USP6NL mediated by LINC00689/miR-142-3p promotes the development of triple-negative breast cancer.

BACKGROUND: Triple-negative breast cancer (TNBC), in part because of the high metastasis rate, is one of the most prevalent causes of malignancy-related mortality globally. Ubiquitin specific peptidase 6 N-terminal like (USP6NL) has been unmasked to be implicated in some human cancers. However, the precise biological function of USP6NL in TNBC has not been defined. METHODS: RNA expression was examined by real-time quantitative PCR (RT-qPCR), while USP6NL protein level was tested through western blot. Besides, cell proliferation was assessed by using colony formation assay, whereas cell apoptosis estimated by flow cytometry analysis, JC-1 assay and TUNEL assay. Transwell assays were adopted to detect the migration and invasion of indicated TNBC cells. Immunofluorescence (IF) assay evaluated epithelial-mesenchymal transitions (EMT) progress in TNBC. Further, RNA immunoprecipitation (RIP), RNA pull down and luciferase reporter assays were implemented for measuring the mutual interplay among USP6NL, miR-142-3p and long intergenic non-protein coding RNA 689 (LINC00689). RESULTS: Elevated USP6NL level was uncovered in TNBC cells. RNA interference-mediated knockdown of USP6NL inhibited TNBC cell growth, motility and EMT. Further, USP6NL was proved as the target of a tumor-inhibitor miR-142-3p, and LINC00689 augmented USP6NL expression by absorbing miR-142-3p. Importantly, miR-142-3p deficiency or USP6NL overexpression fully abolished the inhibitory effect of LINC00689 silence on TNBC cellular behaviors. CONCLUSION: All data revealed the important role of USP6NL/LINC00689/miR-142-3p signaling in TNBC. The findings might provide a new and promising therapeutic biomarker for treating patients with TNBC.

Tre2 (USP6NL) promotes colorectal cancer cell proliferation via Wnt/ß-catenin pathway.

BACKGROUND: Most colorectal cancer (CRC) patients are diagnosed at an advanced or metastatic stage with poor prognosis. Ubiquitin-specific protease 6 N-terminal-like protein (USP6NL) with high expression in CRC tissues regulates CRC cell proliferation via Wnt/ß-catenin pathway. We hypothesized that USP6NL impacts CRC growth and inhibition of USP6NL may be a novel treatment strategy to improve CRC therapy. METHODS: USP6NL level in human CRC tissues and its association with tumor growth and metastasis were examined. Its roles and potential mechanisms in regulating tumor growth were studied by genetic and pharmacological manipulation of CRC cells in vitro and in vivo. RESULTS: Herein, we found that USP6NL was up-regulated in tumorous tissues of CRC patients. Our data suggested that knockdown of USP6NL in human CRC cell lines (HCT116 and LOVO cells) inhibited cell proliferation, induced G0/G1 cell cycle arrest, and prevented the tumorigenicity of HCT116 cells in nude mice, and which was associated with the prevention of Wnt/ß-catenin pathway. On the contrary, USP6NL overexpression in human CRC cells (SW480) showed the opposite result. Our data suggested that the promoted cell proliferation, G1/S cell cycle progression, and the enhanced expression of ß-catenin Cyclin D1 and C-myc while reduced P27 induced by the overexpression of USP6NL were significantly reversed by additional treatment of XAV939, indicating that activating Wnt/ß-catenin pathway was the mechanism, by which USP6NL exerted carcinogenesis in CRC in vitro. Besides, our data suggested that knockdown of USP6NL increased the ubiquitination of ß-catenin, indicating that USP6NL may serve as a deubiquitinase that regulated ß-catenin accumulation in this process. Furthermore, 10058-F4 down-regulated USP6NL, inhibited CRC cell proliferation and induced cell cycle arrest. The result demonstrated a possible feedback loop between USP6NL, ß-catenin and C-myc in regulating CRC cell growth. CONCLUSION: USP6NL was an oncogene in CRC, and it may be a potential target for the treatment of CRC.

BMSC derived EVs inhibit colorectal Cancer progression by transporting MAGI2-AS3 or something similar.

In this study, we investigated the molecular mechanisms underlying the impact of extracellular vesicles (EVs) derived from bone marrow stromal cells (BMSCs) on colorectal cancer (CRC) development. The focus was on the role of MAGI2-AS3, delivered by BMSC-EVs, in regulating USP6NL DNA methylation-mediated MYC protein translation modification to promote CDK2 downregulation. Utilizing bioinformatics analysis, we identified significant enrichment of MAGI2-AS3 related to copper-induced cell death in CRC. In vitro experiments demonstrated the downregulation of MAGI2-AS3 in CRC cells, and BMSC-EVs were found to deliver MAGI2-AS3 to inhibit CRC cell proliferation, migration, and invasion. Further exploration revealed that MAGI2-AS3 suppressed MYC protein translation modification by regulating USP6NL DNA methylation, leading to CDK2 downregulation and prevention of colorectal cancer. Overexpression of MYC reversed the functional effects of BMSC-EVs-MAGI2-AS3. In vivo experiments validated the inhibitory impact of BMSC-EVs-MAGI2-AS3 on CRC tumorigenicity by promoting CDK2 downregulation through USP6NL DNA methylation-mediated MYC protein translation modification. Overall, BMSC-EVs-MAGI2-AS3 may serve as a potential intervention to prevent CRC occurrence by modulating key molecular pathways.

Ubiquitin-Specific Protease 6 n-Terminal-like Protein (USP6NL) and the Epidermal Growth Factor Receptor (EGFR) Signaling Axis Regulates Ubiquitin-Mediated DNA Repair and Temozolomide-Resistance in Glioblastoma.

Glioblastoma multiforme (GBM) is the most malignant glioma, with a 30-60% epidermal growth factor receptor (EGFR) mutation. This mutation is associated with unrestricted cell growth and increases the possibility of cancer invasion. Patients with EGFR-mutated GBM often develop resistance to the available treatment modalities and higher recurrence rates. The drug resistance observed is associated with multiple genetic or epigenetic factors. The ubiquitin-specific protease 6 N-terminal-like protein (USP6NL) is a GTPase-activating protein that functions as a deubiquitinating enzyme and regulates endocytosis and signal transduction. It is highly expressed in many cancer types and may promote the growth and proliferation of cancer cells. We hypothesized that USP6NL affects GBM chemoresistance and tumorigenesis, and that its inhibition may be a novel therapeutic strategy for GBM treatment. The USP6NL level, together with EGFR expression in human GBM tissue samples and cell lines associated with therapy resistance, tumor growth, and cancer invasion, were investigated. Its pivotal roles and potential mechanism in modulating tumor growth, and the key mechanism associated with therapy resistance of GBM cells, were studied, both in vitro and in vivo. Herein, we found that deubiquitinase USP6NL and growth factor receptor EGFR were strongly associated with the oncogenicity and resistance of GBM, both in vitro and in vivo, toward temozolomide, as evidenced by enhanced migration, invasion, and acquisition of a highly invasive and drug-resistant phenotype by the GBM cells. Furthermore, abrogation of USP6NL reversed the properties of GBM cells and resensitized them toward temozolomide by enhancing autophagy and reducing the DNA damage repair response. Our results provide novel insights into the probable mechanism through which USP6NL/EGFR signaling might suppress the anticancer therapeutic response, induce cancer invasiveness, and facilitate reduced sensitivity to temozolomide treatment in GBM in an autolysosome-dependent manner. Therefore, controlling the USP6NL may offer an alternative, but efficient, therapeutic strategy for targeting and eradicating otherwise resistant and recurrent phenotypes of aggressive GBM cells.