Dysregulation of non-coding RNAs in gastric cancer

Gastric cancer(GC) is one of the most common cancers in the world and a significant threat to the health of patients, especially those from China and Japan. The prognosis for patients with late stage GC receiving the standard of care treatment, including surgery, chemotherapy and radiotherapy, remains poor. Developing novel treatment strategies, identifying new molecules for targeted therapy, and devising screening techniques to detect this cancer in its early stages are needed for GC patients. The discovery of non-coding RNAs(nc RNAs), primarily micro RNAs(mi RNAs) and long non-coding RNAs(lnc RNAs), helped to elucidate the mechanisms of tumorigenesis, diagnosis and treatment of GC. Recently, significant research has been conducted on non-coding RNAs and how the regulatory dysfunction of these RNAs impacts the tumorigenesis of GC. In this study, we review papers published in the last five years concerning the dysregulation of noncoding RNAs, especially mi RNAs and lnc RNAs, in GC. We summarize instances of aberrant expression of the ncR NAs in GC and their effect on survival-related events, including cell cycle regulation, AKT signaling, apoptosis and drug resistance. Additionally, we evaluate how nc RNA dysregulation affects the metastatic process, including the epithelial-mesenchymal transition, stem cells, transcription factor activity, and oncogene and tumor suppressor expression. Lastly, we determine how ncR NAs affect angiogenesis in the microenvironment of GC. We further discuss the use of ncR NAs as potential biomarkers for use in clinical screening, early diagnosis and prognosis of GC. At present, no ideal ncR NAs have been identified as targets for the treatment of GC.