AUTHOR=Sharma Uttam , Barwal Tushar Singh , Khandelwal Akanksha , Rana Manjit Kaur , Rana Amrit Pal Singh , Singh Karuna , Jain Aklank 

TITLE=Circulating Long Non-Coding RNAs LINC00324 and LOC100507053 as Potential Liquid Biopsy Markers for Esophageal Squamous Cell Carcinoma: A Pilot Study

JOURNAL=Frontiers in Oncology

VOLUME=12

YEAR=2022

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2022.823953

DOI=10.3389/fonc.2022.823953

ISSN=2234-943X

ABSTRACT=<sec><title>Background</title><p>Despite the availability of advanced technology to detect and treat esophageal squamous cell carcinoma (ESCC), the 5-year survival rate of ESCC patients is still meager. Recently, long non-coding RNAs (lncRNAs) have emerged as essential players in the diagnosis and prognosis of various cancers.</p></sec><sec><title>Objective</title><p>This pilot study focused on identifying circulating lncRNAs as liquid biopsy markers for the ESCC.</p></sec><sec><title>Methodology</title><p>We performed next-generation sequencing (NGS) to profile circulating lncRNAs in ESCC and healthy individuals’ blood samples. The expression of the top five upregulated and top five downregulated lncRNAs were validated through quantitative real-time PCR (qRT-PCR), including samples used for the NGS. Later, we explored the diagnostic/prognostic potential of lncRNAs and their impact on the clinicopathological parameters of patients. To unravel the molecular target and pathways of identified lncRNAs, we utilized various bioinformatics tools such as lncRnome, RAID v2.0, Starbase, miRDB, TargetScan, Gene Ontology, and KEGG pathways.</p></sec><sec><title>Results</title><p>Through NGS profiling, we obtained 159 upregulated, 137 downregulated, and 188 neutral lncRNAs in ESCC blood samples compared to healthy individuals. Among dysregulated lncRNAs, we observed <italic>LINC00324 significantly upregulated</italic> (2.11-fold; <italic>p-value</italic> = 0.0032) and <italic>LOC100507053</italic> significantly downregulated (2.22-fold; <italic>p-value</italic> = 0.0001) in ESCC patients. Furthermore, we found <italic>LINC00324</italic> and <italic>LOC100507053</italic> could discriminate ESCC cancer patients’ from non-cancer individuals with higher accuracy of Area Under the ROC Curve (AUC) = 0.627 and 0.668, respectively. The Kaplan-Meier and log-rank analysis revealed higher expression levels of <italic>LINC00324</italic> and lower expression levels of <italic>LOC100507053</italic> well correlated with the poor prognosis of ESCC patients with a Hazard ratio of <italic>LINC00324</italic> = 2.48 (95% CI: 1.055 to 5.835) and Hazard ratio of <italic>LOC100507053</italic> = 4.75 (95% CI: 2.098 to 10.76)]. Moreover, we also observed lncRNAs expression well correlated with the age (&gt;50 years), gender (Female), alcohol, tobacco, and hot beverages consumers. Using bioinformatics tools, we saw miR-493-5p as the direct molecular target of <italic>LINC00324</italic> and interacted with the MAPK signaling pathway in ESCC pathogenesis.</p></sec><sec><title>Conclusion</title><p>This pilot study suggests that circulating <italic>LINC00324</italic> and <italic>LOC100507053</italic> can be used as a liquid biopsy marker of ESCC; however, multicentric studies are still warranted.</p></sec>