Tumors are less aggressive in space than down on Earth, space study says

Some tumors seem to be less aggressive in the microgravity space environment than down on Earth, according to space station research published in the FASEB Journal.

The true weightlessness of space affects cells in such a way that they more closely resemble what actually happens in the body. For example, cells grown in space arrange themselves into three-dimensional groupings, or aggregates, similar to cancer cells.

"Without gravitational pull, cells form three-dimensional aggregates, or spheroids," explains Dr. Daniela Gabriele Grimm, author and researcher with the Department of Biomedicine, Pharmacology at Aarhus University in Aarhus, Denmark, in a statement. "Spheroids from cancer cells share many similarities with metastases, the cancer cells which spread throughout the body." Determining the molecular mechanisms behind spheroid formation might therefore improve our understanding of how cancer spreads.

Investigators in the Science in Microgravity Box (SIMBOX) facility aboard Shenzhou-8 compared cells grown in space and in simulated microgravity on the ground. After analyzing changes in gene expression and secretion profiles, the researchers found a decrease in the expression of genes that suggest high malignancy in cancer cells.

Another recent study examined nearly 200 papers on cell biology research in microgravity over the course of 40 years. This collective work shows that a cell's architecture changes in microgravity and the immune system also is suppressed. Other studies in addition to Grimm's have shown microgravity-induced changes in gene expression.

This current research could help scientists understand the tumor mechanism involved in cancer development and lead to drugs targeting tumors that don't respond to current treatments.

Thanks to the space station, scientists can learn more about cancer and look into possible treatments that can be used on our gravity-dependent Earth.

"The station is an invaluable tool for long-term studies of cells in microgravity," Grimm agrees. "Exposure to real microgravity in space will always be the gold standard for all microgravity research and will therefore always be an important cornerstone of our work."