Right now, this instant, on Jan. 27, 2003, the space shuttle Columbia is orbiting Earth at a speed of roughly 17,300 mph, 150 miles above the planet’s surface—and researchers from the Winship Cancer Institute are using the shuttle as a “zero gravity” laboratory to learn more about prostate cancer and bone metastasis.

Leland Chung will be the first cancer investigator to grow a prostate cancer “organoid,” or artificial tumor, in space. Launched from Cape Canaveral, Fla., on Jan. 16, the shuttle is carrying prostate cancer cells and bone stroma (tissue framework) cells into space in a NASA-engineered “bioreactor,” which recreates the natural environment for tumor development and progression. The Columbia is scheduled to return on Feb. 2.

Chung, professor of urology, is seeking to understand how prostate cancer cells grow and communicate with other cells in the body. He and his co-investigators at NASA also are studying how zero gravity can be used as a tool to advance science, using the space shuttle as a laboratory to study the behavior of prostate cancer cells in the body.

An important goal of this experiment, Chung said, is to discover relevant genes that may “turn on or turn off” during the cascade of prostate cancer cells to the bone. “This study may provide us with insight into novel genes of diagnostic or prognostic value and may offer new targets for treatment of cancer metastasis,” said Chung, who has conducted prostate cancer research with NASA funding since 1995.

Increasingly, scientists are using zero gravity to create three-dimensional organoids in order to study the interaction of cells within organisms. Experi-ments in zero gravity have helped scientists understand development of heart, bone, muscle, endocrine organs and the locomotion of inflammatory cells and tumor cells.

“In space, we are able to create a ‘micro-environment’ that very closely resembles what happens at the cellular level in our bodies,” Chung said. “Zero gravity provides the opportunity to analyze the ‘cross talk’ between cells, because they will grow under a low shearing force and they are not in contact with other solids, including plastic or glass, which can inhibit or modulate growth factors.”

Previous experiments indicate that, under these conditions, the organoid may grow to a size not possible in Earth’s gravity. Chung will use this three-dimensional organoid to better understand the basic molecular process that occurs between cancer cells and their environment.

In addition to growing the organoid, investigators will recover cells and media from the space flight for future behavioral, genetic and gene expression studies back on earth.

Researchers will study prostate cancer cells’ ability to migrate, invade and respond to hormones and drugs, and results will be compared with prostate cancer specimens obtained from patients. Mahul Amin, associate professor of pathology and urology, provided the clinical cell samples for this experiment.

“We have to remember that cancer is not just a cell,” Chung said, “it is an organ that is made up of cancer cells, blood vessels, fibromuscular stroma, neural and inflammatory cells. We don’t understand how cancer cells compartmentalize themselves locally or why and when they metastasize. We are working to recreate cancer in a microenvironment to better understand how it works. Zero gravity provides us with an attractive opportunity in which to do this.”

The combination of prostate cancer cells and healthy bone stroma cells is important because of the high rate of bone metastasis among prostate cancer patients. Nearly 90 percent of all terminal prostate cancer patients have bone metastasis.