MicroRNA in Human Cancer: One Step Forward in Diagnosis and Treatment

Cancer is a disease involving multistep dynamic changes in the genome. However, studies to date on the cancer genome have focused most heavily on protein-coding genes, and our knowledge on alterations of the functional noncoding sequences in cancer is largely absent. MicroRNAs (miRNAs) are ~22 nucleotide (nt) noncoding RNAs, which regulate gene expression in a sequence-specific manner via translational inhibition or mRNA degradation. Mounting evidence shows that miRNAs may play an important role in tumor development, and a better understanding of their alteration in cancer genome and oncogenic property should contribute to the diagnosis and treatment of cancer.