The research team, which includes researchers from Columbia University, then delved into the mechanism by which vitamin C may be protecting these cells, and discovered that it wasn't because the nutrient was neutralizing oxygen-free radicals.
They found instead that DHA was restoring viability to the cancer cell's damaged mitochondria the cell's all-important power plant that, when injured, sends signals to force a cell to die.
"Vitamin C appears to protect the mitochondria from extensive damage, thus saving the cell," Heaney said. "And whether directly or not, all anticancer drugs work to disrupt the mitochondria to push cell death."
Heaney says that the amount of DHA used in the experiments resulted in an intracellular buildup similar to what could be seen in cancer patients using large supplemental doses of vitamin C.
Researchers at Memorial Sloan-Kettering Cancer Center have long been researching the connection between vitamin C and cancer therapy, and these new findings expand on their earlier observation that vitamin C seems to accumulate within cancer cells more than in normal cells.
"We recognized that DHA is the form of vitamin C that gets into cells, and that the tumor microenvironment allows cancer cells to convert more vitamin C into DHA," he said. "Inside the cell, DHA is converted back into ascorbic acid, and it gets trapped there and so is available to safeguard the cell."
Heaney says that he suspects that vitamin C is good for the cells of normal tissue because it provides more protection for the mitochondria, and thus probably extends cell life. "But that isn't what you want when you are trying to eliminate cancer cells," said Heaney, who notes that cancer patients should eat a healthy diet, which includes foods rich in vitamin C. It is use of la
|Contact: Jeremy Moore|
American Association for Cancer Research