ACPP Human, Sf9

Human Prostatic Acid Phosphatase (PAcP) is a 100 kDa glycoprotein composed of two subunits . It functions as a protein tyrosine phosphatase by dephosphorylating ErbB-2/Neu/HER-2 at the phosphotyrosine residues in prostate cancer (PCa) cells, which results in reduced tumorigenicity . The interaction of cellular PAcP (cPAcP) and ErbB-2 regulates androgen sensitivity of PCa cells . Knockdown of cPAcP expression allows androgen-sensitive PCa cells to develop the castration-resistant phenotype, where cells proliferate under an androgen-reduced condition .

Prostatic Acid Phosphatase can be purified from seminal fluid, prostate tissue, or as a recombinant protein . High-scale purification methods are essential to obtain mass amounts of homogeneous, purified protein required for structural and functional studies such as inhibitor and activator analyses . The production of PAP as a recombinant protein enables obtaining mass amounts of homogeneous, glycosylated protein . In this context, recombinant PAP has been produced in mass-scale using a baculovirus expression system in Spodoptera frugiperda 9 (Sf9) insect cells .

The enzyme has significant implications in prostate cancer research. Serum PAcP activity is notably higher in prostate cancer patients, particularly those with bone metastasis, than in normal adult males . This correlation was first documented in 1941, highlighting the enzyme’s potential as a biomarker for prostate cancer . Further understanding of PAcP function and regulation of expression will have a significant impact on understanding prostate cancer progression and therapy .

Promoter analysis suggests that PAcP expression can be regulated by NF-κB, via a novel binding sequence in an androgen-independent manner . This regulation is crucial for understanding how PAcP influences prostate cancer cell growth and its potential as a therapeutic target .