Fragile histidine triad (FHIT) gene deletion, methylation, and reduced Fhit protein expression occur in about 70% of human epithelial tumors and are clearly associated with tumor progression.
Loss of the FHIT protein because of the alteration or loss of heterozygosity by genetic deletion occurs in a variety of epithelial tumors including head and neck cancer.
The expression of two tumor suppressor genes, fragile histidine triad (FHIT) and WW domain containing oxidoreductase (WWOX), encompassing common chromosome fragile regions, FRA3B at 3p14.2 and FRA16D at 16q23, is altered in many epithelial tumors.
Through investigation of hemizygous and homozygous deletions in common human cancers, including lung cancer, we have cloned and characterized a gene at chromosome region 3p14.2, FHIT, that is inactivated in epithelial tumors, particularly in tumors resulting from exposure to environmental carcinogens.
Abnormal FHIT gene expression has been reported in a variety of epithelial tumors shown to harbor deletions of chromosome 3p14, the chromosomal assignment of this gene.