CLK2 mediates IκBα-independent early termination of NF-κB activation by inducing cytoplasmic redistribution and degradation.

Activation of the NF-κB pathway is strictly regulated to prevent excessive inflammatory and immune responses. In a well-known negative feedback model, IκBα-dependent NF-κB termination is a delayed response pattern in the later stage of activation, and the mechanisms mediating the rapid termination of active NF-κB remain unclear. Here, we showed IκBα-independent rapid termination of nuclear NF-κB mediated by CLK2, which negatively regulated active NF-κB by phosphorylating the RelA/p65 subunit of NF-κB at Ser180 in the nucleus to limit its transcriptional activation through degradation and nuclear export. Depletion of CLK2 increased the production of inflammatory cytokines, reduced viral replication and increased the survival of the mice. Mechanistically, CLK2 phosphorylated RelA/p65 at Ser180 in the nucleus, leading to ubiquitin‒proteasome-mediated degradation and cytoplasmic redistribution. Importantly, a CLK2 inhibitor promoted cytokine production, reduced viral replication, and accelerated murine psoriasis. This study revealed an IκBα-independent mechanism of early-stage termination of NF-κB in which phosphorylated Ser180 RelA/p65 turned off posttranslational modifications associated with transcriptional activation, ultimately resulting in the degradation and nuclear export of RelA/p65 to inhibit excessive inflammatory activation. Our findings showed that the phosphorylation of RelA/p65 at Ser180 in the nucleus inhibits early-stage NF-κB activation, thereby mediating the negative regulation of NF-κB.

Crosstalk between metabolism and cell death in tumorigenesis.

It is generally recognized that tumor cells proliferate more rapidly than normal cells. Due to such an abnormally rapid proliferation rate, cancer cells constantly encounter the limits of insufficient oxygen and nutrient supplies. To satisfy their growth needs and resist adverse environmental events, tumor cells modify the metabolic pathways to produce both extra energies and substances required for rapid growth. Realizing the metabolic characters special for tumor cells will be helpful for eliminating them during therapy. Cell death is a hot topic of long-term study and targeting cell death is one of the most effective ways to repress tumor growth. Many studies have successfully demonstrated that metabolism is inextricably linked to cell death of cancer cells. Here we summarize the recently identified metabolic characters that specifically impact on different types of cell deaths and discuss their roles in tumorigenesis.

Hedyotis diffusa Willd and Astragalus membranaceus May Exert Anti-colon Cancer Effects by Affecting AKTI Expression, as Determined by Network Pharmacology and Molecular Docking.

BACKGROUND: Network pharmacology is a novel approach that uses bioinformatics to predict multitarget drugs and ingredient-target interactions in various diseases. A thorough search of previously published studies revealed that Hedyotis diffusa Willd (HDW) and Astragalus membranaceus (AM) possess anticancer activity. Colon cancer (CC) is one of the most common malignant tumors of the digestive tract and occurs in the colon. Herein, we explored the effect of two drugs in the treatment of CC. OBJECTIVE: The present study aimed to predict and verify the effect of these two drugs in the treatment of CC. METHODS: To explore the molecular mechanisms of the "HDW-AM" drug in the treatment of CC, we analyzed its principal efficiency in terms of ingredients, target spots, and pathways via network pharmacology, molecular docking, and experimental verification. The ingredients and their gene target sites were searched and screened through the TCMSP platform according to specific filtering conditions. Subsequently, components corresponding to the gene targets were chosen to construct the drug component-target network. The GEO (Gene Expression Omnibus) dataset was used to collect and screen for gene chips under CC and normal conditions, obtain differential genes, and construct a volcano map. The intersection genes between drug and disease targets were screened, the ".tsv" file was downloaded from the STRING platform and imported into Cytoscape 3.8.0 for visualization, a protein-protein interaction (PPI) network was constructed, the core targets were identified, and the common components with core targets were docked through Autodock Tools-1.5.6. Gene Ontology (GO) analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis were carried out through the Metascape platform to determine the major pathways. The CCK-8 (Cell Counting Kit-8) assay verified the effect of AKT1 on cell proliferation after treatment with quercetin. RESULTS: After the screening, 3658 DEGs (1841 downregulated and 1817 upregulated) were obtained from the GSE75970 gene chip; 21 active components and 220 targets were identified from the drugs. Subsequently, ten core genes (including AKT1, P53, and CASP3) and six major components were screened. GO functional analysis and KEGG analysis revealed that "HDWAM" regulates cell migration and motility through the combination of a transcription regulator complex, membrane rafts, vesicle lumen, and protein kinases via the MAPK, PI3K-Akt, and IL17 signaling pathways. The molecular docking results suggested that quercetin binds to AKT1, TP53, TNF, and CASP3. HDW-AM may exert a therapeutic effect on CC by modulating AKT1, TP53, TNF, and CASP3 and through signaling pathways. A CCK-8 cytotoxicity assay verified that quercetin affects cell viability through AKT1. CONCLUSIONS: The current study provides a theoretical basis for an in-depth investigation into the molecular mechanism of the "HDW-AM" drug in CC treatment via network pharmacology, molecular docking, and experimental verification.

USP5 facilitates bladder cancer progression by stabilizing the c-Jun protein.

BACKGROUND: Bladder cancer is the second most common genitourinary malignancy worldwide. The death rate of bladder cancer has increased every year. However, the molecular mechanism of bladder cancer is not sufficiently studied. Deubiquitinating enzymes (DUBs) play an important role in carcinogenesis. Several studies have demonstrated that USP5 associated with malignancy and pathological progression in hepatocellular carcinoma, colorectal and non-small cell lung cancer. However, the role of USP5 in bladder cancer need to be explored. METHODS: The USP5 expression was analysed using the web server GEPIA. To explore USP5 function in bladder cancer, we constructed USP5-knockout cell lines in T24 cells. A FLAG-USP5 (WT USP5) plasmid and a plasmid FLAG-USP5 C335A (catalytic-inactive mutant) used to overexpress USP5 in EJ cells. CCK8, colony formation, transwell and scratch assays were used to assess cell viability, proliferation and migration. RNA sequencing (RNA-seq) and dual-luciferase reporter assays were performed to screen the pathway. Coimmunoprecipitation and immunofluorescence were used to explore the interaction between USP5 and c-Jun. Cycloheximide (CHX) chase assays were performed to establish the effect of USP5 on c-Jun stability. Xenograft mouse model was used to study the role of USP5 in bladder cancer. RESULTS: USP5 expression is increased in bladder cancer patients. Genetic ablation of USP5 markedly inhibited bladder cancer cell proliferation, viability, and migration both in vitro and in vivo. RNA-seq and luciferase pathway screening showed that USP5 activated JNK signalling, and we identified the interaction between USP5 and c-Jun. USP5 was found to activate c-Jun by inhibiting its ubiquitination. CONCLUSIONS: Our results show that high USP5 expression promotes bladder cancer progression by stabilizing c-Jun and that USP5 is a potential therapeutic target in bladder cancer.

Predicting the anti-inflammatory mechanism of Radix Astragali using network pharmacology and molecular docking.

According to current research, the primary active ingredients of Radix Astragali (RA), such as saponins, flavonoids, and polysaccharides, play an important role in anti-inflammatory effects. However, the exact molecular mechanism underlying the action was not elucidated to date. Our research attempted to determine the active components in RA and to investigate the interaction between the active components and targets involved in the anti-inflammation activity by network pharmacology and molecular docking. The active components and targets of RA were screened out by TCMSP. Thereafter, through the "anti-inflammation effect" and "inflammation" as the keywords, disease targets were obtained from the GeneCards database. The PPI network was constructed with Cytoscape 3.8.0 software to screen core targets. The GO function and KEGG analysis were enriched and analyzed through the Metascape platform, obtaining the 3-dimensional view of the core targets from the PDB database, and then, performing molecular docking in AutoDock Vina, a heatmap was constructed using the binding free energies in GraphPad Prism 8. The Discovery Studio software was used for docking analysis, and eventually, the docking results were visualized. We also explored the targets and signaling pathways of Astragaloside IV acting on anti-inflammatory effects via constructing compound-disease-target-pathway network. 18 active components and 45 targets of RA were screened out. The main anti-inflammatory active components of RA were quercetin, Astragaloside IV, kaempferol, 7-O-methylisomucronulatol, and formononetin, and the strongly interacting core proteins were TNF, IL6, IL1B, TLR4, CXCL8, CCL2, IL10, VEGFA, and MMP9. The signal pathways mainly involved include Lipid and atherosclerosis, IL-17 signaling pathway, Chagas disease, leishmaniasis, and TNF signaling pathway. Moreover, molecular docking showed that the 2 most active compounds, Astragaloside IV and kaempferol, could efficiently bind with the targets TNF, TLR4, and IL10. Astragaloside IV may play a part in anti-inflammatory effects through pathways such as HIF-1 signaling pathway, Inflammatory bowel disease and Hepatitis B ect. RA exhibits the characteristic of multicomponent and multitarget synergistic effects in exerting anti-inflammatory effects and the effective component of RA is Astragaloside IV, targeting TNF, TLR4, and IL10.

Activation of CTNNB1 by deubiquitinase UCHL3-mediated stabilization facilitates bladder cancer progression.

BACKGROUND: The catenin beta 1 gene (CTNNB1) plays a crucial role in the malignant progression of various cancers. Recent studies have suggested that CTNNB1 hyperactivation is closely related to the occurrence and development of bladder cancer (BCa). As a member of the deubiquitinating enzyme (DUB) family, ubiquitin C-terminal hydrolase L3 (UCHL3) is abnormally expressed in various cancers. In this study, we discovered that UCHL3 is a novel oncogene in bladder cancer, suggesting it is a promising target against bladder cancer. METHODS: We utilized CRISPR‒Cas9 technology to construct cell lines with UCHL3 stably overexpressed or knocked out. The successful overexpression or knockout of UCHL3 was determined using Western blotting. Then, we performed CCK-8, colony formation, soft agar and Transwell migration assays to determine the impact of the UCHL3 gene on cell phenotype. RNA-seq was performed with UCHL3-depleted T24 cells (established via CRISPR-Cas9-mediated genomic editing). We analyzed differences in WNT pathway gene expression in wild-type and UCHL3-deficient T24 cell lines using a heatmap and by gene set enrichment analysis (GSEA). Then, we validated the effect of UCHL3 on the Wnt pathway using a dual fluorescence reporter. We then analyzed the underlying mechanisms involved using Western blots, co-IP, and immunofluorescence results. We also conducted nude mouse tumor formation experiments. Moreover, conditional UCHL3-knockout mice and bladder cancer model mice were established for research. RESULTS: We found that the overexpression of UCHL3 boosted bladder cancer cell proliferation, invasion and migration, while the depletion of UCHL3 in bladder cancer cells delayed tumor tumorigenesis in vitro and in vivo. UCHL3 was highly associated with the Wnt signaling pathway and triggered the activation of the Wnt signaling pathway, which showed that its functions depend on its deubiquitination activity. Notably, Uchl3-deficient mice were less susceptible to bladder tumorigenesis. Additionally, UCHL3 was highly expressed in bladder cancer cells and associated with indicators of advanced clinicopathology. CONCLUSION: In summary, we found that UCHL3 is amplified in bladder cancer and functions as a tumor promoter that enhances proliferation and migration of tumor cells in vitro and bladder tumorigenesis and progression in vivo. Furthermore, we revealed that UCHL3 stabilizes CTNNB1 expression, resulting in the activation of the oncogenic Wnt signaling pathway. Therefore, our findings strongly suggest that UCHL3 is a promising therapeutic target for bladder cancer.

Exosomes derived from Mouse Bone Marrow Mesenchymal Stem Cells Attenuate Nucleus Pulposus Cell Apoptosis via the miR-155- 5p/Trim32 Axis.

BACKGROUND: Lower back pain, shown to be strongly associated with IVDD, affects approximately 60%-80% of adults and has a considerable societal and economic impact. Evidence suggests that IVDD, caused by abnormal apoptosis of nucleus pulposus cells (NPCs), can be treated using MSC-derived exosomes. OBJECTIVE: This study aimed to evaluate the role of miR155-5p/Trim32 in intervertebral disc disease (IVDD) and elucidate the underlying molecular mechanisms. Deregulating miR-155 has been shown to promote Fas-mediated apoptosis in human IVDD. Evidence also suggests that tripartite motif (TRIM)-containing protein 32 (Trim32) is regulated by miR-155. However, the role of miR155-5p/Trim32 in IVDD remains unclear. METHODS: Cell viability was checked using CCK-8 kits, and flow cytometry was used to analyze cell cycle and apoptosis. Cell migration was measured with a Transwell assay, while a luciferase assay was adopted to study how miR-155-5p interacts with Trim32. The roles of Trim32 and miR-155-5p were studied by silencing or up-regulating them in NPCs, while qPCR and immunoblots were used to evaluate mRNA and protein changes, respectively. RESULTS: TNF-α treatment significantly inhibited cell viability but promoted Trim32 expression in primary mouse NPCs. Administration of bone marrow mesenchymal stem cells (BMSCs) attenuated primary NPC cell cycle arrest and apoptosis induced by TNFα. BMSCs-derived exosomes could be taken up by NPCs to inhibit TNF-α-induced cell cycle arrest and apoptosis through miR-155-5p. Examination of the underlying mechanism showed that miR-155-5p targeted Trim32. Moreover, Trim32 overexpression inhibited the effect of BMSCs-derived exosomes on primary mouse NPC cell apoptosis induced by TNF-α. CONCLUSION: Overall, these findings suggest that exosomes from BMSCs can suppress TNF-α-induced cell cycle arrest and apoptosis in primary mouse NPCs through the delivery of miR-155-5p by targeting Trim32. This study provides a promising therapeutic strategy for IVDD.

Mitochondrial dynamics in neurological diseases: a narrative review.

Background and Objective: The mitochondrion is a crucial organelle for aerobic respiration and energy metabolism. It undergoes dynamic changes, including changes in its shape, function, and distribution through fission, fusion, and movement. Under normal conditions, mitochondrial dynamics are in homeostasis. However, once the balance is upset, the nervous system, which has high metabolic demands, will most likely be affected. Recent studies have shown that the imbalance of mitochondrial dynamics is involved in the occurrence and development of various neurological diseases. However, whether the regulation of mitochondrial dynamics can be used to treat neurological diseases is still unclear. We aimed to comprehensively analyze mitochondrial dynamics regulation and its potential role in the treatment of neurological diseases. Methods: A comprehensive literature review was carried out to understand the mechanisms and applications of mitochondrial dynamics in neurological diseases based on the literature available in PubMed, Web of Science, and Google Scholar. Key Content and Findings: This review discusses the molecular mechanisms related to mitochondrial dynamics and expounds upon the role of mitochondrial dynamics in the occurrence and development of neurodegenerative diseases, epilepsy, cerebrovascular disease, and brain tumors. Several clinically tested drugs with fewer side effects have been shown to improve the mitochondrial dynamics and nervous system function in neurological diseases. Conclusions: Disorders of mitochondrial dynamics can cause various neurological diseases. Elucidation of mechanisms and applications involved in mitochondrial dynamics will inform the development of new therapeutic targets and strategies for neurological diseases. Dynamin-related protein 1 (Drp1), as a highly relevant molecular for mitochondrial dynamics, might be a potential target for treating neurological diseases in the future.

Genome-Wide Analysis of MYB Transcription Factor Gene Superfamily Reveals BjPHL2a Involved in Modulating the Expression of BjCHI1 in Brassica juncea.

Brassica juncea is an economically important vegetable and oilseed crop. The MYB transcription factor superfamily is one of the largest transcription factor families in plants, and plays crucial roles in regulating the expression of key genes involved in a variety of physiological processes. However, a systematic analysis of the MYB transcription factor genes in Brassica juncea (BjMYB) has not been performed. In this study, a total of 502 BjMYB superfamily transcription factor genes were identified, including 23 1R-MYBs, 388 R2R3-MYBs, 16 3R-MYBs, 4 4R-MYBs, 7 atypical MYBs, and 64 MYB-CCs, which is approximately 2.4-fold larger than that of AtMYBs. Phylogenetic relationship analysis revealed that the MYB-CC subfamily consists of 64 BjMYB-CC genes. The expression pattern of members of PHL2 subclade homologous genes in Brassica juncea (BjPHL2) after Botrytis cinerea infection were determined, and BjPHL2a was isolated from a yeast one-hybrid screen with the promoter of BjCHI1 as bait. BjPHL2a was found to localize mainly in the nucleus of plant cells. An EMSA assay confirmed that BjPHL2a binds to the Wbl-4 element of BjCHI1. Transiently expressed BjPHL2a activates expression of the GUS reporter system driven by a BjCHI1 mini-promoter in tobacco (Nicotiana benthamiana) leaves. Taken together, our data provide a comprehensive evaluation of BjMYBs and show that BjPHL2a, one of the members of BjMYB-CCs, functions as a transcription activator by interacting with the Wbl-4 element in the promoter of BjCHI1 for targeted gene-inducible expression.

Immune Checkpoint Inhibitors in HBV-Caused Hepatocellular Carcinoma Therapy.

Hepatitis B virus (HBV) infection is the main risk factor for the development of hepatocellular carcinoma (HCC), the most common type of liver cancer, with high incidence and mortality worldwide. Surgery, liver transplantation, and ablation therapies have been used to treat early HBV-caused HCC (HBV-HCC); meanwhile, in the advanced stage, chemoradiotherapy and drug-targeted therapy are regularly considered, but with limited efficacy. Recently, immunotherapies, such as tumor vaccine therapy, adoptive cell transfer therapy, and immune checkpoint inhibitor therapy, have demonstrated promising efficacy in cancer treatment. In particular, immune checkpoint inhibitors can successfully prevent tumors from achieving immune escape and promote an anti-tumor response, thereby boosting the therapeutic effect in HBV-HCC. However, the advantages of immune checkpoint inhibitors in the treatment of HBV-HCC remain to be exploited. Here, we describe the basic characteristics and development of HBV-HCC and introduce current treatment strategies for HBV-HCC. Of note, we review the principles of immune checkpoint molecules, such as programmed cell death protein 1(PD-1) and cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) in HBV-HCC, as well as related inhibitors being considered in the clinic. We also discuss the benefits of immune checkpoint inhibitors in the treatment of HBV-HCC and the efficacy of those inhibitors in HCC with various etiologies, aiming to provide insights into the use of immune checkpoint inhibitors for the treatment of HBV-HCC.

USP14 promotes colorectal cancer progression by targeting JNK for stabilization.

MAPK/JNK signaling is pivotal in carcinogenesis. However, ubiquitin-mediated homeostasis of JNK remains to be verified. Here, with results from RNA sequencing (RNA-seq) and luciferase reporter pathway identification, we show that USP14 orchestrates MAPK/JNK signaling and identify USP14 as a deubiquitinase that interacts and stabilizes JNK. USP14 is elevated in colorectal cancer patients and is positively associated with JNK protein and downstream gene expression. USP14 ablation reduces cancer cell proliferation in vitro and colorectal tumorigenesis in vivo by downregulating MAPK/JNK pathway activation. Moreover, USP14 expression is induced by TNF-α, forming a feedback loop with JNK and leading to tumor amplification. Our study suggests that elevated expression of USP14 promotes MAPK/JNK signaling by stabilizing JNK, which in turn augments colorectal carcinogenesis, indicating a potential therapeutic target for colorectal cancer patients with increased USP14 expression.

SUMO E3 ligase AtMMS21-dependent SUMOylation of AUXIN/INDOLE-3-ACETIC ACID 17 regulates auxin signaling.

Changes in plant auxin levels can be perceived and converted into cellular responses by auxin signal transduction. AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) proteins are auxin transcriptional inhibitors that play important roles in regulating auxin signal transduction. The stability of Aux/IAA proteins is important for transcription initiation and downstream auxin-related gene expression. Here, we report that the Aux/IAA protein IAA17 interacts with the small ubiquitin-related modifier (SUMO) E3 ligase METHYL METHANESULFONATE-SENSITIVE 21 (AtMMS21) in Arabidopsis (Arabidopsis thaliana). AtMMS21 regulated the SUMOylation of IAA17 at the K41 site. Notably, root length was suppressed in plants overexpressing IAA17, whereas the roots of K41-mutated IAA17 transgenic plants were not significantly different from wild-type roots. Biochemical data indicated that K41-mutated IAA17 or IAA17 in the AtMMS21 knockout mutant was more likely to be degraded compared with nonmutated IAA17 in wild-type plants. In conclusion, our data revealed a role for SUMOylation in the maintenance of IAA17 protein stability, which contributes to improving our understanding of the mechanisms of auxin signaling.

Activating PPARß/δ Protects against Endoplasmic Reticulum Stress-Induced Astrocytic Apoptosis via UCP2-Dependent Mitophagy in Depressive Model.

As energy metabolism regulation factor, peroxisome proliferator-activated receptor (PPAR) is thought to be a potential target for the treatment of depression. The present study was performed to evaluate the effects of activating PPARß/δ, the most highly expressed subtype in the brain, in depressive in vivo and in vitro models. We observed that PPARß/δ agonist GW0742 significantly alleviated depressive behaviors in mice and promoted the formation of autophagosomes around the damaged mitochondria in hippocampal astrocytes. Our in vitro experiments showed that GW0742 could reduce mitochondrial oxidative stress, and thereby attenuate endoplasmic reticulum (ER) stress-mediated apoptosis pathway via inhibiting IRE1α phosphorylation, subsequently protect against astrocytic apoptosis and loss. Furthermore, we found that PPARß/δ agonist induces astrocytic mitophagy companied with the upregulated UCP2 expressions. Knocking down UCP2 in astrocytes could block the anti-apoptosis and pro-mitophagy effects of GW0742. In conclusion, our findings reveal PPARß/δ activation protects against ER stress-induced astrocytic apoptosis via enhancing UCP2-mediated mitophagy, which contribute to the anti-depressive action. The present study provides a new insight for depression therapy.

NLK is required for Ras/ERK/SRF/ELK signaling to tune skeletal muscle development by phosphorylating SRF and antagonizing the SRF/MKL pathway.

Serum response factor (SRF) regulates differentiation and proliferation by binding to RhoA-actin-activated MKL or Ras-MAPK-activated ELK transcriptional coactivators, but the molecular mechanisms responsible for SRF regulation remain unclear. Here, we show that Nemo-like kinase (NLK) is required for the promotion of SRF/ELK signaling in human and mouse cells. NLK was found to interact with and phosphorylate SRF at serine residues 101/103, which in turn enhanced the association between SRF and ELK. The enhanced affinity of SRF/ELK antagonized the SRF/MKL pathway and inhibited mouse myoblast differentiation in vitro. In a skeletal muscle-specific Nlk conditional knockout mouse model, forming muscle myofibers underwent hypertrophic growth, resulting in an increased muscle and body mass phenotype. We propose that both phosphorylation of SRF by NLK and phosphorylation of ELKs by MAPK are required for RAS/ELK signaling, confirming the importance of this ancient pathway and identifying an important role for NLK in modulating muscle development in vivo.

The different sensitivities of aerosol optical properties to particle concentration, humidity, and hygroscopicity between the surface level and the upper boundary layer in Guangzhou, China.

This study investigates the impact of aerosol liquid water content (ALWC) and related factors, i.e., relative humidity (RH), aerosol mass concentration (PM2.5), and aerosol hygroscopicity, on aerosol optical properties, based on field measurements made in the Pearl River Delta (PRD) region of China at the surface (1 November 2019 to 21 January 2020) and in the upper boundary layer (the 532-m Guangzhou tower from 1 February to 21 March 2020). In general, temporal variations in the ambient aerosol backscattering coefficient (ßp) and ALWC followed each other. However, the surface ßp and 532-m ßp had generally opposite diurnal variation patterns, caused by dramatic differences in PM2.5 and ambient RH between the surface and the upper boundary layer. The ambient 532-m RH was systematically higher than the surface RH, with the latter having a much pronounced diurnal cycle than the former. The surface PM2.5 concentration was systematically higher than the PM2.5 concentration at 532 m, and their diurnal cycle patterns were overall opposite. These dramatic differences reveal that the atmospheric variables, i.e., ambient RH and the PM2.5 concentration in the upper boundary layer, cannot be directly represented by the same variables at the surface. Vertical variability should be considered. Clear differences in the sensitivities of aerosol light scattering to ambient RH, PM2.5, and aerosol hygroscopicity between the two levels were found and examined. Aerosol chemical composition played a minor role in causing the differences between the two levels. In particular, ßp was more sensitive to PM2.5 at the surface level but more to the ambient RH in the upper boundary layer. The larger contribution of aerosol loading to the variability in ßp at the surface implies that local emission controls can decrease ßp and further improve atmospheric visibility effectively at the surface during winter in the PRD region.

BRCC3 Promotes Tumorigenesis of Bladder Cancer by Activating the NF-κB Signaling Pathway Through Targeting TRAF2.

NF-κB signaling is very important in cancers. However, the role of BRCC3-associated NF-κB signaling activation in bladder cancer remains to be characterized. Western blotting and IHC of tissue microarray were used to confirm the abnormal expression of BRCC3 in bladder cancer. Growth curve, colony formation, soft agar assay and Xenograft model were performed to identify the role of BRCC3 over-expression or knock-out in bladder cancer. Further, RNA-Seq and luciferase reporter assays were used to identify the down-stream signaling pathway. Finally, co-immunoprecipitation and fluorescence confocal assay were performed to verify the precise target of BRCC3. Here, we found that high expression of BRCC3 promoted tumorigenesis through targeting the TRAF2 protein. BRCC3 expression is up-regulated in bladder cancer patients which indicates a negative prognosis. By in vitro and in vivo assays, we found genetic BRCC3 ablation markedly blocks proliferation, viability and migration of bladder cancer cells. Mechanistically, RNA-Seq analysis shows that NF-κB signaling is down-regulated in BRCC3-deficient cells. BRCC3 binds to and synergizes with TRAF2 to activate NF-κB signaling. Our results indicate that high BRCC3 expression activates NF-κB signaling by targeting TRAF2 for activation, which in turn facilitates tumorigenesis in bladder cancer. This finding points to BRCC3 as a potential target in bladder cancer patients.

PTPN18 promotes colorectal cancer progression by regulating the c-MYC-CDK4 axis.

Protein tyrosine phosphatase non-receptor type 18 (PTPN18) is often highly expressed in colorectal cancer (CRC), but its role in this disease remains unclear. We demonstrated that PTPN18 overexpression promotes growth and tumorigenesis in CRC cells and that PTPN18 deficiency yields the opposite results in vitro. Moreover, a xenograft assay showed that PTPN18 deficiency significantly inhibited tumorigenesis in vivo. PTPN18 activated the MYC signaling pathway and enhanced CDK4 expression, which is tightly associated with the cell cycle and proliferation in cancer cells. Finally, we found that MYC interacted with PTPN18 and increased the protein level of MYC. In conclusion, our results suggest that PTPN18 promotes CRC development by stabilizing the MYC protein level, which in turn activates the MYC-CDK4 axis. Thus, PTPN18 could be a novel therapeutic target in the future.

OTUB1 facilitates bladder cancer progression by stabilizing ATF6 in response to endoplasmic reticulum stress.

The unfolded protein response (UPR) plays an important role in carcinogenesis, but the functional role and mechanism of UPR-associated bladder carcinogenesis remain to be characterized. Upon UPR activation, ATF6α is activated to upregulate the transcription of UPR target genes. Although the mechanism of ATF6 activation has been studied extensively, the negative regulation of ATF6 stabilization is not well understood. Here, we report that the deubiquitinase otubain 1 (OTUB1) facilitates bladder cancer progression by stabilizing ATF6 in response to endoplasmic reticulum stress. OTUB1 expression is raised in bladder cancer patients. Genetic ablation of OTUB1 markedly inhibited bladder cancer cell proliferation, viability, and migration both in vitro and in vivo. Mechanistically, luciferase pathway screening showed that ATF6 signaling was clearly activated compared with other pathways. OTUB1 was found to activate ATF6 signaling by inhibiting its ubiquitylation, thereby remodeling the stressed cells through transcriptional regulation. Our results show that high OTUB1 expression promotes bladder cancer progression by stabilizing ATF6 and that OTUB1 is a potential therapeutic target in bladder cancer.

HDAC2 inhibits EMT-mediated cancer metastasis by downregulating the long noncoding RNA H19 in colorectal cancer.

BACKGROUND: Emerging evidence suggests that epithelial mesenchymal transition (EMT) and epigenetic mechanisms promote metastasis. Histone deacetylases (HDACs) and noncoding RNAs (ncRNAs) are important epigenetic regulators. Here, we elucidated a novel role of histone deacetylase 2 (HDAC2) in regulating EMT and CRC metastasis via ncRNA. METHODS: The expression of HDACs in CRC was analyzed using the public databases and matched primary and metastatic tissues, and CRC cells with different metastatic potentials (DLD1, HCT116, SW480 and SW620). Microarray analysis was used to identify differential genes in parental and HDAC2 knockout CRC cells. EMT and histone modifications were determined using western blot and immunofluorescence. Migration ability was assessed by transwell assay, and metastasis was assessed in vivo using a tail vain injection. Gene expression and regulation was assessed by RT-PCR, chromatin immunoprecipitation and reporter assays. Protein interaction was assessed by immunoprecipitation. Specific siRNAs targeting H19, SP1 and MMP14 were used to validate their role in HDAC2 loss induced EMT and metastasis. RESULTS: Reduced HDAC2 expression was associated with poor prognosis in CRC patients and found in CRC metastasis. HDAC2 deletion or knockdown induced EMT and metastasis by upregulating the long noncoding RNA H19 (LncRNA H19). HDAC2 inhibited LncRNA H19 expression by histone H3K27 deacetylation in its promoter via binding with SP1. LncRNA H19 functioned as a miR-22-3P sponge to increase the expression of MMP14. HDAC2 loss strongly promoted CRC lung metastasis, which was suppressed LncRNA H19 knockdown. CONCLUSION: Our study supports HDAC2 as a CRC metastasis suppressor through the inhibition of EMT and the expression of H19 and MMP14.