Evaluation of andalpha;-Smooth Muscle Actin (andalpha;-SMA) in Intraosseous Lesions of Jaw-An Immunohistochemical Study

Introduction: Fibroblasts associated with tumor stroma called as “peritumoral fibroblasts”, “cancer-associated fibroblasts” or “myofibroblasts” encompass heterogenous and multifunctional cell populations, manifesting various phenotypes. Myofibroblasts are known to play a pivotal role in normal growth and development, wound healing, organ fibrosis and cancers. The role of myofibroblasts in the remodeling of ECM in various intraosseous lesions may affect the nature and growth of these lesions by influencing matrix formation, cellular proliferation, cellular migration, angiogenesis, and extracellular proteolytic activity. Aim and Objective: The following study was undertaken to evaluate the expression of α- smooth muscle actin in intraosseous lesions of the jaw and to correlate their role with the pathogenesis or progression of these diseases if any. Material and Methods: A total of 75 cases of Intraosseous lesions of the jaw formed the study sample. The study sample was further categorized into six groups as- Inflammatory lesions, Reactive Lesions, Benign Neoplasms, Malignant Neoplasms, Odontogenic Cysts, and Fibro-osseous Lesions. The sections were stained using Standard Hematoxylin and Eosin staining and Immunohistochemical staining for α-Smooth Muscle Actin (α- SMA). The sections were scanned at low magnification to identify positively stained areas (Hot Spots). Maximum of 10 hotspots (positive fields) were selected for quantitative scores. Statistical Analysis: Data was examined for statistical significance (p-value) using One-way analysis of variance (ANOVA) for four groups and Post Hoc tests for multiple comparisons (Tukey HSD). Results: Group II (Reactive lesions) shows highest immunoexpression (2.56) followed by Group IV (Malignant neoplasms-1.83), Group III (Benign neoplasms-1.67), Group VI (Fibro-osseous lesions-1.57), Group V (Odontogenic jaw cysts-1.50) and Group I (Inflammatory lesions-0.40). Conclusion: The understanding of expression and activity of myofibroblasts may thus be necessary for the application of anti-Myofibroblastic drugs in the therapy.