AMACR

Alpha-methylacyl-CoA racemase (AMACR) was first discovered by using cDNA microarray technology as a molecular marker for prostate cancer.

Pathology

 Racemùase has been shown to be highly expressed in a number of malignancies :

• prostatic adenocarcinoma (prostae cancer)
• colorectal adenocarcinomas (62%) (15958853)
• non-ampullary (low frequency) (4%) (15958853)
• ampullary small intestinal adenocarcinoma (low frequency) (6%) (15958853)
• high-grade prostatic intraepithelial neoplasia (PIN) (15297968)
• prostatic nephrogenic adenoma
• papillary renal cell carcinoma (14707866)

 Alpha-methyl CoA racemase (AMACR) is a molecular marker for prostate cancer.

• Alpha-methylacyl coenzyme A racemase (AMACR) is a immunomarker for prostatic adenocarcinoma.
• Racemase (alpha methylacyl-CoA racemase) is expressed at high levels in both prostate cancer and high-grade PIN.

 AMACR is a marker of papillary renal cell carcinoma (14707866)

• Some microarray analyses of renal cell carcinomas showed a significant increase of AMACR mRNA levels in papillary renal cell carcinomas, but not in other subtypes.
• AMACR as a marker for papillary renal cell carcinoma, which could be valuable in subclassification of renal cell carcinomas and in the differential diagnosis of a metastatic papillary carcinoma.
• It has been reported to be one of the most highly expressed genes in papillary renal cell carcinomas (RCCs). Because high expression of AMACR is found in papillary RCCs (type 1 and 2) and in mucinous, tubular, and spindle cell carcinomas of the kidney, immunostaining for AMACR should be used in conjunction with other markers when histological typing of a renal tumor is difficult. (16733210)

Immunochemistry

 Alpha-Methylacyl-CoA racemase is a tumor marker over-expressed in several human cancers and their precursor lesions. (12131161)

 P504S/alpha-methylacyl-CoA racemase is a useful marker for diagnosis of small foci of prostatic carcinoma on needle biopsy. (12218573)

 The p63/P504S monoclonal antibody cocktail localizes P504S in the cytoplasm of prostate carcinoma cells and high-grade PIN and demonstrates the nuclei of prostatic basal cells, providing information on both the status of P504S and the presence or absence of basal cells with a single immunostain. This cocktail can be of great utility in the examination of diagnostically challenging prostate specimens.

α-Methyl-CoA racemase (AMACR)

AMACR mRNA was identified as being overexpressed in prostatic adenocarcinoma by cDNA library subtraction utilizing high throughput RNA microarray analysis.

This mRNA was found to encode a racemase protein, for which polyclonal and monoclonal antibodies have been produced which are active in formalin-fixed, paraffin- embedded tissue.

Immunohistochemical studies on biopsy material with an antibody directed against AMACR (P504S) demonstrate that over 80% of prostatic adenocarcinomas are labeled.

Certain subtypes of prostate cancer, such as foamy gland carcinoma, atrophic carcinoma, pseudohyperplastic, and treated carcinoma show lower AMACR expression.

However, AMACR is not specific for prostate cancer and is present in nodular hyperplasia (12%), atrophic glands, high grade PIN (>90%) 2935, and adenosis (atypical adenomatous hyperplasia) (17.5%).

AMACR may be used as a confirmatory stain for prostatic adenocarcinoma, in conjunction with H&E morphology and a basal cell specific marker.

AMACR is expressed in other non-prostatic neoplasms including urothelial and colon cancer.

References

 Alpha-methyl CoA racemase expression in renal cell carcinomas. Molinié V, Balaton A, Rotman S, Mansouri D, De Pinieux I, Homsi T, Guillou L. Hum Pathol. 2006 Jun;37(6):698-703. PMID: 16733210

 Use of p63/P504S monoclonal antibody cocktail in immunohistochemical staining of prostate tissue. Tacha DE, Miller RT. Appl Immunohistochem Mol Morphol. 2004 Mar;12(1):75-8. PMID: 15163024

 Alpha-methylacyl-CoA racemase: a variably sensitive immunohistochemical marker for the diagnosis of small prostate cancer foci on needle biopsy. Magi-Galluzzi C, Luo J, Isaacs WB, Hicks JL, de Marzo AM, Epstein JI. Am J Surg Pathol. 2003 Aug;27(8):1128-33. PMID: 12883245

 Expression and diagnostic utility of alpha-methylacyl-CoA-racemase (P504S) in foamy gland and pseudohyperplastic prostate cancer. Zhou M, Jiang Z, Epstein JI. Am J Surg Pathol. 2003 Jun;27(6):772-8. PMID: 12766580

P504S immunohistochemical detection in 405 prostatic specimens including 376 18-gauge needle biopsies.

Beach R, Gown AM, De Peralta-Venturina MN, Folpe AL, Yaziji H, Salles PG, Grignon DJ, Fanger GR, Amin MB.

Am J Surg Pathol. 2002 Dec;26(12):1588-96.PMID: 12459625 [PubMed - indexed for MEDLINE]

 P504S/alpha-methylacyl-CoA racemase: a useful marker for diagnosis of small foci of prostatic carcinoma on needle biopsy. Jiang Z, Wu CL, Woda BA, Dresser K, Xu J, Fanger GR, Yang XJ. Am J Surg Pathol. 2002 Sep;26(9):1169-74. PMID: 12218573

 Alpha-Methylacyl-CoA racemase: a novel tumor marker over-expressed in several human cancers and their precursor lesions. Zhou M, Chinnaiyan AM, Kleer CG, Lucas PC, Rubin MA. Am J Surg Pathol. 2002 Jul;26(7):926-31. PMID: 12131161