As the search for new drugs to treat cancer continues, additional help may come from already approved medications. In a new study from the University of Turku in Finland, researchers may have found a new path to treatment for breast and pancreatic cancers using calcium channel blockers, or CCBs.
Calcium channel blockers have been in use since the 1960s to treat hypertension, commonly known as high blood pressure. Their efficacy rests in their ability to prevent calcium from entering cells of the heart and arteries, relaxing and widening arterial walls. They also slow heart rate. This new research has uncovered an added, heretofore unrealized, benefit.
A research team headed by Guillaume Jacquemet and Johanna Ivaska discovered that CCBs target filopodia-- sticky, finger-shaped substances associated with Myosin-10 - protein expressed by aggressively spreading cancers. The filopodia extend from plasma membrane and accepted theory holds that these “sticky fingers” are how cancers spread, assembling along the leading perimeter of invading cells and reaching out for new areas to invade. The study found that L-type CCBs deactivated the filopodia by blocking their signaling channels, thereby stopping their spread (metastasis). Specifically, it was amlodipine besylate, felodipine, manidipine dichloride and cilnidipine, four distinct formulations of CCBs that delivered these results.
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| Preventing metastasis is key to stopping the spread of cancer throughout the body, as occurs in Stage IV breast cancer. Source: cancer.gov |
Because metastasis is the leading cause of death in those with breast or pancreatic cancer, these new uses of calcium channel blockers could be revolutionary. If drugs already approved by the FDA can be repurposed and effectively integrated into a breast and pancreatic cancer treatment program, the wait may soon be over for countless individuals who have been dealing with a slow-moving approval process.
It must be pointed out that this research is still in its earliest stages, and further tests are needed. However, if the results hold, they open the door to a new pathway to breast and pancreatic cancer treatment by eliminating the extended research, development, testing, and approval phases associated with bringing new drugs to market. If existing drugs can be effectively used to target and treat diseases that were not part of their original design, new markets for them will open up while at the same time allowing research into new treatments to continue without interruption.
