Research has shown that the antioxidant effects of vitamin E could protect healthy cells from the damaging effects of free radicals helping to keep cancer at bay. Vitamin C has also been studied for its impact on cancer with research showing the vitamin can limit cancer cell growth in mesothelioma, colon cancer, and prostate cancers, among others. Now, researchers report that high-dose, intravenous delivery of Vitamin C in lung cancer patients could kill the cancer cells.
According to a Jan. 9 article in the Science Daily, researchers from the University of Iowa believe that many attempts at using Vitamin C in cancer care have failed because delivery has been oral. However, in their study, high doses of Vitamin C were given intravenously. This method of delivery, as opposed to oral delivery, results in very high blood levels of vitamin C – 100-500 times higher – by bypassing normal ingestion and excretion processes. According to the researchers, “It is this super-high concentration in the blood that is crucial to vitamin C’s ability to attack cancer cells.” At this high level, cancer cells are killed, but the other cells are left intact.
The researchers used a mouse study to understand the underlying biological processes of the high-dosage vitamin C and cancer.
The team found that when vitamin C breaks down it generates hydrogen peroxide that can lead to tissue and DNA damage. Normal cells can process, or remove, the peroxide, but cancerous cells cannot making the cancer cells more prone to death when they are hit with high doses of vitamin C. The researchers determined that the healthy cells used an enzyme called catalase to decompose the vitamin and remove the hydrogen peroxide keeping the cells healthy and undamaged. Not so for the cancerous cells, they had lower amounts of catalase, thus, making them more susceptible to death with high amounts of vitamin C.
“Our results suggest that cancers with low levels of catalase are likely to be the most responsive to high-dose vitamin C therapy, whereas cancers with relatively high levels of catalase may be the least responsive,” said Garry Buettner, a professor of radiation oncology and a member of Holden Comprehensive Cancer Center at the University of Iowa.
A future goal of the research is to develop methods to measure catalase levels in tumors, said Buettner.
Pleural mesothelioma is a serious and rare cancer affecting the lining of the lungs in individuals who were exposed to asbestos fibers in the past. Like lung cancer, mesothelioma is highly aggressive and is resistant to many standard cancer treatments, making breakthroughs of effective treatments critical to the mesothelioma community. Currently there is no known cure for mesothelioma, and the average survival time varies from 4 – 18 months after diagnosis.
The treatments for lung cancer and pleural mesothelioma are very similar bringing hope to the mesothelioma community when success is seen in studies in the lung cancer community. Continued research for bringing improved treatment options to mesothelioma patients can increase survival and improve their quality of life.
Read the full study in the Dec. 2016 issue of Redox Biology.