Aim: To investigate the alteration of molecular events and the early carcinogenesis mechanism of esophageal epithelial cells in the high incidence area of esophageal cancer.
Methods: Esophageal epithelial cells of esophageal cancer patients were collected from the high incidence area in China. Content of DNA and telomerase as well as multi-gene expressions such as p53, p21 and cyclin D1 in esophageal precancer cells were quantitatively analysed by flow cytometry (FCM) with indirect immunofluorescence technique and DNA propidium iodide fluorescence staining.
Results: FCM analysis results showed the DNA content increased significantly and the heteroploid rate was 87.9% in occurred carcinogenesis. P53 protein accumulation and ras p21 increase were seen in the early carcinogenesis of the esophagus. The positive rate of p53 and ras p21 was 100% (5/5, 4/4 respectively) in the cancer group. Telomerase and oncogene cyclin D1 were over- expressed in all of the cancer patients.
Conclusion: Increased DNA content and heteroploid rate, accumulation of p53 protein, and over-expression of p21, telomerase and cyclin D1 proteins were early molecular events during the development of esophageal cancer.