T cells mark cancers for destruction by homing in on unique proteins that tumor cells display on their surfaces called tumor-specific antigens, in a process that leaves healthy cells untouched. This can lead to the regression and sometimes disappearance of tumors, but so far, scientists have yet to discern the sequences of the vast majority of tumor-specific antigens or how they arise.
Two new studies in mice and human tumors—both published on February 3 in Science—bring researchers a step closer to finding the origin of tumor-specific antigens. In both, scientists showed that some tumor-specific antigens might be the result of transposable elements, also called “jumping genes,” sneaking into an mRNA molecule by tacking themselves onto exons. Some of the resulting peptides are exclusively found on tumor cells and were shown to trigger an immune response. The finding could help researchers design more effective cancer therapies that can be better directed ...
