Within systems biology there is an increasing interest in the stochastic behavior of genetic and biochemical reaction networks. An appropriate stochastic description is provided by the chemical master equation, which represents a continuous time Markov chain (CTMC). In this paper we consider the stochastic properties of a toggle switch, involving a protein compound (E2Fs and Myc) and a miRNA cl...

The transcription factor E2F4 plays a critical role in cell cycle progression of normal and cancerous intestinal epithelial cells. Contrary to other E2Fs, the coding region of the E2F4 gene contains a longer spacer segment of a CAG trinucleotide repeat sequence encoding 13 consecutive serine residues, which is highly vulnerable to frameshift mutations in situations of genetic instability. Mutat...

PURPOSE The retinoblastoma (Rb) gene family member p130 binds preferentially to the E2F5 transcription factor and forms a repressive E2F5/p130 complex that inhibits cell cycle progression and tumor growth. It is unclear whether E2F5, either alone or in combination with p130, can interfere with the transcriptional activity of other E2F family members, such as E2F1 and E2F3a, in vivo. In this stu...

microRNAs (miR) are small noncoding RNAmolecules that have recently emerged as critical regulators of gene expression and are often deregulated in cancer. In particular, miRs encoded by the miR-15a, miR-16-1 cluster seem to act as tumor suppressors. Here, we evidence that the miR-15a, miR-16-1 cluster and related miR-15b, miR-16-2 cluster comprise miRs regulated by E2F1, a pivotal transcription...

The simian virus 40 large T antigen contributes to neoplastic transformation, in part, by targeting the Rb family of tumor suppressors. There are three known Rb proteins, pRb, p130, and p107, all of which block the cell cycle by preventing the transcription of genes regulated by the E2F family of transcription factors. T antigen interacts directly with Rb proteins and disrupts Rb-E2F complexes ...

PURPOSE ARHI expression is lost or markedly down-regulated in the majority of ovarian cancers. The mechanism by which ARHI is down-regulated in ovarian cancers is still not clear. Our previous reports indicated that ARHI promoter activity was reduced in ovarian cancer cells, due in part to the effects of negative regulatory transcription factor(s). EXPERIMENTAL DESIGN AND RESULTS We now show ...

Master regulator protein p53, popularly known as the "guardian of genome" is the hub for regulation of diverse cellular pathways. Depending on the cell type and severity of DNA damage, p53 protein mediates cell cycle arrest or apoptosis, besides activating DNA repair, which is apparently achieved by regulation of its target genes, as well as direct interaction with other proteins. p53 is known ...

in the popular tale " Ozma of Oz, " Lyman Frank Baum describes the princess Langwidere, who is capable of interchanging her currently worn head with another one, using a collection of heads stored in a cabinet. Remarkably, she changes her character as well when putting a new head on her neck. in the December 15, 2012 issue of Cell Cycle, Kurt Engeland and colleagues report a similar phenomenon ...

in the popular tale " Ozma of Oz, " Lyman Frank Baum describes the princess Langwidere, who is capable of interchanging her currently worn head with another one, using a collection of heads stored in a cabinet. Remarkably, she changes her character as well when putting a new head on her neck. in the December 15, 2012 issue of Cell Cycle, Kurt Engeland and colleagues report a similar phenomenon ...

The growth plate lacks vascular tissues and is solely composed of chondrocytes. The growth plate is composed of three layers, i.e., the resting, proliferating and hyper-trophic chondrocyte layers. The chon-drocytes in the resting and proliferating layers proliferate and then they uniformly maturate toward the diaphysis to become hypertrophic chondrocytes, which lose the ability to proliferate. ...