Although it is the most widely used
biomarker for
prostate cancer, the use of
prostate specific antigen (PSA) is controversial due to its limitations in specificity and sensitivity. The
proteasome is a complex associated with cell proliferation and apoptosis, and the abnormity of these processes may lead to
tumor occurrence. Previous studies have reported that proteasomal activity is associated with
cancer progression and can be used in risk stratification. The purpose of the present study was thus to investigate the feasibility of
proteasome activity as a
biomarker for
prostate cancer.
Proteasome activity in vitro and in vivo was detected, along with the expression of the substrate
proteins NF-κB inhibitor-α (IκB-α), Bcl-2-associated X (Bax) and p27.
Chymotrypsin-like proteasomal activity was elevated by 70% in vitro and 23% in vivo, and the expression levels of the
proteasome substrate
proteins IκB-α, Bax and p27 were decreased in
prostate cancer cells and prostate
tumor xenografts compared with normal mouse prostate tissue. In conclusion, proteasomal
chymotrypsin-like activity maybe a potential
biomarker for
prostate cancer, and may be suitable to supplement PSA in clinical application for
prostate cancer diagnosis.