Involved in control of cell division, they activate abnormally in malignant cells
MONDAY, Jan. 7 (HealthDay News) -- An international team of scientists has pinpointed 480 genes that play a role in cell division, and in the process they also discovered that more than 100 of those genes show an abnormal pattern of activation in cancer cells.
The findings are published in this week's issue of the Proceedings of the National Academy of Sciences.
The American, German and Israeli scientists, who used computational biology techniques to pinpoint the genes, noted that many cancer studies seek to identify "missing" genes that might cause cancer. This study shows that genes can contribute to cancer in less obvious ways.
"What we see is that there are many genes that are present and yet still involved in cancer, because they are not activated, or expressed, in the way they normally are," study co-author Itamar Simon, a molecular biologist at Hebrew University Medical School in Israel, said in a prepared statement.
Instead of the normal cycling on and off during cell replication and development, these genes are expressed continuously or not at all, Simon explained.
A few of the genes identified by Simon and his colleagues have previously been linked to cancer, but most haven't, including at least three genes responsible for repairing genetic mutations that occur as DNA is replicated in a cell.
The failure of these DNA repair genes to cycle properly in cancer cells suggests that some mutations associated with cancer may not actually cause cancer, the researchers said.
"Some of the mutations may be caused by the non-cycling genes, rather than the other way around," study leader Ziv Bar-Joseph, a computational biologist at Carnegie Mellon University in Pittsburgh, said in a prepared statement.
Further investigation is needed to determine if some genetic mutations are a side effect, rather than a cause, of certain cancers and to identify which of the 118 genes that do not cycle on and off normally in cancer cells are most significant.
"These genes seem to be important, but we don't yet know which ones play key roles or might be targets for drug therapy. We have narrowed down the field of candidates. Instead of looking at thousands of genes, now we can concentrate on about 100," Simon said.
The U.S. National Cancer Institute explains gene therapy for cancer.
-- Robert Preidt
SOURCE: Carnegie Mellon University, news release, Jan. 7, 2008
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