Department of Surgical Education, Wroclaw Medical University, 50-368 Wroclaw, Poland.
Department of Biochemistry and Immunochemistry, Wroclaw Medical University, 50-368 Wroclaw, Poland.
Int J Mol Sci. 2022 Dec 16;23(24):16062. doi: 10.3390/ijms232416062.
Cell migration is an essential part of the complex and multistep process that is the development of cancer, a disease that is the second most common cause of death in humans. An important factor promoting the migration of cancer cells is TNF-α, a pro-inflammatory cytokine that, among its many biological functions, also plays a major role in mediating the expression of MMP9, one of the key regulators of cancer cell migration. It is also known that TNF-α is able to induce the Warburg effect in some cells by increasing glucose uptake and enhancing the expression and activity of lactate dehydrogenase subunit A (LDHA). Therefore, the aim of the present study was to investigate the interrelationship between the TNF-α-induced promigratory activity of cancer cells and their glucose metabolism status, using esophageal cancer cells as an example. By inhibiting LDHA activity with sodium oxamate (SO, also known as aminooxoacetic acid sodium salt or oxamic acid sodium salt) or siRNA-mediated gene silencing, we found using wound healing assay and gelatin zymography that LDHA downregulation impairs TNF-α-dependent tumor cell migration and significantly reduces TNF-α-induced MMP9 expression. These effects were associated with disturbances in the activation of the ERK1/2 signaling pathway, as we observed by Western blotting. We also reveal that in esophageal cancer cells, SO effectively reduces the production of lactic acid, which, as we have shown, synergizes the stimulating effect of TNF-α on MMP9 expression. In conclusion, our findings identified LDHA as a regulator of TNF-α-induced cell migration in esophageal cancer cells by the ERK1/2 signaling pathway, suggesting that LDHA inhibitors that limit the migration of cancer cells caused by the inflammatory process may be considered as an adjunct to standard therapy in esophageal cancer patients.
细胞迁移是癌症发展这一复杂多步骤过程的重要组成部分，癌症是人类第二大常见死因。促进癌细胞迁移的一个重要因素是 TNF-α，一种促炎细胞因子，在其众多生物学功能中，它在调节 MMP9 的表达方面也起着主要作用，MMP9 是癌细胞迁移的关键调节因子之一。众所周知，TNF-α 能够通过增加葡萄糖摄取和增强乳酸脱氢酶亚单位 A (LDHA) 的表达和活性来诱导一些细胞中的瓦博格效应。因此，本研究旨在以食管癌细胞为例，研究 TNF-α 诱导的癌细胞促迁移活性与其葡萄糖代谢状态之间的相互关系。通过用氨基氧乙酸钠 (SO，也称为氨基氧乙酸钠或氨甲酰乙酸钠) 抑制 LDHA 活性或 siRNA 介导的基因沉默，我们发现，通过划痕愈合实验和明胶酶谱分析，LDHA 下调会损害 TNF-α 依赖性肿瘤细胞迁移，并显著降低 TNF-α 诱导的 MMP9 表达。这些效应与 ERK1/2 信号通路的激活紊乱有关，如我们通过 Western blot 观察到的。我们还揭示，在食管癌细胞中，SO 可有效减少乳酸的产生，正如我们所表明的，乳酸协同 TNF-α 对 MMP9 表达的刺激作用。总之，我们的研究结果确定了 LDHA 通过 ERK1/2 信号通路作为 TNF-α 诱导的食管癌细胞迁移的调节剂，这表明限制炎症过程引起的癌细胞迁移的 LDHA 抑制剂可能被认为是食管癌患者标准治疗的辅助手段。
