6533b872fe1ef96bd12d43d3

RESEARCH PRODUCT

Involvement of the transcription factor FoxM1 in contact inhibition

Firas Al-butmehDagmar FaustBerenike LinzCornelia Dietrich

subject

MAPK/ERK pathwayCyclin ABiophysicsDown-RegulationCell Cycle ProteinsCyclin AProtein Serine-Threonine KinasesBiochemistryMiceDownregulation and upregulationProto-Oncogene ProteinsAnimalsPhosphorylationRNA Small InterferingExtracellular Signal-Regulated MAP KinasesMolecular BiologyTranscription factorTissue homeostasisbiologyContact InhibitionKinaseForkhead Box Protein M1Contact inhibitionForkhead Transcription FactorsCell BiologyG1 Phase Cell Cycle CheckpointsCell biologyNIH 3T3 Cellsbiology.proteinEctopic expression

description

Contact inhibition is a crucial mechanism regulating proliferation in vitro and in vivo. Although it is generally accepted that contact inhibition plays a pivotal role in maintaining tissue homeostasis, the molecular mechanisms of contact inhibition are still not fully understood. FoxM1 is known as a proliferation-associated transcription factor and is upregulated in many cancer types. Vice versa, anti-proliferative signals, such as TGF-β and differentiation signals decrease FoxM1 expression. Here we investigated the role of FoxM1 in contact inhibition in fibroblasts. We show that protein expression of FoxM1 is severely and rapidly downregulated upon contact inhibition, probably by inhibition of ERK activity, which then leads to decreased expression of cyclin A and polo-like kinase 1. Vice versa, ectopic expression of FoxM1 prevents the decrease in cyclin A and polo-like kinase 1 and causes a two-fold increase in saturation density indicating loss of contact inhibition. Hence, we show that downregulation of FoxM1 is required for contact inhibition by regulating expression of cyclin A and polo-like kinase 1.

yearjournalcountryeditionlanguage
2012-10-01Biochemical and Biophysical Research Communications
https://doi.org/10.1016/j.bbrc.2012.09.013