Schematic illustration of the regulatory role of some microRNAs Biology Diagrams However, the biological relevance of such an miRNA-mediated regulation of the cell-cycle machinery in vivo remains unclear. One of the best-described examples of miRNAs that target cell-cycle proteins is the miR-34 family, which includes family members miR-34a, miR-34b, and miR-34c.
The cell division cycle is regulated through multiple molecular pathways and checkpoints. Most adult mammalian cells are quiescent (i.e. out of the cell cycle) and re-entry into the cell cycle requires the inactivation of the retinoblastoma protein (pRB) and the transcription of genes required for DNA replication during S (for DNA Synthesis) phase or chromosome segregation during mitosis (M The miR-16 family, which targets genes important for the G1-S transition, is a known modulator of the cell cycle, and members of this family are often deleted or downregulated in many types of cancers. Here, we report the reciprocal relationship—that of the cell cycle controlling the miR-16 family. Levels of this family increase rapidly as cells are arrested in G0. Conversely, as cells are miRNA-mediated regulation of cell cycle in HSCs. (a) The schematic describes miRNAs (e.g. miR-125, miR-126, miR-33, miR-146 and let-7) with critical roles in the cell cycle regulation in adult HSCs by directly targeting cell cycle components. Furthermore, miR-29 and miR-124, which target components involved in DNA methylation, indirectly
targeting microRNAs promote differentiation by enforcing ... Biology Diagrams
Moreover, alteration of microRNA levels can contribute to pathological conditions, including tumorigenesis, that are associated with loss of cell cycle control. In this review we highlight recent data linking microRNAs to mammalian cell cycle regulation. We describe how specific miRNAs function within pathways that control cell cycle checkpoints. 2.3. Cell Cycle Regulation. Next, we study the roles of microRNA in modulation of cell cycle by incorporating a microRNA, that is, miR369-3, into a detailed model. Recently, experimental report by Vasudevan et al. revealed that microRNA can up-regulate gene expression in G0/G1 arrest during mammalian cell cycle [].In fact, they carried out a series of experiments by connecting a reporter mRNA
In this study, we have analyzed microRNA regulation of translation at additional stages of the cell cycle. We observe the strongest repressive potential in the S and S/G 2 phases with minimal repression in the G 1 phase. Since asynchronously growing cells are predominantly in G 1, these data may explain the variability in magnitude of microRNA-mediated repression reported in the literature.
MicroRNAs and the cell cycle Biology Diagrams
The control of cell proliferation by microRNAs (miRNAs) is well established and the alteration of these small, non-coding RNAs may contribute to tumor development by perturbing critical cell cycle regulators. Oncogenic miRNAs may facilitate cell cycle entry and progression by targeting CDK inhibitor …
