Circulating Long Non-Coding RNAs Could Be the Potential Prognostic Biomarker for Liquid Biopsy for the Clinical Management of Oral Squamous Cell Carcinoma

SIMPLE SUMMARY: Oral squamous cell carcinoma (OSCC) ranks as one of the deadliest cancers in India. Only early detection of the disease with specific prognostic subtype, is the key to reducing OSCC related death. Long non-coding RNAs (lncRNA) are master regulator of almost all biological processes. Evidences have shown that the aberrant expression of lncRNAs are found to exceed their role in different pathophysiological conditions including OSCC. The distinct expression profile of dysregulated lncRNAs in circulation could be a potential indicator to predict the OSCC-disease prognostications. The present review demonstrates that these aberrant expression of circulating lncRNAs may become powerful information regarding the blood-based biomarkers for the early prediction of disease-prognosis in OSCC. The present review also demonstrates clinical significance, limitations and challenges of circulating lncRNAs to be a potential reliable biomarker for the development of liquid biopsy technique which will be very useful, rapid, easy for clinicians for prognosis, disease monitoring, and clinical decision making to manage the treatment modality accurately in OSCC. ABSTRACT: Long non-coding RNA (lncRNA) have little or no coding potential. These transcripts are longer than 200 nucleotides. Since lncRNAs are master regulators of almost all biological processes, recent evidence proves that aberrantly expressed lncRNAs are pathogenic for oral squamous cell carcinoma (OSCC) and other diseases. LncRNAs influence chromatin modifications, transcriptional modifications, post-transcriptional modifications, genomic imprinting, cell proliferation, invasion, metastasis, and apoptosis. Consequently, they have an impact on the disease transformation, progression, and morbidity in OSCC. Therefore, circulating lncRNAs could be the potential cancer biomarker for the better clinical management (diagnosis, prognosis, and monitoring) of OSCC to provide advanced treatment strategies and clinical decisions. In this review, we report and discuss the recent understandings and perceptions of dysregulated lncRNAs with a focus on their clinical significance in OSCC-disease monitoring and treatment. Evidence clearly indicates that a specific lncRNA expression signature could act as an indicator for the early prediction of diagnosis and prognosis for the initiation, progression, recurrence, metastasis and other clinical prognostic-factors (overall survival, disease-free survival, etc.) in OSCC. The present review demonstrates the current knowledge that all potential lncRNA expression signatures are molecular biomarkers for the early prediction of prognosis in OSCC. Finally, the review provides information about the clinical significance, challenges and limitations of the clinical usage of circulating lncRNAs in a liquid biopsy method in early, pre-symptomatic, sub-clinical, accurate OSCC prognostication. More studies on lncRNA are required to unveil the biology of the inherent mechanisms involved in the process of the development of differential prognostic outcomes in OSCC.