Exploiting salivary miR-375 as a clinical biomarker of oral potentially malignant disorder.

BACKGROUND/PURPOSE: Oral potentially malignant disorder (OPMD) is an important premalignancy worldwide. MicroRNAs (miRNAs) are endogenously expressed non-coding RNAs that regulate the post-transcriptional levels of targeted mRNAs. () is markedly downregulated in oral carcinoma tissues and plays an oncogenic role in oral carcinogenesis. We explored the potential of the deregulated salivary levels in OPMD patients.

MATERIALS AND METHODS

We analyzed the levels of in the saliva of patients with OPMD ( = 45) and healthy controls ( = 24) by quantitative RT-PCR. The cell lysates and supernatants were treated with the miR-375 mimic and inhibitor.

RESULTS

Salivary levels were decreased markedly in the patients with OPMD, compared with the controls. OPMD patients with non-dysplasia showed a higher abundance of in the saliva than dysplasia patients, suggesting that salivary is a more sensitive marker for OPMD. Patients with malignant transformation during the follow-up period showed lower expression of saliva than the others. expression was markedly decreased by treatment with the miR-375 inhibitor, and the supernatants of both NHOK and SAS cells showed a corresponding decline in expression.

CONCLUSION

Our results indicate the potential application of salivary as a biomarker for the detection and long-term follow-up of OPMD.