Antagonistic activities of CDC14B and CDK1 on USP9X regulate WT1-dependent mitotic transcription and survival

EZH2 modulates mRNA splicing and exerts part of its oncogenic function through repression of splicing factors in CML

The polycomb protein EZH2 is up-regulated in Chronic Myeloid Leukaemia (CML) and associated with transcriptional reprogramming. Here we tested whether EZH2 might also act as a modulator of the mRNA splicing landscape to elicit its oncogenic function in CML. We treated CML cell lines with EZH2 inhibitors and detected differential splicing of several hundreds of events, potentially caused by the transcriptional regulation of splicing factors. Amongst those genes, CELF2 was identified as a candidate to mediate part of the EZH2 inhibitor induced phenotype. Upon over-expression, we observed (1) reduced cell growth, viability, and colony formation of CML cell lines, (2) a change in the splicing landscape, partially overlapping with EZH2 mediated changes, (3) the down-regulation of MYC signalling. Importantly, these findings were successfully validated in a cohort of CML patient samples, confirming the role of CELF2 as EZH2-regulated tumour-suppressor, contributing to the severe splicing de-regulation present in CML. Based on this we propose that EZH2 exerts part of its oncogenic function in CML through the transcriptional repression of splicing factors. Finally, analysis of publicly available datasets suggests that splicing modulation by EZH2 might not be restricted to CML.

SKAP1 Expression in Cancer Cells Enhances Colon Tumor Growth and Impairs Cytotoxic Immunity by Promoting Neutrophil Extracellular Trap Formation via the NFATc1/CXCL8 Axis

The mechanisms underlying the development and progression of colon cancer are not fully understood. Herein, Src kinase associated phosphoprotein 1 (SKAP1), an immune cell adaptor, is identified as a novel colon cancer-related gene. SKAP1 expression is significantly increased in colon cancer cells. High SKAP1 levels are independently predictive of poor survival in patients with colon cancer. Notably, SKAP1 expression in colon cancer cells exerted a significant tumor-promoting effect in vivo rather than in vitro. Screening of tumor-infiltrating immune cells revealed the involvement of neutrophils in SKAP1-induced colon tumor promotion. Enhanced formation of neutrophil extracellular traps (NETs) is found to be a key downstream event that contributed to the pro-tumor role of SKAP1. In colon cancer cells, SKAP1 increased the expression of C-X-C motif chemokine ligand 8 (CXCL8) via nuclear factor of activated T cells c1 (NFATc1). The blockade of CXCL8 or NFATc1 largely attenuated neutrophil infiltration, NET formation, and tumor promotion induced by SKAP1. Furthermore, inhibiting SKAP1-induced NET significantly enhanced the antitumor efficiency of adoptive natural killer cell therapy in colon tumor models. In conclusion, SKAP1 significantly promotes colon cancer growth via the cancer cell/neutrophil NFATc1/CXCL8/NET axis, suggesting that SKAP1 is a potential target for colon cancer therapy.

The deubiquitinase USP9X regulates RIT1 protein abundance and oncogenic phenotypes

RIT1 is a rare and understudied oncogene in lung cancer. Despite structural similarity to other RAS GTPase proteins such as KRAS, oncogenic RIT1 activity does not appear to be tightly regulated by nucleotide exchange or hydrolysis. Instead, there is a growing understanding that the protein abundance of RIT1 is important for its regulation and function. We previously identified the deubiquitinase USP9X as a RIT1 dependency in RIT1-mutant cells. Here, we demonstrate that both wild-type and mutant forms of RIT1 are substrates of USP9X. Depletion of USP9X leads to decreased RIT1 protein stability and abundance and resensitizes cells to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors in vitro and in vivo. Our work expands upon the current understanding of RIT1 protein regulation and presents USP9X as a key regulator of RIT1-driven oncogenic phenotypes.

Cdc14B/Cyclin B1 signaling modulates the pathogenesis of sonic hedgehog subtype medulloblastoma

Medulloblastoma (MB) is a severe malignancy of the central nervous system that predominantly occurs in the cerebellum of children. Overactivation of the sonic hedgehog (Shh) signaling pathway is the primary cause of the development and progression of Shh subtype MB, although the detailed mechanisms underlying this process remain largely elusive. In this study, we discovered that Shh can promote proliferation in MB cells through non-canonical Hedgehog signaling. This involves Shh binding to Patched 1, disrupting its interaction with Cyclin B1, allowing for nuclear translocation of Cyclin B1, and inducing the activation of genes involved in cell division. Furthermore, we observed that deregulation of Cdc14B leads to the stabilization of the Cyclin B1/CDK1 complex in MB cells through activating Cdc25C, a phosphatase known to help maintain Cyclin B1 stability. Our findings highlight the role of Cdc14B/Cdc25C/CDK1/Cyclin B1 in mediating Hedgehog signaling-driven pathogenesis in MB and have implications for identifying potential therapeutic targets.

Cellular functions, molecular signalings and therapeutic applications: Translational potential of deubiquitylating enzyme USP9X as a drug target in cancer treatment

Protein ubiquitination, one of the most significant post-translational modifications, plays an important role in controlling the proteins activity in diverse cellular processes. The reversible process of protein ubiquitination, known as deubiquitination, has emerged as a critical mechanism for maintaining cellular homeostasis. The deubiquitinases (DUBs), which participate in deubiquitination process are increasingly recognized as potential candidates for drug discovery. Among these DUBs, ubiquitin-specific protease 9× (USP9X), a highly conserved member of the USP family, exhibits versatile functions in various cellular processes, including the regulation of cell cycle, protein endocytosis, apoptosis, cell polarity, immunological microenvironment, and stem cell characteristics. The dysregulation and abnormal activities of USP9X are influenced by intricate cellular signaling pathway crosstalk and upstream non-coding RNAs. The complex expression patterns and controversial clinical significance of USP9X in cancers suggest its potential as a prognostic biomarker. Furthermore, USP9X inhibitors has shown promising antitumor activity and holds the potential to overcome therapeutic resistance in preclinical models. However, a comprehensive summary of the role and molecular functions of USP9X in cancer progression is currently lacking. In this review, we provide a comprehensive delineation of USP9X participation in numerous critical cellular processes, complicated signaling pathways within the tumor microenvironment, and its potential translational applications to combat therapeutic resistance. By systematically summarizing the updated molecular mechanisms of USP9X in cancer biology, this review aims to contribute to the advancement of cancer therapeutics and provide essential insights for specialists and clinicians in the development of improved cancer treatment strategies.

The Cdc14 phosphatase, Clp1, does not affect genome expression

Schizosaccharomyces pombe Clp1 is a Cdc14-family phosphatase that reverses mitotic Cdk1 phosphorylation. Despite evolutionary conservation, Clp1 's mammalian orthologs do not share this function. Rather, higher eukaryotic Cdc14 enzymes act in DNA repair, ciliogenesis, and gene regulation. To examine if Clp1 regulates gene expression, we compared the transcriptional profiles of cells lacking Clp1 function to that of wildtype. Because clp1∆ cells are sensitive to the actin depolymerizing drug, LatrunculinA, we also investigated whether a transcriptional response was involved. Our results indicate that Clp1 does not detectably affect gene expression and highlight the organism-specific functions of this conserved phosphatase family.

The deubiquitinase USP9X regulates RIT1 protein abundance and oncogenic phenotypes

RIT1 is a rare and understudied oncogene in lung cancer. Despite structural similarity to other RAS GTPase proteins such as KRAS, oncogenic RIT1 activity does not appear to be tightly regulated by nucleotide exchange or hydrolysis. Instead, there is a growing understanding that the protein abundance of RIT1 is important for its regulation and function. We previously identified the deubiquitinase USP9X as a RIT1 dependency in RIT1-mutant cells. Here, we demonstrate that both wild-type and mutant forms of RIT1 are substrates of USP9X. Depletion of USP9X leads to decreased RIT1 protein stability and abundance and resensitizes cells to EGFR tyrosine kinase inhibitors. Our work expands upon the current understanding of RIT1 protein regulation and presents USP9X as a key regulator of RIT1-driven oncogenic phenotypes.

Roles of USP9X in cellular functions and tumorigenesis (Review)

Ubiquitin-specific peptidase 9X (USP9X) is involved in certain human diseases, including malignancies, atherosclerosis and certain diseases of the nervous system. USP9X promotes the deubiquitination and stabilization of diverse substrates, thereby exerting a versatile range of effects on pathological and physiological processes. USP9X serves vital roles in the processes of cell survival, invasion and migration in various types of cancer. The present review aims to highlight the current knowledge of USP9X in terms of its structure and the possible mediatory mechanisms involved in certain types of cancer, providing a thorough introduction to its biological functions in carcinogenesis and further outlining its oncogenic or suppressive properties in a diverse range of cancer types. Finally, several perspectives regarding USP9X-targeted pharmacological therapeutics in cancer development are discussed.

Prostate cancer cell-derived exosomal IL-8 fosters immune evasion by disturbing glucolipid metabolism of CD8+ T cell

Depletion of CD8+ T cells is a major obstacle in immunotherapy; however, the relevant mechanisms remain largely unknown. Here, we showed that prostate cancer (PCa) cell-derived exosomes hamper CD8+ T cell function by transporting interleukin-8 (IL-8). Compared to the low IL-8 levels detected in immune cells, PCa cells secreted the abundance of IL-8 and further accumulated in exosomes. The delivery of PCa cell-derived exosomes into CD8+ T cells exhausted the cells through enhanced starvation. Mechanistically, exosomal IL-8 overactivated PPARα in recipient cells, thereby decreasing glucose utilization by downregulating GLUT1 and HK2 but increasing fatty acid catabolism via upregulation of CPT1A and ACOX1. PPARα further activates uncoupling protein 1 (UCP1), leading to fatty acid catabolism for thermogenesis rather than ATP synthesis. Consequently, inhibition of PPARα and UCP1 restores CD8+ T cell proliferation by counteracting the effect of exosomal IL-8. This study revealed that the tumor exosome-activated IL-8-PPARα-UCP1 axis harms tumor-infiltrating CD8+ T cells by interfering with energy metabolism.

The diverging role of CDC14B: from mitotic exit in yeast to cell fate control in humans

CDC14, originally identified as crucial mediator of mitotic exit in budding yeast, belongs to the family of dual-specificity phosphatases (DUSPs) that are present in most eukaryotes. Contradicting data have sparked a contentious discussion whether a cell cycle role is conserved in the human paralogs CDC14A and CDC14B but possibly masked due to redundancy. Subsequent studies on CDC14A and CDC14B double knockouts in human and mouse demonstrated that CDC14 activity is dispensable for mitotic progression in higher eukaryotes and instead suggested functional specialization. In this review, we provide a comprehensive overview of our current understanding of how faithful cell division is linked to phosphorylation and dephosphorylation and compare functional similarities and divergences between the mitotic phosphatases CDC14, PP2A, and PP1 from yeast and higher eukaryotes. Furthermore, we review the latest discoveries on CDC14B, which identify this nuclear phosphatase as a key regulator of gene expression and reveal its role in neuronal development. Finally, we discuss CDC14B functions in meiosis and possible implications in other developmental processes.

Identification of several inflammation-related genes based on bioinformatics and experiments

BACKGROUND

Osteoarthritis (OA) is a common disease of elderly individuals, with an unclear pathogenesis and limited treatment options to date. Inflammation occurs prominently in osteoarthritis, thereby making anti-inflammatory treatments promising in clinical outcomes. Therefore, it is of diagnostic and therapeutic significance to explore more inflammatory genes.

METHOD

In this study, appropriate datasets were first acquired through gene set enrichment analysis (GSEA), followed by inflammation-related genes through weighted gene coexpression network analysis (WGCNA). Two machine learning algorithms (random forest-RF and support vector machine-recursive feature elimination, SVM-RFE) were used to capture the hub genes. In addition, two genes negatively associated with inflammation and osteoarthritis were identified. Afterwards, these genes were verified through experiments and network pharmacology. Due to the association between inflammation and many diseases, the expression levels of the above genes in various inflammatory diseases were determined through literature and experiments.

RESULT

Two hub genes closely related to osteoarthritis and inflammation were obtained, namely, lysyl oxidase-like 1 (LOXL1) and pituitary tumour-transforming gene (PTTG1), which were shown to be highly expressed in osteoarthritis according to the literature and experiments. However, the expression levels of receptor expression-enhancing protein (REEP5) and cell division cycle protein 14B (CDC14B) remained unchanged in osteoarthritis. This finding was consistent with our verification from the literature and experiments that some genes were highly expressed in numerous inflammation-related diseases, while REEP5 and CDC14B were almost unchanged. Meanwhile, taking PTTG1 as an example, we found that inhibition of PTTG1 expression could suppress the expression of inflammatory factors and protect the extracellular matrix through the microtubule-associated protein kinase (MAPK) signalling pathway.

CONCLUSIONS

LOXL1 and PTTG1 were highly expressed in some inflammation-related diseases, while that of REEP5 and CDC14B were almost unchanged. PTTG1 may be a potential target for the treatment of osteoarthritis.

Targeting USP10 induces degradation of oncogenic ANLN in esophageal squamous cell carcinoma

Anillin (ANLN) is a mitosis-related protein that promotes contractile ring formation and cytokinesis, but its cell cycle-dependent degradation mechanisms in cancer cells remain unclear. Here, we show that high expression of ANLN promotes cytokinesis and proliferation in esophageal squamous cell carcinoma (ESCC) cells and is associated with poor prognosis in ESCC patients. Furthermore, the findings of the study showed that the deubiquitinating enzyme USP10 interacts with ANLN and positively regulates ANLN protein levels. USP10 removes the K11- and K63-linked ubiquitin chains of ANLN through its deubiquitinase activity and prevents ANLN ubiquitin-mediated degradation. Importantly, USP10 promotes contractile ring assembly at the cytokinetic furrow as well as cytokinesis by stabilizing ANLN. Interestingly, USP10 and the E3 ubiquitin ligase APC/C co-activator Cdh1 formed a functional complex with ANLN in a non-competitive manner to balance ANLN protein levels. In addition, the macrolide compound FW-04-806 (F806), a natural compound with potential for treating ESCC, inhibited the mitosis of ESCC cells by targeting USP10 and promoting ANLN degradation. F806 selectively targeted USP10 and inhibited its catalytic activity but did not affect the binding of Cdh1 to ANLN and alters the balance of the USP10-Cdh1-ANLN complex. Additionally, USP10 expression was positively correlated with ANLN level and poor prognosis of ESCC patients. Overall, targeting the USP10-ANLN axis can effectively inhibit ESCC cell-cycle progression.

WT1 Trio Peptide-Based Cancer Vaccine for Rare Cancers Expressing Shared Target WT1

No standard treatment has been established for most rare cancers. Here, we report a clinical trial of a biweekly WT1 tri-peptide-based vaccine for recurrent or advanced rare cancers. Due to the insufficient number of patients available for a traditional clinical trial, the trial was designed for rare cancers expressing shared target molecule WT1. The recruitment criteria included WT1-expressing tumors as well as HLA-A*24:02 or 02:01. The primary endpoints were immunoglobulin G (IgG) antibody (Ab) production against the WT1-235 cytotoxic T lymphocyte (CTL) epitope and delayed-type hypersensitivity (DTH) skin reactions to targeted WT1 CTL epitopes. The secondary endpoints were safety and clinical efficacy. Forty-five patients received WT1 Trio, and 25 (55.6%) completed the 3-month protocol treatment. WT1-235 IgG Ab was positive in 88.0% of patients treated with WT1 Trio at 3 months, significantly higher than 62.5% of the weekly WT1-235 CTL peptide vaccine. The DTH positivity rate in WT1 Trio was 62.9%, which was not significantly different from 60.7% in the WT1-235 CTL peptide vaccine. The WT1 Trio safety was confirmed without severe treatment-related adverse events, except grade 3 myasthenia gravis-like symptoms observed in a patient with thymic cancer. Fifteen (33.3%) patients achieved stable disease after 3 months of treatment. In conclusion, the biweekly WT1 Trio vaccine containing the WT1-332 helper T lymphocyte peptide induced more robust immune responses targeting WT1 than the weekly WT1-235 CTL peptide vaccine. Therefore, WT1-targeted immunotherapy may be a potential therapeutic strategy for rare cancers.

Dual role of deubiquitinating enzyme USP19 regulates mitotic progression and tumorigenesis by stabilizing survivin

Survivin is a component of the chromosomal passenger complex, which includes Aurora B, INCENP, and Borealin, and is required for chromosome segregation and cytokinesis. We performed a genome-wide screen of deubiquitinating enzymes for survivin. For the first time, we report that USP19 has a dual role in the modulation of mitosis and tumorigenesis by regulating survivin expression. Our results found that USP19 stabilizes and interacts with survivin in HCT116 cells. USP19 deubiquitinates survivin protein and extends its half-life. We also found that USP19 functions as a mitotic regulator by controlling the downstream signaling of survivin protein. Targeted genome knockout verified that USP19 depletion leads to several mitotic defects, including cytokinesis failure. In addition, USP19 depletion results in significant enrichment of apoptosis and reduces the growth of tumors in the mouse xenograft. We envision that simultaneous targeting of USP19 and survivin in oncologic drug development would increase therapeutic value and minimize redundancy.

The OTUD6B-LIN28B-MYC axis determines the proliferative state in multiple myeloma

Deubiquitylases (DUBs) are therapeutically amenable components of the ubiquitin machinery that stabilize substrate proteins. Their inhibition can destabilize oncoproteins that may otherwise be undruggable. Here, we screened for DUB vulnerabilities in multiple myeloma, an incurable malignancy with dependency on the ubiquitin proteasome system and identified OTUD6B as an oncogene that drives the G1/S‐transition. LIN28B, a suppressor of microRNA biogenesis, is specified as a bona fide cell cycle‐specific substrate of OTUD6B. Stabilization of LIN28B drives MYC expression at G1/S, which in turn allows for rapid S‐phase entry. Silencing OTUD6B or LIN28B inhibits multiple myeloma outgrowth in vivo and high OTUD6B expression evolves in patients that progress to symptomatic multiple myeloma and results in an adverse outcome of the disease. Thus, we link proteolytic ubiquitylation with post‐transcriptional regulation and nominate OTUD6B as a potential mediator of the MGUS‐multiple myeloma transition, a central regulator of MYC, and an actionable vulnerability in multiple myeloma and other tumors with an activated OTUD6B‐LIN28B axis.

The CDK1-Related lncRNA and CXCL8 Mediated Immune Resistance in Lung Adenocarcinoma

Background: Limited therapeutic options are available for advanced LUAD without driver gene mutations. Anti-CDK therapy has shown effectiveness in several kind of cancers, however, the mechanisms still need to be elucidated. Materials and Methods: The lncRNA associated with CDK1 and the immunomodulatory factors that regulate CDK1 were found by bioinformatics analysis and experimental verification. The prognostic model and immune resistance mechanism of lung adenocarcinoma were revealed by single cell analysis, immune infiltration analysis, and signal pathway analysis. Results: LINC00261 was found to be an important CDK1-related lncRNA with a better prognosis in LUAD. In addition, high CDK1 expression indicates a poor immunotherapy response, which may be associated with overexpression of CXCL8. CXCL8 decreased in patients who were immunotherapy-responsive but increased in patients who were immunotherapy-resistant. Signaling pathway analysis suggested that increased CXCL8 and decreased LINC00261 may participate in hypoxia-induced tumor angiogenesis and cause a poor prognosis for the patients. CXCL8 and CDK1 may change G2-M transformation and EMT and promote tumor proliferation. Conclusion: This study explained that LINC00261, CDK1, and CXCL8 may have a mutual regulation relationship, which affects the occurrence of LUAD and the efficacy of immunotherapy.

Transcription factor Sp1 regulates mitotic chromosome assembly and segregation

Aneuploidy is a pervasive feature of cancer cells that results from chromosome missegregation. Several transcription factors have been associated with aneuploidy; however, no studies to date have demonstrated that mammalian transcription factors directly regulate chromosome segregation during mitosis. Here, we demonstrate that the ubiquitously expressed transcription factor specificity protein 1 (Sp1), which we have previously linked to aneuploidy, has a mitosis-specific role regulating chromosome segregation. We find that Sp1 localizes to mitotic centromeres and auxin-induced rapid Sp1 degradation at mitotic onset results in chromosome segregation errors and aberrant mitotic progression. Furthermore, rapid Sp1 degradation results in anomalous mitotic chromosome assembly characterized by loss of condensin complex I localization to mitotic chromosomes and chromosome condensation defects. Consistent with these defects, Sp1 degradation results in reduced chromosome passenger complex activity and histone H3 serine 10 phosphorylation during mitosis, which is essential for condensin complex I recruitment and chromosome condensation. Together, these data provide the first evidence of a mammalian transcription factor acting specifically during mitosis to regulate chromosome segregation.

Gene Expression Monotonicity across Bladder Cancer Stages Informs on the Molecular Pathogenesis and Identifies a Prognostic Eight-Gene Signature

Despite advancements in molecular classification, tumor stage and grade still remain the most relevant prognosticators used by clinicians to decide on patient management. Here, we leverage publicly available data to characterize bladder cancer (BLCA)’s stage biology based on increased sample sizes, identify potential therapeutic targets, and extract putative biomarkers. A total of 1135 primary BLCA transcriptomes from 12 microarray studies were compiled in a meta-cohort and analyzed for monotonal alterations in pathway activities, gene expression, and co-expression patterns with increasing stage (Ta–T1–T2–T3–T4), starting from the non-malignant tumor-adjacent urothelium. The TCGA-2017 and IMvigor-210 RNA-Seq data were used to validate our findings. Wnt, MTORC1 signaling, and MYC activity were monotonically increased with increasing stage, while an opposite trend was detected for the catabolism of fatty acids, circadian clock genes, and the metabolism of heme. Co-expression network analysis highlighted stage- and cell-type-specific genes of potentially synergistic therapeutic value. An eight-gene signature, consisting of the genes AKAP7, ANLN, CBX7, CDC14B, ENO1, GTPBP4, MED19, and ZFP2, had independent prognostic value in both the discovery and validation sets. This novel eight-gene signature may increase the granularity of current risk-to-progression estimators.

TGFBR2 is a novel substrate and indirect transcription target of deubiquitylase USP9X in granulosa cells

The ubiquitin-specific peptidase 9 X-linked (USP9X) is one of the highly conserved members belonging to the ubiquitin-specific proteases (USPs) family, which has been reported to control substrates-mediated biological functions through deubiquitinating and stabilizing substrates. Here, we have found that TGFBR2, the type II receptor of the transforming growth factor beta (TGF-β) signaling pathway, is a novel substrate and indirect transcription target of deubiquitylase USP9X in granulosa cells (GCs). Mechanically, USP9X positively influences the expression of TGFBR2 at different levels through two independent ways: (i) directly targets and deubiquitinates TGFBR2, which maintains the protein stability of TGFBR2 through avoiding degradation mediated by ubiquitin-proteasome system; (ii) indirectly maintains TGFBR2 messenger RNA (mRNA) expression via SMAD4/miR-143 axis. Specifically, SMAD4, another substrate of USP9X, acts as a transcription factor and suppresses miR-143 which inhibits the mRNA level of TGFBR2 by directly binding to its 3'-untranslated region. Functionally, the maintenance of TGFBR2 by USP9X activates the TGF-β signaling pathway, which further represses GC apoptosis. Our study highlights a functional micro-regulatory network composed of deubiquitinase (USP9X), small noncoding RNA (miR-143) and the TGF-β signaling pathway, which plays a crucial role in the regulation of GC apoptosis and female fertility.

Autophagy regulates differentiation of ovarian granulosa cells through degradation of WT1

Ovarian granulosa cells (GCs) proliferate and differentiate along with follicular growth, and this is indispensable for oocyte development and female fertility. Although the role of macroautophagy/autophagy in ovarian function has been reported, its contribution to the regulation of GC characteristics remains elusive. The siRNA-mediated knockdown of two key autophagy-related genes ATG5 and BECN1 and the autophagy inhibitor chloroquine were used to interfere with autophagy in GCs. Inhibition of autophagy both genetically and pharmacologically resulted in decreased expression of genes associated with GC differentiation, including CYP19A1/Aromatase and FSHR, as well as in reduced estradiol synthesis. Mechanistically, when autophagy was disrupted, the transcription factor WT1 accumulated in GCs due to its insufficient degradation by the autophagic pathway, and this inhibited GC differentiation. Finally, decreased expression of several autophagy-related genes, as well as reduced LC3-II:LC3-I and elevated SQSTM1/p62 protein levels, which are indications of decreased autophagy, were detected in GCs from biochemical premature ovarian insufficiency patients. In summary, our study reveals that autophagy regulates the differentiation of ovarian GCs by degrading WT1 and that insufficient autophagy might be involved in ovarian dysfunction.

Deubiquitinating enzymes (DUBs): Regulation, homeostasis, and oxidative stress response

Ubiquitin signaling is a conserved, widespread, and dynamic process in which protein substrates are rapidly modified by ubiquitin to impact protein activity, localization, or stability. To regulate this process, deubiquitinating enzymes (DUBs) counter the signal induced by ubiquitin conjugases and ligases by removing ubiquitin from these substrates. Many DUBs selectively regulate physiological pathways employing conserved mechanisms of ubiquitin bond cleavage. DUB activity is highly regulated in dynamic environments through protein-protein interaction, posttranslational modification, and relocalization. The largest family of DUBs, cysteine proteases, are also sensitive to regulation by oxidative stress, as reactive oxygen species (ROS) directly modify the catalytic cysteine required for their enzymatic activity. Current research has implicated DUB activity in human diseases, including various cancers and neurodegenerative disorders. Due to their selectivity and functional roles, DUBs have become important targets for therapeutic development to treat these conditions. This review will discuss the main classes of DUBs and their regulatory mechanisms with a particular focus on DUB redox regulation and its physiological impact during oxidative stress.

Emerging role of RNA modification N6-methyladenosine in immune evasion

The innate and adaptive immune cells have complex signaling pathways for sensing and initiating immune responses against disease. These pathways are interrupted at different levels to occur immune evasion, including by N6-methyladenosine (m6A) modification. In this review, we discuss studies revealing the immune evasion mechanism by m6A modification, which underlies the retouching of these signaling networks and the rapid tolerance of innate and adaptive immune molecules during disease. We also focus on the functions of m6A in main chemokines regulation, and their roles in promotive and suppressive immune cell recruitment. We then discuss some of the current challenges in the field and describe future directions for the immunological mechanisms of m6A modification.