Objective: To observe the expression patterns of salivary mRNA 21 in different stages and
grades of OSMF and also in habitual areca nut chewers without OSMF.
Subjects and Methods: The study consisted of a total of 185 samples, where 61 patients had chewing
habits (chewing gutkha and other forms of areca nut) and had OSMF (Group 1). 61 patients had
chewing habits but did not have OSMF (Group 2), and 63 were normal healthy patients (control
group) without any chewing habits (Group 3). Unstimulated saliva samples were collected from patients
following the standard operating procedures. miRNA 21 was isolated and purified from saliva
samples using the miRNeasy Mini Kit, Qiagen. The primers for miRNA relative quantification analysis
were designed using the Primer Express software of Applied Biosystems. Quantification of all
the samples was carried out using SYBR chemistry in an Applied Biosystems Real-Time PCR.
Results: There was no statistically significant difference between the demographic characteristics of
patients. There was a statistically significant difference between the expressions of miRNA 21
amongst the three groups noted in Kruskal Wallis test. (<0.001*) A post hoc test was perfomed to
confirm the statistical difference between patients within all three groups. There was no statistically
significant difference noted between the OSMF group and patients with chewing habits group (G1
vs. G2 p: 0.10), but there was a significant difference when compared with normal patients. (G1 vs.
G3 p: <0.001*) and (G2 vs. G3 <0.001*).
Conclusion: This study concludes that miRNA 21 is overexpressed in OSMF and chewing habit patients.
But the expression levels were not significantly associated with the severity of the disease process.
A long term and large scale studies are required to assess its application as a diagnostic profibrotic
marker in OSMF.