The E3 Ubiquitin Ligase TRIM11 Facilitates Gastric Cancer Progression by Activating the Wnt/β-Catenin Pathway via Destabilizing Axin1 Protein

The therapeutic potential of RNA m(6)A in lung cancer

Lung cancer (LC) is a highly malignant and metastatic form of cancer. The global incidence of and mortality from LC is steadily increasing; the mean 5-year overall survival (OS) rate for LC is less than 20%. This frustrating situation may be attributed to the fact that the pathogenesis of LC remains poorly understood and there is still no cure for mid to advanced LC. Methylation at the N6-position of adenosine (N6mA) of RNA (m(6)A) is widely present in human tissues and organs, and has been found to be necessary for cell development and maintenance of homeostasis. However, numerous basic and clinical studies have demonstrated that RNA m(6)A is deregulated in many human malignancies including LC. This can drive LC malignant characteristics such as proliferation, stemness, invasion, epithelial-mesenchymal transition (EMT), metastasis, and therapeutic resistance. Intriguingly, an increasing number of studies have also shown that eliminating RNA m(6)A dysfunction can exert significant anti-cancer effects on LC such as suppression of cell proliferation and viability, induction of cell death, and reversal of treatment insensitivity. The current review comprehensively discusses the therapeutic potential of RNA m(6)A and its underlying molecular mechanisms in LC, providing useful information for the development of novel LC treatment strategies.

SPIN1 accelerates tumorigenesis and confers radioresistance in non-small cell lung cancer by orchestrating the FOXO3a/FOXM1 axis

Despite the importance of radiation therapy as a nonsurgical treatment for non-small cell lung cancer (NSCLC), radiation resistance has always been a concern because of poor patient response and outcomes. Therefore, it is crucial to identify novel targets to increase the effectiveness of radiotherapy and investigate the mechanisms underlying radioresistance. Previously, we demonstrated that Spindlin 1 (SPIN1) was related to tumour initiation and progression. In this study, we found that SPIN1 expression was higher in NSCLC tissues and cell lines than in the corresponding controls. SPIN1 overexpression in NSCLC patients was closely correlated with disease progression and poor prognosis. Functionally, SPIN1 depletion inhibited cell proliferation, decreased the percentage of cells in the G2/M phase and suppressed cell migration and invasion. Moreover, SPIN1 knockdown decreased the clonogenic capacity, impaired double-strand break (DSB) repair and increased NSCLC radiosensitivity. Mechanistically, forkhead box M1 (FOXM1) was identified as a key downstream effector of SPIN1 in NSCLC cells. Furthermore, SPIN1 was found to facilitate MDM2-mediated FOXO3a ubiquitination and degradation, leading to FOXM1 upregulation. Moreover, restoration of FOXM1 expression markedly abolished the inhibitory effects and increased radiosensitivity induced by SPIN1 depletion. These results indicate that the SPIN1-MDM2-FOXO3a/FOXM1 signalling axis is essential for NSCLC progression and radioresistance and could serve as a therapeutic target for increasing radiotherapy efficacy.

Erythropoietin regulates energy metabolism through EPO-EpoR-RUNX1 axis

Erythropoietin (EPO) plays a key role in energy metabolism, with EPO receptor (EpoR) expression in white adipose tissue (WAT) mediating its metabolic activity. Here, we show that male mice lacking EpoR in adipose tissue exhibit increased fat mass and susceptibility to diet-induced obesity. Our findings indicate that EpoR is present in WAT, brown adipose tissue, and skeletal muscle. Elevated EPO in male mice improves glucose tolerance and insulin sensitivity while reducing expression of lipogenic-associated genes in WAT, which is linked to an increase in transcription factor RUNX1 that directly inhibits lipogenic genes expression. EPO treatment in wild-type male mice decreases fat mass and lipogenic gene expression and increase in RUNX1 protein in adipose tissue which is not observed in adipose tissue EpoR ablation mice. EPO treatment decreases WAT ubiquitin ligase FBXW7 expression and increases RUNX1 stability, providing evidence that EPO regulates energy metabolism in male mice through the EPO-EpoR-RUNX1 axis.

UBE2N promotes cell viability and glycolysis by promoting Axin1 ubiquitination in prostate cancer cells

BACKGROUND

Ubiquitin-conjugating enzyme E2 N (UBE2N) is recognized in the progression of some cancers; however, little research has been conducted to describe its role in prostate cancer. The purpose of this paper is to explore the function and mechanism of UBE2N in prostate cancer cells.

METHODS

UBE2N expression was detected in Cancer Genome Atlas Prostate Adenocarcinoma (TCGA-PRAD) data, prostate cancer tissue microarrays, and prostate cancer cell lines, respectively. UBE2N knockdown or overexpression was used to analyze its role in cell viability and glycolysis of prostate cancer cells and tumor growth. XAV939 or Axin1 overexpression was co-treated with UBE2N overexpression to detect the involvement of the Wnt/β-catenin signaling and Axin1 in the UBE2N function. UBE2N interacting with Axin1 was analyzed by co-immunoprecipitation assay.

RESULTS

UBE2N was upregulated in prostate cancer and the UBE2N-high expression correlated with the poor prognosis of prostate cancer. UBE2N knockdown inhibited cell viability and glycolysis in prostate cancer cells and restricted tumor formation in tumor-bearing mice. Wnt/β-catenin inhibition and Axin1 overexpression reversed the promoting viability and glycolysis function of UBE2N. UBE2N promoted Axin1 ubiquitination and decreased Axin1 protein level.

The scaffold protein AXIN1: gene ontology, signal network, and physiological function

AXIN1, has been initially identified as a prominent antagonist within the WNT/β-catenin signaling pathway, and subsequently unveiled its integral involvement across a diverse spectrum of signaling cascades. These encompass the WNT/β-catenin, Hippo, TGFβ, AMPK, mTOR, MAPK, and antioxidant signaling pathways. The versatile engagement of AXIN1 underscores its pivotal role in the modulation of developmental biological signaling, maintenance of metabolic homeostasis, and coordination of cellular stress responses. The multifaceted functionalities of AXIN1 render it as a compelling candidate for targeted intervention in the realms of degenerative pathologies, systemic metabolic disorders, cancer therapeutics, and anti-aging strategies. This review provides an intricate exploration of the mechanisms governing mammalian AXIN1 gene expression and protein turnover since its initial discovery, while also elucidating its significance in the regulation of signaling pathways, tissue development, and carcinogenesis. Furthermore, we have introduced the innovative concept of the AXIN1-Associated Phosphokinase Complex (AAPC), where the scaffold protein AXIN1 assumes a pivotal role in orchestrating site-specific phosphorylation modifications through interactions with various phosphokinases and their respective substrates.

Tripartite motif 31 drives gastric cancer cell proliferation and invasion through activating the Wnt/β-catenin pathway by regulating Axin1 protein stability

Mounting evidence has proposed the importance of the Wnt/β-catenin pathway and tripartite motif 31 (TRIM31) in certain malignancies. Our research aimed to clarify the correlation between aberrant TRIM31 expression and the Wnt/β-catenin pathway during gastric cancer (GC) oncogenesis and development. TRIM31 was drastically elevated in GC tissues and was closely associated with aggressive clinical outcomes and poor prognosis. Moreover, TRIM31 downregulation attenuated GC cell proliferation and invasion in vitro. Mechanistically, TRIM31 could bind and ubiquitinate Axin1 protein, thereby facilitating the activation of the Wnt/β-catenin pathway. Additionally, Axin1 knockdown partially abrogated the inhibitory effects on the proliferative, invasive and migratory abilities of GC cells induced by TRIM31 silencing. Furthermore, TRIM31 was negatively correlated with Axin1 protein expression in GC tissues. In summary, we revealed a new TRIM31-Axin1-Wnt/β-catenin axis that contributed greatly to the progression of GC, and targeting this regulatory axis may represent an effective treatment for GC patients.

miR-3133 inhibits gastrointestinal cancer progression through activation of Hippo and p53 signalling pathways via multi-targets

BACKGROUND

Malignant cell growth and chemoresistance, the main obstacles in treating gastrointestinal cancer (GIC), rely on the Hippo and p53 signalling pathways. However, the upstream regulatory mechanisms of these pathways remain complex and poorly understood.

METHODS

Immunohistochemistry (IHC), western blot and RT-qPCR were used to analyse the expression of RNF146, miR-3133 and key components of Hippo and p53 pathway. CCK-8, colony formation, drug sensitivity assays and murine xenograft models were used to investigate the effect of RNF146 and miR-3133 in GIC. Further exploration of the upstream regulatory mechanism was performed using bioinformatics analysis, dual-luciferase reporter gene, immunoprecipitation assays and bisulfite sequencing PCR (BSP).

RESULTS

Clinical samples, in vitro and in vivo experiments demonstrated that RNF146 exerts oncogenic effects in GIC by regulating the Hippo pathway. Bioinformatics analysis identified a novel miRNA, miR-3133, as an upstream regulatory factor of RNF146. fluorescence in situ hybridization and RT-qPCR assays revealed that miR-3133 was less expressed in gastrointestinal tumour tissues and was associated with adverse pathological features. Functional assays and animal models showed that miR-3133 promoted the proliferation and chemotherapy sensitivity of GIC cells. miR-3133 affected YAP1 protein expression by targeting RNF146, AGK and CUL4A, thus activating the Hippo pathway. miR-3133 inhibited p53 protein degradation and extended p53's half-life by targeting USP15, SPIN1. BSP experiments confirmed that miR-3133 promoter methylation is an important reason for its low expression.

CONCLUSION

miR-3133 inhibits GIC progression by activating the Hippo and p53 signalling pathways via multi-targets, including RNF146, thereby providing prognostic factors and valuable potential therapeutic targets for GIC.

Ischemia-reperfusion injury in human AC16 cardiomyocytes is modulated by AXIN1 depending on c-Myc regulation

Objective

A major consequence of acute myocardial infarction is myocardial ischemia-reperfusion (I/R) injury. Collecting proof demonstrates that AXIN1 assume a basic part in different disease; however, the role of AXIN1 in I/R injury remains to a great extent obscure.

Methods

The I/R injury model on AC16 cells was constructed. siRNA transfection was used to knockdown AXIN1. The qRT-PCR assays and western blot assays were used to detect the expression level of AXIN1 and other key proteins. CCK-8 assays and cell apoptosis assays were used to detect cell proliferation and cell apoptosis.

Results

AXIN1 was significantly overexpressed in an in vitro model of I/R injury. Knockdown of AXIN1 significantly restored the cell proliferation inhibition caused by IR injury, while inhibiting apoptosis and inflammation. Further mechanistic studies revealed that the transcription factor c-Myc could regulate the expression of AXIN1. The effects of I/R injury on AC16 cells after overexpression of c-Myc were reversed by knockdown of AXIN1. Meanwhile, AXIN1 could regulate the SIRT1/p53/Nrf 2 pathway.

Conclusion

Our results show an important role for AXIN1 and provide new targets for avoiding and treating I/R injury.

TRIM37 promotes gallbladder cancer proliferation by activating the Wnt/β-catenin pathway via ubiquitination of Axin1

BACKGROUND

Gallbladder cancer (GBC) is among the most lethal malignancies in the world, with a prognosis that is extremely poor. The results of previous studies suggest that tripartite motif containing 37 (TRIM37) contributes to the progression of numerous types of cancer. Nevertheless, there is little knowledge about the molecular mechanisms and functions of TRIM37 in GBC.

METHODS

A clinical significance assessment was conducted on TRIM37 following its detection by immunohistochemistry. In vitro and in vivo functional assays were performed to investigate the role of TRIM37 in GBC.

RESULTS

In this study, TRIM37 is upregulated in GBC tissues, which is associated with decreased histological differentiation, advanced TNM stage, and shorter overall survival rates. In vitro, TRIM37 knockdown inhibited cell proliferation and promoted apoptosis, and in vivo, TRIM37 knockdown suppressed GBC growth. Contrary to this, cell proliferation is increased in GBC cells when overexpression of TRIM37 is expressed. Mechanistic investigations revealed that TRIM37 promotes GBC progression through activation of the Wnt/β‑catenin signaling pathway via degradation of Axin1.

CONCLUSION

The present study suggests that TRIM37 contributes to the development of GBC and thus provides an important biomarker for predicting GBC prognosis and an effective target for therapeutic intervention.