Metabolic reprogramming and tumor progression in LKB1 deficient NSCLC

项目总结 细胞代谢失调是癌症的一个共同特征，但越来越多的研究 突出了在原发肿瘤内和在肿瘤细胞中代谢表型的显著差异 转移到远处的器官。虽然高增殖的原发肿瘤细胞通常表现出沃伯格效应， 以有氧糖酵解为特征的，以产生ATP，线粒体生物发生和基因 据报道，氧化磷酸化在转移性癌细胞中上调。因此，详细的 肺癌中重新编程的代谢途径的特征可能揭示有用的靶点 肿瘤进展和提高患者存活率。为了转移，癌细胞必须首先抵抗失巢凋亡： 一种由失去与细胞外基质的适当接触而触发的细胞死亡机制。我们的实验室有 先前证明，线粒体酶谷氨酸脱氢酶1(GDH1)有助于 通过激活AMPK调节细胞的生物能量反应与肿瘤细胞的失巢抵抗和转移 LKB1基因缺陷的肺癌。然而，其他线粒体酶在失巢失巢抵抗中的作用仍然存在。 人们对此知之甚少。为了确定癌细胞失巢抵抗的其他重要因素，我们进行了一项 以肺癌细胞中120个线粒体酶为靶点的无偏RNAi筛选及鉴定 特异性琥珀酰辅酶A合成酶β亚基(SUCLA2)可能是癌细胞的重要因子 ECM脱离后存活。SUCLA2致敏肺癌细胞株对失巢凋亡的稳定抑制作用 在非贴壁条件下体外培养。对公开数据的生物信息学分析表明 较高的肿瘤SUCLA2 mRNA表达与患者较差的生存有关，而我们的 免疫组织化学染色显示转移性肺癌中SUCLA2蛋白水平较高 与匹配的原发肿瘤相比。此外，我们的数据表明，SUCLA2基因显著下调 增加ECM分离的癌细胞中的活性氧(ROS)的生成和失巢敏感性， 补充抗氧化剂NAC可以逆转这种情况。在本研究提案的前半部分，我们将 使用多种方法来破译SUCLA2如何调节细胞氧化还原状态以促进失巢凋亡 耐药与肿瘤转移。提案的后半部分列出了一个富有成效的博士后计划 奖学金(K00)将建立在申请者F99博士前培训的基础上，并为他开始职业生涯做好准备 一个独立的癌症研究人员。

PROJECT SUMMARY Dysregulated cellular metabolism is a common characteristic of cancer, but a growing body of research highlights significant differences in metabolic phenotypes both within primary tumors, and in tumor cells that metastasize to distant organs. While highly proliferative primary tumor cells often exhibit the Warburg effect, marked by a preference for aerobic glycolysis to generate ATP, genes for mitochondrial biogenesis and oxidative phosphorylation are reported to be upregulated in metastatic cancer cells. Therefore, detailed characterization of reprogrammed metabolic pathways in lung cancer may reveal useful targets to combat tumor progression and improve patient survival. In order to metastasize, cancer cells must first resist anoikis: an apoptotic cell death mechanism triggered by loss of proper contact with the extracellular matrix. Our lab has previously demonstrated that the mitochondrial enzyme glutamate dehydrogenase 1 (GDH1) contributes to anoikis resistance and metastasis by regulating the bioenergetic response through reactivation of AMPK in LKB1-deficient lung cancer. However, the role of other mitochondrial enzymes in anoikis resistance remains poorly understood. To identify other factors important for cancer cell anoikis resistance, we performed an unbiased RNAi screen targeting 120 mitochondrial enzymes in lung cancer cells and identified the ATP- specific Succinyl-CoA Synthetase beta subunit (SUCLA2) as a factor that may be important for cancer cell survival after ECM detachment. Stable knockdown of SUCLA2 sensitized lung cancer cell lines to anoikis when cultured under non-adherent conditions in vitro. Bioinformatic analysis of publicly available data indicates that higher tumor SUCLA2 mRNA expression is associated with poor patient survival, and our immunohistochemistry staining suggests that SUCLA2 protein levels are higher in metastatic lung cancer compared to matched primary tumors. Additionally, our data suggests that SUCLA2 knockdown significantly increases reactive oxygen species (ROS) production and anoikis sensitivity in ECM detached cancer cells, which can be reversed with antioxidant NAC supplementation. In the first half of this research proposal, we will employ multiple approaches to decipher how SUCLA2 modulates cellular redox status to promote anoikis resistance and tumor metastasis. The second half of the proposal lays out a plan for a productive postdoctoral fellowship (K00) that will build on applicant's predoctoral F99 training and prepare him well to start a career as an independent cancer researcher.