Telomerase activity of the Lugol-stained and -unstained squamous epitheliain the process of oesophageal carcinogenesis

Up-regulation of telomerase has been reported in many cancers. Our aim was to characterize telomerase activity in various states of the oesophagus to facilitate better understanding of carcinogenesis of oesophageal squamous c ell carcinoma. During endoscopic examinations, we obtained 45 Lugol-stained normal epithelia, 31 Lugol-unstained epithelia (14 oesophagitis, 7 mild dy splasia, 5 severe dysplasia and 5 intramucosal cancer) and 9 advanced cance r. Telomerase activity was semi-quantified by a telomeric repeat amplificat ion protocol using enzyme-linked immunosorbent assay, and expression of hum an telomerase reverse transcriptase mRNA was examined by in situ hybridizat ion. In the Lugol-stained normal epithelia, telomerase activity increased i n proportion to the increase of severity of the accompanying lesions, with a rank order of advanced cancer, intramucosal cancer, mild dysplasia and oe sophagitis. In the Lugol-unstained lesions and advanced cancer, telomerase activity was highest in advanced cancer. Up-regulation of telomerase in nor mal squamous epithelium may be a marker of progression of oesophageal squam ous cell carcinoma. (C) 2001 Cancer Research Campaign http://www.bicancer.c om.