Exploring the influence of intra-tumor heterogeneity on drug resistance in KRAS drivenpancreatic cancer

KRAS癌基因在超过95%的胰腺导管腺癌(PDAC)中发生突变，是PDAC生长的有效驱动因素。然而，直接靶向致癌KRAS或间接抑制KRAS效应信号的有效性受到治疗诱导耐药的开始，导致治疗失败的限制。耐药性是由肿瘤细胞的异质性和新生耐药变异亚群的产生所驱动的。虽然PDAC在肿瘤间的遗传异质性已经得到了很好的证明，但肿瘤内的异质性还没有被研究过，这可能如何影响KRAS信号，从而对信号抑制的反应，是目前还不清楚的重要问题。在拟议的研究中，我将在最近开发的PDAC患者衍生的三维器官培养中探索肿瘤内的异质性。这些培养物比传统的二维细胞培养模型更准确地模拟癌症。我将监测癌细胞的异质性形成的适应性格局，以及它们在KRAS抑制和信号抑制方面的变化。为了做到这一点，我将应用先进的方法，使我能够在单细胞水平上分析PDAC有机化合物。这包括分析基因组突变、基因转录和效应器信号。我的研究将指导制定克服肿瘤细胞异质性的治疗策略，以实现对抗KRAS治疗策略更有效和更长期的反应。

The KRAS oncogene is mutated in more than 95% of pancreatic ductal adenocarcinoma (PDAC) and a well-validated driver of PDAC growth. However, the effectiveness of direct targeting of oncogenic KRAS or indirect inhibition of KRAS effector signaling is limited by treatment-induced onset of drug resistance, resulting in treatment failure. Resistance is driven by tumor cell heterogeneity and the outgrowth of de novo resistant variant subpopulations. Although PDAC inter-tumor genetic heterogeneity is well-documented, intra-tumor heterogeneity has not been studied and how this may impact KRAS signaling, and consequently, response to signaling inhibition, are important issues not yet understood. In the proposed study I will explore intra-tumor heterogeneity in recently developed PDAC patient-derived three-dimensional organoid cultures. These cultures model cancer more accurately than conventional two-dimensional cell culture models. I will monitor the fitness landscape shaped by heterogeneity of the cancer cells and their changes upon KRAS suppression and signaling inhibition. To accomplish this, I will apply advanced methodologies that will allow me to analyze PDAC organoids at the single cell level. This includes profiling genomic mutations, gene transcription and effector signaling. My study will guide the development of therapeutic strategies to overcome tumor cell heterogeneity to achieve a more effective and long-term response to anti-KRAS treatment strategies.