Identifying targets for combination therapy with FOLFIRINOX and investigating cell polarity loss as a potential driver of invasion in basal-like PDAC

摘要 胰腺导管腺癌（PDAC）是一种致死性疾病， 9%，即使是目前的治疗。PDAC有两种分子肿瘤亚型;基底样PDAC更多 攻击性强，生存期短。最近的临床试验发现，基底样PDAC 患者对包括FOLFIRINOX在内的一线化疗没有反应，因此寻找更好的 治疗方案，针对这种亚型。为了研究PDAC亚型，利用类器官，因为它们已经显示 以代表两种分子亚型，不像传统的2D细胞系。首先，这项研究旨在确定基因 其消耗使用CRISPR/Cas9功能丧失增加基底样PDAC对FOLFIRINOX的敏感性 在基底样PDAC类器官中筛选靶向395个基底样标记基因。合成致命攻击可能是 未来将作为药物靶点与FOLFIRINOX联合使用，作为更有效的治疗药物进行研究 基底样PDAC策略。为了研究基底样PDAC的生物学，我将研究 使用类器官模型的PDAC亚型中细胞极性的失调。初步数据显示， 基底样PDAC的特征在于细胞极性的丧失，而经典PDAC维持细胞极性。 类器官不像经典类器官那样组织形成中空腔， 磷酸化蛋白质和亚型之间的途径涉及细胞粘附和细胞极性。失调 细胞极性的改变可能增加癌细胞的侵袭，可能导致基底样PDAC的不良结局。 使用荧光显微镜，这项研究将确定细胞极性标记的定位是否是 与经典相比，基底样PDAC以与细胞极性丧失一致的方式改变。它还将 测试细胞极性基因的遗传缺失是否会导致从经典型向基底型的转变 表型，如通过类器官腔损失和侵袭增加所测量的。了解这方面的 亚型生物学可能导致未来的治疗策略，利用细胞极性将基底样PDAC转化为 更经典的表型，因为经典PDAC对当前治疗更敏感。总的来说，这个项目 这将促进我们对PDAC亚型的生物学基础的理解，并朝着以下方向发展： 基底样PDAC的治疗策略。该项目将得到 由查佩尔山和药理学系以及Jen Jen Yeh博士和 高拉夫·古普塔

Abstract Pancreatic ductal adenocarcinoma (PDAC) is a lethal disease with a dismal five-year survival rate of 9% even with current treatments. There are two molecular tumor subtypes of PDAC; basal-like PDAC is more aggressive and associated with shorter survival times. Recent clinical trials have found that basal-like PDAC patients fail to respond to first-line chemotherapies including FOLFIRINOX, so it is critical to find better treatment options for this subtype. To study PDAC subtypes, organoids are utilized as they have been shown to represent both molecular subtypes, unlike conventional 2D cell lines. First, this study aims to identify genes whose depletion increases basal-like PDAC sensitivity to FOLFIRINOX using a CRISPR/Cas9 loss-of-function screen targeting 395 basal-like marker genes in basal-like PDAC organoids. The synthetic lethality hits may be studied in the future as drug targets for use in combination with FOLFIRINOX as a more efficacious therapeutic strategy for basal-like PDAC. To study the biology of basal-like PDAC, I will investigate the role of dysregulation of cell polarity in the PDAC subtypes using organoid models. Preliminary data suggest that basal-like PDAC is characterized by a loss of cell polarity while classical PDAC maintains it. Basal-like organoids do not organize to form hollow lumens like classical organoids and the most differentially phosphorylated proteins and pathways between subtypes involve cell adhesion and cell polarity. Dysregulation of cell polarity may increase cancer cell invasion, potentially contributing to poor outcomes in basal-like PDAC. Using fluorescence microscopy, this study will determine whether the localization of cell polarity markers is altered in basal-like PDAC compared to classical in a manner consistent with a loss of cell polarity. It will also be tested whether genetic depletion of cell polarity genes results in a shift from classical to basal-like phenotype, as measured by loss of organoid lumens and increased invasion. Understanding this facet of subtype biology could lead to future therapeutic strategies leveraging cell polarity to convert basal-like PDAC to a more classical phenotype, as classical PDAC is more responsive to current treatments. Overall, this project will advance our understanding of the biology underlying PDAC subtypes and move toward the development of therapeutic strategies for basal-like PDAC. This project will be supported by the extensive resources of the UNC Chapel Hill and the Department of Pharmacology as well as by co-mentorship by Drs. Jen Jen Yeh and Gaorav Gupta.