Hypomethylation of DNA from Benign and Malignant Human Colon Neoplasms

TLDR

The study used restriction endonuclease analysis and gene‑specific probes to assess DNA methylation in 23 human colon neoplasms. Both benign polyps and malignant carcinomas showed substantial hypomethylation compared to adjacent normal tissue, indicating that hypomethylation is a consistent early biochemical hallmark of colonic tumors.

Abstract

The methylation state of DNA from human colon tissue displaying neoplastic growth was determined by means of restriction endonuclease analysis. When compared to DNA from adjacent normal tissue, DNA from both benign colon polyps and malignant carcinomas was substantially hypomethylated. With the use of probes for growth hormone, γ-globin, α-chorionic gonadotropin, and γ-crystallin, methylation changes were detected in all 23 neoplastic growths examined. Benign polyps were hypomethylated to a degree similar to that in malignant tissue. These results indicate that hypomethylation is a consistent biochemical characteristic of human colonic tumors and is an alteration in the DNA that precedes malignancy.