BackgroundMetabolic programs in cancer cells are influenced by genotype and the tissue of origin. We have previously shown that central carbon metabolism is rewired in pancreatic ductal adenocarcinoma (PDA) to support proliferation through a glutamate oxaloacetate transaminase 1 (GOT1)-dependent pathway.MethodsWe utilized a doxycycline-inducible shRNA-mediated strategy to knockdown GOT1 in PDA and colorectal cancer (CRC) cell lines and tumor models of similar genotype. These cells were analyzed for the ability to form colonies and tumors to test if tissue type impacted GOT1 dependence. Additionally, the ability of GOT1 to impact the response to chemo- and radiotherapy was assessed. Mechanistically, the associated specimens were examined using a combination of steady-state and stable isotope tracing metabolomics strategies and computational modeling. Statistics were calculated using GraphPad Prism 7. One-way ANOVA was performed for experiments comparing multiple groups with one changing variable. Student’s t test (unpaired, two-tailed) was performed when comparing two groups to each other. Metabolomics data comparing three PDA and three CRC cell lines were analyzed by performing Student’s t test (unpaired, two-tailed) between all PDA metabolites and CRC metabolites.ResultsWhile PDA exhibits profound growth inhibition upon GOT1 knockdown, we found CRC to be insensitive. In PDA, but not CRC, GOT1 inhibition disrupted glycolysis, nucleotide metabolism, and redox homeostasis. These insights were leveraged in PDA, where we demonstrate that radiotherapy potently enhanced the effect of GOT1 inhibition on tumor growth.ConclusionsTaken together, these results illustrate the role of tissue type in dictating metabolic dependencies and provide new insights for targeting metabolism to treat PDA.

中文翻译：

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组织来源决定了 GOT1 依赖性并赋予放射治疗综合致死性

背景癌细胞的代谢程序受到基因型和起源组织的影响。我们之前已经表明，胰腺导管腺癌 (PDA) 中的中心碳代谢被重新连接，以通过谷氨酸草酰乙酸转氨酶 1 (GOT1) 依赖性途径支持增殖。方法我们利用强力霉素诱导的 shRNA 介导的策略来敲低 PDA 和结直肠癌中的 GOT1类似基因型的癌症（CRC）细胞系和肿瘤模型。分析这些细胞形成集落和肿瘤的能力，以测试组织类型是否影响 GOT1 依赖性。此外，还评估了 GOT1 影响化疗和放疗反应的能力。从机制上讲，结合稳态和稳定同位素追踪代谢组学策略和计算模型对相关标本进行了检查。使用 GraphPad Prism 7 计算统计数据。单向方差分析用于比较多个组与一个变化变量的实验。在比较两组时进行学生 t 检验（未配对，双尾）。通过对所有 PDA 代谢物和 CRC 代谢物进行 Student t 检验（不配对，双尾）来分析比较三种 PDA 和三种 CRC 细胞系的代谢组学数据。结果虽然 PDA 在 GOT1 敲低后表现出深刻的生长抑制，但我们发现 CRC 不敏感。在 PDA 中，但在 CRC 中，GOT1 抑制破坏了糖酵解、核苷酸代谢和氧化还原稳态。这些见解在 PDA 中得到了利用，我们证明放疗有效增强了 GOT1 抑制对肿瘤生长的影响。结论综上所述，这些结果说明了组织类型在决定代谢依赖性中的作用，并为靶向代谢治疗 PDA 提供了新见解。