June 25, 2013
Cancer Research In Space: Microgravity Could Be The Key
Lee Rannals for redOrbit.com – Your Universe Online
The International Space Station (ISS) has been helping provide cancer biologists a laboratory 220 miles above the surface of the Earth.Although it may seem a little odd, NASA says the orbiting laboratory acts as a great place to study cancer, along with other diseases. Cells in the human body normally grow within support structures made up of proteins and carbohydrates in three-dimensional shape. In a laboratory setting, however, these structures grow flat, not duplicating the shapes they normally would make in the body.
Scientists need cells to grow more like they do in the body in order to see how genetic changes affect growth and development. Researchers have developed several laboratory methods to mimic normal cellular behavior, but none of them work the way the body does. Cells that are not arranged in a living organism still arrange themselves into three-dimensional groupings while in space.
Microgravity allows the cells to clump together easier, and reduce fluid shear stress. All of these factors allow scientists to study cell behavior 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, PhD, a cell biologist 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."
Experiments in space have shown changes in immune cells, including changes in cell-signaling cytokines. The architecture of cells can change in microgravity, with changes to cell walls, internal organization and even their basic shapes.
The Cellular Biotechnology Operations Support System (CBOSS-01-Ovarian) investigation currently aboard the ISS has allowed scientists to examine changes to human colon, ovarian and other cancer cells.
Becker found a reduced production of cytokines in a human Muellerian ovarian tumor cell line in one study. These are small proteins that are secreted to mediate and regulate immunity and inflammation. By understanding the changes in production of these proteins, as well as the changes in cell signaling, researchers could have greater knowledge about the mechanisms of tumor cell development.
Cells growing in three-dimensional structures in microgravity do not possess blood vessels, so the cells at the center of an aggregate will likely die. However, Becker says this isn't necessarily a bad thing.
In tumors, "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," says Becker. "That mirrors exactly what you see in human cancer."
She said the space station is the only laboratory of its kind, and that it would be a shame not to take advantage of this platform for discovery. Microgravity research could eventually help researchers pinpoint cellular changes that lead to cancer, helping to find new ways to prevent it.