Big roles of microRNAs in tumorigenesis and tumor development

Jun Tie and Daiming Fan

State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi’an, Shaanxi, China.

Offprint requests to: Jun Tie and Daiming Fan, State Key Laboratoy of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi’an, Shaanxi 710032, China. e-mail: Fandaim@fmmu.edu.cn


Summary. MicroRNAs (miRNAs) are a class of endogenous non-protein-coding small RNAs that are evolutionarily conserved and widely distributed among species. Their major function is to negatively regulate target gene expression. A single miRNA can regulate multiple target genes, indicating that miRNAs may regulate multiple signaling pathways and participate in a variety of physiological and pathological processes. Currently, approximately 50% of identified human miRNA-coding genes are located at tumor-related fragile chromosome regions. Abnormal miRNA expression and/or mutations have been found in almost all types of malignancies. These abnormally expressed miRNAs play roles similar to tumor suppressor genes or oncogenes by regulating the expression and/or function of tumor-related genes. Therefore, miRNAs, miRNA target genes, and the genes regulating miRNAs form a regulatory network with miRNAs in the hub. This network plays a pivotal role in tumorigenesis and tumor development. Histol Histopathol 26, 1353-1361 (2011)

Key words: MicroRNAs, Gene expression regulations, Neoplasms

DOI: 10.14670/HH-26.1353