title: Co-occurrence of resonant activation and noise-enhanced stability in a model of cancer growth in the presence of immune response.
abstract: We investigate a stochastic version of a simple enzymatic reaction which follows the generic Michaelis-Menten kinetics. At sufficiently high concentrations of reacting species, that represent here populations of cells involved in cancerous proliferation and cytotoxic response of the immune system, the overall kinetics can be approximated by a one-dimensional overdamped Langevin equation. The modulating activity of the immune response is here modeled as a dichotomous random process of the relative rate of neoplastic cell destruction. We discuss physical aspects of environmental noises acting in such a system, pointing out the possibility of coexistence of dynamical regimes where noise-enhanced stability and resonant activation phenomena can be observed together. We explain the underlying mechanisms by analyzing the behavior of the variance of first passage times as a function of the noise intensity.
authors.affiliation: Dipartimento di Fisica e Tecnologie Relative and CNISM, Group of Interdisciplinary Physics, Università di Palermo, Viale delle Scienze, I-90128 Palermo, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Fiasconaro
authors.forename: Bernardo
authors.initials: B
authors.lastname: Spagnolo
authors.forename: Anna
authors.initials: A
authors.lastname: Ochab-Marcinek
authors.forename: Ewa
authors.initials: E
authors.lastname: Gudowska-Nowak
mesh_terms: D000818:Animals; D049109:Cell Proliferation; D003198:Computer Simulation; D006801:Humans; D007113:Immunity, Innate / Q000276:immunology*; D007155:Immunologic Factors / Q000276:immunology*; D018448:Models, Immunological; D015233:Models, Statistical; D009369:Neoplasms / Q000503:physiopathology*; D015398:Signal Transduction / Q000276:immunology*; D013269:Stochastic Processes
chemical_list: D007155:Immunologic Factors