Role of Gstt1 in metastatic maintenance and self-renewal in PDA

项目总结 只有0.01%的癌细胞进入循环，存活并产生转移，而转移的疾病 占癌症相关死亡的90%。在胰腺导管腺癌(PDA)中，大多数患者 表现为胰腺外侵犯和转移性疾病，其五年存活率令人沮丧 没有针对转移性疾病治疗的具体治疗策略。值得注意的是，许多 对转移机制的研究一直集中在确定原发肿瘤内的早期驱动因素， 然而，对已建立的病变内转移生长的中心驱动因素的识别在很大程度上仍然存在。 未被开发的。最近，我们已经证明了SIRT6的失活显著加速了PDA 发展，导致在Kras-p53 GEM模型中发生高度侵袭性的转移性疾病。采用这种方式 高度侵袭性的PDA转移模型，除了已建立的乳腺癌转移模型外，这 这项研究旨在确定转移性病变的潜在脆弱性，这些转移性病变可以被用来治疗 晚期转移疾病。对匹配的原发灶和转移灶组织进行无偏的RNA-Seq 紧随其后的是新开发的96孔软琼脂筛查，我们确定了 已建立的转移细胞的非锚定生长。利用这一功能筛选和验证，我们 已经确定GSTT1(谷胱甘肽S转移酶theta 1)是肺癌转移生长的首要候选驱动因素 多种小鼠转移模型。初步数据表明，GSTT1在 转移性细胞株与匹配的原代细胞系相比，GSTT1的抑制作用显著降低 在不影响原发肿瘤生长的情况下，转移衍生细胞的转移潜能，提示一个重要的 GSTT1在已建立的转移灶生长中的作用。此外，在转移灶内，GSTT1 显示异质性表达模式，其中Gstt1高表达细胞代表侵袭性、非增殖性亚细胞 人口。此外，我们还证明了GSTT1是形成乳腺肿瘤球体所必需的。 和PDA转移衍生的体外细胞系，提示GSTT1在转移中作为自我更新的驱动因素发挥作用 细胞。在这项建议中，我们试图确定Gstt1高PDA来源转移灶的独特特征。这个 拟议的研究将为GSTT1及其下游靶点提供重要的临床前论证 是转移性肿瘤持续生长所必需的，因此确定了一个可能的治疗窗口。 转移性动脉导管未闭的亚群。

PROJECT SUMMARY Only 0.01% of cancer cells enter circulation, survive & produce metastasis, however, metastatic disease accounts for 90% of cancer-related deaths. In pancreatic ductal adenocarcinoma (PDA), the majority of patients present with extra-pancreatic invasion and metastatic disease for which the there is a dismal five-year survival rate and no specific therapeutic strategies directed at the treatment of metastatic disease. Notably, much of the research into the mechanisms of metastasis has been focused on identifying early drivers within primary tumors, however, the identification of central drivers of metastatic outgrowth within established lesions largely remain unexplored. Recently, we have demonstrated that SIRT6 inactivation dramatically accelerates PDA development, resulting in highly aggressive metastatic disease in the Kras-p53 GEM model. Employing this highly aggressive PDA metastasis model, in addition to an established breast cancer metastasis model, this study aims to identify potential vulnerabilities of metastatic lesions that could be exploited to treat patients with advanced metastatic disease. Performing unbiased RNA-Seq on matched primary and metastatic tissues followed by a newly developed 96-well soft agar screen, we identified factors that are uniquely required for anchorage-independent growth of established metastatic cells. Utilizing this functional screen and validation, we have identified Gstt1 (glutathione S-transferase theta 1) as a top candidate driver of metastatic outgrowth in multiple mouse models of metastasis. Preliminary data demonstrates that Gstt1 is differentially expressed in metastatic cell lines compared to matched primary-derived cell lines and inhibition of Gstt1 significantly reduced metastatic potential of metastases-derived cells, without affecting primary tumor growth, suggesting an important role for Gstt1 in the outgrowth of established metastatic lesions. Additionally, within metastatic lesions, Gstt1 shows a heterogenous expression pattern, where Gstt1high cells represent an aggressive, non-proliferative sub- population. Additionally, we have demonstrated that Gstt1 is required for the formation of tumor spheres in breast and PDA metastatic-derived cell lines in vitro, suggesting a role for Gstt1 as a driver of self-renewal in metastatic cells. In this proposal we seek to identify characteristics unique to Gstt1high PDA-derived metastatic lesions. The proposed studies will provide important preclinical demonstration of whether Gstt1 and its downstream targets are required for sustained growth of metastatic tumors, thus identifying a possible therapeutic window for this subset of metastatic PDA.