title: Evaluation of myofibroblasts by expression of alpha smooth muscle actin: a marker in fibrosis, dysplasia and carcinoma.
abstract: OBJECTIVE
  Evaluation of Myofibroblasts by studying expression of Alpha smooth muscle actin: A marker of Fibrosis, Dysplasia and Carcinoma.
  
  
  BACKGROUND
  Myofibroblasts are cells that have contractile properties and are involved in inflammation, wound healing, fibrosis and oncogenesis in most of the organs and tissues. They are involved in healing and granulation tissue formation which occur after tissue injuries, also produce inflammatory mediators, growth factors and help in extracellular matrix reorganization by secretion of proteins like collagen, fibronectin, etc. Because of their component, Alpha smooth muscle actin ([alpha]-SMA), they are involved in the contraction of extracellular matrix and aid in tissue contraction. The myofibroblasts disappear by apoptosis after completion of repair, but their persistence causes a dysfunction in the repair mechanism, leading to excessive contraction and extracellular matrix (ECM) secretion and thus, fibrosis. The purpose of this study was to evaluate the presence of myofibroblasts in cases of Oral Submucous fibrosis (OSMF), which consisted of very early, early and moderately advanced OSMF, OSMF with dysplasia and oral squamous cell carcinoma (OSCC), by detecting (alpha)-SMA, which is a specific marker for myofibroblasts.
  
  
  METHODS
  The study sample consisted of three groups which comprised of 41 cases of OSMF, 10 cases of OSMF with dysplasia and 11 cases of OSCC. All the cases were subjected to immunohistochemistry by using (alpha)-SMA antibody for detection of myofibroblasts.
  
  
  RESULTS
  The presence of myofibroblasts was significantly higher in oral squamous cell carcinomas as compared to that in OSMF with dysplasia and OSMF. A statistical significance was also noted between the staining index and age of the individuals and the staining index and duration of the habit.
  
  
  CONCLUSIONS
  Myofibroblasts play a role in fibrosis, as was seen in OSMF. Activated myofibroblasts secrete proteolytic enzymes and cause matrix degradation, which is instrumental in cancer cell invasion and metastasis. Further studies in which the myofibroblasts are targetted, may help in providing therapeutic regimens in fibrosis, dysplasia and cancer.
authors: Assistant Professor, Department of Oral Biology, Faculty of Dentistry, Melaka Manipal Medical College (MMMC), Manipal University , Karnataka, Manipal, India .
authors: Bharath
authors: B
authors: Rao K
authors: Professor and Head, Department of Oral Pathology and Microbiology, Sri Ramachandra Dental College, Sri Ramachandra University , Chennai, India .
authors: N
authors: N
authors: Malathi
authors: Assistant Professor, Department of Oral Pathology and Microbiology, Sri Ramachandra Dental College, Sri Ramachandra University , Chennai, India .
authors: Sangeetha
authors: S
authors: Narashiman
authors: Assistant Professor, Department of Oral Pathology and Microbiology, Sri Ramachandra Dental College, Sri Ramachandra University , Chennai, India .
authors: Sharada T
authors: ST
authors: Rajan
keywords: Alpha smooth muscle actin; Oral squamous cell carcinoma; Oral submucous fibrosis