RESUMO
AIM: To propose a quantitative method to detect heparanase-2 (HPA2) and syndecan-1 (Syn-1) using immunohistochemistry in colorectal (colon and rectal) carcinomas compared with nonneoplastic tissues and evaluate the possible role of these molecules in tumor development and extracellular remodeling. METHODS: Cytoplasmic staining of HPA2 and Syn-1 was obtained by standard immunohistochemical reactions in 50 colorectal carcinoma and 20 nonneoplastic large bowels tissues. An image system was used to quantify the immunoexpression by digital computer-assisted method (Matos et al. 2006). The cutoff point for the immunohistochemistry variable was defined by sensibility and specificity curves. Statistical analysis was performed using SPSS version 13.0. RESULTS: HPA2 was over-expressed in colorectal cancer (131.1+/-24.9 o.u./microm) when compared with nonneoplastic tissues (27.9+/-12.2 o.u./microm) (P<0.0001). However, an opposite correlation was observed between Syn-1 and tumor presence, where colorectal tissues expressed lower Syn-1 proteoglycan compared with nonneoplastic tissues, respectively (39.2+/-17.8 o.u./microm) and (102.2+/-25.2 o.u./microm) (P<0.0001). CONCLUSION: A methodology with high sensitivity and specificity is proposed with a cutoff value for HPA2 and Syn-1 in the immunohistochemistry assay to define the presence of tumor. It was demonstrated for the first time in the literature that HPA2 is over-expressed in colorectal carcinoma tissues compared with nonneoplastic tissues. HPA2 over-expression could be possibly related to Syn-1 shedding despite the fact that HPA2 does not present enzymatic activity as HPA1.
