Evaluation of the presence of myofibroblasts and MMP-1 expression in the stroma of oral verrucous hyperplasia and verrucous carcinoma

Objective: This study is designed to understand the differences in the presence of cancer associated fibroblasts (CAFs) and expression of matrix metalloproteinase-1 (MMP-1) in the adjacent stroma of verrucous carcinoma (VC) and oral verrucous hyperplasia (OVH).Study Design: Twenty-seven OVH, 19 OVC and 8 Cutaneous verrucous carcinoma (CVC) specimens were analyzed for immunohistochemical (IHC) expression of smooth muscle actin (SMA) and MMP-1.Results: IHC studies for SMA expression in non-vascular stromal cells of the adjacent stroma, revealed that 88.8% of the OVH cases showed less than 33% or no SMA expression, and none of the cases demonstrated more than 67% positive cells. In the oral verrucous carcinoma (OVC) and CVC groups, 10.5% and 37.5% of the cases had more than 67% SMA positive cells respectively. The mean percentage of MMP-1 positive stromal cells were 2.63 (OVH), 9.63 (OVC) and 31.88 (CVC). Statistical analysis demonstrated that SMA expression level (PV=0.003) and MMP-1 expression level (PV < 0.001) were significantly higher in VCs compared to OVHs. Also, there is a significant correlation between the presence of myofibroblasts and the expression of MMP-1 in these lesions.

Keywords:

Verrucous carcinoma , Oral verrucous hyperplasia , Cancer associated fibroblasts , Matrix metalloproteinase-1 , Smooth muscle actin