Forkhead box C1, also known as FOXC1, is a

protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...

which in humans is encoded by the ''FOXC1''

gene In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a b ...

Function

This gene belongs to the forkhead family of

transcription factor In molecular biology, a transcription factor (TF) (or sequence-specific DNA-binding factor) is a protein that controls the rate of transcription of genetic information from DNA to messenger RNA, by binding to a specific DNA sequence. The f ...

s which is characterized by a distinct DNA-binding

fork head domain The fork head domain is a type of protein domain that is often found in transcription factors and whose purpose is to bind DNA. Function The fork head protein of ''Drosophila melanogaster'', a transcription factor that promotes terminal rath ...

. The specific function of this gene has not yet been determined; however, it has been shown to play a role in the regulation of embryonic and ocular development.

Heart development and somitogenesis

FOXC1 and its close relative,

FOXC2 Forkhead box protein C2 (FOXC2) also known as forkhead-related protein FKHL14 (FKHL14), transcription factor FKH-14, or mesenchyme fork head protein 1 (MFH1) is a protein that in humans is encoded by the ''FOXC2'' gene. FOXC2 is a member of the ...

are both critical components in the development of the heart and blood vessels, as well as the segmentation of the paraxial mesoderm and the formation of somites. Expression of the Fox proteins range from low levels in the posterior pre-somitic mesoderm (PSM) to the highest levels in the anterior PSM. Homozygous mutant embryos for both Fox proteins failed to form somites 1-8, which indicates the importance of these proteins early on in somite development. In cardiac morphogenesis, FOXC1 and FOXC2 are required for the proper development of the cardiac outflow tract. The outflow tract forms from a cell population known as the secondary heart field. The Fox proteins are transcribed in the secondary heart field where they regulate the expression of key signaling molecules such as

Fgf8 Fibroblast growth factor 8 (FGF-8) is a protein that in humans is encoded by the ''FGF8'' gene. Function The protein encoded by this gene is a member of the fibroblast growth factor (FGF) family. FGF family members possess broad mitogenic an ...

, Fgf10,

Tbx1 T-box transcription factor TBX1 also known as T-box protein 1 and testis-specific T-box protein is a protein that in humans is encoded by the TBX1 gene. Genes in the T-box family are transcription factors that play important roles in the formation ...

, Isl1, and

Bmp4 Bone morphogenetic protein 4 is a protein that in humans is encoded by ''BMP4'' gene. BMP4 is found on chromosome 14q22-q23. BMP4 is a member of the bone morphogenetic protein family which is part of the transforming growth factor-beta superfamil ...

Clinical significance

Mutations in this gene cause various

glaucoma Glaucoma is a group of eye diseases that result in damage to the optic nerve (or retina) and cause vision loss. The most common type is open-angle (wide angle, chronic simple) glaucoma, in which the drainage angle for aqueous humor, fluid withi ...

phenotypes including primary congenital glaucoma, autosomal dominant iridogoniodysgenesis anomaly, and

Axenfeld–Rieger syndrome Axenfeld–Rieger syndrome is a rare autosomal dominant disorder, which affects the development of the teeth, eyes, and abdominal region. Axenfeld–Rieger syndrome is part of the so-called iridocorneal or anterior segment dysgenesis syndromes, ...

type 3. FOXC1 mutations are also found in association with

Dandy–Walker malformation Dandy–Walker malformation (DWM), also known as Dandy–Walker syndrome (DWS), is a rare congenital brain malformation in which the part joining the two hemispheres of the cerebellum (the cerebellar vermis) does not fully form, and the fourth ...

Role in cancer

FOXC1 induces the epithelial to mesenchymal transition (EMT), which is a process where epithelial cells separate from surrounding cells and begin migration. This process is involved in metastasis, giving FOXC1 a crucial role in cancer. The over expression of FOXC1 results in the up-regulation of

fibronectin Fibronectin is a high- molecular weight (~500-~600 kDa) glycoprotein of the extracellular matrix that binds to membrane-spanning receptor proteins called integrins. Fibronectin also binds to other extracellular matrix proteins such as coll ...

vimentin Vimentin is a structural protein that in humans is encoded by the ''VIM'' gene. Its name comes from the Latin ''vimentum'' which refers to an array of flexible rods. Vimentin is a type III intermediate filament (IF) protein that is expresse ...

, and

N-cadherin Cadherin-2 also known as Neural cadherin (N-cadherin), is a protein that in humans is encoded by the ''CDH2'' gene. CDH2 has also been designated as CD325 (cluster of differentiation 325). Cadherin-2 is a transmembrane protein expressed in multip ...

, which contribute to cellular migration in nasopharyngeal carcinoma (NPC). The knockout of FOXC1 in human NPC cells down-regulated vimentin, fibronectin, and N-cadherin expression. FOXC1 transcription factor regulates EMT in basal-like breast cancer (BLBC). Activation of SMO-independent Hedgehog signaling by FOXC1 alters the cancer stem cell (CSC) properties in BLBC cells. These CSCs, which are regulated by FOXC1 signaling, contribute to tumor proliferation, tissue invasion, and relapse.

References

External links

* {{Transcription factors, g3 Forkhead transcription factors