Expression Of AMACR In Laryngeal Carcinoma

ObjectiveLaryngeal carcinoma is a common malignant tumor in otorhinolaiyngology and the morbidity increases year by year. Unfortunately, there is still no specific biomaker for diagnosis of laryngeal carcinoma. Recently, scientists are more in-terseted in a tumor - associated antigen, AMACR/P504S. AMACR, a recently described cytoplasmic protein, was identified by cDNA library subtraction in conjunction with high - throughput microarray screening from prostate carcinoma. P504S, is a 1621 - bp cDNA with an open reading frame that encodes a 382 ami-no acid protein , which has been identified as human a. - methylacyl ?coA race-mase ( AMACR). AMACR ( also termed P504S or 2 - arylpropionyl - coA epi-merase) belongs to the CAIB - BAIF CoA transferase family and is involved in fatty acid and bile acid intermediate metabolism and the inversion metabolism of the anti - flammatory cyclooxegenase inhibitor ibuprofen. AMACR activity was found predominantly in the mitochondria of rat liver; it has dual compartmental-ization in human liver and fibroblasts, with its enzyme activity mainly associated with peroxisomes but also with mitochondria. Immunohistochemical staining of tissue microarrays using a polyclonal antibody and a monoclonal antibody against AMACR identified overexpression of AMACR protein in a number of other cancer types. At present AMACR was fonud to overexpression mainly in prostate, kidney and colon carcinomas, its intensity of expression was associated with differentiation of tumor cells. Detected by immunohistochemistry, AMACR was not found in skin and mucosa squamous cell carcinomas. To date,to the best of our knowledge, there was no report on expression of AMACR in laryngeal carcinomas. The aim of this study was to establish the pattern of expression ofAMACR in laryngeal carcinomas and benign laryngeal tissues. We investigated 40 primary laryngeal squamous cell carcinomas,2 neck metastatic lymph nodes,20 laryngealpolyps and 10 para -tumor tissues by immunohistochemistry (Elivision檖lus, Fuzhou Maixin) , to explor the roles of AMACR in the development, growth and invasion of laryngeal carcinomas.Material and Methods1. MaterialA total of 40 primary laryngeal carcinomas, 2 neck metastatic lymph nodes and 10 para - tumor tissues were selected from the surgical pathology files of the Department of Otorhinolaryngology of NO. 1 Hospital of China medical university. All 40 laryngeal carcinomas,34 men,6 women,ranged in age from 39 to 80 years,with an average of 59 years. These cases were classified according to TNM classification of UICC in 1997. There were 19 supraglottic carcinomas, 17 glottic ones,l subglottic case,and 3 transglottic ones respectively. Well,moderately and poor differentiated laryngeal carcinomas were 20, 15, and 5 respectively. All specimens were diagnosed as laryngeal squamous cell carcinomas by H&E stain. 20 cases of laryngeal polyps were got from the Department of Pathology of Shaox-ing Hoyo Hospital.2. Methods2. 1 H&E stainH&E stain is used to confirm the characters of the tissues and the differentiation degree of laryngeal squamous cell carcinomas.2. 2 Immunohistochemical methodImmunohistochemical staining technique Elivision plus was performed with rabbit monoclonal antibody anti - human AMACR/P504S , using protocols according to Fuzhou Maixin. Briefly,formaldehyde - fixed,paraffin - embedded tissue blocks were cut into 4 - u,m sections, transferred to glass slides, and treeted with 0.01 mol/Lcitate buffer ( pH 6.0) in an 800 - W microwave oven for antigen retrieval before immunostaining. The slides were stained using Elivision plus kit from Fuzhou Maixin,then reacted with diaminobenzidine and hydrogen peroxide to visualize the end product. The sections were counterstained with he-matoxylin. A duplicate set of slides was also stained with diluent (no antibody)as a negative control. Immunostaining of AMACR in prostate carcinoma was ob-stained as positive control.2.2.1 Detection of stain resultPositive immunostaining of AMACR was identified as a brown granular cy...