Background: The neddylation pathway is overactivated in human cancers. Inhibition of neddylation pathway has emerged as an attractive anticancer strategy. The mechanisms underlying neddylation overactivation in cancer remain elusive. MLN4924/Pevonedistat, a first-in-class NEDD8-activating enzyme (NAE, E1) inhibitor, exerts significant anti-tumor effects, but its mutagenic resistance remains unresolved.
Methods: The expression of NEDD8-conjugating enzyme UBC12/UBE2M(E2) and NEDD8 were estimated by bioinformatics analysis and western blot in human lung cancer cell lines. The malignant phenotypes of lung cancer cells were evaluated both in vitro and in vivo upon UBC12 knockdown. Cell-cycle arrest was evaluated by quantitative proteomic analysis and propidium iodide stain and fluorescence - activated cell sorting (FACS). The growth of MLN4924 - resistant H1299 cells was also evaluated upon UBC12 knockdown.
Findings: The mRNA level of UBC12 in lung cancer tissues was much higher than that in normal lung tissues, increased with disease deterioration, and positively correlated with NEDD8 expression. Moreover, the overexpression of UBC12 significantly enhanced protein neddylation modification whereas the downregulation of UBC12 reduced neddylation modification of target proteins. Functionally, neddylation inactivation by UBC12 knockdown suppressed the malignant phenotypes of lung cancer cells both in vitro and in vivo. The quantitative proteomic analysis and cell cycle profiling showed that UBC12 knockdown disturbed cell cycle progression by triggering G(2) phase cell-cycle arrest. Further mechanistical studies revealed that UBC12 knockdown inhibited Cullin neddylation, led to the inactivation of CRL E3 ligases and induced the accumulation of tumor-suppressive CRL substrates (p21, p27 and Wee1) to induce cell cycle arrest and suppress the malignant phenotypes of lung cancer cells. Finally, UBC12 knockdown effectively inhibited the growth of MLN4924-resistant lung cancer cells.
Interpretation: These findings highlight a crucial role of UBC12 in fine-tuned regulation of neddylation activation status and validate UBC12 as an attractive alternative anticancer target against neddylation pathway. (C) 2019 The Authors. Published by Elsevier B.V.
[1]Shanghai Univ Tradit Chinese Med, Longhua Hosp, Canc Inst Tradit Chinese Med, Shanghai, Peoples R China.
[2]Fudan Univ, Shanghai Canc Ctr, Canc Inst, Shanghai, Peoples R China.
[3]Fudan Univ, Huadong Hosp, Dept Lab Med, Shanghai, Peoples R China.
[4]Zhejiang Chinese Med Univ, Zhejiang Prov Hosp Tradit Chinese Med, Affiliated Hosp 1, Hangzhou, Zhejiang, Peoples R China.
[5]Southern Univ Sci & Technol, Sch Med, Shenzhen, Peoples R China.
[6]Shanghai Jiao Tong Univ, Xinhua Hosp, Shanghai, Peoples R China.
(8.0+极速模式)