High molecular weight cytokeratins are expressed in a variety of normal and neoplastic epithelial tissues (1). In prostate, CK HMW [34βE12] has been shown to be a useful marker of basal cells of normal glands and prostatic intraepithelial neoplasia (PIN), a precursor lesion to prostatic adenocarcinoma; whereas invasive prostatic adenocarcinoma typically lacks a basal cell layer (2-4).
p63, a homolog of the tumor suppressor p53, has been identified in proliferating basal cells in the epithelial layers of a variety of tissues, including epidermis, cervix, urothelium and prostate (5). p63 was detected in nuclei of the basal epithelium in normal prostate glands; however, it was not expressed in malignant tumors of the prostate (6).
α-Methylacyl coenzyme A racemase (AMACR), also known as P504S, is a peroxisomal and mitochondrial enzyme that plays a role in bile acid synthesis and β-oxidation of branched chain fatty acids (7). AMACR was initially identified from a cDNA library as a gene that is overexpressed in human prostate cancer; with little or no expression in normal prostate (8,9). In immunohistochemistry, AMACR has been shown to be a specific marker of prostatic adenocarcinoma (8-11). Additionally, prostate glands involved in PIN have been found to express AMACR, whereas AMACR was nearly undetectable in benign glands (11,12).
Studies have shown that combinations of CK HMW [34βE12], p63, and/or AMACR may be useful in the evaluation of normal prostate glands, PIN and prostatic adenocarcinoma (13,14).
U.S. Patent 8,603,765 and patents pending