MicroRNAs as Tools for Early Diagnosis and Predicting Responses to Therapy in Oesophageal Cancer

Oesophageal cancer (EC) is an aggressive and invasive cancer with limited diagnosis and survival. EC usually occurs as either oesophageal adenocarcinoma (EAC) or oesophageal squamous cell carcinomas (ESCC). Despite advancements in the currently available disease treatments, including surgery, chemotherapy and radiotherapy, its prevalence and mortality have escalated. Therefore, there has been a constant necessity for enhancing our understanding of the underlying mechanism of this disease. MicroRNAs (miRNAs) are small, noncoding RNAs that can regulate gene expression and are associated with the majority of all known pathological and physiological processes in cancer. Cancer pathogenesis is affected by miRNAs playing a vital role as either tumour suppressors or oncogenes. The recent studies on miRNA dysregulation in oesophageal cancer have led to many investigations into their involvement in the disease. In oesophageal cancer, miRNA dysregulation plays a vital role in the diagnosis and the responsiveness of patients to neoadjuvant and adjuvant treatments. This chapter summarizes the miRNAs as tumour suppressors, oncogenes and drug resistance-related genes and their involvement in the therapies for oesophageal cancer.