Lactate Dehydrogenase is Unrelated to Lactic Acid Production in MDA-MB-231 Human Breast Cancer Cells

Background: A well-known characteristic of tumor cells is the propensity to produce lactic acid under normoxia and hyperoxia, also referred to as the Warburg effect. High levels of lactic acid are believed to be associated with elevated expression of lactate dehydrogenase A (LDHA), a gene upregulated in diverse aggressive malignancies. Methods: In this study, ShRNAs were used to permanently knock down the expression of LDHA in human breast cancer MDA-MB 231 cells. LDHA knockdown was confirmed by Western Blot analysis. Dual analysis of lactic acid production was done via colormetric assay and HPLC, where the data shows no reduction in lactic acid production in knockdowns versus controls. Protein expression of various subtypes of LDH was investigated in order to determine if other subtypes were upregulated. Results: There was no change in the protein expression of other subtypes of LDH. Conclusion: Lactate production in LDHA knockdowns is unrelated to the LDH protein, which calls into question the relations...