Screening could lead to more potent cancer drugs

Source: nytimes.com Author: Nicholas Wade 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 anticancer medicines and a new strategy of treatment. Many researchers believe that tumor growth is driven by cancerous stem cells that, for reasons not understood, are highly resistant to standard treatments. Chemotherapy agents may kill off 99 percent of cells in a tumor, but the stem cells that remain can make the cancer recur, the theory holds, or spread to other tissues 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 recognize and have proved elusive targets. But a team at the Broad Institute, a Harvard-M.I.T. 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 Piyush B. Gupta, screened 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 [...]

Forgotten leukemia drug shows promise

Source: www.ivanhoe.com Author: staff Doctors found a new weapon in the fight against an incurable form of leukemia, and it's a drug that was once dismissed as ineffective in battling the disease. Flavopiridol has shown promising results in phase I and II clinical trials that involved 116 patients with advanced chronic lymphocytic leukemia (CCL), according to researchers at The Ohio State University Comprehensive Cancer Center-James Cancer Hospital and Solove Research Institute. Responses were seen in about half of the patients, many of whom had chromosomal abnormalities that made it unlikely that they would be helped by standard therapies. In recent years, treatment of CLL has improved, but the disease, which strikes 15,000 people each year and is the most common type of adult leukemia, remains incurable. Patients often suffer significant infections caused by the disease and treatment. Flavopiridol showed promise as a potent cancer-fighter in the 1980s when it was tested on animals, but when it was given to humans in repeated trials, it proved ineffective and was essentially forgotten, researchers said. Ohio State researchers said they later discovered that flavopiridol binds to proteins in human blood, which ties up much of the available drug and leaves less free drug in the bloodstream to kill cancer cells. So, in the earlier trials, humans were not getting enough of the drug for it to be effective. The Ohio State researchers developed a new dosing schedule, and it increased the drug's blood level enough to kill cancer cells in humans, they said. [...]

2008-12-23T06:42:01-07:00December, 2008|Oral Cancer News|
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