Parameters of the model.

Note: Because many of the parameters have not been determined experimentally, and since the study focuses on the dynamic implications of the regulatory structure of the epigenetic switch linking inflammation to cell transformation —i.e., its wiring diagram, or topology, which is crucial for the network behavior (see [65])— the numerical values have been selected so as to yield a non-transformed state without the inflammatory signal, Src; or a transformed state within 36 h–60 h depending on the duration of the transient inflammatory signal (see Fig. 2 as well as experimental observations in Ref. [7]). The time units for the parameters in the model are expressed in minutes, while the concentrations are expressed in µM.
The mechanisms of control of miRNA degradation are complex and not fully understood [66]. To keep the model simple, we hypothesize that each complex between a messenger RNA and its regulating miRNA is rapidly targeted for degradation.
Moreover, the rates of synthesis and degradation of messenger RNAs and proteins considered in the model are in the same order of magnitude as observed experimentally in a global quantification of mammalian gene expression control [67].
Finally, to compensate for our lack of knowledge about parameter values, we performed many bifurcation analyses, which bring to light the dynamical behaviors of the model as parameter values vary. In our experience, the dynamical properties of such models depend more on its network structure than on precise values of the parameters.