title: Big roles of microRNAs in tumorigenesis and tumor development.
abstract: 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.
authors.affiliation: State Key Laboratory of Cancer Biology and Xijing Hospital of Digestive Diseases, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: J
authors.initials: J
authors.lastname: Tie
authors.forename: D
authors.initials: D
authors.lastname: Fan
mesh_terms: D000818:Animals; D002471:Cell Transformation, Neoplastic / Q000235:genetics*; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D006801:Humans; D009369:Neoplasms / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics*
chemical_list: D012333:RNA, Messenger