Again and again, research on the parasite toxoplasma gondii, commonly found in cat feces, reveals just how nasty and widespread it is. It's linked to rage disorder, might boost one's risk of schizophrenia and other mental disorders, and in an odd and probably fatal twist, makes the mice it infects no longer fear cats. But new research out of Dartmouth's Geisel School of Medicine suggests that, at least in mice, it has a major upside: The parasite secretes specific proteins that direct its immune system to attack ovarian tumors, the researchers report in the journal PLOS Genetics. They built upon previous research to produce a vaccine that's a safe strain of T. gondii, one that could cure mice of multiple types of solid tumors, not just ovarian.
Ovarian cancer usually isn't detected until it has metastasized, meaning it has spread to other tissues and organs. As a result, it accounts for the fifth-most cancer deaths among women, claiming more than 14,000 lives a year, per the American Cancer Society. Researchers note in a press release that clinical trials are already underway exploring the use of the bacterium Listeria monocytogenes to break the body's immune tolerance of pancreatic tumors and essentially whip the immune system into attack mode; T. gondii could work in a strikingly similarly way. What works in mice doesn't always work in humans, but scientists are hoping to develop therapies that attack the most aggressive tumors. (See why the "Holy Grail" of ovarian cancer may be near.)