Wnt/beta-catenin signaling in early-onset colorectal cancer

项目摘要 结直肠癌（CRC）仍然是美国癌症相关死亡的第三大原因。尽管过度- 所有的发病率都在下降，年轻人群的发病率在过去一直在稳步上升 三十年虽然西方饮食和久坐不动的生活方式是导致早期肥胖的环境因素之一， 发病性结直肠癌（EOCRC;定义为<50岁的个体），遗传研究也表明 Wnt/β-catenin信号通路作为EOCRC的驱动因素。腺瘤性结肠息肉病（APC）的突变 一种肿瘤抑制基因，编码该通路的负调控蛋白， 自发性CRC。这些突变驱动由β-连环蛋白控制的致癌基因表达程序， 转录辅助调节因子。APC突变和Wnt/β-连环蛋白信号传导的其他调节因子也在 在EOCRC肿瘤样品中，Wnt/β-连环蛋白信号转导失调的作用尚不清楚。的 该提案的目标是阐明关键的下游Wnt/β-连环蛋白基因靶点，并鉴定新的Wnt- 驱动EOCRC的通路调节剂。在目标1中，我们将使用RNA-seq来定义差异基因表达 患者匹配的结肠段和肿瘤中的特征。我们将重点关注已知的下游靶基因 的Wnt/β-连环蛋白信号传导，并使用人源性类肿瘤测试它们在驱动EOCRC中的作用。在目标2中， 将使用CRISPR/Cas9敲除筛选来鉴定负调控Wnt/β-连环蛋白的新蛋白质 来源于EOCRC患者的人结肠类器官培养物中的信号传导。这项工作将确定新的驱动程序 这是需要更好地了解疾病的发病机制，并揭示新的途径， 治疗干预

PROJECT SUMMARY Colorectal cancer (CRC) remains the third leading cause of cancer related deaths in the US. Although the over- all incidence is declining, the incidence in the younger population has been steadily increasing over the past thirty years. While a western diet and a sedentary lifestyle are among contributing environmental factors to early onset colorectal cancer (EOCRC; as defined in individuals <50 years old), genetic research has also implicated the Wnt/ß-catenin signaling pathway as a driver of EOCRC. Mutations in the adenomatous polyposis coli (APC) gene, which is a tumor suppressor and encodes a negative regulatory protein of the pathway, are highly prevalent in spontaneous CRC. These mutations drive an oncogenic gene expression program controlled by the ß-catenin transcriptional co-regulator. APC mutations, and other regulators of Wnt/ß-catenin signaling, are also found in EOCRC tumor samples, but the role of deregulated Wnt/ß-catenin signaling in EOCRC is not understood. The goals of this proposal are to elucidate critical downstream Wnt/ß-catenin gene targets and to identify novel Wnt- pathway modulators that drive EOCRC. In Aim 1, we will use RNA-seq to define differential gene expression signatures in patient-matched colonic segments and tumors. We will focus on known downstream target genes of Wnt/ß-catenin signaling and test their role(s) in driving EOCRC using human-derived tumoroids. In Aim 2, we will use a CRISPR/Cas9 knockout screen to identify novel proteins that negatively regulate Wnt/ß-catenin signaling in human colonic organoid cultures derived from EOCRC patients. This work will identify novel drivers of EOCRC which is needed to better understand disease pathogenesis and to reveal new avenues for potential therapeutic intervention.