ABSTRACT: The Forkhead family of transcription factors comprises numerous members and is implicated in various cellular functions, including cell growth, apoptosis, migration and differentiation.In this study we identified the Forkhead factor FoxQ1 as increased in expression during TGF-beta1 induced changes in epithelial differentiation, suggesting functional roles of FoxQ1 for epithelial plasticity.The repression of FoxQ1 in mammary epithelial cells led to a change in cell morphology characterized by an increase in cell size, pronounced cell-cell contacts and an increased expression of several junction proteins (e.g. E-cadherin). In addition, FoxQ1 knock-down cells revealed rearrangements in the actin-cytoskeleton and slowed down cell cycle G1-phase progression.Furthermore, repression of FoxQ1 enhanced the migratory capacity of coherent mammary epithelial cells.Gene expression profiling of NM18 cells indicated that FoxQ1 is a relevant downstream mediator of TGF-beta1 induced gene expression changes. This included the differential expression of transcription factors involved in epithelial plasticity, e.g. Ets-1, Zeb1 and Zeb2.In summary, this study has elucidated the functional impact of FoxQ1 on epithelial differentiation Cells treated with 200µM 4sU for 2h, biological replicate 1:2h_co._total1, Cells treated with 200µM 4sU for 2h, biological replicate 2:2h_co._total2, Cells treated with 200µM 4sU for 2h, biological replicate 3 :2h_co._total3, Cells treated with 200µM 4sU for 2h and enriched for 4sU labelled RNA, biological replicate 1: 2h_co._enriched1, Cells treated with 200µM 4sU for 2h and enriched for 4sU labelled RNA, biological replicate 2: 2h_co._enriched2, Cells treated with 200µM 4sU for 2h and enriched for 4sU labelled RNA, biological replicate 3:2h_co._enriched3, Cells treated with 5 ng/ml TGF-b1 and 200µM 4sU for 2h, biological replicate 1:2h_TGFbeta_total1, Cells treated with 5 ng/ml TGF-b1 and 200µM 4sU for 2h, biological replicate 2:2h_TGFbeta_total2, Cells treated with 5 ng/ml TGF-b1 and 200µM 4sU for 2h, biological replicate 3:2h_TGFbeta_total3, Cells treated with 5 ng/ml TGF-b1 and 200µM 4sU for 2h and enriched for 4sU labelled RNA, biological replicate 1:2h_TGFbeta_enriched1, Cells treated with 5 ng/ml TGF-b1 and 200µM 4sU for 2h and enriched for 4sU labelled RNA, biological replicate 2:2h_TGFbeta_enriched2, Cells treated with 5 ng/ml TGF-b1 and 200µM 4sU for 2h and enriched for 4sU labelled RNA, biological replicate 3:2h_TGFbeta_enriched3, FoxQ1 dataset Cells transfected with 25nm scrambled siRNA for 48hrs, biological replicate 1:ns-siRNA 48hrs 1, Cells transfected with 25nm scrambled siRNA for 48hrs, biological replicate 2:ns-siRNA 48hrs 2, Cells transfected with 25nm scrambled siRNA for 48hrs, biological replicate 3:ns-siRNA 48hrs 3, Cells transfected with 25nm scrambled siRNA for 48hrs and treated with TGF-b1 for 40hrs biological replicate 1:ns-siRNA 48hrs TGF-b1 40hrs 1, Cells transfected with 25nm scrambled siRNA for 48hrs and treated with TGF-b1 for 40hrs biological replicate 2:ns-siRNA 48hrs TGF-b1 40hrs 2, Cells transfected with 25nm scrambled siRNA for 48hrs and treated with TGF-b1 for 40hrs biological replicate 3:ns-siRNA 48hrs TGF-b1 40hrs 3, Cells transfected with 25nm FoxQ1 siRNA for 48hrs and treated with TGF-b1 for 40hrs biological replicate 1:FoxQ1 siRNA 48hrs TGF-b1 40hrs 1, Cells transfected with 25nm FoxQ1 siRNA for 48hrs and treated with TGF-b1 for 40hrs biological replicate 2:FoxQ1 siRNA 48hrs TGF-b1 40hrs 2 Cells transfected with 25nm FoxQ1 siRNA for 48hrs and treated with TGF-b1 for 40hrs biological replicate 3:FoxQ1 siRNA 48hrs TGF-b1 40hrs 3
