Scientists at the University of California have found a potential new use for human embryonic stem cells: helping cancer patients recover the cognitive function lost when their brains are treated with radiation.
People with tumors in their head or neck often undergo radiation therapy after the cancer is surgically removed. Radiation helps kill malignant cells left behind. But it also can debilitate the hippocampus, the brain region responsible for learning, memory and processing of spatial information.
The researchers wondered whether embryonic stem cells could pick up the slack.
So they radiated the heads of 18 rats. Two days later, six of those rats got two injections of human embryonic stem cells directly into the hippocampus. After four months, the researchers measured the rats’ cognitive abilities. They placed the rats in an arena with two Lego blocks and let them explore. When they were done, the researchers took the rats out of the arena and moved one block. Five minutes later, the rats went back in.
All of the animals studied both of the blocks, but the rats that were treated with stem cells spent far more time nosing around the one that had been moved. And the radiated rats that didn’t get stem cells lost half of their cognitive function, according to the study, published in the Proceedings of the National Academy of Sciences.
The results suggest that embryonic stem cells could spare cancer patients much of the short-term memory loss from cranial radiation.