Keratinocyte transglutaminase expression varies in squamous cell carcinomas

J Invest Dermatol. 1994 Apr;102(4):462-9. doi: 10.1111/1523-1747.ep12373021.


Type I transglutaminase (TGase I, keratinocyte or particulate transglutaminase) is a 92-kilodalton (kDa) protein expressed in abundance in cultured keratinocytes and in the hyperproliferative skin disorder psoriasis. To determine the expression of TGase I protein and mRNA, we studied tissue and established squamous carcinoma lines derived from different sources. Immunohistochemistry and Western blotting were used to detect TGase I protein with the B.C1 mouse monoclonal antibody. Only well-differentiated, skin-derived squamous carcinomas stained for TGase I. However, a precocious pattern of expression was seen overlying less-differentiated tumors. Compared to cultured human keratinocytes, squamous cell carcinoma (SCC) had many times less to 7.8 times more TGase I protein, greatest in the two most differentiated tumor lines 14-83 and ME-180. TGase I mRNA levels ranged from 0.010 to 0.00004 pg/microgram total RNA by reverse transcriptase-polymerase chain reaction using an internal standard. Protein expression correlated with mRNA levels in most SCC lines. When a human TGase I promoter was isolated and used to study genomic DNA, SCC1-83 was shown to have unique restriction enzyme fragments, including one indicative of methylation differences, also present within DNA from the KB line. These studies suggest that transcriptional control of TGase I gene expression in squamous carcinomas may be influenced both by cis elements in the promoter and by the degree of tumor squamous differentiation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Alleles
  • Base Sequence
  • Blotting, Northern
  • Blotting, Southern
  • Carcinoma, Squamous Cell / enzymology*
  • Carcinoma, Squamous Cell / genetics
  • Humans
  • Immunohistochemistry
  • KB Cells
  • Keratinocytes / enzymology*
  • Molecular Sequence Data
  • Polymerase Chain Reaction / methods
  • RNA, Messenger / analysis
  • Skin Neoplasms / enzymology*
  • Skin Neoplasms / genetics
  • Transglutaminases / analysis*
  • Transglutaminases / genetics


  • RNA, Messenger
  • Transglutaminases