There are a number of health risks that come with going to space. Aside from the increased exposure to solar radiation and cosmic rays, there are the notable effects that microgravity can have on human physiology.
As Scott Kelly can attest, these go beyond muscle and bone degeneration and include diminished organ function, eyesight, and even changes at the genetic level.
Interestingly enough, there are also a number of potential medical benefits to microgravity. Since 2014, Joshua Choi, a senior lecturer in biomedical engineering at the University of Technology Sydney, has been investigating how microgravity affects medicine and cells in the human body.
Early next year, he and his research team will be traveling to the ISS to test a new method for treating cancer that relies on microgravity.
According to Chou, the inspiration for his research came from a conversation he had with the late and great Stephen Hawking. During the conversation, Hawking remarked how nothing in the Universe defies gravity.
Later, when a friend of Chou's had been diagnosed with cancer, he recalled what Dr. Hawking had said and began to wonder, "What would happen to cancer cells if we take them out of gravity?"
Simply put, cancer is a disease where cells begin dividing uncontrollably and spread to certain parts of the body and take them over. Cancer cells do this by coming together to form a solid tumor in the body, which then grows until the cells are signaled to invade healthy tissues – such as the heart, lungs, brain, liver, pancreas, etc.
One of the biggest stumbling blocks with cancer research is that no one knows exactly when that point is reached. However, the process through which cancer grows and spreads would seem to indicate that there is a means through which the cells are able to sense each other and gravitate together to form a tumor.
However, biomedical researchers do understand that the only way cancer cells could sense each other is through mechanical forces, and that those forces evolved to work in an environment where there's gravity. This motivated Chou to think of ways in which the lack of gravity might impede cancer cells' ability to divide and spread.
Chou has some experience in conducting space-based medical research. While working at Harvard, he took part in a project that resulted in the creation of a drug to treat osteoporosis. Part of their research took place aboard the International Space Station (ISS). As Chou explained:
"This first experience of seeing how the space environment impacts our understanding of cell biology and disease progression inspired me to ask: 'Why can't we apply the same strategy to studying other cells and diseases?'"
Already, Chou and his team have tested the effects of microgravity on cancer cells in their laboratory. To do this, one of his graduate students created a device that is essentially a tissue box-sized container with a small centrifuge inside. The cells of different diseases are contained in a series of pods within the centrifuge, which then spins them up until they experience the sensation of microgravity.
As Chou indicated, the results were rather encouraging. "Our work has found that when placed in a microgravity environment, 80 to 90 percent of the cells in the four different cancer types we tested – ovarian, breast, nose and lung – were disabled," he said.
"By disabled, I mean they either die or float off because they can no longer hold on. Those four cancer types are some of the hardest cancers to kill."
Even more impressive is the fact that these results were obtained by simply altering the gravitational forces – i.e. without the help of drugs. When subjected to microgravity-conditions, the cancer cells were unable to sense each other and therefore had a very hard time coming together.
"Driving this mission has been a whole team effort – I feel very fortunate to be supported by my faculty and a group of very talented female engineering students who inspire me to keep going. They do so much of the hard work in making this project a reality."
The next step, which will be happening early next year, will involve the team sending their experiment to the ISS aboard a specially-designed space module (SpaceX will be providing launch services). Chou and his colleagues will spend the duration of the experiment (seven days) on the ground, where they will monitor the experiment's progress and conduct live-cell imaging via data feeds.
Once the experiment is complete, the cells will be frozen for their return trip to Earth, whereupon Chou and his colleagues will examine them for genetic changes. If the results aboard the ISS confirm what Chou and his team found in the lab, he hopes that they will be able to develop new treatments that can have the same effect as microgravity and neutralize cancer cells' ability to sense each other.
Ideally, these treatments would not constitute a cure but could supplement existing anti-cancer medical regimens. Combined with drugs and chemotherapy, treatments arising from this research would effectively slow the spread of cancer in the human body, thereby making conventional treatments more effective and shorter-lived (and less costly too).
"I also hope this is one of many Australian space research missions. My team and I are so fortunate to get the opportunity to do this research as it's so rare and we'll use our mission findings to signal to the Australian research community that the era of space biology and medicine is well and truly here."
This research will also come in handy in space, where astronauts are forced to spend months in microgravity and are exposed to considerably more radiation (and therefore at an increased risk of developing cancer).
These and other strides that are being made in the field of space medicine further demonstrate how space-based research can lead to commercial and medical benefits for people here on Earth.