COLUMBUS , Ohio New research shows how a particular small molecule blocks the activity of a cancer-suppressing gene, allowing liver-cancer cells to grow and spread.
This molecule is a microRNA, a recently discovered class of tiny molecules used by cells to help control the kinds and amounts of proteins they make. More than 250 different microRNAs have been discovered, and several have been linked to cancer.
These findings show exactly how one specific microRNA, called miR-21, helps cancer develop.
This molecule occurs at unusually high levels in many kinds of cancer cells. The study looked at a gene called PTEN (pronounced P-TEN), which normally protects cells from becoming cancerous. Researchers know that the abnormal silencing of this tumor-suppressor gene contributes to the development of liver cancer and other malignancies.
The findings help explain how liver cancer develops and may identify new drug targets for treating the disease. This particular microRNA might also provide a marker to help determine a patient's prognosis.
The study, led by researchers at the Ohio State University Comprehensive Cancer Center, is published in the August issue of the journal Gastroenterology.
Our findings essentially describe a new mechanism used by cells to regulate PTEN, says principal investigator Tushar Patel, professor of internal medicine, director of hepatology and a liver-cancer specialist at Ohio State University Medical Center.
They show that high levels of miR-21 block the PTEN gene, he explained. This, in turn, activates chemical pathways that enable cancer cells to proliferate, migrate and invade other tissues, all of which are features of tumor formation.
Patel and his collaborators began the study by measuring the relative levels of 197 microRNAs in normal liver cells and in liver cancer cells from human tumors and in four liver cancer cell lines.
Levels of miR-
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Contact: Eileen Scahill
Eileen.Scahill@osumc.edu
614-293-3737
Ohio State University
1-Aug-2007