RNF115 promotes lung adenocarcinoma through Wnt/β-catenin pathway activation by mediating APC ubiquitination

Diaphorina citri E3 ubiquitin ligase RNF115 inhibits CLas bacterial proliferation by targeting to the host histone H1

The Asian citrus psyllid (ACP), Diaphorina citri, serves as the primary vector for Candidatus Liberibacter asiaticus (CLas), the pathogen responsible for citrus Huanglongbing (HLB). D. citri modulates the expression of its key proteins in response to CLas infection. Previous research has revealed that CLas infection significantly alters the expression levels of E3 ubiquitin ligases in D. citri; however, the specific functions of these E3 ligases remain largely uncharacterized. In this study, a total of 11 E3 ubiquitin ligases were identified from the proteomics database of D. citri, among which E3 ubiquitin ligase RNF115 was significantly upregulated following CLas infection. RING finger protein 115 (RNF115) consists of 156 amino acids and contains a RING finger domain at its N-terminus. Silencing RNF115 via RNA interference (RNAi) and injecting the inhibitor disulfiram, which targets RNF115, significantly increased CLas bacterial content in D. citri. In contrast, injection of recombinant RNF115 protein markedly inhibited CLas bacterial proliferation. Furthermore, interaction between RNF115 and D. citri histone H1 was confirmed using yeast 2-hybrid assay, pull-down experiments and molecular docking analysis. Knockdown of histone H1 via RNAi significantly reduced CLas bacterial content, whereas injection of recombinant histone H1 protein led to an increase in CLas content within D. citri. These findings suggest that CLas infection may induce an upregulation of RNF115 expression in D. citri, leading to subsequent interactions with histone H1 that facilitate the ubiquitination of histone H1, ultimately resulting in reduced expression levels and inhibiting CLas proliferation within D. citri.

USP31 Activates the Wnt/β-catenin Signaling Pathway and Promotes Gastric Cancer Cell Proliferation, Invasion and Migration

BACKGROUND

Gastric cancer (GC) has a poor prognosis because it is highly aggressive, yet there are currently few effective therapies available. Although protein ubiquitination has been shown to play a complex role in the development of gastric cancer, to date, no efficient ubiquitinating enzymes have been identified as treatment targets for GC.

METHODS

The TCGA database was used for bioinformatic investigation of ubiquitin-specific protease 31 (USP31) expression in GC, and experimental techniques, including Western blotting, qRT-PCR, and immunohistochemistry, were used to confirm the findings. We also analyzed the relationship between USP31 expression and clinical prognosis in patients with GC. We further investigated the effects of USP31 on the proliferation, invasion, migration, and glycolysis of GC cells in vitro and in vivo by using colony formation, CCK-8 assays, Transwell chamber assays, cell scratch assays, and cell-derived xenograft. Furthermore, we examined the molecular processes by which USP31 influences the biological development of GC.

RESULTS

Patients with high USP31 expression have a poor prognosis because USP31 is abundantly expressed in GC. Therefore, USP31 reduces the level of ubiquitination of the Wnt/β-catenin pathway by binding to β-catenin, thereby activating glycolysis, which ultimately promotes GC proliferation and aggressive metastasis.

CONCLUSION

USP31 inhibits ubiquitination of β-catenin by binding to it, stimulates the Wnt/β-- catenin pathway, activates glycolysis, and accelerates the biology of GCs, which are all demonstrated in this work.

LEF1 is associated with immunosuppressive microenvironment of patients with lung adenocarcinoma

Wnt/β-Catenin pathway plays an important role in the occurrence and progression of malignant tumors, especially PD-L1-mediated tumor immune evasion. However, the role of TCF/LEF, an important member of the Wnt/β-catenin pathway, in the tumor immunosuppressive microenvironment of lung adenocarcinoma (LUAD) remains unknown. LUAD tissue-coding RNA expression data from The Cancer Genome Atlas and TIMER databases were used to analyze the expression of TCF/LEF transcription factors and their correlation with various immune cell infiltration. Immunohistochemistry and immunofluorescence were used to detect tissue protein staining in 105 patients with LUAD. LEF1, TCF7, TCF7L1 and TCF7L2 were all aberrantly expressed in the tumor tissues of LUAD patients with the data from The Cancer Genome Atlas (TCGA) database, tumor immune estimation resource (TIMER) database and results of immunohistochemistry, but only LEF1 expression was associated with 5-year overall survival in LUAD patients. LEF1 protein expression was associated with advanced tumor node metastasis (TNM) stage, lymphatic metastasis and local invasion in 105 cases LUAD patients. At the same time, LEF1 mRNA expression was also associated with immunosuppressive microenvironment in LUAD patients with the data from TCGA database and TIMER database. Results of immunohistochemistry and immunofluorescence in tumor tissues of 105 cases LUAD patients showed that there was a positively correlation between LEF1 protein expression and the infiltration of M2 macrophages and Treg cells. LEF1 was highly expressed in tumor tissues of LUAD patients, and highly expressed LEF1 was associated with the immunosuppressive microenvironment of LUAD patients.

Crosstalk among Alternative Polyadenylation, Genetic Variants and Ubiquitin Modification Contribute to Lung Adenocarcinoma Risk

Ubiquitin modification and alternative polyadenylation play crucial roles in the onset and progression of cancer. Hence, this study aims to comprehensively and deeply understand gene regulation and associated biological processes in lung adenocarcinoma (LUAD) by integrating both mechanisms. Alternative polyadenylation (APA)-related E3 ubiquitin ligases in LUAD were identified through multiple databases, and the association between selected genetic loci influencing gene expression (apaQTL-SNPs) and LUAD risk were evaluated through the GWAS database of the Female Lung Cancer Consortium in Asia (FLCCA). Subsequently, the interaction between RNF213 and ZBTB20, as well as their functional mechanisms in LUAD, were investigated using bioinformatics analysis, Western blot, co-immunoprecipitation, and colony formation experiments. A total of five apaQTL-SNPs (rs41301932, rs4494603, rs9890400, rs56066320, and rs41301932), located on RNF213, were significantly associated with LUAD risk (p < 0.05), and they inhibit tumor growth through ubiquitin-mediated degradation of ZBTB20.

Multi-Omics Characterization of E3 Regulatory Patterns in Different Cancer Types

Ubiquitination, a post-translational modification, refers to the covalent attachment of ubiquitin molecules to substrates. This modification plays a critical role in diverse cellular processes such as protein degradation. The specificity of ubiquitination for substrates is regulated by E3 ubiquitin ligases. Dysregulation of ubiquitination has been associated with numerous diseases, including cancers. In our study, we first investigated the protein expression patterns of E3 ligases across 12 cancer types. Our findings indicated that E3 ligases tend to be up-regulated and exhibit reduced tissue specificity in tumors. Moreover, the correlation of protein expression between E3 ligases and substrates demonstrated significant changes in cancers, suggesting that E3-substrate specificity alters in tumors compared to normal tissues. By integrating transcriptome, proteome, and ubiquitylome data, we further characterized the E3-substrate regulatory patterns in lung squamous cell carcinoma. Our analysis revealed that the upregulation of the SKP2 E3 ligase leads to excessive degradation of BRCA2, potentially promoting tumor cell proliferation and metastasis. Furthermore, the upregulation of E3 ubiquitin-protein ligase TRIM33 was identified as a biomarker associated with a favorable prognosis by inhibiting the cell cycle. This work exemplifies how leveraging multi-omics data to analyze E3 ligases across various cancers can unveil prognosis biomarkers and facilitate the identification of potential drug targets for cancer therapy.

Canonical WNT/β-catenin signaling upregulates aerobic glycolysis in diverse cancer types

Despite many efforts, a comprehensive understanding and clarification of the intricate connections within cancer cell metabolism remain elusive. This might pertain to intracellular dynamics and the complex interplay between cancer cells, and cells with the tumor stroma. Almost a century ago, Otto Warburg found that cancer cells exhibit a glycolytic phenotype, which continues to be a subject of thorough investigation. Past and ongoing investigations have demonstrated intricate mechanisms by which tumors modulate their functionality by utilizing extracellular glucose as a substrate, thereby sustaining the essential proliferation of cancer cells. This concept of "aerobic glycolysis," where cancer cells (even in the presence of enough oxygen) metabolize glucose to produce lactate plays a critical role in cancer progression and is regulated by various signaling pathways. Recent research has revealed that the canonical wingless-related integrated site (WNT) pathway promotes aerobic glycolysis, directly and indirectly, thereby influencing cancer development and progression. The present review seeks to gather knowledge about how the WNT/β-catenin pathway influences aerobic glycolysis, referring to relevant studies in different types of cancer. Furthermore, we propose the concept of impeding the glycolytic phenotype of tumors by employing specific inhibitors that target WNT/β-catenin signaling.

NTSR1 promotes epithelial-mesenchymal transition and metastasis in lung adenocarcinoma through the Wnt/β-catenin pathway

BACKGROUND

Lung adenocarcinoma (LUAD) patients are implicated in poor prognoses and increased mortality rates. Metastasis, as a leading cause of LUAD-related deaths, requires further investigation. Highly metastatic cancer cells often exhibit extensive characteristics of epithelial-mesenchymal transition (EMT). This study attempted to identify novel targets associated with LUAD metastasis and validate their specific molecular mechanisms.

METHODS

Bioinformatics was conducted to determine NTSR1 expression in LUAD and the enriched pathways. Immunohistochemical analysis was used to assess NTSR1 expression in LUAD tissue. qRT-PCR examined expressions of NTSR1 and Wnt/β-Catenin pathway-related genes in LUAD cells. Transwell assayed cell migration and invasion. Cell adhesion experiments were conducted to evaluate cell adhesion capacity. Western blot analysis was employed to examine expression of EMT, Wnt/β-Catenin pathway, and cell adhesion markers.

RESULTS

NTSR1 was upregulated in LUAD tissues and cells, and enriched in EMT pathway. Knockdown of NTSR1 reduced migration, invasion, and adhesion abilities in LUAD cells, and inhibited EMT progression and Wnt/β-Catenin pathway. Rescue experiments demonstrated that β-Catenin activator SKL2001 reversed repressive influence of NTSR1 knockdown on LUAD cell malignant phenotypes and EMT progression.

CONCLUSION

The data obtained in this study suggested that NTSR1 stimulated EMT and metastasis in LUAD via Wnt/β-Catenin pathway. This finding may provide options for overcoming LUAD metastasis.

Knockdown of GNL3 inhibits LUAD cell growth by regulating Wnt-β-catenin pathway

BACKGROUND

Lung adenocarcinoma (LUAD) is a leading cause of tumor-associated mortality, and it is needed to find new target to combat this disease. Guanine nucleotide-binding -protein-like 3 (GNL3) mediates cell proliferation and apoptosis in several cancers, but its role in LUAD remains unclear.

OBJECTIVE

To explore the expression and function of Guanine nucleotide-binding protein-like 3 (GNL3) in lung adenocarcinoma (LUAD) and its potential mechanism in inhibiting the growth of LUAD cells.

METHODS

We evaluated the expression of GNL3 in LUAD tissues and its association with patient prognosis using databases and immunohistochemistry. Cell proliferation was assessed by CCK-8 assay as well as colony formation, while apoptosis was evaluated by FCM. The effect of GNL3 knockdown on the Wnt/β-catenin axis was investigated by Immunoblot analysis.

RESULTS

GNL3 is overexpressed in LUAD tissues and is correlated with poor prognosis. Knockdown of GNL3 significantly inhibited the growth as well as induced apoptosis in A549 as well as H1299 cells. Furthermore, we found that the inhibitory effect of GNL3 knockdown on LUAD cell growth is associated with the downregulation of the Wnt/β-catenin axis.

CONCLUSION

GNL3 is key in the progression of LUAD by metiating Wnt/β-catenin axis. Targeting GNL3 may represent a novel therapeutic method for LUAD treatment.

Advances of E3 ligases in lung cancer

Lung cancer is a leading cause of cancer-related death, and the most common type of lung cancer is non-small cell lung cancer, which accounts for approximately 85 % of lung cancer diagnoses. Recent studies have revealed that ubiquitination acts as a crucial part of the development and progression of lung cancer. The E1-E2-E3 three-enzyme cascade has a core function in ubiquitination, so targeted adjustments of E3 ligases could be used in lung cancer treatment. Hence, we elucidate research advances in lung cancer-related E3 ligases by briefly describing the structure and categorization of E3 ligases. Here, we provide a detailed review of the mechanisms by which lung cancer-related E3 ligases modify substrate proteins and regulate signaling pathways to facilitate or suppress cancer progression. We hope to show a new perspective on targeted precision therapy for lung cancer.

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

Wnt/β-catenin signaling is a critical pathway that influences development and therapeutic response of non-small cell lung cancer (NSCLC). In recent years, many Wnt regulators, including proteins, miRNAs, lncRNAs, and circRNAs, have been found to promote or inhibit signaling by acting on Wnt proteins, receptors, signal transducers and transcriptional effectors. The identification of these regulators and their underlying molecular mechanisms provides important implications for how to target this pathway therapeutically. In this review, we summarize recent studies of Wnt regulators in the development and therapeutic response of NSCLC.

Temporin-GHaK Exhibits Antineoplastic Activity against Human Lung Adenocarcinoma by Inhibiting the Wnt Signaling Pathway through miRNA-4516

(1) Background: GHaK is derived from the antimicrobial peptide temporin-GHa by substituting the amino acid H with K to enhance its bactericidal activity. The present research aims to broaden the pharmacological potential of GHaK by exploring its antineoplastic activity against human lung adenocarcinoma. (2) Methods: The cell viability, migration, invasion, apoptosis, and cell cycle of A549 and PC-9 cells were tested after GHaK treatment. miRNA sequencing, RT-PCR, Western blotting, and luciferase reporter gene assay were further performed to reveal the potential mechanism. (3) Results: GHaK significantly suppressed cell viability, migration, and invasion; induced apoptosis; and caused cell cycle arrest in the G2/M and S phase in PC-9 and A549 cells, respectively. The miRNA sequencing results show a total of 161 up-regulated and 115 down-regulated miRNAs. Furthermore, the study identified six up-regulated miRNAs (miR-4516, miR-4284, miR-204-5p, miR-12136, miR-4463, and miR-1296-3p) and their inhibitory effects on the expressions of target genes (Wnt 8B, FZD2, DVL3, and FOSL1) caused by miR-4516 directly interacting with Wnt 8B. Western blotting revealed the down-regulation of p-GSK-3β, along with a decreased expressions of cyclin A1 and CDK2 in A549 cells and cyclin B1 and CDK1 in PC-9 cells. (4) Conclusions: Temporin-GHaK exhibits antineoplastic activity against human lung adenocarcinoma by inhibiting the Wnt signaling pathway through miRNA-4516.

E3 ubiquitin ligase BCA2 promotes breast cancer stemness by up-regulation of SOX9 by LPS

Triple-negative breast cancer (TNBC) is the most malignant subtype of breast cancer. Breast cancer stem cells (BCSCs) are believed to play a crucial role in the carcinogenesis, therapy resistance, and metastasis of TNBC. It is well known that inflammation promotes stemness. Several studies have identified breast cancer-associated gene 2 (BCA2) as a potential risk factor for breast cancer incidence and prognosis. However, whether and how BCA2 promotes BCSCs has not been elucidated. Here, we demonstrated that BCA2 specifically promotes lipopolysaccharide (LPS)-induced BCSCs through LPS induced SOX9 expression. BCA2 enhances the interaction between myeloid differentiation primary response protein 88 (MyD88) and Toll-like receptor 4 (TLR4) and inhibits the interaction of MyD88 with deubiquitinase OTUD4 in the LPS-mediated NF-κB signaling pathway. And SOX9, an NF-κB target gene, mediates BCA2's pro-stemness function in TNBC. Our findings provide new insights into the molecular mechanisms by which BCA2 promotes breast cancer and potential therapeutic targets for the treatment of breast cancer.

PIEZO1 acts as a cancer suppressor by regulating the ROS/Wnt/β-catenin axis

BACKGROUND

PIEZO1 works differently in different cancers and at different stages of development. The objective of the current study was to explore the function and underlying mechanism of PIEZO1 in lung adenocarcinoma (LUAD) cells.

METHODS

Different LUAD cell lines were treated with PIEZO1 inhibitor (GsMTx4) and agonist (Yoda1), and the expression of PIEZO1 in LUAD cells was detected using real-time quantitative PCR (RT-qPCR) and western blotting. The effects of PIEZO1 on invasion, migration and epithelial-mesenchymal transition (EMT) markers protein expression of LUAD cells were detected using the MTT assay, flow cytometry, transwell assay, wound-healing assay, and western blotting. Reactive oxygen species (ROS) agonists (BAY 87-2243) and inhibitors (NAC) and Wnt/β-catenin pathway inhibitors (iCRT3) were selected to treat A549 cells to investigate the mechanism of PIEZO1 on ROS production and Wnt/β-catenin expression in A549 cells.

RESULTS

In A549, NCI-H1395, and NCI-H1975 cells, GsMTx4 promoted cell proliferation, invasion, migration, upregulated EMT-related marker protein expression, and inhibited cell apoptosis, while Yoda1 exerted effects opposite to those of GsMTx4. In A549 cells, GsMTx4 can reduce ROS production, it also inhibited ROS production, apoptosis, and downregulated proapoptotic markers induced by BAY 87-2243. Importantly, BAY 87-2243 blocked the effect of GSMTX4-induced Wnt/β-catenin overexpression. Similarly, Yoda1 can reduce the effect of NAC. In addition, iCRT3 can block the upregulation of EMT-related marker proteins by GsMTx4, and increase apoptosis and decrease cell invasion and migration.

CONCLUSION

In summary, PIEZO1 acts as a cancer suppressor by regulating the ROS/Wnt/β-catenin axis, providing a new perspective on the role of mechanosensitive channel proteins in cancer.

RNF115 aggravates tumor progression through regulation of CDK10 degradation in thyroid carcinoma

BACKGROUND

RING Finger Protein 115 (RNF115), a notable E3 ligase, is known to modulate tumorigenesis and metastasis. In our investigation, we endeavor to unravel the putative function and inherent mechanism through which RNF115 influences the evolution of thyroid carcinoma (THCA).

METHODS

We analyzed RNF115 expression in THCA using the Cancer Genome Atlas (TCGA) database. The influence of RNF115 on the progression of THCA was evaluated using both in vitro and in vivo experimental approaches. The protein regulated by RNF115 was identified through bioinformatics analysis, and its biological significance was further explored.

RESULTS

In both THCA tissues and cells, RNF115 showed elevated expression levels. Enhanced expression of RNF115 fostered cell proliferation, tumor growth, and the exacerbation of epithelial-mesenchymal transition (EMT) in THCA, while also promoting tumor lung metastasis. Bioinformatics analysis identified cyclin-dependent kinase 10 (CDK10) as a downstream target of RNF115, which was found to be ubiquitinated and degraded by RNF115 in THCA cells. Functionally, overexpression of CDK10 was found to counteract the promotion of malignant phenotype in THCA induced by RNF115. From a mechanistic perspective, RNF115 activated the Raf-1 pathway and enhanced cancer cell cycle progression by degrading CDK10 in THCA cells.

CONCLUSION

RNF115 triggers cell proliferation, EMT, and tumor metastasis by ubiquitinating and degrading CDK10. The regulation of the Raf-1 pathway and cell cycle progression in THCA may be profoundly influenced by this process.

E3 ubiquitin ligases in lung cancer: Emerging insights and therapeutic opportunities

Aim In this review, we have attempted to provide the readers with an updated account of the role of a family of proteins known as E3 ligases in different aspects of lung cancer progression, along with insights into the deregulation of expression of these proteins during lung cancer. A detailed account of the therapeutic strategies involving E3 ligases that have been developed or currently under development has also been provided in this review. MATERIALS AND METHODS: The review article employs extensive literature search, along with differential gene expression analysis of lung cancer associated E3 ligases using the DESeq2 package in R, and the Gene Expression Profiling Interactive Analysis (GEPIA) database (http://gepia.cancer-pku.cn/). Protein expression analysis of CPTAC lung cancer samples was carried out using the UALCAN webtool (https://ualcan.path.uab.edu/index.html). Assessment of patient overall survival (OS) in response to high and low expression of selected E3 ligases was performed using the online Kaplan-Meier plotter (https://kmplot.com/analysis/index.php?p=background). KEY FINDINGS: SIGNIFICANCE: The review provides an in-depth understanding of the role of E3 ligases in lung cancer progression and an up-to-date account of the different therapeutic strategies targeting oncogenic E3 ligases for improved lung cancer management.

RNF115/BCA2 deficiency alleviated acute liver injury in mice by promoting autophagy and inhibiting inflammatory response

The E3 ubiquitin ligase RING finger protein 115 (RNF115), also known as breast cancer-associated gene 2 (BCA2), has been linked with the growth of some cancers and immune regulation, which is negatively correlated with prognosis. Here, it is demonstrated that the RNF115 deletion can protect mice from acute liver injury (ALI) induced by the treatment of lipopolysaccharide (LPS)/D-galactosamine (D-GalN), as evidenced by decreased levels of alanine aminotransaminase, aspartate transaminase, inflammatory cytokines (e.g., tumor necrosis factor α and interleukin-6), chemokines (e.g., MCP1/CCL2) and inflammatory cell (e.g., monocytes and neutrophils) infiltration. Moreover, it was found that the autophagy activity in Rnf115-/- livers was increased, which resulted in the removal of damaged mitochondria and hepatocyte apoptosis. However, the administration of adeno-associated virus Rnf115 or autophagy inhibitor 3-MA impaired autophagy and aggravated liver injury in Rnf115-/- mice with ALI. Further experiments proved that RNF115 interacts with LC3B, downregulates LC3B protein levels and cell autophagy. Additionally, Rnf115 deletion inhibited M1 type macrophage activation via NF-κB and Jnk signaling pathways. Elimination of macrophages narrowed the difference in liver damage between Rnf115+/+ and Rnf115-/- mice, indicating that macrophages were linked in the ALI induced by LPS/D-GalN. Collectively, for the first time, we have proved that Rnf115 inactivation ameliorated LPS/D-GalN-induced ALI in mice by promoting autophagy and attenuating inflammatory responses. This study provides new evidence for the involvement of autophagy mechanisms in the protection against acute liver injury.

Heat shock protein B7 (HSPB7) inhibits lung adenocarcinoma progression by inhibiting glycolysis

In the present study, it was aimed to investigate the effects and potential mechanisms of heat shock protein B7 (HSPB7) on lung adenocarcinoma (LUAD). Bioinformatic analysis was performed to explore the association between HSPB7 expression and patients with LUAD. MTT, colony formation, wound healing and Transwell assays were performed to examine the proliferative, migratory and invasive abilities of H1975 and A549 cells. Western blot analysis was conducted to determine the corresponding protein expression. Co‑Immunoprecipitation and Chromatin immunoprecipitation assays were carried out to reveal the interaction between HSPB7 and myelodysplastic syndrome 1 and ecotropic viral integration site 1 complex locus (MECOM). In addition, an animal model was conducted by the subcutaneous injection of A549 cells into BALB/c nude mice, and tumor weight and size were measured. HSPB7 was downregulated in LUAD tissues and cells, and its expression level correlated with patient prognosis. Cell functional data revealed that silencing of HSPB7 promoted lung cancer cell proliferation, migration, invasion and epithelial mesenchymal transition (EMT); whereas overexpression of HSPB7 led to the opposite results. Furthermore, bioinformatics analysis showed that HSPB7 inhibited glycolysis. HSPB7 decreased glucose consumption, lactic acid production, and lactate dehydrogenase A, hexokinase 2 and pyruvate kinase muscle isoform 2 protein levels. The results demonstrated that MECOM was a transcription factor of HSPB7. Collectively, these results suggested that HSPB7 is regulated by MECOM, and that HSPB7 attenuates LUAD cell proliferation, migration, invasion and EMT by inhibiting glycolysis.

Myoglobin in Brown Adipose Tissue: A Multifaceted Player in Thermogenesis

Brown adipose tissue (BAT) plays an important role in energy homeostasis by generating heat from chemical energy via uncoupled oxidative phosphorylation. Besides its high mitochondrial content and its exclusive expression of the uncoupling protein 1, another key feature of BAT is the high expression of myoglobin (MB), a heme-containing protein that typically binds oxygen, thereby facilitating the diffusion of the gas from cell membranes to mitochondria of muscle cells. In addition, MB also modulates nitric oxide (NO•) pools and can bind C16 and C18 fatty acids, which indicates a role in lipid metabolism. Recent studies in humans and mice implicated MB present in BAT in the regulation of lipid droplet morphology and fatty acid shuttling and composition, as well as mitochondrial oxidative metabolism. These functions suggest that MB plays an essential role in BAT energy metabolism and thermogenesis. In this review, we will discuss in detail the possible physiological roles played by MB in BAT thermogenesis along with the potential underlying molecular mechanisms and focus on the question of how BAT-MB expression is regulated and, in turn, how this globin regulates mitochondrial, lipid, and NO• metabolism. Finally, we present potential MB-mediated approaches to augment energy metabolism, which ultimately could help tackle different metabolic disorders.

Ring finger protein 12 activates AKT signalling to promote the progression of liver cancer by interacting with EGFR

Liver cancer is one of the most common solid tumours, and ranks as the third leading cause of cancer-associated mortality around the world. This study has linked RNF12 to the pathogenesis of liver cancer. Based on the analysis of patient samples and database data, high RNF12 expression was found in liver cancer, in correlation with worse clinicopathological features and a poor prognosis. Meantime, RNF12 could promote the progression of liver cancer in vitro and in vivo. Mechanistically, RNF12 could interact with EGFR and decrease the internalization of EGFR to activate EGF/EGFR signalling. In addition, PI3K-AKT signalling takes part in the regulation of liver cancer cell proliferation and migration of RNF12. And AKT inhibitor MK2206 could reverse RNF12-mediated cellular proliferation and migration in liver cancer. The possibility of the physical interaction between RNF12 and EGFR might lay a foundation to develop intervention strategies for liver cancer prevention and therapy.

Wnt signaling pathway-derived score for predicting therapeutic resistance and tumor microenvironment in lung adenocarcinoma

Background: Lung adenocarcinoma (LUAD) is the most common subtype of lung cancer. Due to tumor heterogeneity, understanding the pathological mechanism of tumor progression helps to improve the diagnosis process and clinical treatment strategies of LUAD patients. Methods: The transcriptome pattern, mutant expression and complete clinical information were obtained from the cancer genome atlas (TCGA) database and microarray data from gene expression omnibus (GEO) database. Firstly, we used single sample Gene Set Enrichment Analysis (ssGSEA) to estimate the activation of Wnt signaling pathway in each sample. Consensus clustering algorithm was used to classify LUAD samples into different subgroups according to the transcription patterns of 152 Wnt signaling pathway related genes. Then, ESTIMATE, ssGSEA and Gene Set Variation Analysis (GSVA) algorithms were used to assess the biological pathways and immunocytes infiltration between different subtypes. LASSO-COX algorithm was conducted to construct prognostic model. Kaplan-Meier and multivariate Cox analysis were performed to evaluate the predictive performance of risk model. Gene features were further confirmed using external datasets. Finally, we conducted vitro assay for validating hub gene (LEF1). Results: Based on the transcription patterns of 152 Wnt signaling pathway related genes, four different subtypes of LUAD patients were screened out by consensus clustering algorithm. Subsequently, it was found that patients with cluster A and B had massive immunocytes infiltration, and the survival rate of patients with cluster B was better than that of other subgroups. According to the coefficients in the LASSO- Cox model and the transcriptome patterns of these 18 genes, the risk score was constructed for each sample. The degree of malignancy of LUAD patients with high-risk subgroup was remarkable higher than that of patients with low-risk subgroup (p < 0.001). Subsequently, five top prognostic genes (AXIN1, CTNNB1, LEF1, FZD2, FZD4.) were screened, and their expression values were different between cancer and normal tissues. FZD2 and LEF1 were negatively related to ImmunoScore, and AXIN1 was negatively related to ImmunoScore. The significant correlation between LUAD patient risk score and overall survival (OS) was verified in external datasets. In the A549 cell line, knockdown of LEF1 can reduce the invasive and proliferation ability of LUAD cells. Conclusion: A innovative 18 genes predictive feature based on transcriptome pattern was found in patients with lung adenocarcinoma. These investigations further promote the insight of the prognosis of lung adenocarcinoma and may contribute to disease management at risk stratification.

The Systematic Analyses of RING Finger Gene Signature for Predicting the Prognosis of Patients with Hepatocellular Carcinoma

RING finger (RNF) proteins are frequently dysregulated in human malignancies and are tightly associated with tumorigenesis. However, the expression profiles of RNF genes in hepatocellular carcinoma (HCC) and their relations with prognosis remain undetermined. Here, we aimed at constructing a prognostic model according to RNF genes for forecasting the outcomes of HCC patients using the data from The Cancer Genome Atlas (TCGA) program. We collected HCC datasets to validate the values of our model in predicting prognosis of HCC patients from International Cancer Genome Consortium (ICGC) platform. Then, functional experiments were carried out to explore the roles of the representative RNF in HCC progression. A total of 107 differentially expressed RNFs were obtained between TCGA-HCC tumor and normal tissues. After comprehensive evaluation, a prognostic signature composed of 11 RNFs (RNF220, RNF25, TRIM25, BMI1, RNF216P1, RNF115, RNF2, TRAIP, RNF157, RNF145, and RNF19B) was constructed based on TCGA cohort. Then, the Kaplan-Meier (KM) curves and the receiver operating characteristic curve (ROC) were employed to evaluate predictive power of the prognostic model in testing cohort (TCGA) and validation cohort (ICGC). The KM and ROC curves illustrated the good predictive power in testing and validation cohort. The areas under the ROC curve are 0.77 and 0.76 in these two cohorts, respectively. Among the prognostic signature genes, BMI1 was selected as a representative for functional study. We found that BMI1 protein level was significantly upregulated in HCC tissues. Moreover, the inhibitor of BMI1, PTC-209, displayed an excellent anti-HCC effect in vitro. Enrichment analysis of BMI1 downstream targets showed that BMI1 might be involved in tumor immunotherapy. Together, our overall analyses revealed that the 11-RNFs prognostic signature might provide us latent chances for evaluating HCC prognosis and developing novel HCC therapy.

Multifaceted Roles of the E3 Ubiquitin Ligase RING Finger Protein 115 in Immunity and Diseases

Ubiquitination is a post-translational modification that plays essential roles in various physiological and pathological processes. Protein ubiquitination depends on E3 ubiquitin ligases that catalyze the conjugation of ubiquitin molecules on lysine residues of targeted substrates. RING finger protein 115 (RNF115), also known as breast cancer associated gene 2 (BCA2) and Rab7-interacting RING finger protein (Rabring7), has been identified as a highly expressed protein in breast cancer cells and tissues. Later, it has been demonstrated that RNF115 catalyzes ubiquitination of a series of proteins to modulate a number of signaling pathways, and thereby regulates viral infections, autoimmunity, cell proliferation and death and tumorigenesis. In this review, we introduce the identification, expression and activity regulation of RNF115, summarize the substrates and functions of RNF115 in different pathways, and discuss the roles of RNF115 as a biomarker or therapeutic target in diseases.

RNF115 Inhibits the Post-ER Trafficking of TLRs and TLRs-Mediated Immune Responses by Catalyzing K11-Linked Ubiquitination of RAB1A and RAB13

The subcellular localization and intracellular trafficking of Toll-like receptors (TLRs) critically regulate TLRs-mediated antimicrobial immunity and autoimmunity. Here, it is demonstrated that the E3 ubiquitin ligase RNF115 inhibits the post-endoplasmic reticulum (ER) trafficking of TLRs and TLRs-mediated immune responses by catalyzing ubiquitination of the small GTPases RAB1A and RAB13. It is shown that the 14-3-3 chaperones bind to AKT1-phosphorylated RNF115 and facilitate RNF115 localizing on the ER and the Golgi apparatus. RNF115 interacts with RAB1A and RAB13 and catalyzes K11-linked ubiquitination on the Lys49 and Lys61 residues of RAB1A and on the Lys46 and Lys58 residues of RAB13, respectively. Such a modification impairs the recruitment of guanosine diphosphate (GDP) dissociation inhibitor 1 (GDI1) to RAB1A and RAB13, a prerequisite for the reactivation of RAB proteins. Consistently, knockdown of RAB1A and RAB13 in Rnf115+/+ and Rnf115-/- cells markedly inhibits the post-ER and the post-Golgi trafficking of TLRs, respectively. In addition, reconstitution of RAB1AK49/61R or RAB13K46/58R into Rnf115+/+ cells but not Rnf115-/- cells promotes the trafficking of TLRs from the ER to the Golgi apparatus and from the Golgi apparatus to the cell surface, respectively. These findings uncover a common and step-wise regulatory mechanism for the post-ER trafficking of TLRs.

Knockdown of RNF183 suppressed proliferation of lung adenocarcinoma cells via inactivating the STAT3 signaling pathway

Proteins of the RNF183 (RING finger 183) family proteins have been reported to be of great importance in tumor the initiation and progression. However, the biological role and regulatory mechanism of RNF183 in non small cell lung cancer (NSCLC) development and progression are poorly defined. Hence, lung adenocarcinoma (LUAD) cell proliferation, cell apoptosis and cell cycle were measured using Cell Counting Kit-8 and flow cytometry analysis, respectively. The correlation between RNF183 and SHP2 (Src homology-2 domain-containing protein tyrosine phosphatase) was measured using coimmunoprecipitation and ubiquitination analysis in vitro. Tumor growth of NSCLC cells in vivo was measured using the nude mouse xenograft model. In this study, we verify that elevated RNF183 expression in tumor tissues of LUAD, origin from the TCGA, GEPIA, TIMER, and UALCAN database. RNF183 regulates apoptosis and cell cycle in vitro and tumor growth in vivo by activating the STAT3 pathway through ubiquitination of SHP2, a negative feedback regulator of the STAT3 pathway. Taken together, our results demonstrate that RNF183 regulates proliferation, apoptosis, and cell cycle in LUAD cells via modulation of SHP2/STAT3 signaling, suggesting the potential for targeting the RNF183-SHP2/STAT3 pathway for use in LUAD treatment.