Biogenesis of microRNAs and their role in the developmentand course of selected hematologic disorders

摘要

MicroRNAs (miRNAs) are a group of small molecules, about twenty nucleotides in length.They are involved in the regulation of gene expression mainly at a posttranscriptional level. Thisfunction depends on their complementarity to the 3’UTR regions of mRNAs. MicroRNAsare essential for proper development and functioning of the organism. They are so importantbecause of their participation in such processes as angiogenesis, apoptosis, cell cycle control andoncogenesis. Over thirty percent of human genes are controlled by miRNAs. This indicates thegreat importance of these molecules. Alterations of numerous cellular processes can be causedby the dysregulation of miRNA expression. Such disturbances are observed in cancer cells, andsignatures of microRNA expression are specific to particular types of cancer. It is suggested thatmiRNAs may serve as diagnostic and prognostic factors in oncologic and hematooncologic disorders. The expression of specific miRNAs can indicate benign or aggressive course of disease.The overall survival or time to treatment are also possible to estimate based on the microRNAexpression profile. Knowledge about changes in miRNA expression observed in leukemia patientsmay enable the selection of appropriate individual therapy. Recent reports indicate that varioushematooncologic disorders may be well characterized by microRNAs circulating in plasma orserum. It is of great potential importance, considering the availability of material for analysis,simplicity of diagnostic procedures and shortening of time required to conduct them.