Circulating long non-coding RNA EWSAT1 acts as a liquid biopsy marker for esophageal squamous cell carcinoma: A pilot study

The widespread public health problem of esophageal squamous cell carcinoma (ESCC) is the cause of an increasing number of deaths each year due to delayed diagnosis. Therefore, we require specific and sensitive new biomarkers to manage ESCC better. The detection of diseases, such as cancer, can now be achieved through non-invasive circulating blood-based methods. Blood-based circulating non-coding RNAs, such as miRNA and lncRNA, have been extensively used as valuable markers for lung, esophageal, and breast cancer diagnostic purposes, as quoted in our previous research. Herein, we investigated the role of novel long non-coding RNA EWSAT1 as a blood-based liquid biopsy biomarker for the ESCC. Our findings indicate that EWSAT1 lncRNA has an increased tumor suppressive activity in ESCC, as it reduces by ∼2.59-fold relative to healthy controls. Moreover, we established that EWSAT1 expression can significantly distinguish between clinicopathological characteristics, including age, gender, and lifestyle choices such as smoking, alcohol consumption, and drinking hot beverages among patients with ESCC and healthy individuals. In addition, the expression levels of lncRNA EWSAT1 could distinguish between individuals with more advanced ESCC cancer and those without it, as illustrated by the ROC curve (AUC = 0.7174, 95 % confidence intervals = 0.5901 to 0.8448, p-value = 0.001). Our in-silico prediction methods demonstrated that miR-873-5p is the direct target of EWSAT1, which competes with the tumor suppressor candidate 3 (TUSC3) and EGL-9 family hypoxia-inducible factor 3 (EGLN3) mRNAs through a sponging mechanism, creating the EWSAT1/miR-873-5p/mRNA axis. We have analyzed the role of EWSAT1 in various cellular processes and signaling pathways, including mTOR, Wnt, and MAPK signaling pathways. Circulating EWSAT1 can be used as a liquid biopsy marker for diagnosis of ESCC and has the potential to serve as an effective therapeutic biomarker, according to this pilot study.