Project description:Intracellular pH (pHi) dynamics regulates diverse cell processes such as proliferation, dysplasia, and differentiation, often mediated by the protonation state of a functionally critical histidine residue in endogenous pH sensing proteins. How pHi dynamics can directly regulate gene expression and whether transcription factors can function as pH sensors has received limited attention. We tested the prediction that transcription factors with a histidine in their DNA binding domain (DBD) that forms hydrogen bonds with nucleotides can have pH-regulated activity, which is relevant to more than 85 transcription factors in distinct families, including FOX, KLF, SOX and MITF/Myc. Focusing on FOX family transcription factors, we used unbiased SELEX-seq to identify pH-dependent DNA binding motif preferences, then confirm pH-regulated binding affinities for FOXC2, FOXM1, and FOXN1 to a canonical FkhP DNA motif that are 2.5 to 7.5 greater at pH 7.0 compared with pH 7.5. For FOXC2, we also find greater activity for an FkhP motif at lower pHi in cells and that pH-regulated binding and activity are dependent on a conserved histidine (His122) in the DBD. RNA-seq with FOXC2 also reveals pH-dependent differences in enriched promoter motifs. Our findings identify pH-regulated transcription factor-DNA binding selectivity with relevance to how pHi dynamics can regulate gene expression for myriad cell behaviours.
Project description:Intracellular pH (pHi) dynamics regulates diverse cell processes such as proliferation, dysplasia, and differentiation, often mediated by the protonation state of a functionally critical histidine residue in endogenous pH sensing proteins. How pHi dynamics can directly regulate gene expression and whether transcription factors can function as pH sensors has received limited attention. We tested the prediction that transcription factors with a histidine in their DNA binding domain (DBD) that forms hydrogen bonds with nucleotides can have pH-regulated activity, which is relevant to more than 85 transcription factors in distinct families, including FOX, KLF, SOX and MITF/Myc. Focusing on FOX family transcription factors, we used unbiased SELEX-seq to identify pH-dependent DNA binding motif preferences, then confirm pH-regulated binding affinities for FOXC2, FOXM1, and FOXN1 to a canonical FkhP DNA motif that are 2.5 to 7.5 greater at pH 7.0 compared with pH 7.5. For FOXC2, we also find greater activity for an FkhP motif at lower pHi in cells and that pH-regulated binding and activity are dependent on a conserved histidine (His122) in the DBD. RNA-seq with FOXC2 also reveals pH-dependent differences in enriched promoter motifs. Our findings identify pH-regulated transcription factor-DNA binding selectivity with relevance to how pHi dynamics can regulate gene expression for myriad cell behaviours.
Project description:The FOXC2 transcription factor regulates a variety of developmental and biological processes in both embryonic and adult tissues. Importantly, overexpression or dysregulation of FOXC2 is also associated with oncogenic activity in numerous cancer types, though the function of FOXC2 in the context of melanoma has not been previously investigated. Therefore, the goal of this study was to assess FOXC2's regulation of gene expression in melanoma cells. To this end, we employed CRISPR-Cas9 gene editing technology to disrupt the Foxc2 gene in B16-F1 melanoma, and we performed RNA-seq analysis to assess differential gene expression between the wild-type B16-F1 melanoma cell line and our novel FOXC2-deficient B16-F1ΔFOXC2 gene-edited variant cell line.
Project description:Investigation of whole genome gene expression level changes in a colorectal cancer cell line SW480 expressing FOXC2, compared to the pBabe control cells. Genes associated with metastasis regulated by FOXC2 in colorectal cancer were analysed. The role of FOXC2 in breast cancer metastasis are further described in Mani SA, Yang J et al. Mesenchyme Forkhead 1 (FOXC2) plays a key role in metastasis and is associated with aggressive basal-like breast cancers. PNAS 2007; 104: 10069-10074 . A six chip study using total RNA recovered from three separate cultures of SW480/pBabe and three separate cultures of SW480/FOXC2. Each chip measures the expression level of 45033 genes from SW480/pBabe or SW480/FOXC2.
Project description:Investigation of whole genome gene expression level changes in a colorectal cancer cell line SW480 expressing FOXC2, compared to the pBabe control cells. Genes associated with metastasis regulated by FOXC2 in colorectal cancer were analysed. The role of FOXC2 in breast cancer metastasis are further described in Mani SA, Yang J et al. Mesenchyme Forkhead 1 (FOXC2) plays a key role in metastasis and is associated with aggressive basal-like breast cancers. PNAS 2007; 104: 10069-10074 .
Project description:To determine gene expression changes in vasculogenic mimicry competent human breast cancer cells with loss of FOXC2 we performed RNA-seq of MDA-MB-231 cells with FOXC2 knockdown.
Project description:Foxc1 and Foxc2 are highly expressed in adult podocytes. To bypass embryonic lethality of Foxc1 and Foxc2 KO, mice ubiquitously expressing inducible-Cre (ROSA26-CreERT2) were mated with floxed-Foxc1 and floxed-Foxc2 mice. We used microarrays to detail effects of deletions of Foxc1 and Foxc2 on podocyte gene expression profiles in adult podocyte in vivo and in vitro.
Project description:We used microarrays to investigate the transcription profile of FOXC2 expression in a human mammary epithelial cell line. HMLER cells were infected with either a control vector or a retroviral vector expressing FOXC2.