Ring finger protein 125, as a potential highly aggressive and unfavorable prognostic biomarker, promotes the invasion and metastasis of human gallbladder cancers via activating the TGF- β1-SMAD3-ID1 signaling pathway

RNF125, transcriptionally regulated by NFATC2, alleviates osteoarthritis via inhibiting the Wnt/β-catenin signaling pathway through degrading TRIM14

Osteoarthritis (OA) is a chronic joint disease characterized by the progressive degradation of articular cartilage. In this study, as determined by histological staining, the cartilage surface of the OA rats was damaged, defective and broken, and chondrocytes and proteoglycan were reduced. While moderate physical exercise showed protective effects on the cartilage. Besides, RNA-seq was performed to select a target protein and RNF125 (an E3 ubiquitin ligase) was decreased in the cartilage tissues of OA rats and increased after physiological exercise. However, the precise role of RNF125 in OA is still unknown. This work aimed to investigate the involvement and underlying mechanism of RNF125 in OA pathogenesis. Our results defined that adenovirus-mediated overexpression of RNF125 inhibited the degradation of extracellular matrix of chondrocytes induced by IL-1β, as revealed by increased chondrocyte viability, upregulated COL2A1 and ACAN levels, and downregulated MMP1, MMP13 and ADAMTS5 levels, which was abrogated by NR4A2 knockdown. In vivo, RNF125 relieved OA, manifested as reduced cartilage injury and increased chondrocytes. Mechanically, NFATC2 bound to the RNF125 promoter and directly regulated RNF125 transcription, as illustrated by luciferase reporter, Ch-IP and DNA pull-down assays. Furthermore, RNF125 overexpression inhibited the nuclear translocation of β-catenin, thus suppressing activation of the Wnt/β-catenin signaling pathway. Also, RNF125 as E3 ubiquitin ligase led to the ubiquitination and degradation of TRIM14 protein, and TRIM14 overexpression efficiently reversed the effects of RNF125 overexpression on OA progression. Totally, this study provides new insights into OA pathogenesis regulated by RNF125. RNF125 may be a novel biomarker for OA therapy.

Zinc finger 1 of the RING E3 ligase, RNF125, interacts with the E2 to enhance ubiquitylation

Inflammation is essential for healthy immune function, wound healing, and resolution of infection. RIG-I is a key RNA sensor that initiates an immune response, with activation and termination of RIG-I signaling reliant on its modification with ubiquitin. The RING E3 ubiquitin ligase, RNF125, has a critical role in the attenuation of RIG-I signaling, yet it is not known how RNF125 promotes ubiquitin transfer or how its activity is regulated. Here we show that the E3 ligase activity of RNF125 relies on the first zinc finger (ZF1) as well as the RING domain. Surprisingly, ZF1 helps recruit the E2, while residues N-terminal to the RING domain appear to activate the E2∼Ub conjugate. These discoveries help explain how RNF125 brings about the termination of RIG-I dependent inflammatory responses, and help account for the contribution of RNF125 to disease. This study also reveals a new role for ZF domains in E3 ligases.

Hypermethylation of RNF125 promotes autophagy-induced oxidative stress in asthma by increasing HMGB1 stability

Asthma is a global chronic airway disease. The expression and role of RNF125, an E3 ubiquitin ligase, in asthma remain uncertain. In this study, we revealed that RNF125 was downregulated in the bronchial epithelium of mice and patients with asthma. Rnf125 hypermethylation was responsible for the low expression of RNF125 in primary airway epithelial cells of mice treated with OVA. Moreover, we demonstrated that RNF125 could attenuate autophagy, oxidative stress, and protect epithelial barrier in vivo and in vitro. Additionally, we identified HMGB1 as a substrate of RNF125, which interacted with the HMG B-box domain of HMGB1 and induced degradation via the ubiquitin proteasome system, reducing autophagy and oxidative stress. Overall, our findings elucidated that hypermethylation of Rnf125 reduced its expression, which promoted autophagy-induced oxidative stress in asthma by increasing HMGB1 stability. These findings offer a theoretical and experimental basis for the pathogenesis of asthma.

A Comprehensive narrative review of transcriptomics and epigenomics of gallbladder cancer

ABSTRACTS

Gallbladder cancer (GBC) is one of the quiet prevalent and aggressive biliary tract malignant neoplasms distinguished by significant cellular heterogeneity, metastatic activity, and a poor prognosis, with varied frequency worldwide. Most cases are detected incidentally while routine screening imaging or pathological investigation of cholecystectomy tissues and usually present with advanced disease. The surgical resection is usually done in the initial clinical stage having limited spread. Despite the surgical therapy, the death rate is significant. Furthermore, the molecular mechanisms affecting the clinical course of inflammatory gallbladder to carcinogenesis remain poorly understood. There is an impending need for developing diagnostic biomarkers and targeted approaches for GBC. The newer molecular platform, such as next-generation sequencing (NGS), such as RNA-sequencing (RNAseq), single-cell sequencing, and microarray technology, has revolutionized the field of genomics, opened a new perspective in defining genetic and epigenetic characteristics identifying molecules as possible therapeutic targets. Therefore, in this review, we would analyze transcriptomic and epigenomics profiles of GBC using already published high-throughput sequencing-based studies published between 2010 and 2023. The review would also analyze the possible impact of the technological advancement on the patient management strategy and overall survival. This may also help identify target genes and pathways linked to GBC, which may help establish molecular biomarkers, for early GBC diagnosis, personalized therapy, and management.

RNF38 suppress growth and metastasis via ubiquitination of ACTN4 in nasopharyngeal carcinoma

Background

Accumulated evidence suggests that RING finger proteins (RNFs) are involved in the carcinogenesis of cancers. However, RNF38, a member of the RNF protein family, has not been studied in nasopharyngeal carcinoma (NPC).

Methods

RNF38 expression was analyzed by RT-PCR, Western blotting and Immunohistochemistry. Biological functions of RNF38 were evaluated by cell growth, colony formation, apoptosis, migration and invasion assays in vitro. Xenograft growth and lung metastasis models were conducted to investigate the effect of RNF38 in vivo. Liquid chromatography coupled with tandem mass spectrometry, co-immunoprecipitation, and CHX assay were implemented to detect the interaction among RNF38 and ACTN4.

Results

RNF38 was significantly downregulated in NPC cells and tissues. Immunohistochemistry implied that loss of RNF38 was an independent prognostic factor for poor outcomes of NPC patients. Gain- and loss-of-function experiments showed that RNF38 inhibited proliferation and metastasis in NPC in vitro and in vivo. Upregulation of RNF38 promoted apoptosis of NPC cells to etoposide but not cisplatin. ACTN4 was upregulated in NPC and negatively correlated with RNF38. Mechanistic investigations suggested that RNF38 inactivates the NF-𝛋B and ERK1/2 signaling pathways by inducing ubiquitination and degradation of ACTN4. RNF38 suppress the development of NPC by interacting with ACTN4.

Conclusions

RNF38 plays a potential cancer suppressor gene role in NPC tumorigenesis and is a prognostic biomarker in NPC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-09641-x.

Tenorio syndrome: Description of 14 novel cases and review of the clinical and molecular features

Tenorio syndrome (TNORS) (OMIM #616260) is a relatively recent disorder with very few cases described so far. Clinical features included macrocephaly, intellectual disability, hypotonia, enlarged ventricles and autoimmune diseases. Molecular underlying mechanism demonstrated missense variants and a large deletion encompassing RNF125, a gene that encodes for an U3 ubiquitin ligase protein. Since the initial description of the disorder in six patients from four families, several new patients were diagnosed, adding more evidence to the clinical spectrum. In this article, we described 14 additional cases with deep phenotyping and make an overall review of all the cases with pathogenic variants in RNF125. Not all patients presented with overgrowth, but instead, most patients showed a common pattern of neurodevelopmental disease, macrocephaly and/or large forehead. Segregation analysis showed that, though the variant was inherited in some patients from an apparently asymptomatic parent, deep phenotyping suggested a mild form of the disease in some of them. The mechanism underlying the development of this disease is not well understood yet and the report of further cases will help to a better understanding and clinical characterization of the syndrome.

Negative Regulation of the Innate Immune Response through Proteasomal Degradation and Deubiquitination

The rapid and dynamic activation of the innate immune system is achieved through complex signaling networks regulated by post-translational modifications modulating the subcellular localization, activity, and abundance of signaling molecules. Many constitutively expressed signaling molecules are present in the cell in inactive forms, and become functionally activated once they are modified with ubiquitin, and, in turn, inactivated by removal of the same post-translational mark. Moreover, upon infection resolution a rapid remodeling of the proteome needs to occur, ensuring the removal of induced response proteins to prevent hyperactivation. This review discusses the current knowledge on the negative regulation of innate immune signaling pathways by deubiquitinating enzymes, and through degradative ubiquitination. It focusses on spatiotemporal regulation of deubiquitinase and E3 ligase activities, mechanisms for re-establishing proteostasis, and degradation through immune-specific feedback mechanisms vs. general protein quality control pathways.

The microRNA cluster miR-214/miR-3120 prevents tumor cell switching from an epithelial to a mesenchymal-like phenotype and inhibits autophagy in gallbladder cancer

Tumor cells switch from an epithelial to a mesenchymal-like phenotype, which represents a key hallmark of human cancer metastasis, including gallbladder cancer (GBC). A large set of microRNAs (miRNAs/miRs) have been studied to elucidate their functions in initiating or inhibiting this phenotypic switching in GBC cells. In this paper, we attempted to identify the expression pattern of the miR-214/-3120 cluster and its mode of action in the context of GBC, with a specific focus being placed on their effects on EMT and autophagy in GBC cells. Human GBC cells GBC-SD were assayed for their migration, invasion, and autophagy using the Transwell chamber system, MDC staining, and transmission electron microscopy. The tumorigenicity and metastatic behavior of GBC-SD cells were tested in nude mice. The expression of EMT- and autophagy-specific markers (E-cadherin, N-cadherin, vimentin, ATG5, LC3II/LC3I, and Beclin1) was analyzed in cultured GBC-SD cells and in human GBC-SD xenografts. The E2F3 luciferase reporter activity in the presence of miR-214/-3120 was evaluated by a dual luciferase assay. The miR-214/-3120 was downregulated in GBC. Exogenous miR-214/-3120 inhibited the phenotypic switching of GBC cells from epithelial to mesenchymal, prevented autophagy, and suppressed the tumorigenicity and metastatic behavior of GBC-SD cells in vitro and in vivo. E2F3 was demonstrated to be the target gene of miR-214/-3120, and its knockdown in part mimicked the effect of miR-214/-3120 on the EMT, autophagy, tumorigenicity, and metastatic behavior of GBC-SD cells. These results demonstrated that the miR-214/-3120 cluster blocks the process of EMT and autophagy to limit GBC metastasis by repressing E2F3 expression.

RNF113A promotes the proliferation, migration and invasion, and is associated with a poor prognosis of esophageal squamous cell carcinoma

Ring finger protein 113A (RNF113A) possesses a C3HC4 zinc finger domain and this domain is found in E3 ubiquitin ligase and is involved in tumorigenesis. To date, and at least to the best of our knowledge, there are no studies available which have investigated RNF113A in cancer. Thus, this study aimed to explore the role of RNF113A in the development of esophageal squamous cell carcinoma (ESCC). For this purpose, paraffin-embedded samples from 117 patients with ESCC were selected, as well as 41 pairs of fresh-frozen ESCC and adjacent normal tissue samples. RNF113A expression was examined by immunohistochemistry and reverse transcription-quantitative PCR (RT-qPCR). RNF113A was overexpressed or silenced in the EC9706 and Eca109 cells. The cells were examined for cell cycle progression, apoptosis, invasiveness and migration. Xenograft tumors were also created in mice using the Eca109 cells. Tumor differentiation (P=0.008) and T classification (P<0.001) were found to be significantly associated with RNF113A expression. No statistically significant association was observed between RNF113A expression and sex, age, histological type, tumor location and lymph node metastasis (N classification). Kaplan-Meier analysis revealed that the patients with ESCC with ahigh expression of RNF113A had a lower survival rate than those with a low expression (P=0.002). Multivariate analysis revealed that RNF113A expression (HR=2.406; 95% CI, 1.301-4.449, P=0.005) was independently associated with overall survival in patients with ESCC. The overexpression of RNF113A promoted proliferation, migration, and invasiveness of ESCC cell lines in vitro, and RNF113A silencing reversed these malignant behaviors. RNF113A knockdown inhibited tumor growth in vivo. Thus, these results indicate that RNF113A promotes the proliferation, migration and invasiveness of ESCC cell lines. RNF113A expression in ESCC is this associated with a poor prognosis of affected patients.