Fighting cancer with microgravity research

June 25, 2013 by Rebecca Boyle
Tumor cells grow on microcarrier beads (indicated by arrow) within a NASA bioreactor. These cells were grown as part of NASA-sponsored breast cancer research. (Dr. Jeanne Becker/NASA Spinoff)

(Phys.org) —For lab-coated cancer biologists, peering through microscopes at stained tissue samples under fluorescent lights, the International Space Station may be the last thing that comes to mind. But 40 years of microgravity research proves cancer biologists may indeed want to look 220 miles up. Space provides physical conditions that are not possible on Earth, and as it turns out, those conditions may be ripe for studying cancer—along with a wide range of other diseases.

in the human body normally grow within support structures made up of proteins and carbohydrates, which is how organs—and tumors—maintain their three-dimensional shapes. In lab settings, however, cells grow flat, spreading out in sheets. Because they don't duplicate the shapes they normally would make in the body, they don't behave the way they would in the body, either. This poses problems for scientists who study cancer by examining affecting cell growth and development.

Scientists have devised several to mimic normal , but none of them work exactly the way the body does. In space, however, cells that are not inside a , called in vitro cells, still arrange themselves into three-dimensional groupings, or aggregates. These aggregates more closely resemble what happens in the body. Cells in microgravity also can clump together more easily, and they experience reduced fluid shear stress—a type of turbulence that can affect their behavior. All these factors can help scientists study —and how changes in that behavior can lead to cancer—in a state more closely resembling cells in the body.

"So many things change in 3-D, it's mind-blowing—when you look at the function of the cell, how they present their proteins, how they activate genes, how they interact with other cells," said Jeanne Becker, Ph.D., a at Nano3D Biosciences in Houston and principal investigator for the CBOSS-1-Ovarian study. "The variable that you are most looking at here is gravity, and you can't really take away gravity on Earth. You have to go where gravity is reduced."

Fighting cancer with microgravity research
Scanning Electron Micrograph of a human Muellerian ovarian cancer cell nurtured in microgravity conditions. The three-dimensional structure shown is much closer in true size and form to natural tumor cells found in cancer patients. (NASA)

Becker is the author of a recent paper in Nature Reviews Cancer that surveys the past four decades of cell biology research in microgravity, and how the findings continue to inform cancer research on Earth. Starting with Skylab in the 1970s and leading up to current in-orbit investigations, Becker and co-author Glauco R. Souza highlight nearly 200 scientific papers drawn from space-based experiments and investigations.

Experiments on the space shuttle, Russian vehicles and the space station have shown changes in immune cells, including changes in cell-signaling cytokines, indicating the immune system is suppressed in microgravity. Even the architecture of cells changes in microgravity, with changes to cell walls, internal organization and even their basic shapes. In space, according to Becker's review, cells are more round.

Other studies have shown many changes in genetic expression. During an investigation on the STS-90 mission aboard space shuttle Columbia in 1998, cells were cultured for six days and returned to Earth for analysis. Afterward, an examination of 10,000 genes revealed the expressions of 1,632 genes were altered in microgravity, relative to ground controls. This was the first experiment to show reduced gravity can affect a wide range of genes.

Aboard Columbia during its STS-107 mission, prostate cancer and bone cells grew in a three-dimensional structure inside the Bioreactor Demonstration System (BDS–05). Early indications showed large aggregates of cells, indicating large growth, Becker said. But the study was lost, along with the shuttle and its crew, during re-entry on Feb. 1, 2003.

The Cellular Biotechnology Operations Support System (CBOSS-01-Ovarian) investigation aboard the space station contains a cell incubator that can grow 3-D clusters of cells, and scientists have used it to examine changes to human colon, ovarian and other cancer cells. In one recent result, Becker noted reduced production of cytokines in a human Muellerian ovarian (LN1) tumor cell line. Cytokines are small proteins that are secreted to mediate and regulate immunity and inflammation. Understanding changes in production of these proteins, and the changes in cell signaling that contribute to those production changes, could help researchers understand the mechanisms of tumor cell development.

Time-lapse exposure of Bioreactor rotation. The bioreactor is a special incubator that gently spins to circulate cells’ growth medium, while preventing turbulence that can harm the cells. (NASA/Dennis Olive)

Although cells grow in three-dimensional structures in microgravity, they don't possess blood vessels that can provide oxygen and nutrients, so the cells at the center of an aggregate will likely die. But that's still not a disadvantage, Becker said. Bulky tumors also have areas of dead tissue near their centers, which coincides with a slow cancer growth rate."You also have nearby cells that are not dead, but they're not really cycling. They are very much still cancer, and they can develop increased areas of chemo resistance," said Becker. "That mirrors exactly what you see in human cancer."

Even while they're sitting at the lab bench, researchers could reach new heights using the station's microgravity environment, Becker said. "I've had the chance to see firsthand the things that can happen. It's pretty amazing. It's a shame to not take full advantage of this platform for discovery," she said. "It's the only lab of its kind; that's it. And now is the time, because the station is entirely finished and available."

In recent years, research on Earth has caught up with 3-D cell structures. Investigations examining cancer cells and other tissues use a collagen gel matrix, which suspends cells in 3-D. Combining these techniques with the resources available in microgravity may inform entirely new approaches for studying cancer. Ultimately, microgravity- and Earth-based research could help scientists pinpoint the cellular changes that lead to and possibly find new ways to prevent them, leading to new treatments that could enhance the quality of life for patients with the disease.

Explore further: Resistance is futile: Researchers identify gene that mediates cisplatin resistance in ovarian cancer

More information: www.nature.com/nrc/journal/v13 … n5/full/nrc3507.html

Related Stories

Resistance is futile: Researchers identify gene that mediates cisplatin resistance in ovarian cancer

April 15, 2013
Platinum compounds, such as cisplatin and carboplatin, induce DNA cross-linking, prohibiting DNA synthesis and repair in rapidly dividing cells. They are first line therapeutics in the treatment of many solid tumors, but ...

Shape-shifting cells help skin cancer spread

June 10, 2013
(Medical Xpress)—Scientists have discovered genes that control shape changes in melanoma skin cancer cells, allowing them to wriggle free and spread around the body, according to new research published in Nature Cell Biology.

'Chase and run' cell movement mechanism explains process of metastasis

June 16, 2013
A mechanism that cells use to group together and move around the body – called 'chase and run' - has been described for the first time by scientists at UCL.

Ovarian cancer cells hijack surrounding tissues to enhance tumor growth

September 4, 2012
Tumor growth is dependent on interactions between cancer cells and adjacent normal tissue, or stroma. Stromal cells can stimulate the growth of tumor cells; however it is unclear if tumor cells can influence the stroma.

Recommended for you

No dye: Cancer patients' gray hair darkened on immune drugs

July 21, 2017
Cancer patients' gray hair unexpectedly turned youthfully dark while taking novel drugs, and it has doctors scratching their heads.

Shooting the achilles heel of nervous system cancers

July 20, 2017
Virtually all cancer treatments used today also damage normal cells, causing the toxic side effects associated with cancer treatment. A cooperative research team led by researchers at Dartmouth's Norris Cotton Cancer Center ...

Molecular changes with age in normal breast tissue are linked to cancer-related changes

July 20, 2017
Several known factors are associated with a higher risk of breast cancer including increasing age, being overweight after menopause, alcohol intake, and family history. However, the underlying biologic mechanisms through ...

Immune-cell numbers predict response to combination immunotherapy in melanoma

July 20, 2017
Whether a melanoma patient will better respond to a single immunotherapy drug or two in combination depends on the abundance of certain white blood cells within their tumors, according to a new study conducted by UC San Francisco ...

Discovery could lead to better results for patients undergoing radiation

July 19, 2017
More than half of cancer patients undergo radiotherapy, in which high doses of radiation are aimed at diseased tissue to kill cancer cells. But due to a phenomenon known as radiation-induced bystander effect (RIBE), in which ...

Definitive genomic study reveals alterations driving most medulloblastoma brain tumors

July 19, 2017
The most comprehensive analysis yet of medulloblastoma has identified genomic changes responsible for more than 75 percent of the brain tumors, including two new suspected cancer genes that were found exclusively in the least ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.