trefoil factor 1; protein pS2; polypeptide P1.A; hP1.A; breast cancer estrogen-inducible protein; PNR-2 (TFF1, BCEI, PS2)

Function

• stabilizer of the mucous gel overlying the gastrointestinal mucosa that provides a physical barrier against various noxious agents
• may inhibit the growth of Ca+2 oxalate crystals in urine
• heterodimer with GKN2; disulfide linked

Structure

contains 1 P-type (trefoil) domain

Compartment

secreted

Expression

• found in stomach, with highest levels in the upper gastric mucosal cells (at protein level)
• detected in goblet cells of the small & large intestine & rectum, small submucosal glands in the esophagus, mucous acini of the sublingual gland, submucosal glands of the trachea, & epithelial cells lining the exocrine pancreatic ducts but not in the remainder of the pancreas (at protein level)
• scattered expression is detected in the epithelial cells of the gallbladder & submucosal glands of the vagina
• weak expression is observed in the bronchial goblet cells of pseudostratified epithelia in the respiratory system (at protein level)
• detected in urine (at protein level)
• strongly expressed in breast cancer but at low levels in normal mammary tissue
• regulated by estrogen in MCF-7 cells
• strong expression found in normal gastric mucosa & in the regenerative tissues surrounding ulcerous lesions of gastrointestinal tract, but lower expression found in gastric cancer (at protein level)

Pathology

• expressed in a number of carcinomas including:
  • breast carcinoma (50%)
  • pancreatic carcinoma (70-75%)
  • gastric carcinoma (50-55%)
  • colorectal carcinoma (58%)

More general terms

• secreted protein
• growth factor

Database

• UniProt: http://www.uniprot.org/uniprot/P04155.html
• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=7031
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:7031
• OMIM: https://mirror.omim.org/entry/113710