Epidermal growth factor receptor (EGFR) is a target of the tumor-suppressor E3 ligase FBXW7

• 成果类型: Article
• 署名作者: Borettoa, Matteo; Geurtsa, Maarten H.; Gandhia, Shashank; Mac, Zilian; Staliarovae, Nadzeya; Celottia, Martina; Lima, Sangho; Hea, Gui-Wei; Millena, Rosemary; Driehuisa, Else; Begthela, Harry; Smabersf, Lidwien; Roodhartf, Jeanine; van Esa, Johan; Wu, Wei; Clevers, Hans
• 署名单位: Royal Netherlands Academy of Arts & Sciences; Hubrecht Institute (KNAW); Utrecht University; Utrecht University Medical Center; University of California System; University of California Berkeley; Agency for Science Technology & Research (A*STAR); A*STAR - Singapore Immunology Network (SIgN); National University of Singapore; Utrecht University; Utrecht University; Utrecht University; Utrecht University Medical Center; Roche Holding
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-10046
• DOI: 10.1073/pnas.2309902121
• 发表日期: 2024-03-19
• 关键词: colorectal-cancer; cyclin-e; ubiquitin ligase; genomic dna; organoids; fbw7; phosphorylation; mutations; diversity; degradation

摘要

FBXW7 is an E3 ubiquitin ligase that targets proteins for proteasome- mediated degradation and is mutated in various cancer types. Here, we use CRISPR base editors to introduce different FBXW7hotspot mutations in human colon organoids. Functionally, FBXW7 mutation reduces EGF dependency of organoid growth by similar to 10,000-fold. Combined transcriptomic and proteomic analyses revealed increased EGFR protein stability in FBXW7 mutants. Two distinct phosphodegron motifs reside in the cytoplasmic tail of EGFR. Mutations in these phosphodegron motifs occur in human cancer. CRISPR- mediated disruption of the phosphodegron motif at T693 reduced EGFR degradation and EGF growth factor dependency. FBXW7 mutant organoids showed reduced sensitivity to EGFR-MAPK inhibitors. These observations were further strengthened in CRC- derived organoid lines and validated in a cohort of patients treated with panitumumab. Our data imply that FBXW7 mutations reduce EGF dependency by disabling EGFR turnover.