Identification of proteins in human prostate tumor material by two-dimensional gel electrophoresis and mass spectrometry

Protein patterns in cells collected from benign prostatic tissues and prost ate carcinomas were analyzed using two-dimensional polyacrylamide gel elect rophoresis and mass spectrometry. Polypeptide expression was evaluated by c omputer-assisted image analysis (PDQUEST). Proteins expressed by prostate t umors were identified via in-gel digestion and subsequent matrix-assisted l aser desorption/ionization mass spectrometry. In addition to cytoskeletal a nd mitochondrial proteins, a 40-kDa protein was identified as prostatic aci d phosphatase (PAP). PAP expression decreased approximately twofold between benign and malignant tissue. increased expression of heat shock protein 70 and decreased expression of tropomyosin 1 were also observed in the malign ant tissue. The analysis of prostate material by two-dimensional gel electr ophoresis and mass spectrometry shows that particular proteins are of inter est as markers of disease.