PSA

Prostate specific antigen (PSA) is a serine protease secreted by prostate epithelial cells, which can liquefy semen by catalyzing the hydrolysis of semenogelin to improve sperm motility and survival, ensuring the human insemination ability. In clinical practice, PSA is an important marker for the diagnosis of primary and metastatic prostate cancer. It can be applied to differentiate prostate cancer (+) from urinary bladder cancer (-) and nephrogenic adenoma (-). However, PSA is also expressed in some pathological tissues such as prostatitis and prostatic hyperplasia, lacking the ability to distinguish between benign and malignant lesions. Therefore, PSA is often used in combination with CK5/6, PSAP, P504s, P63 and other antibodies. In addition, some research has found a negative correlation between the expression level of PSA and the pathological grading of prostate cancer, which has potential prognostic value. This may be because the decreased gland in poorly differentiated tumors leads to the reduced PSA secretion of cancer cells.