Ubiquitin-specific peptidase 5 facilitates cancer stem cell-like properties in lung cancer by deubiquitinating β-catenin

Abstract

Background Lung cancer has the highest mortality rate in the world, and mounting evidence suggests that cancer stem cells (CSCs) are associated with poor prognosis, recurrence, and metastasis of lung cancer. It is urgent to identify new biomarkers and therapeutic targets for targeting lung CSCs. Methods We computed the single-sample gene set enrichment analysis (ssGSEA) of 1554 Reactome gene sets to identify the mRNA expression-based stemness index (mRNAsi)-associated pathways using the genome-wide RNA sequencing data of 509 patients from The Cancer Genome Atlas (TCGA) cohort of lung adenocarcinoma (LUAD). Phenotypic effects of ubiquitin-specific peptidase 5 (USP5) on the CSC-like properties and metastasis were examined by in vitro sphere formation assay, migration assay, invasion assay, and in vivo xenografted animal models. Cycloheximide chase assay, co-immunoprecipitation assay, and deubiquitination assay were performed to confirm the effect of USP5 on the deubiquitination of β-catenin. Results We demonstrated that USP5 expression were positively correlated with the stemness-associated signatures and poor outcomes in lung cancer specimens. Silencing of endogenous USP5 reduced CSC-like characteristics, epithelial-mesenchymal transition (EMT), and metastasis in vitro and in vivo. Furthermore, USP5 interacted with β-catenin, which resulted in deubiquitination, stabilization of β-catenin, and activation of Wnt/β-catenin pathway. Accordingly, expression of USP5 was positively correlated with the enrichment score of the Wnt/TCF pathway signature in human lung cancer. Silencing of β-catenin expression suppressed USP5-enhancing sphere formation. Targeting USP5 with the small molecule WP1130 promoted the degradation of β-catenin, and showed great inhibitory effects on sphere formation, migration, and invasion. Finally, we identified a poor-prognosis subset of tumors characterized by high levels of USP5, Wnt signaling score, and Stemness score in both TCGA-LUAD and Rousseaux_2013 datasets. Conclusions These findings reveal a clinical evidence for USP5-enhanced Wnt/β-catenin signaling in promoting lung cancer stemness and metastasis, implying that targeting USP5 could provide beneficial effects to improve lung cancer therapeutics.

NR5A2 gene affects the overall survival of LUAD patients by regulating the activity of CSCs through SNP pathway by OCLR algorithm and immune score

“…This study showed significant advancements and characteristics in the regulation of CSC activity by the NR5A2 gene [ [46] , [47] , [48] , [49] , [50] ]. First, we used the OCLR algorithm and immune score to fully reveal the expression pattern of NR5A2 in patients with LUAD and systematically elaborated its regulatory mechanism on CSC activity.…”

Wnt/β-catenin signaling in the development and therapeutic resistance of non-small cell lung cancer

“…The deubiquitination is closely related to Wnt/β-catenin pathway and that many regulators have been found to mediate the ubiquitination level of β-catenin, including lncRNA PKMYT1AR [ 99 ], FABP7 [ 121 ], and USP5 [ 122 ] (Table 2 ). Of them, the PKMYT1AR/miR-485-5p/PKMYT1 axis inhibits ubiquitin-mediated degradation of β-catenin, which in turn promotes CSC maintenance and enhances tumorigenesis in NSCLC [ 99 ].…”

“…USP5 encodes ubiquitin-specific peptidase 5, one of the deubiquitinating enzymes remove ubiquitin from target proteins. USP5 directly interacts with β-catenin, leading to deubiquitination, stabilization of β-catenin in NSCLC cells [ 122 ].…”

“…USP5 has also been found to be a positive regulator of Wnt/β‑catenin signaling in NSCLC. Targeting USP5 with the small molecule WP1130 induced the degradation of β-catenin, and showed markedly inhibitory effects on tumor growth and metastasis [ 122 ].…”

Promotion of stem cell-like phenotype of lung adenocarcinoma by FAM83A via stabilization of ErbB2

“…Although a large amount of patients have received clinical treatment, they still experience poor prognosis due to drug resistance, recurrence, or metastasis, which is attributed to the presence of CSCs. Compelling evidence has uncovered that tumor progression is intricately associated with the existence of CSCs within the tumor bulk, including LUAD, ovarian cancer, hematologic tumors, and so on [ 11 , 12 ]. CSC-like phenotypes also play important roles in metastasis, recurrence, and other malignant phenotypes, which can be characterized by several methods including spheroid formative capacity, stem cell marker expression, tumorigenic potential, and increased invasiveness [ 12 – 14 ].…”