Atiyeh Poursadoughian Yaran
Soyar Sari

Gastric cancer (GC) is the fourth most common cancer and one of the leading cancers of cancer-related deaths in the world. GC is an asymptomatic disease at early stages and is thus often diagnosed late. The treatment approaches for gastric cancer contain systematic chemotherapy and radiotherapy, whereas these methods are limited by their side effect and insensitivity. On the other hand, the prognosis of GC also remains poor because the molecular mechanisms are incompletely understood. Thus, the development of novel therapies to improve the prognosis of patients with GC is critical. MicroRNAs are a class of small endogenous and highly conserved non-coding RNAs with a length of approximately 22 (18 to22) nucleotides, which, by binding to target gene’s mRNA, regulate its expression and play an important role in tumor suppression. dysregulation in expression level of microRNA related to the development of multiple cancers through abnormal proliferation of cells, apoptosis, anddifferentiation. With the discovery of circulating miRNA a non-invasive approach for the diagnosis and treatment of cancer has been identified. This review summarized the role of miRNAs in the development of gastric cancer.Discussion Regulation of miRNA in cancers directly affects cell proliferation and apoptosis. In addition, various studies have demonstrated coloration between dysregulation of miRNA and intracellular signal transduction pathway abnormalities, as well as tumorigenesis. Amongprevious studies, a large number of miRNAs which related to some gene that they are association with growth and proliferation of cells were significantly overexpressed like miRNA-21, -433, -422, -199a, -181a. In contrast, several miRNA which targeted suppressor genes were underexpressed including miRNA-449, -223, -34a/34b in gastric cancer tissues. ConclusionThe changes in miRNAs expression effect on various growth and proliferation and, signal transduction pathways, apoptosis associated with cancers and may play important roles in thedevelopment of GC. Therefore, more studies with larger and well-defined populations are clearly needed to resolve this multifaceted miRNA-mediated regulatory connection.

MicroRNA, Gastric Cancer, GC, Expression