Salivary micro RNA s in oral cancer

Objective This study investigated the use of three salivary micro RNA s (mi RNA ‐21, mi RNA ‐184, and mi RNA ‐145) as possible markers for malignant transformation in oral mucosal lesions. Materials and methods Salivary whole unstimulated samples were collected from a study group of 100 subjects, consisting of 20 clinically healthy controls, 40 patients with oral potentially malignant disorders ( PMD s) [20 with dysplastic lesions and 20 without dysplasia], 20 with biopsy‐confirmed oral squamous cell carcinoma ( OSCC ), and 20 with recurrent aphthous stomatitis ( RAS ) as disease controls. Total RNA was isolated and purified from saliva samples using the micro RNA Isolation Kit ( Q iagen, UL ). mi RNA expression analysis was performed using qRT ‐ PCR ( A pplied B iosystems). Results There was a highly significant increase in salivary mi RNA ‐21 and mi RNA ‐184 in OSCC and PMD (with and without dysplasia) when compared to healthy and disease controls ( P  < 0.001). Conversely, mi RNA ‐145 levels showed a highly significant decrease in OSCC and PMD overall ( P  < 0.001). RAS cases showed no significant difference from normal controls in any measured mi RNA ( P  > 0.05). The only micro RNA to discriminate between OSCC and PMD with dysplasia was mi RNA ‐184. When receiver operating characteristic curves were designed for the three mi RNA s, cutoff points delineating the occurrence of malignant change were a fourfold increase in mi RNA ‐21 with specificity 65% and sensitivity 65%, a 0.6 decrease in mi RNA ‐145, with specificity 70% and sensitivity 60%, and a threefold increase of mi RNA ‐184, with specificity 75% and sensitivity 80%. Calculating the area under the curve revealed that mi RNA ‐184 was the only one among the studied mi RNA s that provided good diagnostic value. Conclusion Salivary determination of the mi RNA s tested might furnish a noninvasive, rapid adjunctive aid for revealing malignant transformation in oral mucosal lesions, particularly mi RNA ‐184.