Biologists unravel drug-resistance mechanism in tumor cells
About half of all tumors are missing a gene called p53, which helps healthy cells prevent genetic mutations. Many of these tumors develop resistance to chemotherapy drugs that kill cells by damaging their DNA. MIT cancer biologists have now discovered how this happens: A backup system that takes over when p53 is disabled encourages cancer cells to continue dividing even when they have suffered extensive DNA damage. The researchers also discovered that an RNA-binding protein called hnRNPA0 is a key player in this pathway. “I would argue that this particular RNA-binding protein is really what makes tumor cells resistant to being killed by chemotherapy when p53 is not around,” says Michael Yaffe, the David H. Koch Professor in Science, a member of the Koch Institute for Integrative Cancer Research, and the senior author of the study, which appears in the Oct. 22 issue of Cancer Cell. The findings suggest that shutting off this...