| Abstract: |
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/μg 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, SCC 1-83 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. © 1994. |
| Keywords: |
immunohistochemistry; clinical article; controlled study; human tissue; squamous cell carcinoma; carcinoma, squamous cell; polymerase chain reaction; gene expression; skin neoplasms; epidermis; skin cancer; alleles; keratinocyte; molecular sequence data; rna, messenger; base sequence; molecular biology; keratinocytes; blotting, northern; blotting, southern; epidermal differentiation; human; priority journal; article; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; kb cells; protein glutamine gamma glutamyltransferase; transglutaminases; cornified envelope
|
