“That was mind-boggling, that bacteria could cause cancer,” Salama said. “That captivated me and I thought, ‘Wow, I don’t know how I’m going to do it, but I’m going to study H. pylori.’”
Salama is also studying how other bugs in our body interact with H. pylori and whether that bacterial interplay could push an infected person toward developing gastric cancer.
And to help them untangle exactly how H. pylori contributes the tissue changes that precede stomach cancer, she and her team are capitalizing on a new preclinical model of the process.
After H. pylori infects the stomach, it causes inflammation that can prompt the lining of the stomach to undergo characteristic changes that raise a person’s risk of cancer. First the cells that secrete acid and those that release digestive enzymes are destroyed, and the stomach’s pH increases. Then the cells lining the stomach take on characteristics of the cells that line the intestine, a process called intestinal metaplasia.
“People with these metaplasias are at much higher risk for gastric cancer,” Salama said. “I’ve always been interested in how H. pylori interacts with metaplasias, but it’s very difficult to study.”
Using the new model, Salama’s team was able to show that the bacterium exacerbates and hastens the stomach’s metaplastic tissue changes. Now, they’re exploring whether H. pylori does more to promote cancer than maintain stomach inflammation, and how the bug itself adapts to the environmental changes it triggered.
Salama is also branching out: H. pylori is not the only bacteria that infects the stomach, and she is investigating whether other bacterial species contribute to the development of stomach cancer. It may be that H. pylori teams up with — or is replaced by — other bacteria at later stages of disease.
Salama said collaboration and a risk-taking culture have propelled her work at Fred Hutch. "Isolation really stifles creativity," she said. "But working together to blend creative approaches is encouraged here. I love that we're constantly getting reseeded with new ideas."
Taking chances and exploring unexpected research paths are the essence of good science, Salama said. "You have an idea to bring things together one way, but you don't know where things are going to go. Just starting the process is critical — if you never start, you'll never learn."
— By Rachel Tompa, updated Dec. 12, 2022