Image cytometry DNA analysis of diethylnitrosamine-induced dysplasias and invasive squamous cell carcinomas of the esophagus in mice.

The nuclear DNA content was assessed by image cytometry in squamous epithelial dysplasias and invasive squamous cell carcinomas of the esophagus induced by diethylnitrosamine (DEN) in mice. The study comprises 48 lesions: 27 lesions with low grade (i.e. slight and moderate) dysplasia, 18 with high grade dysplasia (i.e. severe dysplasia and CIS), and 3 with invasive squamous cell carcinoma. In addition, 5 parallel run control specimens were also investigated. The results demonstrated that only 3.7% (or 1/27) low grade dysplasias but as much as 72.2% (or 13/18) high grade dysplasias, and all three invasive squamous cell carcinomas displayed non-diploid DNA values. Three of 18 high grade dysplasias and all three invasive squamous cell carcinomas demonstrated aneuploid cell nuclei. The results of the present work indicate that the esophageal mucosa of the mouse permit investigation--under controlled conditions--of the nuclear DNA alterations occurring during carcinogenesis in this organ. The results presented herein thus substantiate the theory of increasing DNA aberrations occurring during carcinogenesis in the human esophagus.