jstdzy Posted March 31, 2009 Share Posted March 31, 2009 I was looking up information on Metformin which is a drug for Type 2 diabetics and trying to find information on conflicts between it and contrast on scans. I found this instead: 21. Aug 2007 - Dow JonesCommon diabetes drug may attack some cancerBy Dinah Wisenberg Brin A widely used diabetes drug, metformin, holds promise as a potential treatment for a wide array of cancers, according to recent university research involving laboratory animals. Metformin is a generic drug that is also sold by Bristol-Myers Squibb Co. under the brand name Glucophage. It's been found to kill tumor cells that lack a key gene, according to researchers at the University of Pennsylvania, who published their findings recently in Cancer Research. Cancers in more than half of all patients lack that tumor-suppressing gene, and its absence is associated with more virulent forms of the disease, the senior researcher said. "There's definitely evidence that would suggest that either regular or intermittent use of drugs like metformin could reduce the risk of cancer," said Dr. Craig Thompson, director of the Abramson Cancer Center at Penn. "We would believe, based on our evidence, that it's directly treating the cancer." Epidemiologists previously had noticed that diabetics on metformin, which controls blood-sugar levels and increases the body's sensitivity to insulin, appeared to have lower incidence and severity of cancer than those not taking the drug, according to Thompson. The recent study at Penn and separate findings by researchers at McGill University in Montreal suggest the drug can directly suppress tumor growth. Metformin is a relatively low-cost tablet that "has been used in millions of people worldwide. It's a remarkably safe agent given to people with Type 2 diabetes," and also as a fertility treatment for women with polycystic ovarian syndrome, Thompson said. It doesn't produce the kind of toxic side effects associated with such cancer treatments as chemotherapy and radiation, and might help people with tumors that are resistant to those therapies, his research suggests. But since the drug is already available as an inexpensive generic, it's not evident that any drug company would be able to cash in on a new use for it. If findings on studies of lab mice bear out in human clinical trials, Thompson said, the drug might be used as part of primary cancer treatment and may enhance the effectiveness of other cancer drugs. Also, people at high risk for developing cancer might one day take metformin as a preventive measure, much as people now take low-dose aspirin to help prevent heart attacks, he said. Lab tests on mice The Penn researchers injected nondiabetic mice with human colorectal cancer cells, some of which had the p53 gene while the others didn't. They found that metformin injected into the mice significantly reduced the growth of tumors that lacked the gene. In the mice given metformin for tumors lacking the p53 gene, the tumors were half the size of those in mice given only saline. In the mice whose cancer had the gene, there was no difference in the size of tumors between those who received metformin and those who didn't. The drug told the cells to switch to an alternative energy source to produce the molecules necessary for survival and without the p53 gene, the cells couldn't respond to this metabolic change, the researchers concluded. That killed the cells, according to the Penn research, which received grants from the National Cancer Institute. "Metformin was having a direct effect on the tumors that lacked p53," Thompson said. His team has been talking to clinical researchers at Penn about possible testing on humans, he said. The Penn researchers also found that an agent called AICAR had a similar effect as metformin on the same type of cancer cells. Metformin and AICAR both act as activators of AMP-activated protein kinase, which plays an important role in cell metabolism. Researchers at McGill University independently found through in vitro experiments that metformin suppressed the growth of breast cancer cells, said Michael Pollak, professor of oncology at McGill. Their research was published in November in Cancer Research. "I think it's pretty important because it suggests that an old drug that we have been using for a long time for Type 2 diabetes may have a role in cancer treatment or cancer prevention in certain subsets of the population," Pollak said. Researchers are now testing metformin in a small clinical trial of breast cancer patients in Montreal, and more clinical studies are needed, he said. Doctors shouldn't prescribe off-label use of metformin for cancer treatment without further study, he said. "In cancer research we never go directly from laboratory studies to clinical recommendations. We always need clinical trials. There are lots of laboratory leads that fail to have the expected result at the clinical level," Pollak said. Population studies suggesting that diabetics on metformin have a lower incidence and severity of cancer than those on other treatments are "suggestive but it is early evidence," Pollak said. Other researchers in the past have theorized that metformin lowers the cancer risk in diabetics by reducing diabetes or lowering the insulin, according to Penn's Thompson. He said his research suggests that it's not "the diabetes effect" but rather the drug's work on a genetic level against the cancer. McGill's Pollak said metformin may work to reduce cancer in diabetics via several mechanisms, including insulin reduction and genetic mechanisms that directly inhibit cancer growth. Glucophage contributed $2.7 billion to Bristol-Myers Squibb's 2001 sales before the blockbuster drug went off patent in the U.S. The company lost a battle in late 2001 to extend its exclusive right to sell the drug for three years. Metformin is produced by several generic pharmaceutical companies. Bristol-Myers had no comment on the recent research, as metformin isn't approved for cancer treatment and the pharmaceutical company isn't involved in the studies, a spokesman said. "It's kind of left for the academics to work on this issue" since there is little financial incentive for drug companies to conduct the cancer research on metformin, Pollak said. "The private sector would not necessarily expect to recoup investment for a new indication for this drug because it's already on the market at a very low price." Walgreens.com sells 180 tablets of 500 milligram metformin, produced by Teva Pharmaceutical Industries Ltd., for about $48. Quote Link to comment Share on other sites More sharing options...
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.