Epithelial Mesenchymal Transition Markers in OSMF

Epithelial-mesenchymal transition (EMT) describes the process whereby cells shed their epithelial properties and adopt a more mesenchymal and invasive phenotype. A continuous molecular cross talk between epithelial and mesenchymal cells is required during embryonic development (epithelial mesenchymal transition) and probably plays an important role in pathologic process like wound healing and tumour progression. The development of carcinomas is due to the genetic changes within the target epithelium. As there is conversion of normal epithelium to potentially malignant and to squamous cell carcinoma, the stroma also changes from normal to activated or tumor associated called as the stromal reaction. 10 EMT can generate mesenchymal cells that express α-smooth muscle actin (αSMA), as seen in myofibroblasts. It is, however, unclear whether functional myofibroblasts seen in fibrosis or cancer derived from epithelial or endothelial cells

Hence EMT markers in OSMF were assessed in this study. the following markers chosen as:

• miRNA-21 regulates cell proliferation, apoptosis and the epithelial to mesenchymal transition during neoplastic progression and is up regulated in a variety of cancers.An increased expression of miRNA-21 is seen in myofibroblasts.12 Since we know the role of myofibroblasts in OSMF, salivary expression of mi RNA- 21 was included as marker.
• Type IV collagen has the unique feature of self-associating through intramolecular covalent bonds, providing barrier and mechanical strength properties to basement membranes.The increased collagen deposition in OSMF involves numerous fibroblasts that are converted to myofibroblasts found in histologic sections of tissue specimens. an altered micro environment or stroma such as persistent myofibroblasts has been shown to result in tumorigenesis and tumor progression
• Cadherins are a class of type-1 trans-membrane proteins known for its calcium-dependent cell-cell adhesion property. E-cadherins are members of this protein family found in epithelial cells which serve important roles in cell adhesion by ensuring that cells within tissues are bound together. The loss of E-cadherin function or expression has been implicated in cancer progression and metastasis.E-cadherin expression in the head and neck epithelium is essential for the morphogenesis and homeostasis of epithelial tissues. The cadherin-mediated cell-cell contacts are required for the anchorage-dependent growth of epithelial cells.

Hence lower expression of E- cadherin is a sign of loss of epithelial integrity

• The intermediate filament protein vimentin is involved in the regulation of cell behavior, morphology, and mechanical properties. Vimentin is a EMT marker expressed in connective tissue. Expression of vimentin in epithelium is a positive signature of EMT, and its evaluation in OSMF can unveil the importance of EMT signature in oral fibrosis.

Inclusion criteria

• Any patient who had history of arecanut chewing habit with clinical manifestations of OSMF.
• Patients who had arecanut chewing habit history of more than 1 year and had no clinical symptoms of OSMF.
• Healthy human volunteers who are indicated for extraction of tooth and had no clinical features of OSMF and had no habit history

Exclusion criteria

• Patients who had bleeding disorders
• patients who are diagnosed with salivary gland disorders that can alter salivary flow or composition