[PDF][PDF] Selective translation of cell fate regulators mediates tolerance to broad oncogenic stress

EY Cai, MN Kufeld, S Schuster, S Arora, M Larkin… - Cell Stem Cell, 2020 - cell.com
EY Cai, MN Kufeld, S Schuster, S Arora, M Larkin, AA Germanos, AC Hsieh, S Beronja
Cell Stem Cell, 2020cell.com
Human skin tolerates a surprisingly high burden of oncogenic lesions. Although adult
epidermis can suppress the expansion of individual mutant clones, the mechanisms behind
tolerance to oncogene activation across broader regions of tissue are unclear. Here, we
uncover a dynamic translational mechanism that coordinates oncogenic HRAS-induced
hyperproliferation with loss of progenitor self-renewal to restrain aberrant growth and
tumorigenesis. We identify translation initiator eIF2B5 as a central co-regulator of HRAS …
Summary
Human skin tolerates a surprisingly high burden of oncogenic lesions. Although adult epidermis can suppress the expansion of individual mutant clones, the mechanisms behind tolerance to oncogene activation across broader regions of tissue are unclear. Here, we uncover a dynamic translational mechanism that coordinates oncogenic HRAS-induced hyperproliferation with loss of progenitor self-renewal to restrain aberrant growth and tumorigenesis. We identify translation initiator eIF2B5 as a central co-regulator of HRAS proliferation and cell fate choice. By coupling in vivo ribosome profiling with genetic screening, we provide direct evidence that oncogene-induced loss of progenitor self-renewal is driven by eIF2B5-mediated translation of ubiquitination genes. Ubiquitin ligase FBXO32 specifically inhibits epidermal renewal without affecting overall proliferation, thus restraining HRAS-driven tumorigenesis while maintaining normal tissue growth. Thus, oncogene-driven translation is not necessarily inherently tumor promoting but instead can manage widespread oncogenic stress by steering progenitor fate to prolong normal tissue growth.
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