Immunochemical detection of 5 alpha-reductase in human serum.
This study represents a continuing effort to find a new biomarker for the diagnosis and management of prostatic cancer. Polyclonal antibodies were prepared to a peptide (CAKP) representing amino acids 28 to 43 of the 5 alpha-reductase type 2 isozyme. Using immunoaffinity-purified antibodies, the sera of 62 patients were examined by Western blot following polyacrylamide gel electrophoresis. A positive band was detected in the sera of several patients at 42 kDa compatible with the purified native glycosylated 5 alpha-reductase type 2. These bands were nullified on coincubation of the antibody with the CAKP peptide. Analysis by high-performance liquid chromatography and amino acid sequencing by N-terminal Edman degradation of the immunoaffinity-purified antigen to the antipeptide antibodies of a patient with adenocarcinoma of the prostate suggests that the 5 alpha-reductase type 2 isozyme may be linked to an immunoglobulin. An identical immunoaffinity-purified antigen to the CAKP peptide was isolated from a section of prostatic tissue from a different patient showing benign prostatic hypertrophy with severe dysplasia. It is suggested that an immunological response to the 5 alpha-reductase type 2 isozyme was elicited in both instances.
Urology Section/Surgical Service, Department of Veterans Affairs Medical Center, Bay Pines, Florida 33504, USA.
M E
ME
Lombardo
P B
PB
Hudson
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000097:blood*; D000230:Adenocarcinoma / Q000097:blood / Q000201:enzymology / Q000276:immunology; D000595:Amino Acid Sequence; D000941:Antigens / Q000097:blood / Q000302:isolation & purification; D015153:Blotting, Western; D002846:Chromatography, Affinity; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D008297:Male; D008969:Molecular Sequence Data; D010455:Peptides / Q000276:immunology; D011471:Prostatic Neoplasms / Q000097:blood / Q000201:enzymology / Q000276:immunology
D000941:Antigens; D010455:Peptides; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase