Published online Jan 15, 2016. doi: 10.4251/wjgo.v8.i1.121
Peer-review started: April 16, 2015
First decision: June 19, 2015
Revised: July 3, 2015
Accepted: August 29, 2015
Article in press: November 19, 2015
Published online: January 15, 2016
There are several malignancies of the digestive system (including gastric, pancreatic and colorectal cancers, and hepatocellular carcinoma), which are the most common types of cancer and a major cause of death worldwide. MicroRNA (miR)-7 is abundant in the pancreas, playing an important role in pancreatic development and endocrine function. Expression of miR-7 is downregulated in digestive system malignancies compared with normal tissue. Although there are contrasting results for miR-7 expression, almost all research reveals that miR-7 is a tumor suppressor, by targeting various genes in specific pathways. Moreover, miR-7 can target different genes simultaneously in different malignancies of the digestive system. By acting on many cytokines, miR-7 is also involved in many gastrointestinal inflammatory diseases as a significant carcinogenic factor. Consequently, miR-7 might be a biomarker or therapeutic target gene in digestive system malignancies.
Core tip: MicroRNA (miR)-7 targets different genes in various complicated pathways and plays diagnostic, prognostic, anti-metastatic, and therapeutic roles in digestive system malignancies. MiR-7 might be a biomarker or therapeutic target gene in digestive system malignancies, even in the precancerous lesions (inflammatory disease).