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S.ravi
Advanced Member
India
4205 Posts |
 Posted - 08/14/2009 : 19:27:26
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Chemicals to attack and kill cancer stem cells identified
Nicholas Wade
Researchers say these drugs leave ordinary cells unharmed
NEW YORK: Researchers have discovered a way to identify drugs that can specifically attack and kill cancer stem cells, a finding that could lead to a new generation of anti-cancer medicines and a new strategy of treatment.
Many researchers believe that tumour growth is driven by cancerous stem cells that, for reasons not yet understood, are highly resistant to standard treatments. Chemotherapy agents may kill off 99 per cent of the cells in a tumour, but the stem cells that remain can make the cancer recur, the theory holds, or spread to other tissues in the body to cause new cancers. Stem cells, unlike mature cells, can constantly renew themselves and are thought to be the source of cancers when, through mutations in their DNA, they throw off their natural restraints.
A practical test of this theory has been difficult because cancer stem cells are hard to recognise and have so far proved elusive targets. But a team at the Broad Institute, a Harvard-MIT collaborative for genomics research, has devised a way of screening for drugs that attack cancer stem cells but leave ordinary cells unharmed.
Cancer stem cells are hard to maintain in sufficient numbers, but the Broad Institute team devised a genetic manipulation to keep breast cancer stem cells trapped in the stem cell state.
The team, led by Dr. Piyush B. Gupta, screened some 16,000 chemicals, including all known chemotherapeutic agents approved by the Food and Drug Administration. The team reported in the Thursday issue of Cell that 32 of the chemicals selectively went after cancer stem cells. These particular chemicals may or may not make good drugs, but the screening system proves for the first time, the researchers say, that it is possible to single out cancer stem cells with drugs that leave ordinary cells alone. Only one of the 32 chemicals is approved as a drug for cancer.
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S.ravi
Advanced Member
India
4205 Posts |
Posted - 10/14/2009 : 10:32:23
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Scientists discover new cancer gene
ANI 14 October 2009, 12:49pm IST
WASHINGTON: A research group at the Sahlgrenska Academy has discovered a new cancer gene.
The gene causes an insidious form of glandular cancer usually in the head and neck and in women also in the breast. The discovery could lead to quicker and better diagnosis and more effective treatment, according to the study which is published in the prestigious scientific journal Proceedings of the National Academy of Sciences (PNAS).
The cancer caused by this new cancer gene is called adenoid cystic carcinoma and is a slow-growing but deadly form of cancer. The research group can now show that the gene is found in 100 percent of these tumours, which means that a genetic test can easily be used to make a correct diagnosis.
"Now that we know what the cancer is down to, we can also develop new and more effective treatments for this often highly malignant and insidious form of cancer," says professor Göran Stenman, who heads the research group at the Lundberg Laboratory for Cancer Research at the Sahlgrenska Academy.
"One possibility might be to develop a drug that quite simply turns off this gene," the expert added.
The newly discovered cancer gene is what is known as a fusion gene, created when two healthy genes join together as a result of a chromosome change.
"Previously it was thought that fusion genes pretty much only caused leukaemia, but our group can now show that this type of cancer gene is also common in glandular cancer," says Stenman.
One of the two genes that form the fusion gene is known as MYB. Among other things, this gene controls cell growth and makes sure that the body gets rid of cells that are no longer needed. It has long been known to be a highly potent cancer gene in animals, but for a long time there was no evidence of the gene being involved in the development of tumours in humans.
"We suggested back in 1986 that the MYB gene might be involved in this form of cancer, but it's only recently that we've had access to the tools needed to prove it," says Stenman.
The research group has also looked at the mechanism behind the transformation of the normal MYB gene into a cancer gene. Genes can be compared to blueprints for proteins. Carefully controlled regulating systems then determine when and how much of each protein is formed. One such regulating system, discovered recently, is microRNA, which can turn genes on and off. When this cancer gene forms, this important control system is put out of action, leading to activation of the gene and massive overproduction of an abnormal MYB protein with carcinogenic properties.
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Chemicals to attack and kill cancer stem cells ide
