Telomere metabolism and diagnostic demonstration of telomere measurement in the human esophagus for distinguishing benign from malignant tissue by tissue quantitative fluorescence in situ hybridization

Abstract

Objective: We have developed a novel method for evaluating telomere length in four different cell types in non-cancerous and cancerous mucosal tissue from 15 cases of squamous cell carcinoma of the esophagus using tissue quantitative fluorescence in situ hybridization (Q-FISH). We hypothesized that the very rapid cell proliferation observed in esophageal squamous cell carcinomas might accelerate the telomere shortening and chromosomal instability associated with carcinogenesis.

Methods: Tissue Q-FISH and the telomere to centromere intensity ratio (TCR) were used to compare telomere shortening in tissue sections taken from esophageal squamous cell carcinomas and adjacent non-cancerous esophageal tissues.

Results: The peak percentage of TCR was <1 for esophageal squamous carcinoma cells and >1 for the non-cancerous esophageal cell types. Basal layer cells had the longest telomeres in comparison with prickle, cancer, and stromal cells, and strongly expressed hTERT, cytokeratin 14 and CD49f, but not MIB-1.

Conclusion: These results suggest the presence of stem cells in the basal layer of the esophagus. Esophageal squamous cell carcinomas also display anaphase bridges, evidencing chromosomal instability. In conclusion, our TCR method can be used to distinguish between benign and malignant tissue in esophageal lesions. In order to apply this approach clinically to individual cases, further studies are in progress.