Colon Cancer Cells Thrive On Foul-Smelling Hydrogen Sulfide Gas

Hydrogen sulfide, the foul-smelling gas produced by rotten eggs, plays a key role in colon cancer metabolism and is a potential target for new treatments for the disease, researchers from the University of Texas Medical Branch at Galveston (UTMB) have discovered.

In a paper appearing in this week’s online edition of the Proceedings of the National Academy of Sciences, the UTMB researchers describe how their cell-culture and mouse experiments illustrated colon cancer cells produce large amounts of the colorless, corrosive and flammable chemical compound.

In fact, the cancer cells rely on the gas for their growth and survival, according to author and professor Csaba Szabo. “They love it and they need it,” he said.

“Colon cancer cells thrive on this stuff – our data show that they use it to make energy, to divide, to grow and to invade the host.”

Szabo and his colleagues linked the majority of hydrogen sulfide produced in colon-cancer cells to a protein known as CBS. This protein is produced at much higher levels in these cancerous cells than in health tissue, the researchers said. However, when CBS was chemically blocked, colon cancer tissue growth was halted while the growth rate of non-cancerous tissue was unaffected.

Furthermore, they observed the anti-colon cancer effects of blocking the protein when studying “nude” mice onto which patient-derived cancer tumor cells had been implanted.

Without hydrogen sulfide, the tumors grew far less quickly, while also displaying a pronounced decrease in angiogenesis – the process by which a tumor stimulates the growth of a host’s blood vessels around itself to essentially hijack oxygen and nutrients for its own use.

“Our work identifies CBS as a new anti-cancer target. By blocking CBS, we can fight colon cancer,” said UTMB professor and study author Mark Hellmich. “This is a chance to do research that really matters. We’re very excited to have that opportunity.”

In addition to Szabo and Hellmich, authors of the study include UTMB associate professor Celia Chao, postdoctoral fellows Ciro Coletta and Katalin Modis, assistant professor Bartosz Szczesny and adjunct professor Andreas Papapetropoulos.

The research was funded by the John Sealy Memorial Endowment Fund, the McLaughlin Foundation, the American Heart Association, the US National Institutes of Health (NIH), the European Union (EU) and the Greek national fund.