Analyzing the Expression Level and Associated Clinical Characteristics of miRNA-138 in Esophageal Squamous Cell Carcinoma in Iranian Patients

Background: Esophageal Squamous Cell Carcinoma (ESCC) is the seventh most common and lethal malignancy worldwide with a high incidence in Iran. Esophageal cancer has a poor prognosis and low 5-years survival rate. Despite several studies on esophageal cancer, its underlying mechanism remains unclear. Therefore, it is significant to analyze the molecular factors involved in disease for introducing effective diagnosis and therapeutic approaches. Accordingly, the aberrant expression of miRNA was demonstrated in the etiology of esophageal cancer, and applying them as detecting biomarkers was further considered by researchers. This study aimed to evaluate the expression level of miRNA-138 in the tumor tissues of ESCC and normal adjacent tissues.  Objective: In total, 35 samples of tumor and normal tissues of the esophagus were collected from ESCC patients.  Methods: Then, RNA extraction was conducted and the expression level of miRNA-138 was assessed in the collected tissue samples, applying real-time RT-PCR. Moreover, the relationship between the miRNA-138 expression level and the patient’s clinical characteristics was assessed.  Results: According to the obtained results, the expression of miR-138 was significantly downregulated in the tumor tissues of ESCC, compared to normal adjacent tissues (P<0.05). Additionally, the level of miRNA-138 downregulation was significantly correlated with tumor differentiation degree and metastasis status (P<0.05). Conclusion: The significant downregulation of miRNA-138 in the tumor samples of ESCC indicated the role of this epigenetic alteration in esophageal carcinogenesis. Therefore, applying the miRNA-138 could be considered as a potential molecular biomarker for ESCC diagnosis and screening.