MaBoSS simulation of wild type, of individual mutations of p53 and NICD and of the double mutant.

<p>The probabilities associated with each phenotype represent the number of stochastic simulations leading to each phenotype from pre-defined initial conditions. A. Wild type, see text. B. p53 LoF, same phenotypes found in (A) are reachable but with different probabilities than wild type conditions. C. NICD GoF, apoptosis is no longer reachable. D. p53 LoF and NICD GoF, only metastasis is observed. Note that HS stands for “Homeostatic State” and CCA for “CellCycleArrest.”</p

MaBoSS simulation of wild type, of individual mutations of p53 and NICD and of the double mutant.

<p>The probabilities associated with each phenotype represent the number of stochastic simulations leading to each phenotype from pre-defined initial conditions. A. Wild type, see text. B. p53 LoF, same phenotypes found in (A) are reachable but with different probabilities than wild type conditions. C. NICD GoF, apoptosis is no longer reachable. D. p53 LoF and NICD GoF, only metastasis is observed. Note that HS stands for “Homeostatic State” and CCA for “CellCycleArrest.”</p

A. Genetic interactions between two mutants leading to the masking or the antagonism of a phenotype (metastasis).

<p>Application of non-linear dimension reduction for visualising the distribution of phenotype probabilities, computed with MaBoSS for all single and double mutants of the model. The grading in the background shows the density of points (mutants) projections. Six clusters are distinguished based on this grading. Wild-type model, all single over-expression and knockout mutants and the NICD GoF / p53 LoF mutant are labelled. Note that each gene pair in this plot is represented by four different double mutants (small red points) corresponding to LoF/LoF, LoF/GoF, GoF/LoF, GoF/GoF combinations. B. Genetic interaction network showing the most significant synergistic (shown in green) and alleviating (masking, showing in red) interactions between GoF and LoF mutants with respect to the probability of having metastasis. The size of the node reflects the metastasis probability for individual mutation. The thickness of the edge reflects the absolute value of epistasis measure (see <a href="http://www.ploscompbiol.org/article/info:doi/10.1371/journal.pcbi.1004571#sec002" target="_blank">Methods</a>).</p

The nine stable states of the mathematical model.

<p>The label of the columns corresponds to the phenotypic outputs.</p

Regulatory networks of mechanisms leading to EMT, invasion, migration and metastasis.

<p>A. Detailed network of the pathways involved in metastasis. B. Modular network derived from network in A.</p

Logical rules describing the activity of a node.

<p>Logical rules describing the activity of a node.</p

The POZ-ZF Transcription Factor Kaiso (ZBTB33) Induces Inflammation and Progenitor Cell Differentiation in the Murine Intestine

<div><p>Since its discovery, several studies have implicated the POZ-ZF protein Kaiso in both developmental and tumorigenic processes. However, most of the information regarding Kaiso’s function to date has been gleaned from studies in <i>Xenopus laevis</i> embryos and mammalian cultured cells. To examine Kaiso’s role in a relevant, mammalian organ-specific context, we generated and characterized a Kaiso transgenic mouse expressing a murine Kaiso transgene under the control of the intestine-specific <i>villin</i> promoter. Kaiso transgenic mice were viable and fertile but pathological examination of the small intestine revealed distinct morphological changes. Kaiso transgenics (<i>Kaiso^Tg/+</i>) exhibited a crypt expansion phenotype that was accompanied by increased differentiation of epithelial progenitor cells into secretory cell lineages; this was evidenced by increased cell populations expressing Goblet, Paneth and enteroendocrine markers. Paradoxically however, enhanced differentiation in <i>Kaiso^Tg/+</i> was accompanied by reduced proliferation, a phenotype reminiscent of Notch inhibition. Indeed, expression of the Notch signalling target HES-1 was decreased in <i>Kaiso^Tg/+</i> animals. Finally, our Kaiso transgenics exhibited several hallmarks of inflammation, including increased neutrophil infiltration and activation, villi fusion and crypt hyperplasia. Interestingly, the Kaiso binding partner and emerging anti-inflammatory mediator p120^ctn is recruited to the nucleus in <i>Kaiso^Tg/+</i> mice intestinal cells suggesting that Kaiso may elicit inflammation by antagonizing p120^ctn function.</p></div

Generation of transgenic mouse lines ectopically expressing <i>villin</i>-Kaiso.

<p>(<b>A</b>) Myc-tagged murine <i>Kaiso</i> cDNA was cloned downstream of the 9 kb v<i>illin</i> promoter sequence. (<b>B</b>) The transgene copy number in each transgenic line was evaluated via PCR. Line A transgenic animals have the greatest copy number. (<b>C</b>) RT-PCR confirmed expression of the Kaiso transgene in <i>villin</i>-expressing tissues of transgenic mice, <i>i.e.</i> the small intestine, large intestine, and kidneys. (<b>D</b>) Immunoblot analysis shows increased Kaiso expression in both small and large intestines in Kaiso transgenic (<i>Kaiso^Tg</i>^/+) Line A mice compared to non-transgenic (Non-Tg) siblings.</p

<i>Kaiso^Tg</i>^/+ mice display decreased HES-1 expression in the small intestine.

<p>Both Non-Tg and <i>Kaiso^Tg</i>^/+ tissues displayed nuclear HES-1 expression in the crypts of the small intestine, however <i>Kaiso^Tg</i>^/+ tissue displays significantly decreased HES-1 expression in the villi. Quantitative RT-PCR showed a significant decrease in HES-1 expression in <i>Kaiso^Tg</i>^/+ mice. Values were first normalized to the GAPDH housekeeping gene, followed by normalizing to non-Tg HES-1 expression (** represents p<0.05).</p

Secretory cell lineages are expanded in the intestines of <i>Kaiso^Tg</i>^/+ mice.

<p>(<b>A</b>) PAS stain for Goblet cells (black arrowheads) revealed increased numbers of Goblet cells in both the villi and crypts of <i>Kaiso^Tg</i>^/+ intestines, p = 0.011 & 0.002. (<b>B</b>) Lysozyme staining revealed increased Paneth cell numbers in <i>Kaiso^Tg</i>^/+ mice, p = 0.017. (<b>C</b>) Synaptophysin positive enteroendocrine cells (arrowheads) are increased in <i>Kaiso^Tg</i>^/+ mice, p = 0.031. n = 3 mice/genotype; measurements performed by two independent blind observers; T-test used for p-value. ** represents significance.</p