title: The universal growth rate behavior and regime transition in adherent cell colonies.
abstract: In this work, we used five cell lineages, cultivated in vitro, to show they follow a common functional form to the growth rate: a sigmoidal curve, suggesting that competition and cooperation (usual mechanisms for systems with this behavior) might be present. Both theoretical and experimental investigations, on the causes of this behavior, are challenging for the research field; since the sigmoidal form to the growth rate seems to absorb important properties of such systems, e.g., cell deformation and statistical interactions. We shed some light on this subject by showing how cell spreading affects the radius behavior of the growing colonies. Doing numerical time derivatives of the experimental data, we obtained the growth rates. Using reduced variables for the time and rates, we obtained the collapse of all colonies growth rates onto one curve with sigmoidal shape. This suggests a universal-type behavior, with regime transition related to a morphological transition of adherent cell colonies.
authors.affiliation: Departamento de Física, FFCLRP; Universidade de São Paulo, 14040-901; Ribeirão Preto, São Paulo, Brazil. Electronic address: fhscosta@usp.br.
authors.forename: F H S
authors.initials: FH
authors.lastname: Costa
authors.affiliation: Departamento de Química e Ciências Ambientais, IBILCE, Universidade Estadual Paulista Júlio de Mesquita Filho, 15054-000 São José do Rio Preto, São Paulo, Brazil.
authors.forename: M
authors.initials: M
authors.lastname: Campos
authors.affiliation: Departamento de Física, FFCLRP; Universidade de São Paulo, 14040-901; Ribeirão Preto, São Paulo, Brazil; Departamento de Física e Química, FCFRP; Universidade de São Paulo, 14040-903; Ribeirão Preto, São Paulo, Brazil. Electronic address: maasilva@fcfrp.br.
authors.forename: M A A
authors.initials: MA
authors.lastname: da Silva
mesh_terms: D000818:Animals; D002448:Cell Adhesion; D045744:Cell Line, Tumor; D048430:Cell Shape; D006801:Humans; D051379:Mice; D008954:Models, Biological; D013997:Time Factors
keywords: Cancer; Growth rate; Mathematical model