Expression of various cellular markers in genitourinary rhabdomyosarcoma: immunohistochemical study using tma methodology
Purpose Immunohistochemical analysis of the expression of various cellular markers in rhabdomyosarcoma (RMS) may improve the design of therapeutic schedules according to individualized risk-based data and may even define specific therapeutic targets in RMS. The aim of this study was to evaluate the extent of the expression of various cellular markers in RMS, using tissue microarray (TMA) technique. Material and methods TMA paraffin embedded block was constructed of 8 samples of RMS from different patients. Each tumour sample was presented in the block by several cores, 2 mm in diameter, containing tumour tissue with adjacent transitional epithelium and normal detrusor which served as positive and negative controls. After serial slicing of 4 μm thickness, the histological slides were stained with hematoxylin & eosin (H&E) and immunostained with antibodies against Erb-B2, p53, c-kit, Ki 67, Caspase 3, EGFR, N-CAM, TOPO-II and BCL-10. The immunostaining was graded semi quantitatively by the percent of positively staining cells and the intensity of stain. Results Four cellular markers were expressed in RMS including Erb-B2, Ki 67, EGFR and N-CAM. Significant positive staining (grades 2-3), for at least one of these markers, was noted in 5 of the cases. Conclusions The expression of Erb-B2, Ki 67, EGFR and N-CAM in genitourinary RMS may have potential therapeutic implications. Our preliminary results may promote further studies to assess the potential role of these markers to serve as therapeutic targets for specific therapeutic agents and thus decrease the overall treatment burden in children suffering from genitourinary RMS.