UC San Diego is testing a cancer drug for the first time in space using private astronauts

On May 21, 2023, scientists at the University of California San Diego Sanford Stem Cell Institute launched several new nanobioreactor experiments to the International Space Station (ISS) via the second Axiom Space Private Astronaut Mission, Axiom Mission 2 (Ax-2). The latest experiment extends their research into human stem cell aging, inflammation, and cancer in low-Earth orbit.

Increasing evidence suggests that microgravity conditions can accelerate aging, inflammation, and immune dysfunction in human stem cells. Understanding this process not only helps keep astronauts healthy — it can also teach us how to better treat cancer here on Earth.

During Axiom Space’s first Private Astronaut Mission, Axiom Mission 1 (Ax-1), researchers found that in low Earth orbit, cancer stem cells appear to regenerate more easily and become more resistant to standard therapies. The Ax-2 mission will now determine whether the two inhibitory drugs can reverse regeneration in an organoid model of breast cancer. Another experiment will track the health of astronauts’ blood stem cells before, during, and after spaceflight to evaluate the effects of the space environment on stem cell aging, immune function, and cancer stem cell formation.

These projects are part of the NASA-funded Integrated Space Stem Cell Orbital Research Center (ISSCOR), a collaboration between the UC San Diego Sanford Stem Cell Institute, JM Foundation and Axiom Space. The experiment will last 10 days in orbit, with subsequent data collection and analysis taking place at UC San Diego.

“Space is a unique stressful environment,” says Catriona Jamieson, MD, PhD, professor at the UC San Diego School of Medicine, Koman Family Presidential Chair in Cancer Research at UC San Diego Health and director of the Sanford Stem Cell Institute. “By conducting these experiments in low Earth orbit, we can understand the mechanisms of cancer evolution in a compressed time frame and inform the development of new cancer stem cell inhibition strategies.”

These findings will inform the development of predictive models for cancer and diseases related to immune dysfunction and may lead to the development of new drugs to prevent or treat these conditions during space exploration and on Earth.

“We are delighted to have the opportunity with our private astronaut mission to advance this important work, aligned with the White House Cancer Moonshot initiative,” said Christian Maender, executive vice president of in-space solutions at Axiom Space. “Our mission is to enhance life on Earth and foster the possibilities beyond it by building and operating the world’s first commercial space station. Together with the Sanford Stem Cell Institute team, we are building history.”

Cancer in Low Earth Orbit

In an initial UC San Diego experiment under the ISSCOR program, researchers sent blood stem cells to the ISS through four launches and found that some pre-cancer markers increased after one month in space. Of particular note are the activation of APOBEC3C and ADAR1, two enzymes that edit DNA and RNA, respectively, and promote cancer proliferation and immune evasion.

The researchers will now build on these initial findings during the Ax-2 mission, led by Jamieson and his collaborators Sheldon Morris, MD, PhD, and Ludmil Alexandrov, PhD, both associate professors at the UC San Diego School of Medicine.

In its latest launch, scientists have sent organoid models of leukaemic, colorectal, and breast cancer tumors to low-Earth orbit, where microgravity conditions will accelerate insight into how cancers adopt stem cell properties that make them resistant to standard therapies, including dormancy, regeneration . and longevity. The researchers will also test two ADAR1 inhibitors, Fedratinib and Rebecsinib, to see if the drugs can reverse the process of malignant regeneration and potentially prevent cancer development. The experiment marks the start of a development program at the Sanford Stem Cell Institute to expand stem cell translational research and drug discovery in space.

Space Hematopoietic Stem Cell Aging

The second longitudinal study will monitor the health of astronauts’ stem cells over time to study how they are affected by spaceflight. Blood samples will be collected from crew members before, during, and immediately after the mission, with annual follow-up for up to five years after the voyage.

Scientists will assess the activity of DNA and RNA editing enzymes such as APOBEC3C and ADAR1 in blood stem cells and cancer organoids. Dysregulation of these enzymes has been linked to immune dysfunction and potential pre-cancerous changes, so understanding when and how they are disrupted in astronauts will allow researchers to develop potential countermeasures.

“With growing support from NASA, philanthropic funders, and our partners in commercial spaceflight, this is just the start of a long line of exciting and impactful health science advances that space will make possible,” said Jamieson.

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