Role of Insulin Receptor Substrates in Kras-driven lung cancer

项目摘要/摘要 非小细胞肺癌(NSCLC)占肺癌的大部分，至今仍是肺癌的主要疾病。 是美国和世界范围内癌症死亡的主要原因。约25%的非小细胞肺癌含有Kras癌基因 激活突变。由于Kras的直接治疗目标被证明具有挑战性，战略转向 靶向下游效应器信号通路。然而，它们的有效性和毒性仍然不高。 迫切需要进行调查，并采取替代治疗方法。来自药理和药物的证据 细胞培养研究指出胰岛素和胰岛素样生长因子-1(IGF-1)信号在Kras驱动中的作用 肺癌。然而，该通路在Kras驱动的肿瘤发生和发展中的特定贡献 目前尚不清楚，其在改变肺部肿瘤代谢中的作用也不清楚。大多数，如果不是全部，胰岛素/IGF-1信号传导 肺在细胞内会聚到胰岛素受体底物IRS1和IRS2上，然后 分化为包括PI3K/Akt在内的下游信号效应器的复杂网络。叉头 转录因子Foxo1和Foxo3是胰岛素调节的靶标，可被Akt灭活，并影响 细胞新陈代谢、存活和增殖。众所周知，狐狸可以调节肝脏的葡萄糖代谢。 通过促进葡萄糖的产生和抑制其利用。然而，潜在的肿瘤抑制作用 Foxos在Kras驱动的癌症中的作用尚未被研究。在这里，使用不同的遗传条件 Kras肺癌基因工程鼠(GEM)模型的建立及IRS1和IRS2基因消融的影响 肺肿瘤的发生、维持和代谢以及Foxo1和Foxo3在其中的作用 调解这些影响，将进行调查。组织病理学和活体成像技术将用于 在Kras激活的同时或之后的时间点评估IRS基因丢失对肺的影响 这些小鼠的肿瘤潜伏期、肿瘤负担和生存以及Foxo1和Foxo3基因的额外丢失 会逆转这种影响。此外，信号通路的差异激活和基因的表达 将对调节葡萄糖利用的物质进行检测，并进行葡萄糖衍生的质谱分析 在FOXO存在或不存在的情况下，当IRS基因丢失时，将对肿瘤进行代谢物治疗 基因。细胞也将从Kras驱动的肿瘤中分离出来，并在培养中生长。方法类似于 被描述为体内肿瘤的那些将随后在体外的细胞上进行，以确定其下游的靶点 IRSS和FOXOS，它们可以改变葡萄糖的利用，从而影响肺癌的维持。这些因素的作用 然后，可以通过基因敲除/过表达研究来确认靶点。此外，还将进行类似的研究 在已建立的、Kras驱动的、具有稳定的IRS1可诱导敲除的人NSCLC细胞系中执行 和/或IRS2，也可以作为免疫缺陷小鼠的皮下移植。来自这些的结果 研究将揭示可被利用的新陈代谢Kras驱动的肺癌易感性 对非小细胞肺癌患者的治疗作用。 好了！

PROJECT SUMMARY/ABSTRACT Non-small cell lung cancer (NSCLC) accounts for the majority of lung cancer, which to-date remains the leading cause of cancer death in the U.S. and worldwide. About 25% of NSCLC harbors Kras oncogene activating mutations. Because direct therapeutic targeting of Kras proved challenging, strategies shifted to targeting downstream effector signaling pathways. However, their efficacy and toxicity remain under investigation, and alternative therapeutic approaches are urgently needed. Evidence from pharmacological and cell culture studies point to a role for insulin and insulin-like growth factor-1 (IGF-1) signaling in Kras-driven lung cancer. However, the specific contribution of this pathway to Kras-driven tumor initiation and progression is unclear, and its role in altering lung tumor metabolism is unknown. Most, if not all insulin/IGF-1 signaling in the lungs converges intracellularly onto the adaptor proteins insulin receptor substrates IRS1 and IRS2 prior to diverging to a complex network of downstream signaling effectors, including PI3K/Akt. The forkhead transcription factors Foxo1 and Foxo3 are insulin-regulated targets that are inactivated by Akt, and affect cellular metabolism, survival and proliferation. Foxos are well known for regulating hepatic glucose metabolism by promoting glucose production and suppressing its utilization. However, the potential tumor-suppressing roles of Foxos in Kras-driven cancers have not been investigated. Here, using distinct conditional genetically engineered mouse (GEM) models of Kras-driven lung cancer, the effects of genetic ablation of IRS1 and IRS2 on the initiation, maintenance, and metabolism of lung tumors, as well as the roles of Foxo1 and Foxo3 in mediating these effects, will be investigated. Histopathological and in vivo imaging techniques will be used to assess at timepoints concomitant with, or subsequent to Kras activation, the effect of IRS gene loss on lung tumor latency, tumor burden and survival of these mice and whether additional loss of Foxo1 and Foxo3 genes would reverse such effects. Moreover, the differential activation of signaling pathways and expression of genes that regulate glucose utilization will be assayed for, and mass spectrometry analyses of glucose-derived metabolites will be performed on the tumors upon loss of IRS genes in the presence or absence of the Foxo genes. Cells will also be isolated from the Kras-driven tumors and grown in culture. Approaches similar to the ones described for in vivo tumors will then be performed on the cells in vitro, to identify targets downstream of IRSs and Foxos, that can alter glucose utilization and hence affect lung tumor maintenance. The role of these targets can then be confirmed via knockdown/overexpression studies. In addition, similar studies will be performed in established, Kras-driven, human NSCLC cell lines with stable inducible knockdown of IRS1 and/or IRS2 that can also be grown as subcutaneous xenografts in immune-deficient mice. Results from these studies will reveal novel metabolic Kras-driven lung cancer vulnerabilities that could be exploited therapeutically in NSCLC patients. !