UCF RESEARCHER UNCOVERS CANCER LINKS

A University of Central Florida researcher has uncovered an ancient protein that could be a critical link to stopping the uncontrolled division of tumor cells that are the basis of cancer.

The work by Mark T. Muller, a professor in UCF’s Department of Molecular Biology and Microbiology, and In Kwong Chung and colleagues at Yonsei University in Seoul, Korea, was published in the April 15 issue of Genes & Development.

The researchers have found that the protein, called MKRN1, promotes the destruction of an enzyme called telomerase that enables the rapid duplication of cells. While researchers have known for years that healthy cells repress telomerase, they haven’t understood why.

The discovery is sure to generate excitement in the research community, said Lee F. Johnson, chair of the Department of Molecular Genetics at The Ohio State University and an authority in gene expression in mammalian cells.

“To the best of my knowledge, this is the first example of how the enzyme (telomerase) itself can be turned off,” Johnson said.

The work focuses on the role that a long stretch of repeated DNA known as a telomere has in influencing cell length and, in turn, its lifespan. Each of the human’s 46 chromosomes is capped on either end by telomeres, which help protect the cells. Each time a cell divides, the telomeres are shortened until eventually they become so small that the cell stops multiplying and is eventually eliminated from the body.

When telomere ends do not shorten, division continues unabated. The body contains other mechanisms that kick in to stop the errant reproduction unless the telomerase enzyme is present. In laboratory tests, the MKRN1 protein as eliminated the presence of telomerase in tumor cells, said Muller, who conducted genetic research at The Ohio Sate University for 25 years before joining UCF last summer.

Muller said that the MKRN1 gene is incredibly ancient and has likely been part of the human genetic makeup since the beginning of time. “Many different species have these genes which emphasizes important collective roles in life” Muller stated. “Moreover, mutating or altering the MKRN1 gene is lethal, thus, cells cannot live without these genes, further supporting a key role in growth control and cancer.”

mmuller@mail.ucf.edu