salinomycin may kill more breast cancer stem cells

Research indicates salinomycin may kill more breast cancer stem cells than paclitaxel.

In a front-page story, the New York Times (8/14, A1, Wade) reports, "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." According to some researchers, "tumor growth is driven by cancerous stem cells that...are highly resistant to standard treatments." While "chemotherapy agents may kill off 99 percent of cells in a tumor...the stem cells that remain can make the cancer recur." These "cells, unlike mature cells, can constantly renew themselves and are thought to be the source of cancers."

        But, in a report published in the journal Cell, researchers noted that one drug, "salinomycin, cut the number of stem cells at least 100 times more than did Bristol-Myers Squibb Co.'s Taxol [paclitaxel], a common chemotherapy medicine," Bloomberg News (8/14, Waters) reports. For the study, researchers "grew cancer cells from breast tumors in a way that increased the number of stem cells." Using "rapid screening techniques," they tested "16,000 commercially available compounds," and "identified 32 candidates before settling on salinomycin as the most potent."

        AFP (8/14) reports that the researchers found that "the compound showed impressive results, both against naturally-occurring and manipulated cancer stem cells, reducing the proportion of breast cancer stem cells by more than 100-fold compared to" Taxol. And, "when injected into mice," the compound "inhibited the ability of the cancer stem cells to seed new tumors...and slowed the growth of existing tumors in the animals."

        The UK's Telegraph (8/14, Smith) reports that the compound "also seemed to suppress genes that are linked to particularly aggressive tumors and lower chances of survival." Salinomycin is typically "used as an antibacterial and anti-parasite drug to fatten broiler chickens but is toxic to some other animals." Dr John Stingl, group leader in mammary stem cell biology at Cancer Research UK's Cambridge Research Institute, noted that "the challenge for the future is to bring this class of drugs to the clinic and to identify the patients that are likely to respond to them."

        The researchers stated that the study "suggests a general approach to finding novel anti-cancer therapies that can be applied to any solid tumor maintained by cancer stem cells," the UK's Daily Mail (8/14, Macrae) reports. But, "much more work is now needed to in down how [salinomycin] works and to establish whether it will be effective against human tumors," they added. Reuters (8/14, Steenhuysen) and the UK's Press Association (8/13) also cover the story.

http://www.injuryboard.com/national-news/research-drug-compound-destroys-breast-cancer-stem-cells.aspx?googleid=269148

http://www.sciencedaily.com/releases/2009/08/090813142135.htm