Prostate-specific antigen (Kallikrein-3) (PSA)

Prostate-specific antigen (PSA), also known as Kallikrein-3 (KLK3), is a 34-kDa serine protease primarily produced by the epithelial cells of the prostate gland (UniProt P07288). Its primary biological function is the liquefaction of the seminal coagulum through the hydrolysis of semenogelin proteins, which facilitates sperm motility (PubMed: 12670375). While PSA is most widely recognized as a gold-standard clinical biomarker for the detection and monitoring of prostate cancer, it also serves as a therapeutic target (NCBI: Gene ID 354). Various molecular isoforms, such as proPSA and BPSA, provide higher diagnostic specificity to differentiate between prostate cancer and benign conditions like hyperplasia (PubMed: 25230330). In drug development, PSA's enzymatic activity is exploited to activate prodrugs specifically within the prostate, and its status as a tissue-specific antigen makes it a candidate for cancer vaccines and T-cell engaging therapies (PubMed: 21813910).

Other names

Kallikrein-3KLK3Gamma-seminoproteinSemininP-30 antigenhK3Prostate-specific antigen isoforms

PSA is targeted via immunotherapy to induce T-cell responses against PSA-producing cells or utilized as an enzymatic trigger for the site-specific activation of cytotoxic prodrugs (PubMed: 21813910).