Zapojení vybraných mikroRNA do patogeneze kolorektálního karcinomu a jejich korelace s klinicko-patologickými charakteristikami.
| Title in English | Correlation of selected microRNAs with histopathologic features of colorectal cancer |
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| Authors | |
| Year of publication | 2007 |
| Type | Article in Proceedings |
| Conference | Edukační sborník. XXXI. Brněnské onkologické dny s XXI. Konferencí pro sestry a laboranty. |
| MU Faculty or unit | |
| Citation | |
| Web | http://www.mou.cz/mou/section_show.jsp?s=1115 |
| Field | Oncology and hematology |
| Keywords | colorectal cancer; patogenesis; microRNA |
| Description | MicroRNAs (miRNAs) are noncoding single-strand RNA with a length of 18-25 nucleotides forming a new group of regulators of gene expression occurring in both plant and animal cells. Negatively regulate the mRNA encoding one of two mechanisms depending on the degree of complementarity to the miRNA target sequences. When complete or nearly complete complementarity with the miRNA target sequence is the phenomenon of RNA interference. Coding mRNAs are cleaved ribonuclease in multiproteinovém complex associated with miRNAs, RISC (RNA-induced silencing complex), until they are completely degraded. This mechanism has been repeatedly observed in plant cells, but has not yet been demonstrated in animal cells. Animal miRNAs using different mechanism that is associated with degradation of the target mRNA. Regulatory effect by binding to imperfectly made complementary sequences within the 3-netranslatovaných regions (UTR) of target mRNAs and regulate gene expression post-transcriptionally that prevent their translation. The second mechanism is therefore accompanied by a related decrease in levels of encoded protein, whereas the level of the target mRNA is not affected [1]. MiRNA biogenesis from precursor molecules is a two-step process. Primary transcripts, the PRI-miRNAs are often long and several kilobází and are further processed in the nucleus RNase III called Drosha and dvouřetězcovou-RNA-bound protein Pasha to about 70 nucleotides long pre-miRNA-generating imperfect hairpin structures, which are exported to the cytoplasm of the transporter exportinem 5th Pre-miRNAs are further cleaved RNase III called Dicer miRNA duplexes on the final length of approximately 22 bases. One of the miRNA duplex fiber associates with the RISC complex and the second thread is immediately degraded. MiRNA-RISC complex is ready for translational repression or degradation of target mRNA. |