利用干细胞对付脑肿瘤

Harvard Stem Cell Institute scientists at Massachusetts General Hospital have devised a new way to use stem cells in the fight against brain cancer. A team led by neuroscientist Khalid Shah, MS, PhD, who recently demonstrated the value of stem cells loaded with cancer-killing herpes viruses, now has a way to genetically¹ engineer stem cells so that they can produce and secrete² tumor³-killing toxins⁴. In the AlphaMed Press journal Stem Cells, Shah's team shows how the toxin-secreting stem cells can be used to eradicate⁵ cancer cells remaining in mouse brains after their main tumor has been removed. The stem cells are placed at the site encapsulated in a biodegradable gel. This method solves the delivery issue that probably led to the failure of recent clinical trials aimed at delivering purified cancer-killing toxins into patients' brains. Shah and his team are currently pursuing FDA approval to bring this and other stem cell approaches developed by them to clinical trials.   "Cancer-killing toxins have been used with great success in a variety of blood cancers, but they don't work as well in solid tumors because the cancers aren't as accessible and the toxins have a short half-life," said Shah, who directs the Molecular⁶ Neurotherapy and Imaging Lab at Massachusetts General Hospital and Harvard Medical School.   "A few years ago we recognized that stem cells could be used to continuously deliver these therapeutic⁷ toxins to tumors in the brain, but first we needed to genetically engineer stem cells that could resist being killed themselves by the toxins," he said. "Now, we have toxin-resistant stem cells that can make and release cancer-killing drugs."