In addition, this drug--a methylation inhibitor called zebularine--is better at inhibiting cell growth and promoting gene expression in cancer cells, notes Peter Jones, Ph.D., director of the USC/Norris Comprehensive Cancer Center and the principal investigator on the study. In a study of zebularine's effect on the rate of division of cancer cells, Jones and colleagues showed that zebularine slows growth by as much as 68 percent in cancer cells, but only by 21 percent or less in normal cells.
These findings were reported in the August 2004 issue of Cancer Cell.
Only recently have scientists begun to recognize the important role that DNA methylation--the addition of a methyl group to a stretch of DNA, which can lock, or silence, that gene--can play in the development of cancer. If methylation silences a gene that normally would control cell growth or prompt the cell to commit suicide, then the cell will grow unchecked--the hallmark of cancer.
The good news: Methylation--and its effects--can be reversible. Enter the emerging field of epigenetic therapy, in which methylation inhibitors are currently playing a starring role.
"The concept that the silencing of genes is a critical part of the cancer process is a major conceptual advance in this field," Jones says. "Realizing that, it becomes very important to find keys to unlock those silenced genes."
In the Cancer Cell study, Jones, Cheng and graduate student Christine Yoo--along with colleagues from the National Cancer Institute, the University of Miami School of Medicine, and Aarhus University Hospital in Denmark--looked at the effects zebularine had on a panel of sev
Contact: Sarah Huoh
University of Southern California