Protein Expression of STAT3, pSTAT3, MMP-7 and VEGF in Colorectal Adenocarcinoma: An Immunohistochemical Study

Background: The purpose of the present study is to investigate the expression levels of STAT3, pSTAT3, MMP-7 and VEGF in colorectal adenocarcinoma, and also to determine association with the clinico-pathological parameters and co-expression of these genes. Methods: An immunohistochemical method was used to evaluate the expression of MMP-7 and VEGF genes in 93 archival tissues whereas STAT3 and pSTAT3 expression was determined in 75 cases. Results: Overexpression of STAT3 was detected in 26.7% (20/75), pSTAT3 in 13.4% (10/75), MMP-7 in 38.8% (36/93) and VEGF in 59.2% (55/93) of the colorectal carcinomas. STAT3, MMP-7 and VEGF immunopositivity were significantly correlated with poorly-differentiated tumors (P = 0.004; P = 0.03; P = 0.002, respectively) but not with other parameters. However, pSTAT3 immunostaining was not significantly associated with the clinico-pathological characteristics. Significant relationship was noted between overexpression of pSTAT3 and STAT3 (P  Our data suggest that expression of these genes may have an important role in tumor dedifferentiation and may be useful as indicators of biologic aggressiveness. Co-expression of the biomarkers by cancer cells may have important implications in colorectal cancer biology and could be useful biological markers of the malignant phenotype.