate the mechanism employed by PARP10 to modulate PCNA-dependent TLS at the molecular level, using biochemical and cellular localization and interaction assays. Aim 2 will functionally test the impact of this mechanism of cellular processes including genomic stability and DNA replication. Aim 3 will employ a mouse genetic model to unambiguously investigate if Parp10 expression induces tumor formation or promotes tumor growth. Using state-of-the-art cellular, molecular and genomic tools (including: CRISPR/Cas9-mediated genome editing; molecular DNA fiber combing to measure fork stability; next generation sequencing approaches to measure mutagenesis and mutation burden) we will investigate here the molecular mechanisms underlying this novel oncogenic function of PARP10. This may eventually result in validation of a new target for cancer therapy.