Carbon monoxide (CO) could be the next big thing in cancer treatment, according to a new study. Researchers at Beth Israel Deaconess Medical Center (BIDMC) have discovered that CO can be used to slow the proliferation of cancerous cells and amplify the effect of conventional cytotoxic treatment. The findings could inspire a new era of safer and more efficient chemotherapy.
Though toxic, CO has in recent years become subject to a range of clinical applications, particularly in treating inflammatory conditions. Such therapies usually involve small, carefully administered doses of the noxious gas. The new study, which is published in the journal Cancer Research, sought to determine whether this type of treatment can benefit cancer patients as well.
According to senior author Leo Otterbein, the investigation has so far yielded promising results. “We found that in small, carefully controlled doses, CO not only mimicked the effects of chemotherapy agents by blocking proliferation of cancer cells, but also amplified the toxic effects of the chemotherapy drugs doxorubicin and camptothecin to accelerate cancer cell death," he said in a press release. "Importantly and rather unique is that CO also helped to protect normal tissue from chemotherapy, which is an unfortunate side effect of the treatments."
In an experiment with mice, the researchers found that the CO treatment made parallel chemotherapy drugs 1,000 times more effective. Otterbein and his colleagues theorize that this amplifying effect stems from CO’s ability to influence the metabolic state of cancer cells. Basically, the gas causes the tumor growth to work itself to death.
"Cancer cells are able to alter their metabolism in processing sugars and other energy sources, which enable them to rapidly proliferate and spread. This shift in metabolism is known as the Warburg Effect,” Otterbein explained. “Our findings indicate that CO essentially induces an 'anti-Warburg' effect, rapidly fueling cancer cell bioenergetics by compelling the cancer cell to increase respiration, which ultimately results in metabolic exhaustion."
The study dovetails with a number of other research efforts to identify destructive cellular mechanisms in tumors. In another study published earlier this year, researchers from the Massachusetts Institute of Technology showed that a new type of genetic intervention can reverse the process whereby cancerous cells escape apoptosis, or programmed cell death. Similarly, a previous study from Virginia Commonwealth University shows how a certain drug combination can cause cancer cells to eat and digest themselves.
Source: Wegiel B, Gallo D, Csizmadia E, et al. Carbon Monoxide Expedites Metabolic Exhaustion to Inhibit Tumor Growth. Cancer Research, 2013.