OTUD7B deubiquitinates and stabilizes YAP1 to upregulate NUAK2 expression, thus accelerating gastric cancer procession

YAP/TAZ-associated cell signaling - at the crossroads of cancer and neurodevelopmental disorders

YAP/TAZ (Yes-associated protein/paralog transcriptional co-activator with PDZ-binding domain) are transcriptional cofactors that are the key and major downstream effectors of the Hippo signaling pathway. Both are known to play a crucial role in defining cellular outcomes, including cell differentiation, cell proliferation, and apoptosis. Aside from the canonical Hippo signaling cascade with the key components MST1/2 (mammalian STE20-like kinase 1/2), SAV1 (Salvador homologue 1), MOB1A/B (Mps one binder kinase activator 1A/B) and LATS1/2 (large tumor suppressor kinase 1/2) upstream of YAP/TAZ, YAP/TAZ activation is also influenced by numerous other signaling pathways. Such non-canonical regulation of YAP/TAZ includes well-known growth factor signaling pathways such as the epidermal growth factor receptor (EGFR)/ErbB family, Notch, and Wnt signaling as well as cell-cell adhesion, cell-matrix interactions and mechanical cues from a cell's microenvironment. This puts YAP/TAZ at the center of a complex signaling network capable of regulating developmental processes and tissue regeneration. On the other hand, dysregulation of YAP/TAZ signaling has been implicated in numerous diseases including various cancers and neurodevelopmental disorders. Indeed, in recent years, parallels between cancer development and neurodevelopmental disorders have become apparent with YAP/TAZ signaling being one of these pathways. This review discusses the role of YAP/TAZ in brain development, cancer and neurodevelopmental disorders with a special focus on the interconnection in the role of YAP/TAZ in these different conditions.

BIRC5 as a prognostic and diagnostic biomarker in pan-cancer: an integrated analysis of expression, immune subtypes, and functional networks

Introduction

BIRC5 (Survivin) is a crucial anti-apoptotic protein overexpressed in various cancers, promoting tumor growth and treatment resistance. This study investigates its expression across 33 cancer types and explores its diagnostic, prognostic, and immune-related significance.

Methods

We analyzed RNA-seq data from TCGA and protein expression data from the Human Protein Atlas. Expression levels were compared between tumor and normal tissues. Correlations with molecular and immune subtypes were explored using TISIDB. Prognostic significance was evaluated through survival analysis, Cox regression, and ROC curve analysis. The PPI network was constructed using STRING.

Results

BIRC5 was significantly overexpressed in tumor tissues across 33 cancer types, with higher expression levels observed in tumors compared to normal tissues. The protein expression analysis revealed a similar trend. BIRC5 expression was significantly correlated with various molecular and immune subtypes in multiple cancer types. Survival analysis indicated that high BIRC5 expression was associated with poor prognosis across multiple cancers, including lung adenocarcinoma (LUAD) and kidney renal clear cell carcinoma (KIRC). ROC analysis showed that BIRC5 exhibited strong diagnostic potential, with high AUC values (>0.9) in several cancers. The PPI network analysis identified key interacting proteins involved in the cell cycle and tumor progression, further supporting BIRC5's role in cancer biology. Functional experiments in lung adenocarcinoma (LUAD) revealed that BIRC5 upregulation enhances cell proliferation, migration, and invasion, while its knockdown suppresses these activities.

Discussion

BIRC5 is a promising diagnostic and prognostic biomarker in multiple cancers. Its association with immune subtypes suggests a potential role in the tumor immune microenvironment. These findings support BIRC5 as a therapeutic target for cancer treatment.

OTUD7B promotes cell migration and invasion, predicting poor prognosis of gastric cancer

BACKGROUND

OTUD7B, a member of the ovarian tumor (OTU) protein superfamily, functions as a deubiquitinating enzyme and is associated with various biological processes and disease conditions, including tumors. In this study, we aimed to explore the expression patterns, prognostic significance, and the functional roles and underlying mechanisms of OTUD7B in gastric cancer (GC).

MATERIALS AND METHODS

Using a blend of bioinformatics, clinical case reviews, and molecular experiments, we evaluated the expression of OTUD7B in GC at both mRNA and protein levels. We examined the relationship between OTUD7B expression and clinicopathological characteristics of GC patients. Additionally, in vitro assays were utilized to assess the effects of OTUD7B on the migratory and invasive capabilities of GC cells. RNA sequencing analysis was conducted to identify critical genes and pathways linked to OTUD7B in GC.

RESULTS

OTUD7B was found to be significantly overexpressed in GC, both at mRNA and protein levels. Higher levels of OTUD7B were positively associated with advanced tumor TNM stage, higher histological grade, and presence of lymph/vein invasion. These correlations were indicative of poorer overall survival (OS) and disease-free survival (DFS) in GC patients. In vitro assays revealed that genetic knockout of OTUD7B markedly reduced the migration and invasion of GC cells, while overexpression of OTUD7B led to enhanced cellular migration and invasion. Furthermore, RNA sequencing and bioinformatic analyses indicated that the absence of OTUD7B suppressed signaling pathways related to cancer progression, metastasis, and metabolism. Mechanistically, OTUD7B likely promotes GC metastasis through the WNT signaling pathway, specifically targeting β-catenin.

CONCLUSIONS

OTUD7B serves as a novel marker for poor prognosis in GC and actively promotes tumor metastasis. Our results shed light on the signaling pathways regulated by OTUD7B and highlight potential targets for therapeutic intervention.

The suppression of OTUD7B by miR-491-5p enhances the ubiquitination of VEGFA to suppress vascular mimicry in non-small cell lung cancer

BACKGROUND

Non-small cell lung cancer (NSCLC) is the main type of lung cancer with high morbidity and mortality. Vascular mimicry (VM), a distinct microcirculation model in tumors that differs from classical angiogenesis, is strongly associated with poor clinical outcomes in cancer patients. miR-491-5p has been reported to prevent NSCLC progression, including proliferation, metastasis, and angiogenesis. However, the effect and mechanism of miR-491-5p on VM have not been studied in NSCLC.

METHODS

The expression of miR-491-5p was detected by quantitative reverse transcription PCR (qPCR) and fluorescence in situ hybridization (FISH). Cell counting kit-8 (CCK-8) and 5-ethynyl-2'-deoxyuridine (EdU) staining assays were used to examine cell growth. Tube formation assay was used to assess VM in NSCLC cells. Immunohistochemistry (IHC) and western blot were performed to detect protein expression. Immunoprecipitation was used to confirm the interaction between OTU deubiquitinase 7B (OTUD7B) and vascular endothelial growth factor A (VEGFA), and the level of ubiquitinated VEGFA. A nude mouse tumorigenesis model was used to evaluate the carcinogenic capacity of NSCLC cells in vivo. Luciferase reporter assay was used to identify the potential target of miR-491-5p.

RESULTS

MiR-491-5p was found downregulated in NSCLC tissues, and miR-491-5p deficiency was strongly associated with angiogenesis. miR-491-5p mimics suppressed cell viability, migration, and VM. Conversely, an inhibitor of miR-491-5p had the opposite effect. OTUD7B, a deubiquitinase, was identified as a downstream target of miR-491-5p. A luciferase reporter assay indicated that miR-491-5p directly binds to the 3'UTR of OTUD7B. Moreover, mimics of miR-491-5p caused a significant reduction in the OTUD7B protein in NSCLC cells, and an inhibitor of miR-491-5p stabilized the OTUD7B protein. In addition, overexpression of OTUD7B promoted cell proliferation, migration, and VM, similar to the effects of an inhibitor of miR-491-5p. Further exploration revealed that OTUD7B interacts with VEGFA and that the miR-491-5p-OTUD7B axis modulates the ubiquitination of VEGFA. The rescue experiment indicated that OTUD7B compromised the inhibitory effects of miR-491-5p on the cellular function of NSCLC cells.

CONCLUSIONS

Overall, our study first proved that miR-491-5p impedes VM by suppressing OUTD7B and promoting the ubiquitination of VEGFA. The miR-491-5p/OTUD7B axis may be a novel target for antiangiogenic therapy in NSCLC.

Depletion of NUAK2 blocks the stemness and angiogenesis and facilitates senescence of lung adenocarcinoma cells via enhancing ferroptosis

BACKGROUND

NUAK family kinase 2 (NUAK2) has been identified as an important mediator for tumor progression in multiple malignancies. Nevertheless, its role in lung adenocarcinoma (LUAD) remains unclear.

METHODS

Bioinformatic analysis was performed to assess the expression and prognosis of NUAK2 in patients with LUAD. The NUAK2 expression was measured in multiple LUAD cell lines, and the loss-of-function experiment was conducted. Cell proliferation ability was assessed using CCK-8 and colony formation assays. Spheroid formation, alkaline phosphatase (AP) staining, tube formation and SA-β-gal staining assays were performed to examine stemness, angiogenesis and senescence. Lipid peroxidase was assessed by TBARS production and lipid ROS. Western blot was used to detect critical proteins. In addition, A549 cells were treated with ferroptosis inhibitor ferrostatin-1 (Fer-1) for a rescue assay. Finally, A549 cells were subcutaneously injected into the right flank of mice to establish LUAD-bearing mouse model, and the tumor weight and size were detected.

RESULTS

NUAK2 was upregulated in patients with LUAD and LUAD cell lines. NUAK2 depletion inhibited cell viability, colonies, tumor spheres and decreased Oct4 and Nanog expression, confirming NUAK2 depletion inhibited proliferation and stemness of A549 cells. Meanwhile, NUAK2 depletion blocked angiogenesis via reducing formed tubes and VEGFR1/2 expression, and promoted senescence of A549 cells by elevating SA-β-gal-positive cells and p16, p21 and p53 expression. Moreover, NUAK2 depletion elevated lipid ROS, TBARS production and Fe2+ level, demonstrating that NUAK2 depletion could trigger ferroptosis in A549 cells. Furthermore, the rescue experiments revealed that the impacts of NUAK2 depletion on malignant behaviors in A549 cells were partly weakened by additional Fer-1 treatment. Finally, in vivo experiments demonstrated that NUAK2 knockdown greatly inhibited tumor growth in LUAD-bearing mice.

CONCLUSION

In summary, NUAK2 depletion impeded oncogenic phenotypes of A549 cells partly via triggering ferroptosis, suggesting NUAK2 as a novel target for treating LUAD.

OTUD7B knockdown inhibits proliferation and autophagy through AKT/mTOR signaling pathway in human prostate cancer cell

Prostate cancer (PCa) is the second leading disease of cancer-related death in men around the world, and it is almost impossible to treat advanced PCa. OTUD7B is a member of the deubiquitinase family that undergoes a post-translational transformation process, which is essential for cell stability and signaling and is known to play a critical role in cancer. However, its role in PCa has not been discovered. The aim of the study was to investigate the expression and mechanism of OTUD7B in PCa cells. According to the database, high OTUD7B expression showed a poor prognosis. Therefore, we downregulated OTUD7B using siRNA and confirmed the role of OTUD7B in PC3 prostate cancer cells. OTUD7B knockdown effectively induced apoptosis and inhibited the proliferation in PC3 cells. OTUD7B knockdown inhibited autophagy through AKT/mTOR signaling. We also confirmed the relationship between AKT/mTOR signaling and autophagy through rapamycin, an mTOR inhibitor. Taken together, OTUD7B promotes the proliferation, and autophagy, and inhibits apoptosis of prostate cancer cells via the AKT/mTOR signaling pathway.

OTU deubiquitinase 7B facilitates the hyperthermia-induced inhibition of lung cancer progression through enhancing Smac-mediated mitochondrial dysfunction

Hyperthermia, as an adjuvant therapy, has shown promising anti-tumor effects. Ovarian tumor domain-containing 7B (OTUD7B) is a deubiquitinating enzyme that is frequently found in a variety of cancers. The aim of this study is to investigate the role of OTUD7B in lung cancer hyperthermia and the underlying mechanism. A549 and CALU-3 cells were respectively exposed to 42 or 44°C for the indicated times (0, 1, 3, or 6 h) followed by incubation at 37°C for 24 h. We found a temperature- and time-dependent decrease in cell viability and an increase in apoptosis levels. Compared with 0 h, heat treatment for 3 h inhibited the proliferation and invasion of A549 cells, reduced the expression levels of mitochondrial membrane potential, IAP family members (cIAP-1 and XIAP) proteins and ubiquitination of Smac, and increased Smac protein expression. Treatment with 10 μM Smac mimic BV6 further enhanced the anti-tumor effect of hyperthermia. Next, co-IP validation showed that OTUD7B interacted with Smac and stabilized Smac through deubiquitination. OTUD7B overexpression induced damage in A549 and CALU-3 cells, while silencing OTUD7B caused opposite effects. Overexpressing OTUD7B enhanced the anti-cancer effect of hyperthermia, while si-OTUD7B reversed the anti-cancer effect of hyperthermia, which was verified in the xenograft tumor model in nude mice. Taken together, OTUD7B may serve as a potential anticancer factor with potential clinical efficacy in the thermotherapeutic treatment of lung cancer.