Depletion of the E3 ubiquitin ligase HUWE1 impairs Kras-induced lung adenocarcinoma tumorigenesis and induces a senescent phenotype
The E3 ubiquitin ligase HUWE1 modifies a diverse network of substrate proteins by ubiquitination, through which it regulates various intracellular processes and contributes to both oncogenic and tumour suppressor mechanisms in different cancer contexts. Here, by analysing human lung adenocarcinoma (LUAD) patient samples we reveal that HUWE1 protein expression is commonly upregulated in LUAD tumours compared to normal adjacent lung tissue and that this increase is associated with tumour stage. Using multiple, independent murine models of LUAD initiation and growth, we identify that Huwe1 is essential for mutant Kras-induced lung tumour development and reveal a novel, p53-independent requirement for Huwe1 in LUAD. Mechanistically, we demonstrate induction of a senescent phenotype following HUWE1 depletion - characterised by impaired proliferation, an atypical cell cycle distribution, emergence of morphologically abnormal enlarged cells, and transcriptional reprogramming associated with inflammatory SASP signalling and NFkB activation. Together, these data highlight a crucial role for HUWE1 in mutant Kras-induced LUAD tumorigenesis and in the continued growth and proliferation of established LUAD cells, confirming HUWE1 as a rational therapeutic target for LUAD. Overall design: Transcriptomic analysis of H358 LUAD cells -/+ treatment with doxycycline to induce expression of control (shCTRL) or HUWE1 targeting (shHUWE1) shRNA constructs. Three biological replicates of each condition.