Bacterial Protein Presents Clues to Treating Cancer

Author:  Falishia Sloan

Institution:  Eastern Virginia Medical School
Date:  July 2007

Researchers at the University of Central Florida have discovered that a protein present in the bacterial pathogen Listeria monocytogenes induces the internalization and degradation of a human receptor known to be involved in the development of certain cancers. This research, led by Lisa A Elferink of the University of Texas Medical Branch, could lead to a better understanding of cancer treatments.

"We found that Listeria actually provokes' human epithelial cells (cells lining the small intestine) into ingesting bacteria," one of the participants in the study, University of Central Florida Microbiology Professor Keith Ireton, explained. "When Listeria contacts an epithelial cell, the bacterium causes changes in the cell's cytoskeleton' that allow the cell to swallow up the bacterium. We discovered that a human protein called CrkII plays a critical role in stimulating internalization of Listeria by somehow controlling the cytoskeleton."

The researchers found that the ability of a protein found in L. monocytogenes, called InIB, to induce the degradation and internalization of the human receptor known as Met is due to a human protein called Cbl. Met has been implicated in the development of some cancers, and scientists hope that by discovering how to manage Met, they will be able to develop drugs to destroy the receptor and the cancers it helps develop.

Ireton is an expert on L. monocytogenes, including how the bacterium, known for causing food poisoning, enters human body cells. Listeria can be dangerous, and, in some cases, deadly. It has been known to induce abortions in pregnant women and meningitis in those with compromised immune systems.

Written by Falishia Sloan