Biology:TOX3

From HandWiki
Short description: Mammalian protein found in Homo sapiens
TOX high mobility group box family member 3
Identifiers
SymbolTOX3
Alt. symbolsTNRC9, CAGF9
NCBI gene27324
HGNC11972
OMIM611416
RefSeqXM_049037
UniProtO15405
Other data
LocusChr. 16 q12.1

TOX high mobility group box family member 3, also known as TOX3, is a human gene.[1][2]

The protein encoded by this gene is a member of a subfamily of transcription factors that also includes TOX, TOX2, and TOX4 that share almost identical HMG-box DNA-binding domains which function to modify chromatin structure by unwinding and bending DNA.[3] The protein TOX3 has a glutamine-rich C-terminus due to CAG repeats.[4] TOX3 is located on human chromosome band 16q12.1.[5] The gene consists of seven exons and is highly expressed in both the brain and luminal epithelial breast tissue.[6] Mutations in the gene are associated with increased susceptibility to breast cancer.[2] TOX3 plays a role in regulating calcium-dependent transcription and interacts with cAMP-response-element-binding protein (CREB) and CREB-binding protein (CBP).[7] It also increases transcription via interaction with CITED1, a transcription co-regulator that increases transcription factor activity.[7]

Disease linkage

Mutations in the TOX3 gene are associated with an increased risk of breast cancer.[1][2][8][9]

The risk allele rs3803662 is a low-penetrance SNP (single nucleotide polymorphism) associated with decreased expression of TOX3 and an increase in breast cancer risk.[7] The risk locus was reported to regulate affinity of FOXA1 binding to chromatin, potentially affecting TOX3 expression.[6] This locus also interacts with high-penetrance mutations BRCA1 and BRCA2 to increase risk.[10] The rs3803662 variant has a high frequency in the population, with a minor allele frequency of 0.25.[11]

Little is known of the transcriptional mechanisms and protein interactions of TOX3. However, a 2019 publication identified TOX3 as a cancer suppressor gene in clear cell renal cell carcinoma (ccRCC) and reported that downregulation of TOX3 facilitates the epithelial mesenchymal transition by decreasing repression of SNAI1 and SNAI2, resulting in tumor growth and metastasis.[12] Like breast cancer, downregulation of TOX3 is associated with worse prognosis in ccRCC patients.[12]

References

  1. 1.0 1.1 "Genes associated with breast cancer metastatic to bone". Journal of Clinical Oncology 24 (15): 2261–7. May 2006. doi:10.1200/JCO.2005.03.8802. PMID 16636340. 
  2. 2.0 2.1 2.2 "Genome-wide association study identifies novel breast cancer susceptibility loci". Nature 447 (7148): 1087–93. June 2007. doi:10.1038/nature05887. PMID 17529967. Bibcode2007Natur.447.1087E. 
  3. "TOX defines a conserved subfamily of HMG-box proteins". BMC Genomics 4 (1): 13. April 2003. doi:10.1186/1471-2164-4-13. PMID 12697058. 
  4. "TOX3 TOX high mobility group box family member 3 [Homo sapiens (human)"]. Gene - NCBI. National Center for Biotechnology Information (NCBI), U.S. National Library of Medicine. https://www.ncbi.nlm.nih.gov/gene/?term=27324. 
  5. "TOX3 (TOX high mobility group box family member 3)". Atlas of Genetics and Cytogenetics in Oncology and Haematology. http://atlasgeneticsoncology.org/Genes/GC_TOX3.html. 
  6. 6.0 6.1 "TOX3 mutations in breast cancer". PLOS ONE 8 (9): e74102. 2013. doi:10.1371/journal.pone.0074102. PMID 24069272. Bibcode2013PLoSO...874102J. 
  7. 7.0 7.1 7.2 "The risk allele of SNP rs3803662 and the mRNA level of its closest genes TOX3 and LOC643714 predict adverse outcome for breast cancer patients". BMC Cancer 12: 621. December 2012. doi:10.1186/1471-2407-12-621. PMID 23270421. 
  8. "Common variants on chromosomes 2q35 and 16q12 confer susceptibility to estrogen receptor-positive breast cancer". Nature Genetics 39 (7): 865–9. July 2007. doi:10.1038/ng2064. PMID 17529974. 
  9. "Common breast cancer-predisposition alleles are associated with breast cancer risk in BRCA1 and BRCA2 mutation carriers". American Journal of Human Genetics 82 (4): 937–48. April 2008. doi:10.1016/j.ajhg.2008.02.008. PMID 18355772. 
  10. "OMIM Entry - * 611416 - TOX HIGH MOBILITY GROUP BOX FAMILY MEMBER 3; TOX3". Online Mendelian Inheritance in Man (OMIM). https://www.omim.org/entry/611416. 
  11. "Genetic susceptibility to breast cancer". Molecular Oncology 4 (3): 174–91. June 2010. doi:10.1016/j.molonc.2010.04.011. PMID 20542480. 
  12. 12.0 12.1 "TOX3 inhibits cancer cell migration and invasion via transcriptional regulation of SNAI1 and SNAI2 in clear cell renal cell carcinoma". Cancer Letters 449: 76–86. May 2019. doi:10.1016/j.canlet.2019.02.020. PMID 30772441.