Immunohistochemical study of Expression of Myofibroblasts in Oral Submucous Fibrosis, Oral Squamous Cell Carcinoma and Normal Mucosa

The aim of the study was to evaluate expression of myofibroblasts in oral submucous fibrosis, oral squamous cell carcinoma and normal mucosa. • In this study the immunohistochemical analysis was done with α-SMA (smooth muscle actin). Total of 50 blocks from archives were taken. • 20 cases of oral submucous fibrosis(Group I), 20 cases of oral squamous cell carcinoma(Group II) and 10 cases of normal mucosa. • It was observed that Staining Intensity score (S.I- 3) was seen more in oral submucous fibrosis than in oral squamous cell carcinoma. • Staining intensity among grades of oral submucous fibrosis progressively increased from early oral submucous fibrosis to advanced oral submucous fibrosis, but it was not statistically significant. • Among the grades of oral squamous cell carcinoma, higher staining intensity was observed among well differentiated oral squamous cell carcinoma while others show mild staining intensity. • As determined by labeling index, more percentage of cells expressing α SMA in oral submucous fibrosis than in oral squamous cell carcinoma and Normal mucosa. • When comparing the Staining Index between oral submucous fibrosis and normal mucosa, there is a significant difference. Our results suggest that oral submucous fibrosis actually represents an abnormal healing process in response to chronic mechanical and chemical irritation because of areca nut chewing as demonstrated by the increased incidence of myofibroblasts in this disease. Additionally, as myofibroblasts are responsible for producing a variety of factors that are involved in the fibrotic processes, they could be the key link in the pathogenesis of oral submucous fibrosis. Interruption of development, recruitment or activation could provide a unique therapeutic approach to combat fibrosis