Long-used drug shows new promise for cancer
Therapy prescribed for metabolic disorder now found to shrink tumours in lab rats
Imagine, if you will, a drug that shrinks cancer cells and can even make tumours disappear. A couple of spoonfuls a day of powder in a glass of water is all you need.
There are no nasty side effects like nausea and hair loss, and no damage to internal organs such as with traditional chemotherapy. And it costs only about $2 a dose.
Too good to be true?
Not according to a Canadian researcher who stumbled upon the potentially new anti-cancer agent called dichloroacetate, or DCA, a drug long used to treat rare metabolic disorders.
"This is one of the most exciting results I've ever had," said Evangelos Michelakis, an associate professor of medicine at the University of Alberta in Edmonton.
"But I can't be overenthusiastic until it works in a human being."
In a paper published in today's edition of the medical journal Cancer Cell, Dr. Michelakis and a group of researchers from the U of A and the University of Ottawa, report on how they were able to use DCA to shrink human lung-, breast- and brain-cancer tumours in both lab rats and in a test tube.
While this type of research in laboratory animals does not generally generate a lot of enthusiasm, in this case the findings are creating a stir because DCA has actually been used safely in humans for decades -- in treating rare inherited metabolic disorders such as lactic acidosis, not cancer.
"One of the big concerns about drugs is that they can harm people but we already know this drug is safe. It doesn't even affect normal cells," Dr. Michelakis said.
The research challenges one of the fundamental premises of cancer biology, that mitochondria (the energy producing units of cells) are permanently damaged by cancer.
What Dr. Michelakis and his team found is that while mitochondrial function is suppressed, it can be revived with DCA, which makes the cancer cells susceptible to dying. (Most cancers become resistant to standard chemotherapy by suppressing mitochondrial function.)
In other words, the drug works by revving up the engines of normal cells, allowing them to work normally and driving cancer cells to commit suicide.
"This is the holy grail of cancer therapeutics -- how to kill the cancer cells and spare normal cells," Dr. Michelakis said.
Dario Altieri, a professor in the department of cancer biology at the University of Massachusetts Medical School in Worcester, Mass., said the research is "exciting" and that DCA has a lot of potential.
Dr. Altieri said DCA needs to move quickly from the lab into human testing. But he cautioned that there is a real possibility that will not happen, largely for economic reasons.
There is no longer a patent on DCA, meaning it is not owned by any one company. As a result, there is little chance of making a large profit, even if the drug works remarkably well, and hence no incentive for pharmaceutical companies to invest in research.
Dr. Michelakis acknowledged this is a real practical problem, but he expressed hope that public funding bodies like the Canadian Institutes for Health Research (which funded the lab study) will step in.
"Nobody is going to make a billion dollars from this drug," Dr. Michelakis said. "But maybe it will help a lot of people with cancer."