A new collaborative study led by researchers at Northeastern University discovered that supplemental oxygenation can shrink tumors and improve cancer immunotherapy. The study was recently published in the journal Science Translational Medicine and is entitled “Immunological mechanisms of the anti tumor effects of supplemental oxygenation.”
Cancer is responsible for the death of about 8 million people every year, with lung cancer accounting for the highest incidence and primary cause of cancer deaths in both men and women worldwide. Researchers have now found a new approach that can dramatically increase tumor regression and patients’ survival rate.
It has been previously reported that a receptor, called A2A adenosine receptor, present on the surface of immune cells prevented T cells (a type of white blood cell) from invading tumors and inactivated natural killer cells (also a type of white blood cell). It is also known that immune antitumor T cells are inhibited in tumor microenvironments with reduced oxygen content (hypoxic).
In this study, researchers found that the inhalation of 40 to 60% oxygen (the air we breathe has 21% oxygen) reduced cancer-protecting signaling via the A2A adenosine receptor and activated T cells with the ability to invade lung tumors. “Breathing supplemental oxygen opens up the gates of the tumor fortress and wakes up ‘sleepy’ anti-tumor cells, enabling these soldiers to enter the fortress and destroy it,” explained the study’s senior author Dr. Michail V. Sitkovsy in a news release. On the other hand, he added, “if anti-tumor immune cells are not present, oxygen will have no impact.”
The team concluded that supplemental oxygenation can decrease hypoxia and the accumulation of adenosine in the tumor microenvironment, leading to an improved cancer immunotherapy by activation of anti-tumor T cells and natural killer cells, along with improved lung tumor regression and long-term survival in animal models.
Researchers also found that the effects of supplemental oxygenation could be further improved when combined with a synthetic agent referred to as “super-caffeine,” which is known to halt the effect of the adenosine receptor in tumor protection and has been originally developed for individuals with Parkinson’s disease. The team is currently developing a next generation drug of this agent.
“The anti-tumor effects of supplemental oxygen can be further improved by the natural antagonist of the A2A adenosine receptor, which happens to be the caffeine in your coffee,” explained Dr. Sitkovsky. “People drink coffee because caffeine prevents the A2A adenosine receptor in the brain from putting us to sleep.”
Since the effects observed are entirely based on T cells and natural killer cells, the team believes that supplemental oxygen could be a potential immunological coadjuvant to the existing cancer immunotherapies. “Indeed, it is promising that our method could be implemented relatively quickly by testing in clinical trials the effects of oxygenation in combination with different types of already existing immunotherapies of cancer,” concluded Dr. Sitkovsky.