Research Paper Volume 12, Issue 19 pp 19273—19292

USP18 stabilizes and deconjugates K48-linked ubiquitination of Notch1. (A, B) The Pancreatic cancer cells were exposed to cycloheximide (CHX) (20 μmol/L) for the indicated times, and the degradation of Notch1 was detected with an anti-Notch1 antibody. (C and D) USP18 had no effect on Notch1 expression, as assessed by MG132 after transfection with shUSP18 or p-USP18 plasmid in pancreatic cancer cells. (E and F) Knockdown or exogenous expression of USP18 altered the ubiquitination of Notch1. The cells in each group were treated with the proteasomal inhibitor MG132. Cell lysates were prepared and subjected to immunoprecipitation with an anti-Notch1 antibody. The level of ubiquitin binding on Notch1 was detected by western blotting with an anti-Ub-K48 antibody. (G) Proposed model by which USP18 promotes PC progression by modifying Notch1/c-Myc axis.