Cancer-testis antigen lactate dehydrogenase C4 as a novel biomarker of male infertility and cancer

A unique lactate dehydrogenase (LDH) isoenzyme designated as lactate dehydrogenase C4 (LDH-C4) is found in mammalian mature testis and spermatozoa. Thus far, LDH-C4 has been well studied with regard to its gene and amino acid sequences, structure, biological properties, and peptide synthesis. Accumulating evidence has shown that LDH-C4 is closely related to spermatic energy metabolism and plays a critical role in sperm motility, capacitation, and fertilization. Defects in the catalytic activity of LDH-C4 are key to pathophysiological abnormalities underlying infertility. LDH-C4 was originally thought to be present only in mature testis and spermatozoa; however, recent studies have implicated LDH-C4 as a cancer-testis antigen (CTA), owing to its aberrant transcription in a broad spectrum of human neoplasms. This review highlights the recent findings on LDH-C4 with particular emphasis on its role in male infertility and tumors.

Automated summary

A unique lactate dehydrogenase isoenzyme, LDH-C4, is found in mammalian mature testis and spermatozoa. It plays a critical role in sperm motility, capacitation, and fertilization by being closely related to spermatic energy metabolism. Defects in its catalytic activity are key to pathophysiological abnormalities underlying infertility. Recent studies have also identified LDH-C4 as a cancer-testis antigen due to its aberrant transcription in a broad spectrum of human neoplasms.