Expression of MMP-1 in histopathological different grades of oral squamous cell carcinoma and in normal buccal mucosa - an immunohistochemical study

Introduction: Oral Cancer (OC) is the sixth most common cancer worldwide, while being the most common cancer among Indian males and the third most common cause of their deaths. 70-94% of all the malignancies arising within the oral cavity are oral squamous cell carcinomas (OSCC). Researches show that altered expression of matrix metalloproteinases (MMPs) may have a vital role in regulating the tumor microenvironment of head and neck carcinomas. Aim: To evaluate the expression of MMP-1 in histopathologically different grades of OSCC, to evaluate its expression in normal buccal mucosa (NBM). and to compare the expressions between these two groups, using the streptavidin horseradish peroxidase biotin labeled immuno-histochemistry (IHC) technique. Result: 100% of OSCC showed cytoplasmic immune reactivity for MMP-1 in the epithelial and connective tissue cells. Their expression was elevated as the histopathological grade differed from well to poorly differentiated. 100% of epithelial cells and 80% of connective tissue of NBM expressed MMP-1. The immune reactivity was significantly over-expressed in OSCC in comparison to NBM. Conclusion: Evidence indicates that the elevated MMP-1 protein expression is associated with higher histopathological grade of OSCC. NBM express MMP-1 diffusely and weakly. MMP-1 immune reactivity increases as OC progresses from NBM to well to poorly differentiated OSCC.