Pyruvate carboxylase is critical for non-small-cell lung cancer proliferation
Pyruvate carboxylase is critical for non-small-cell lung cancer proliferation
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DOI：
10.1172/jci72873
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发表时间：
2015-02-01
影响因子：
15.9
通讯作者：
Fan, Teresa W. -M.
中科院分区：
文献类型：
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作者：
Sellers, Katherine;Fox, Matthew P.;Fan, Teresa W. -M.
合成代谢生物合成需要克雷布斯循环提供的前体，而克雷布斯循环又需要回补来补充前体中间体。主要的回补来源是丙酮酸和谷氨酰胺，它们分别需要丙酮酸羧化酶（PC）和谷氨酰胺酶1（GLS 1）的活性。由于其快速增殖，癌细胞增加了合成代谢和能量需求;然而，不同的癌细胞类型对PC和GLS介导的回补和细胞增殖途径表现出不同的需求。在这里，我们在组织切除前向早期非小细胞肺癌（NSCLC）患者输注了均匀的C-13标记的葡萄糖，并确定这些患者的癌组织具有增强的PC活性。在C-13（6）-葡萄糖或C-13（5），N-15（2）-谷氨酰胺示踪剂中培养的新鲜切除的成对肺组织切片证实了在NSCLC中PC相对于GLS的选择性活化。与癌旁组织相比，PC在癌组织中的表达明显增强，而GLS 1的表达无变化趋势。此外，配对肺组织的免疫组化分析显示PC在癌细胞中而不是在肿瘤组织的基质细胞中过度表达。在人NSCLC细胞中，PC敲低诱导多核化，减少细胞增殖和集落形成，并减少小鼠异种移植模型中的肿瘤生长。生长抑制伴随着干扰克雷布斯循环活性，抑制脂质和核苷酸的生物合成，并改变谷胱甘肽稳态。这些发现表明，PC介导的回补在早期NSCLC中是肿瘤存活和增殖所必需的。
Anabolic biosynthesis requires precursors supplied by the Krebs cycle, which in turn requires anaplerosis to replenish precursor intermediates. The major anaplerotic sources are pyruvate and glutamine, which require the activity of pyruvate carboxylase (PC) and glutaminase 1 (GLS1), respectively. Due to their rapid proliferation, cancer cells have increased anabolic and energy demands; however, different cancer cell types exhibit differential requirements for PC- and GLS-mediated pathways for anaplerosis and cell proliferation. Here, we infused patients with early-stage non small-cell lung cancer (NSCLC) with uniformly C-13-labeled glucose before tissue resection and determined that the cancerous tissues in these patients had enhanced PC activity. Freshly resected paired lung tissue slices cultured in C-13(6)-glucose or C-13(5),N-15(2)-glutamine tracers confirmed selective activation of PC over GLS in NSCLC. Compared with noncancerous tissues, PC expression was greatly enhanced in cancerous tissues, whereas GLS1 expression showed no trend. Moreover, immunohistochemical analysis of paired lung tissues showed PC overexpression in cancer cells rather than in stromal cells of tumor tissues. PC knockdown induced multinucleation, decreased cell proliferation and colony formation in human NSCLC cells, and reduced tumor growth in a mouse xenograft model. Growth inhibition was accompanied by perturbed Krebs cycle activity, inhibition of lipid and nucleotide biosynthesis, and altered glutathione homeostasis. These findings indicate that PC-mediated anaplerosis in early-stage NSCLC is required for tumor survival and proliferation.