The translational landscape of mTOR signaling steers cancer initiation and metastasis

The mammalian target of rapamycin (mTOR) kinase is a master regulator of protein synthesis that couples nutrient sensing to cell growth and cancer. However, the downstream translationally regulated nodes of gene expression that may direct cancer development are poorly characterized. Employing ribosome profiling we uncover specialized translation of the prostate cancer genome by oncogenic mTOR signaling, revealing a remarkably specific repertoire of genes involved in cell proliferation, metabolism, and invasion. We extend these findings by functionally characterizing a class of translationally controlled pro-invasion mRNAs that we show direct prostate cancer invasion and metastasis downstream of oncogenic mTOR signaling. We further develop a clinically relevant ATP site inhibitor of mTOR, INK128, which reprograms this gene expression signature with therapeutic benefit for prostate cancer metastasis, for which there is presently no cure. Together, these findings significantly extend our understanding of how the “cancerous” translation machinery steers specific cancer cell behaviors and may be therapeutically targeted.