Different effects of LDH-A inhibition by oxamate in non-small cell lung cancer cells

Oncotarget. 2014 Dec 15;5(23):11886-96. doi: 10.18632/oncotarget.2620.

Abstract

Higher rate of glycolysis has been long observed in cancer cells, as a vital enzyme in glycolysis, lactate dehydrogenase A (LDH-A) has been shown with great potential as an anti-cancer target. Accumulating evidence indicates that inhibition of LDH-A induces apoptosis mediated by oxidative stress in cancer cells. To date, it's still unclear that whether autophagy can be induced by LDH-A inhibition. Here, we investigated the effects of oxamate, one classic inhibitor of LDH-A in non-small cell lung cancer (NSCLC) cells as well as normal lung epithelial cells. The results showed that oxamate significantly suppressed the proliferation of NSCLC cells, while it exerted a much lower toxicity in normal cells. As previous studies reported, LDH-A inhibition resulted in ATP reduction and ROS (reactive oxygen species) burst in cancer cells, which lead to apoptosis and G2/M arrest in H1395 cells. However, when being exposed to oxamate, A549 cells underwent autophagy as a protective mechanism against apoptosis. Furthermore, we found evidence that LDH-A inhibition induced G0/G1 arrest dependent on the activation of GSK-3β in A549 cells. Taken together, our results provide useful clues for targeting LDH-A in NSCLC treatment and shed light on the discovery of molecular predictors for the sensitivity of LDH-A inhibitors.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Apoptosis / drug effects
  • Blotting, Western
  • Carcinoma, Non-Small-Cell Lung / metabolism*
  • Carcinoma, Non-Small-Cell Lung / pathology
  • Cell Line, Tumor
  • Cell Proliferation / drug effects
  • Enzyme Inhibitors / pharmacology*
  • Humans
  • Isoenzymes / metabolism
  • L-Lactate Dehydrogenase / metabolism*
  • Lactate Dehydrogenase 5
  • Lung Neoplasms / metabolism*
  • Lung Neoplasms / pathology
  • Oxamic Acid / pharmacology*

Substances

  • Enzyme Inhibitors
  • Isoenzymes
  • L-Lactate Dehydrogenase
  • Lactate Dehydrogenase 5
  • Oxamic Acid