RNF168 is highly expressed in esophageal squamous cell carcinoma and contributes to the malignant behaviors in association with the Wnt/β-catenin signaling pathway

The Emerging Role of the Histone H2AK13/15 Ubiquitination: Mechanisms of Writing, Reading, and Erasing in DNA Damage Repair and Disease

Histone modifications serve as molecular switches controlling critical cellular processes. The ubiquitination of histone H2A at lysines 13 and 15 (H2AK13/15ub) is a crucial epigenetic modification that coordinates DNA repair and genome stability during the DNA damage response (DDR). This epigenetic mark is dynamically regulated by three functional protein groups: "writer" enzymes (e.g., E3 ubiquitin ligase RNF168 that catalyzes H2AK13/15ub formation), "reader" proteins (including 53BP1 and BRCA1-BARD1 that recognize the mark to guide DNA repair), and "eraser" deubiquitinases (such as USP3 and USP16 that remove the modification). Dysregulation of the precisely coordinated network of H2AK13/15ub is strongly associated with various diseases, including RIDDLE syndrome, neurodegenerative disorders, immune deficiencies, and breast cancer. This review systematically analyzes the dynamic regulation of H2AK13/15ub in DDR and explores its therapeutic potential for disease intervention.

EVA1B facilitates esophageal squamous carcinoma progression and recruitment of immunosuppressive myeloid-derived suppressor cells in the tumor microenvironment

Eva-1 Homolog B (EVA1B) has been preliminarily found to be associated with prognostic outcomes and immune microenvironment in several human cancer types, but the implications of EVA1B in ESCC remain unclear. Human ESCC and paracancerous tissues were gathered in this study, and EVA1B expression was measured via immunoblotting. EC109 and KYSE-180 ESCC cells were stably infected by sh-EVA1B lentivirus, and functional experiments were subsequently implemented. Syngeneic mouse models were built, and the expansion and recruitment of myeloid-derived suppressor cells (MDSCs) were then evaluated. The results showed that EVA1B presented the notable up-regulation in clinical ESCC tissues versus controls, and was connected to more advanced stages and the abundance of MDSCs. Silencing EVA1B notably attenuated proliferation of ESCC cells and tumor growth in syngeneic mouse models. Moreover, EVA1B suppression resulted in apoptosis and cell cycle arrest, and impaired ESCC cell aggressiveness. Among ESCC patients, EVA1B was strongly correlated to EMT pathway activity. Targeted suppression of EVA1B mitigated the expression of Wnt3a, β-catenin and LRP6 in ESCC cells and tumor xenografts. Additionally, inhibition of EVA1B attenuated the expansion and recruitment of MDSCs within the immune microenvironment based upon the reduction in the percentage of CD11b+Gr-1+ immunosuppressive MDSCs as well as the expression of MDSC expansion stimulators (S100A8, S100A9, Arg-1, and VEGF). Collectively, our findings unveiled the contribution of high expression of EVA1B to ESCC progression and MDSCs expansion and recruitment, indicating that targeted suppression of EVA1B may be a potential treatment choice for ESCC patients.

Therapeutic implications of signaling pathways and tumor microenvironment interactions in esophageal cancer

Esophageal cancer (EC) is significantly influenced by the tumor microenvironment (TME) and altered signaling pathways. Downregulating these pathways in EC is essential for suppressing tumor development, preventing metastasis, and enhancing therapeutic outcomes. This approach can increase tumor sensitivity to treatments, enhance patient outcomes, and inhibit cancer cell proliferation and spread. The TME, comprising cellular and non-cellular elements surrounding the tumor, significantly influences EC's development, course, and treatment responsiveness. Understanding the complex relationships within the TME is crucial for developing successful EC treatments. Immunotherapy is a vital TME treatment for EC. However, the heterogeneity within the TME limits the application of anticancer drugs outside clinical settings. Therefore, identifying reliable microenvironmental biomarkers that can detect therapeutic responses before initiating therapy is crucial. Combining approaches focusing on EC signaling pathways with TME can enhance treatment outcomes. This integrated strategy aims to interfere with essential signaling pathways promoting cancer spread while disrupting factors encouraging tumor development. Unraveling aberrant signaling pathways and TME components can lead to more focused and efficient treatment approaches, identifying specific cellular targets for treatments. Targeting the TME and signaling pathways may reduce metastasis risk by interfering with mechanisms facilitating cancer cell invasion and dissemination. In conclusion, this integrative strategy has significant potential for improving patient outcomes and advancing EC research and therapy. This review discusses the altered signaling pathways and TME in EC, focusing on potential future therapeutics.

RNF126, 168 and CUL1: The Potential Utilization of Multi-Functional E3 Ubiquitin Ligases in Genome Maintenance for Cancer Therapy

Ubiquitination is a post-translational modification (PTM) that is involved in proteolysis, protein-protein interaction, and signal transduction. Accumulation of mutations and genomic instability are characteristic of cancer cells, and dysfunction of the ubiquitin pathway can contribute to abnormal cell physiology. Because mutations can be critical for cells, DNA damage repair, cell cycle regulation, and apoptosis are pathways that are in close communication to maintain genomic integrity. Uncontrolled cell proliferation due to abnormal processes is a hallmark of cancer, and mutations, changes in expression levels, and other alterations of ubiquitination factors are often involved. Here, three E3 ubiquitin ligases will be reviewed in detail. RNF126, RNF168 and CUL1 are involved in DNA damage response (DDR), DNA double-strand break (DSB) repair, cell cycle regulation, and ultimately, cancer cell proliferation control. Their involvement in multiple cellular pathways makes them an attractive candidate for cancer-targeting therapy. Functional studies of these E3 ligases have increased over the years, and their significance in cancer is well reported. There are continuous efforts to develop drugs targeting the ubiquitin pathway for anticancer therapy, which opens up the possibility for these E3 ligases to be evaluated for their potential as a target protein for anticancer therapy.

Identification of hub genes and microRNAs with prognostic values in esophageal cancer by integrated analysis

Esophageal cancer (EC) is the eighth most common cancer in the world, and the sixth most common cause of cancer-related mortality. The aim of the present study was to identify cell and molecular mechanisms involved in EC, and to provide the potential targets for diagnosis and treatment. Here, a microarray dataset (GSE20347) was screened to find differentially expressed genes (DEGs). Different bioinformatic methods were used to analyze the identified DEGs. The up-regulated DEGs were significantly involved in different biological processes and pathways including extracellular matrix organization and ECM-receptor interaction. FN1, CDK1, AURKA, TOP2A, FOXM1, BIRC5, CDC6, UBE2C, TTK, and TPX2 were identified as the most important genes among the up-regulated DEGs. Our analysis showed that has-miR-29a-3p, has-miR-29b-3p, has-miR-29c-3p, and has-miR-767-5p had the largest number of common targets among the up-regulated DEGs. These findings strengthen the understanding of EC development and progression, as well as representing potential markers for EC diagnosis and treatment.

Ubiquitination Links DNA Damage and Repair Signaling to Cancer Metabolism

Changes in the DNA damage response (DDR) and cellular metabolism are two important factors that allow cancer cells to proliferate. DDR is a set of events in which DNA damage is recognized, DNA repair factors are recruited to the site of damage, the lesion is repaired, and cellular responses associated with the damage are processed. In cancer, DDR is commonly dysregulated, and the enzymes associated with DDR are prone to changes in ubiquitination. Additionally, cellular metabolism, especially glycolysis, is upregulated in cancer cells, and enzymes in this metabolic pathway are modulated by ubiquitination. The ubiquitin-proteasome system (UPS), particularly E3 ligases, act as a bridge between cellular metabolism and DDR since they regulate the enzymes associated with the two processes. Hence, the E3 ligases with high substrate specificity are considered potential therapeutic targets for treating cancer. A number of small molecule inhibitors designed to target different components of the UPS have been developed, and several have been tested in clinical trials for human use. In this review, we discuss the role of ubiquitination on overall cellular metabolism and DDR and confirm the link between them through the E3 ligases NEDD4, APC/C^CDH1, FBXW7, and Pellino1. In addition, we present an overview of the clinically important small molecule inhibitors and implications for their practical use.

Roles of oncogenes in esophageal squamous cell carcinoma and their therapeutic potentials

Esophageal squamous cell carcinoma (ESCC) is the most common type of esophageal cancer (EC) in Asia. It is a malignant digestive tract tumor with abundant gene mutations. Due to the lack of specific diagnostic markers and early cancer screening markers, most patients are diagnosed at an advanced stage. Genetic and epigenetic changes are closely related to the occurrence and development of ESCC. Here, We review the activation of proto-oncogenes into oncogenes through gene mutation and gene amplification in ESCC from a genetic and epigenetic genome perspective, We also discuss the specific regulatory mechanisms through which these oncogenes mainly affect the biological function and occurrence and development of ESCC through specific regulatory mechanisms. In addition, we summarize the clinical application value of these oncogenes is summarized, and it provides a feasible direction for clinical use as potential therapeutic and diagnostic markers.

Wnt signaling pathway-related gene PRICKLE1 is a prognostic biomarker for esophageal squamous cell carcinoma

Esophageal squamous cell carcinoma (ESCC) has become a major health risk to human health. Although significant clinical progress has been made in the treatment of ESCC, the prognosis of patients still needs to be improved. Therefore, it is important to screen effective molecular indicators for the prognosis of ESCC. In this study, the intersection of up-regulated genes, down-regulated genes, and Wnt signaling pathway-related genes in ESCC was taken, and 47 overlapping genes were found. PRICKLE1 was determined to be an independent prognostic factor in ESCC based on univariate and multifactorial COX risk regression models. Kaplan-Meier survival curves showed that patients in the PRICKLE1 high expression group had significantly better overall survival. In addition, we performed various experiments to examine the effects of PRICKLE1 overexpression on proliferation, migration, and apoptosis of ESCC cells. The experimental results showed that the PRICKLE1-OE group had reduced cell viability, significantly lower migration ability and significantly higher apoptosis rate compared to the NC group.Therefore, we hypothesized that high PRICKLE1 expression could be used to predict the survival rate of ESCC patients, which could be used as an independent prognostic indicator for ESCC patients and provide potential applications for ESCC clinical treatment.

Emerging Roles of RNF168 in Tumor Progression

RING finger protein 168 (RNF168) is an E3 ubiquitin ligase with the RING finger domain. It is an important protein contributing to the DNA double-strand damage repair pathway. Recent studies have found that RNF168 is significantly implicated in the occurrence and development of various cancers. Additionally, RNF168 contributes to the drug resistance of tumor cells by enhancing their DNA repair ability or regulating the degradation of target proteins. This paper summarizes and prospects the research progress of the structure and main functions of RNF168, especially its roles and the underlying mechanisms in tumorigenesis.

SYNGR2 serves as a prognostic biomarker and correlates with immune infiltrates in esophageal squamous cell carcinoma

BACKGROUND

Synaptogyrin-2 (SYNGR2) plays an important role in regulating membrane traffic in nonneuronal cells. However, the role of SYNGR2 in esophageal squamous cell carcinoma (ESCC) remains unclear.

METHODS

All original data were downloaded from The Cancer Genome Atlas (TCGA) and Gene Expression Omnibus (GEO) databases and integrated via R 3.5.3. SYNGR2 expression was explored in the TCGA and GEO databases. The correlations between SYNGR2 and cancer immune characteristics were analyzed via the TIMER and TISIDB databases.

RESULTS

In general, SYNGR2 was predominantly overexpressed and had reference value in the diagnosis and prognostic estimation of ESCC. Upregulated SYNGR2 was associated with poorer overall survival, poorer disease-specific survival and T stage in ESCC. Mechanistically, we identified hub genes that included a total of 38 SYNGR2-related genes, which were tightly associated with the protein polyubiquitination pathway in ESCC patients. SYNGR2 expression was negatively related to the infiltrating levels of T helper cells. SYNGR2 methylation was positively correlated with the expression of chemokines (CCL2 and CXCL12), chemokine receptors (CCR1 and CCR2), immunoinhibitors (CXCL12 and TNFRSF4) and immunostimulators (CSF1R and PDCD1LG2) in ESCC.

CONCLUSION

SYNGR2 may be used as a biomarker for determining prognosis and immune infiltration in ESCC.

RNF168 suppresses the cancer stem cell-like traits of nonsmall cell lung cancer cells by mediating RhoC ubiquitination

The critical roles of E3 ubiquitin ligase RNF168 have been widely revealed in various tumors, however, its roles in lung cancer progression are still confusing. Here, we found that RNF168 expression is positively correlated with the overall survival, first-progression survival, and postprogression survival of lung adenocarcinoma, but not correlated with these survivals of squamous cell carcinoma of lung. Furthermore, it was shown that RNF168 mRNA expression is lowly expressed in lung adenocarcinoma tissues, but highly expressed in squamous cell carcinoma of lung. Functional experiments indicated that RNF168 overexpression significantly suppressed the cancer stem cell (CSC)-like traits of nonsmall cell lung cancer (NSCLC) cells, as characterized by the attenuation of sphere-formation ability, ALDH activity, and the expression of lung CSC markers. Mechanistic studies demonstrated that RNF168 facilitated the ubiquitination of RhoC, which had been considered as a fascinating target for CSCs, and thus promoted RhoC protein degradation. Notably, RNF168 failed to affect the mRNA expression of RhoC and overexpression of RhoC rescued the inhibitory effects of RNF168 overexpression on the CSC-like traits of NSCLC cells. Therefore, this study revealed RNF168 as a novel regulator of RhoC protein in NSCLC cells, this RNF168/RhoC regulatory axis might be a potential target for NSCLC treatment.