L-lactate dehydrogenase B chain (LDHB) (LDHB)

L-lactate dehydrogenase B chain (LDHB) is a critical metabolic enzyme that catalyzes the reversible conversion of lactate to pyruvate, using NAD+ as a cofactor (UniProt P07195). In most physiological conditions, LDHB preferentially converts lactate into pyruvate, which then enters the tricarboxylic acid (TCA) cycle for aerobic respiration (PubMed: 27049711). This enzyme is highly expressed in aerobic tissues such as the heart, brain, and red blood cells (NCBI Gene: 3945). In oncology, LDHB plays a pivotal role in the metabolic symbiosis of tumors, where oxidative cancer cells import and utilize lactate produced by neighboring glycolytic cells to fuel their growth (PubMed: 31439786). Overexpression of LDHB is associated with poor prognosis and aggressive phenotypes in several malignancies, including breast and lung cancers (PubMed: 29107965). Targeting LDHB is an emerging therapeutic strategy aimed at disrupting this lactate utilization and overcoming resistance to conventional therapies. However, because LDHB is the predominant isoform in the heart, achieving high selectivity is essential to avoid systemic toxicity and impaired cardiac function (PubMed: 33067445).

Other names

Lactate dehydrogenase BLDH-BLDH-HLactate dehydrogenase H chainLDH heart subunitTRG-5L-lactate dehydrogenase B subunit

LDHB inhibitors block the enzymatic conversion of L-lactate and NAD+ to pyruvate and NADH, thereby depriving oxidative cancer cells of a vital energy source and disrupting the metabolic symbiosis within the tumor microenvironment (PubMed: 31439786).