Silencing UBE2K inhibits the growth of glioma cells by inducing the autophagy-related apoptosis.

Glioma is a central nervous system (CNS) malignant tumor with high heterogeneity and mortality, which severely threatens the health of patients. The overall survival of glioma patients is relatively short and it is critical to identify new molecular targets for developing effective treatment strategies. UBE2K is a ubiquitin conjugating enzyme with oncogenic function in several malignant tumors. However, whether UBE2K participates in gliomas remains unknown. Herein, in glioma cells, UBE2K was found highly expressed in U87 and U251 cells. Subsequently, U87 and U251 cells were transfected with si-UBE2K to silence UBE2K, with the si-NC transfection as the negative control. In both U87 and U251 cells, the cell viability was sharply reduced by transfecting si-UBE2K for 48 and 72 h. Markedly decreased colony number, reduced number of migrated cells and invaded cells, and declined relative wound healing rate were observed in si-UBE2K transfected U87 and U251 cells. Moreover, the Bcl-2 level was markedly reduced, while the Bax and cleaved-caspase-3 levels were sharply increased in U87 and U251 cells after the si-UBE2K transfection. Furthermore, the p62 level was signally declined, while the Beclin-1 and LC-3 II/I levels were greatly increased in U87 and U251 cells by the si-UBE2K transfection. Furthermore, the facilitating effect of si-UBE2K on the apoptosis and autophagy in U87 and U251 cells was abolished by the coculture of 3-MA, an inhibitor of autophagy. Collectively, UBE2K facilitated the in vitro growth of glioma cells, possibly by inhibiting the autophagy-related apoptosis, which might be a promising target for treating glioma.

UBE2C-induced crosstalk between mono- and polyubiquitination of SNAT2 promotes lymphatic metastasis in bladder cancer.

Ubiquitination plays an essential role in protein stability, subcellular localization, and interactions. Crosstalk between different types of ubiquitination results in distinct biological outcomes for proteins. However, the role of ubiquitination-related crosstalk in lymph node (LN) metastasis and the key regulatory factors controlling this process have not been determined. Using high-throughput sequencing, we found that ubiquitin-conjugating enzyme E2 C (UBE2C) was overexpressed in bladder cancer (BCa) and was strongly associated with an unfavorable prognosis. Overexpression of UBE2C increased BCa lymphangiogenesis and promoted LN metastasis both in vitro and in vivo. Mechanistically, UBE2C mediated sodium-coupled neutral amino acid transporter 2 (SNAT2) monoubiquitination at lysine 59 to inhibit K63-linked polyubiquitination at lysine 33 of SNAT2. Crosstalk between monoubiquitination and K63-linked polyubiquitination increased SNAT2 membrane protein levels by suppressing epsin 1-mediated (EPN1-mediated) endocytosis. SNAT2 facilitated glutamine uptake and metabolism to promote VEGFC secretion, ultimately leading to lymphangiogenesis and LN metastasis in patients with BCa. Importantly, inhibition of UBE2C significantly attenuated BCa lymphangiogenesis in a patient-derived xenograft model. Our results reveal the mechanism by which UBE2C mediates crosstalk between the monoubiquitination and K63-linked polyubiquitination of SNAT2 to promote BCa metastasis and identify UBE2C as a promising target for treating LN-metastatic BCa.

Microglial circ-UBE2K exacerbates depression by regulating parental gene UBE2K via targeting HNRNPU.

Background: Knowledge about the pathogenesis of depression and treatments for this disease are lacking. Epigenetics-related circRNAs are likely involved in the mechanism of depression and have great potential as treatment targets, but their mechanism of action is still unclear. Methods: Circular RNA UBE2K (circ-UBE2K) was screened from peripheral blood of patients with major depressive disorder (MDD) and brain of depression model mice through high-throughput sequencing. Microinjection of circ-UBE2K overexpression lentivirus and adeno-associated virus for interfering with microglial circ-UBE2K into the mouse hippocampus was used to observe the role of circ-UBE2K in MDD. Sucrose preference, forced swim, tail suspension and open filed tests were performed to evaluate the depressive-like behaviors of mice. Immunofluorescence and Western blotting analysis of the effects of circ-UBE2K on microglial activation and immune inflammation. Pull-down-mass spectrometry assay, RNA immunoprecipitation (RIP) test and fluorescence in situ hybridization (FISH) were used to identify downstream targets of circ-UBE2K/ HNRNPU (heterogeneous nuclear ribonucleoprotein U) axis. Results: In this study, through high-throughput sequencing and large-scale screening, we found that circ-UBE2K levels were significantly elevated both in the peripheral blood of patients with MDD and in the brains of depression model mice. Functionally, circ-UBE2K-overexpressing mice exhibited worsened depression-like symptoms, elevated brain inflammatory factor levels, and abnormal microglial activation. Knocking down circ-UBE2K mitigated these changes. Mechanistically, we found that circ-UBE2K binds to heterogeneous nuclear ribonucleoprotein U (HNRNPU) to form a complex that upregulates the expression of the parental gene ubiquitin conjugating enzyme E2 K (UBE2K), leading to abnormal microglial activation and neuroinflammation and promoting the occurrence and development of depression. Conclusions: The findings of the present study revealed that the expression of circUBE2K, which combines with HNRNPU to form the circUBE2K/HNRNPU complex, is increased in microglia after external stress, thus regulating the expression of the parental gene UBE2K and mediating the abnormal activation of microglia to induce neuroinflammation, promoting the development of MDD. These results indicate that circ-UBE2K plays a newly discovered role in the pathogenesis of depression.

[Overexpression of ubiquitin-conjugating enzyme 2T induces radiotherapy resistance in hepatocellular carcinoma by enriching regulatory T cells in the tumor microenvironment].

OBJECTIVE: To investigate the effect of overexpression of ubiquitin-conjugating enzyme 2T (UBE2T) on radiosensitivity of hepatocellular carcinoma (HCC). METHODS: Hepa1-6 cells were transfected with a UBE2T-overexpressing or a control lentiviral vector, and the changes in their radiotherapy sensitivity and concentrations of glucose and lactate in the supernatant were assessed using colony-forming assay and colorimetric assay. The transfected cells were inoculated subcutaneously in nude mice or C57BL/6 mice, and tumor growth following irradiation were recorded. The xenografts were collected for analyzing infiltration of CD4+ T cells and regulatory T cells (Tregs) using flow cytometry and detecting expressions of HK1 and LDHA using Western blotting. The correlations of UBE2T expression with immune cell infiltration, glycolysis and Tregs in HCC were analyzed using CIBERSORT algorithm and TCGA database, and the results were verified in a co-culture system of Hepa1-6 cells and Tregs. RESULTS: UBE2T overexpression caused radiotherapy resistance in both cultured Hepa1-6 cells and xenografts in the tumor-bearing mouse models (especially in C57BL/6 mice). CIBERSORT analysis suggested that a high expression of UBE2T was associated with increased percentages of dendritic cells, T follicular helper cells, M2 macrophages, monocytes, lymphocytes and Tregs in HCC. The UBE2T-overexpressing xenografts showed an increased percentage of Tregs and enhanced expressions of HK1 and LDHA, and irradiation increased infiltration of CD4+ T cells and Tregs in the tumor microenvironment. Hepa1-6 cells overexpressing UBE2T showed a decreased glucose concentration and an increased lactate concentration. GSEA analysis suggested that a high UBE2T expression was positively correlated with increased glycolysis and Tregs infiltration in HCC. In the cell co-culture system, UBE2T overexpression significantly enhanced lactate production, proliferation and immunosuppressive functions of Tregs. CONCLUSION: A high UBE2T expression results in radiotherapy resistance of HCC possibly by enhancing glycolysis and cause enrichment of Tregs in the tumor microenvironment.

Protein SUMOylation promotes cAMP-independent EPAC1 activation.

Protein SUMOylation is a prevalent stress-response posttranslational modification crucial for maintaining cellular homeostasis. Herein, we report that protein SUMOylation modulates cellular signaling mediated by cAMP, an ancient and universal stress-response second messenger. We identify K561 as a primary SUMOylation site in exchange protein directly activated by cAMP (EPAC1) via site-specific mapping of SUMOylation using mass spectrometry. Sequence and site-directed mutagenesis analyses reveal that a functional SUMO-interacting motif in EPAC1 is required for the binding of SUMO-conjugating enzyme UBC9, formation of EPAC1 nuclear condensate, and EPAC1 cellular SUMOylation. Heat shock-induced SUMO modification of EPAC1 promotes Rap1/2 activation in a cAMP-independent manner. Structural modeling and molecular dynamics simulation studies demonstrate that SUMO substituent on K561 of EPAC1 promotes Rap1 interaction by increasing the buried surface area between the SUMOylated receptor and its effector. Our studies identify a functional SUMOylation site in EPAC1 and unveil a novel mechanism in which SUMOylation of EPAC1 leads to its autonomous activation. The findings of SUMOylation-mediated activation of EPAC1 not only provide new insights into our understanding of cellular regulation of EPAC1 but also will open up a new field of experimentation concerning the cross-talk between cAMP/EPAC1 signaling and protein SUMOylation, two major cellular stress response pathways, during cellular homeostasis.

Essential roles of Rad6 in conidial property, stress tolerance, and pathogenicity of Beauveria bassiana.

Rad6 functions as a ubiquitin-conjugating protein that regulates cellular processes in many fungal species. However, its role in filamentous entomopathogenic fungi remains poorly understood. This study characterizes Rad6 in Beauveria bassiana, a filamentous fungus widely employed as a critical fungicide globally. The results demonstrate a significant association between Rad6 and conidial properties, heat shock response, and UV-B tolerance. Concurrently, the mutant strain exhibited heightened sensitivity to oxidative stress, cell wall interfering agents, DNA damage stress, and prolonged heat shock. Furthermore, the absence of Rad6 significantly extended the median lethal time (LT50) of Galleria mellonella infected by B. bassiana. This delay could be attributed to reduced Pr1 proteases and extracellular cuticle-degrading enzymes, diminished dimorphic transition rates, and dysregulated antioxidant enzymes. Additionally, the absence of Rad6 had a more pronounced effect on genetic information processing, metabolism, and cellular processes under normal conditions. However, its impact was limited to metabolism in oxidative stress. This study offers a comprehensive understanding of the pivotal roles of Rad6 in conidial and hyphal stress tolerance, environmental adaptation, and the pathogenesis of Beauveria bassiana.

Neddylation activated TRIM25 desensitizes triple-negative breast cancer to paclitaxel via TFEB-mediated autophagy.

BACKGROUND: Paclitaxel (PTX) treatment resistance is an important factor leading to poor prognosis in triple-negative breast cancer (TNBC), therefore there is an urgent need to identify new target for combination therapy. Neddylation is a post-translational process that introduces a ubiquitin-like protein called neural precursor cell expressed developmentally downregulated protein 8 (NEDD8). Previous studies have found that neddylation is activated in multiple tumors, but its relationship with PTX chemotherapy sensitivity has not been reported. METHODS: Differences in UBC12 and NEDD8 expression levels between PTX-sensitive and PTX-insensitive TNBC tissues were validated using public databases and immunohistochemistry. The in vitro and in vivo functional experiments were used to observe the effect of neddylation inhibition combined with PTX therapy on tumor progression. Co-IP, western blot and PCR assays were used to investigate the molecular mechanisms. Molecular docking was used to simulate the protein binding of UBC12 and TRIM25. Molecular dynamics simulation was used to observe the changes in TRIM25 protein conformation. RESULTS: We found that in TNBC that is insensitive to PTX, NEDD8 and NEDD8 conjugating enzyme UBC12 are highly expressed. Treatment with the NEDD8-activating enzyme (NAE) inhibitor mln4924 or knockdown of UBC12 significantly increased the sensitivity of the tumor to PTX, and this increase in sensitivity is related to UBC12-mediated autophagy activation. Mechanistically, UBC12 can transfer NEDD8 to E3 ubiquitin ligase tripartite motif containing 25 (TRIM25) at K117. Molecular dynamics simulations indicate that the neddylation modification of TRIM25 reduces steric hindrance in its RING domain, facilitating the binding of TRIM25 and ubiquitylated substrates. Subsequently, TRIM25 promotes the nuclear translocation of transcription factor EB (TFEB) and transcription of autophagy related genes by increasing K63-polyubiquitination of TFEB, thereby reducing tumor sensitivity to PTX. CONCLUSIONS: Neddylation is activated in PTX-insensitive TNBC. Specifically, autophagy gene transcriptional activation mediated by the UBC12/TRIM25/TFEB axis reduces TNBC sensitivity to PTX. Neddylation suppression combination with PTX treatment shows a synergistic anti-tumor effect.

UBE2D3 facilitates NHEJ by orchestrating ATM signalling through multi-level control of RNF168.

Maintenance of genome integrity requires tight control of DNA damage response (DDR) signalling and repair, with phosphorylation and ubiquitination representing key elements. How these events are coordinated to achieve productive DNA repair remains elusive. Here we identify the ubiquitin-conjugating enzyme UBE2D3 as a regulator of ATM kinase-induced DDR that promotes non-homologous end-joining (NHEJ) at telomeres. UBE2D3 contributes to DDR-induced chromatin ubiquitination and recruitment of the NHEJ-promoting factor 53BP1, both mediated by RNF168 upon ATM activation. Additionally, UBE2D3 promotes NHEJ by limiting RNF168 accumulation and facilitating ATM-mediated phosphorylation of KAP1-S824. Mechanistically, defective KAP1-S824 phosphorylation and telomeric NHEJ upon UBE2D3-deficiency are linked to RNF168 hyperaccumulation and aberrant PP2A phosphatase activity. Together, our results identify UBE2D3 as a multi-level regulator of NHEJ that orchestrates ATM and RNF168 activities. Moreover, they reveal a negative regulatory circuit in the DDR that is constrained by UBE2D3 and consists of RNF168- and phosphatase-mediated restriction of KAP1 phosphorylation.

Role of Ubiquitin-conjugating enzyme E2 (UBE2) in two immune-mediated inflammatory skin diseases: a mendelian randomization analysis.

Psoriasis vulgaris (PV) and Atopic dermatitis (AD) are the two major types of immune-mediated inflammatory skin disease (IMISD). Limited studies reported the association between Ubiquitin-conjugating enzyme E2 (UBE2) and IMISD. We employed a two-sample Mendelian randomization (MR) study to assess the causality between UBE2 and PV & AD. UBE2 association genome-wide association study (GWAS) data were collected. The inverse variance weighted (IVW) method was utilized as the principal method in our Mendelian randomization (MR) study, with additional using the MR-Egger, weighted median, simple mode, and weighted mode methods. The MR-Egger intercept test, Cochran's Q test, MR-Pleiotropy RESidual Sum and Outlier (MR-PRESSO) and leave-one-out analysis were conducted to identify heterogeneity and pleiotropy, colocalization analysis was also performed. The results showed that Ubiquitin-conjugating enzyme E2 variant 1 (UBE2V1) was causally associated with PV (OR = 0.909, 95% CI: 0.830-0.996, P = 0.040), Ubiquitin-conjugating enzyme E2 L3 (UBE2L3) was causally associated with AD (OR = 0.799, 95% CI: 0.709-0.990, P < 0.001). Both UBE2V1 and UBE2L3 may play protective roles in patients with PV or AD, respectively. No other significant result has been investigated. No heterogeneity or pleiotropy was observed. This study provided new evidence of the relationship between UBE2V1 and PV, UBE2L3 and AD. Our MR suggested that UBE2V1 plays an inhibitory role in PV progression, UBE2L3 plays an inhibitory role in AD. These could be novel and effective ways to treat PV and AD.

Proinsulin degradation and presentation of a proinsulin B-chain autoantigen involves ER-associated protein degradation (ERAD)-enzyme UBE2G2.

Type 1 diabetes (T1D) is characterized by HLA class I-mediated presentation of autoantigens on the surface of pancreatic ß-cells. Recognition of these autoantigens by CD8+ T cells results in the destruction of pancreatic ß-cells and, consequently, insulin deficiency. Most epitopes presented at the surface of ß-cells derive from the insulin precursor molecule proinsulin. The intracellular processing pathway(s) involved in the generation of these peptides are poorly defined. In this study, we show that a proinsulin B-chain antigen (PPIB5-14) originates from proinsulin molecules that are processed by ER-associated protein degradation (ERAD) and thus originate from ER-resident proteins. Furthermore, screening genes encoding for E2 ubiquitin conjugating enzymes, we identified UBE2G2 to be involved in proinsulin degradation and subsequent presentation of the PPIB10-18 autoantigen. These insights into the pathway involved in the generation of insulin-derived peptides emphasize the importance of proinsulin processing in the ER to T1D pathogenesis and identify novel targets for future T1D therapies.

UBE2N promotes cell viability and glycolysis by promoting Axin1 ubiquitination in prostate cancer cells.

BACKGROUND: Ubiquitin-conjugating enzyme E2 N (UBE2N) is recognized in the progression of some cancers; however, little research has been conducted to describe its role in prostate cancer. The purpose of this paper is to explore the function and mechanism of UBE2N in prostate cancer cells. METHODS: UBE2N expression was detected in Cancer Genome Atlas Prostate Adenocarcinoma (TCGA-PRAD) data, prostate cancer tissue microarrays, and prostate cancer cell lines, respectively. UBE2N knockdown or overexpression was used to analyze its role in cell viability and glycolysis of prostate cancer cells and tumor growth. XAV939 or Axin1 overexpression was co-treated with UBE2N overexpression to detect the involvement of the Wnt/ß-catenin signaling and Axin1 in the UBE2N function. UBE2N interacting with Axin1 was analyzed by co-immunoprecipitation assay. RESULTS: UBE2N was upregulated in prostate cancer and the UBE2N-high expression correlated with the poor prognosis of prostate cancer. UBE2N knockdown inhibited cell viability and glycolysis in prostate cancer cells and restricted tumor formation in tumor-bearing mice. Wnt/ß-catenin inhibition and Axin1 overexpression reversed the promoting viability and glycolysis function of UBE2N. UBE2N promoted Axin1 ubiquitination and decreased Axin1 protein level.

Swd2/Cps35 determines H3K4 tri-methylation via interactions with Set1 and Rad6.

BACKGROUND: Histone H3K4 tri-methylation (H3K4me3) catalyzed by Set1/COMPASS, is a prominent epigenetic mark found in promoter-proximal regions of actively transcribed genes. H3K4me3 relies on prior monoubiquitination at the histone H2B (H2Bub) by Rad6 and Bre1. Swd2/Cps35, a Set1/COMPASS component, has been proposed as a key player in facilitating H2Bub-dependent H3K4me3. However, a more comprehensive investigation regarding the relationship among Rad6, Swd2, and Set1 is required to further understand the mechanisms and functions of the H3K4 methylation. RESULTS: We investigated the genome-wide occupancy patterns of Rad6, Swd2, and Set1 under various genetic conditions, aiming to clarify the roles of Set1 and Rad6 for occupancy of Swd2. Swd2 peaks appear on both the 5' region and 3' region of genes, which are overlapped with its tightly bound two complexes, Set1 and cleavage and polyadenylation factor (CPF), respectively. In the absence of Rad6/H2Bub, Set1 predominantly localized to the 5' region of genes, while Swd2 lost all the chromatin binding. However, in the absence of Set1, Swd2 occupancy near the 5' region was impaired and rather increased in the 3' region. CONCLUSIONS: This study highlights that the catalytic activity of Rad6 is essential for all the ways of Swd2's binding to the transcribed genes and Set1 redistributes the Swd2 to the 5' region for accomplishments of H3K4me3 in the genome-wide level.

UBE2T mediates SORBS3 ubiquitination to enhance IL-6/STAT3 signaling and promote lung adenocarcinoma progression.

UBE2T is an oncogene in varying tumors, including lung adenocarcinoma (LUAD). SORBS3 is an important signaling regulatory protein that plays a crucial role in many cancers. This study aimed to investigate whether UBE2T promoted LUAD development by mediating the ubiquitination of SORBS3 and further explore its mechanism. Bioinformatics analysis was conducted to examine the expression of SORBS3 in LUAD tissues. Cell Counting Kit-8, Transwell, and flow cytometry were employed to analyze the cellular functions of SORBS3. Co-immunoprecipitation and ubiquitination analysis were employed to observe the correlation between UBE2T and SORBS3. In vitro and in vivo experiments verified the role of UBE2T in mediating SORBS3 ubiquitination to enhance interleukin-6/signal transducer and activator of transcription 3 (IL-6/STAT3) signaling and promote LUAD development. We observed significant downregulation of SORBS3 in LUAD tissues and cells. Furthermore, SORBS3 inhibited the proliferation, migration, and invasion of LUAD cells, while facilitating apoptosis in vitro. UBE2T enhanced IL-6/STAT3 signaling by mediating ubiquitination and degradation of SORBS3, thereby promoting LUAD progression. Additionally, this mechanism was further validated in the xenograft animal model in vivo. This study confirmed that UBE2T-mediated SORBS3 ubiquitination enhanced IL-6/STAT3 signaling and promoted LUAD progression, providing a novel therapeutic target for LUAD.

UBE2C enhances temozolomide resistance by regulating the expression of p53 to induce aerobic glycolysis in glioma.

UBE2C is overexpressed in gliomas, and its overexpression has been reported to be correlated with the drug resistance of gliomas to some extent. In this study, we explore the role of UBE2C in regulating temozolomide (TMZ) resistance in glioma and investigate the underlying mechanisms involved. Twenty normal brain tissues and 100 glioma tissues from 50 TMZ-resistant patients and 50 TMZ-sensitive patients are included in this study. TMZ-resistant cell lines are constructed to explore the role of UBE2C in regulating glioma cell viability and TMZ resistance. Our results show that both the mRNA and protein levels of UBE2C are significantly elevated in the brain tissues of glioma patients, especially in those of TMZ-resistant patients. Consistently, UBE2C expression is markedly upregulated in TMZ-resistant cell lines. Overexpression of UBE2C rescues glioma cells from TMZ-mediated apoptosis and enhances cell viability. In contrast, downregulation of UBE2C expression further enhances TMZ function, increases cell apoptosis and decreases cell viability. Mechanistically, UBE2C overexpression decreases p53 expression and enhances aerobic glycolysis level by increasing ATP level, lactate production, and glucose uptake. Downregulation of p53 level abolishes the role of UBE2C downregulation in inhibiting TMZ resistance and aerobic glycolysis in glioma cells. Moreover, an animal assay confirms that downregulation of UBE2C expression further suppresses tumor growth in the context of TMZ treatment. Collectively, this study reveals that downregulation of UBE2C expression enhances the sensitivity of glioma cells to TMZ by regulating the expression of p53 to inhibit aerobic glycolysis.

Phage defence system CBASS is regulated by a prokaryotic E2 enzyme that imitates the ubiquitin pathway.

The cyclic-oligonucleotide-based anti-phage signalling system (CBASS) is a type of innate prokaryotic immune system. Composed of a cyclic GMP-AMP synthase (cGAS) and CBASS-associated proteins, CBASS uses cyclic oligonucleotides to activate antiviral immunity. One major class of CBASS contains a homologue of eukaryotic ubiquitin-conjugating enzymes, which is either an E1-E2 fusion or a single E2. However, the functions of single E2s in CBASS remain elusive. Here, using biochemical, genetic, cryo-electron microscopy and mass spectrometry investigations, we discover that the E2 enzyme from Serratia marcescens regulates cGAS by imitating the ubiquitination cascade. This includes the processing of the cGAS C terminus, conjugation of cGAS to a cysteine residue, ligation of cGAS to a lysine residue, cleavage of the isopeptide bond and poly-cGASylation. The poly-cGASylation activates cGAS to produce cGAMP, which acts as an antiviral signal and leads to cell death. Thus, our findings reveal a unique regulatory role of E2 in CBASS.

The UBE2F-CRL5ASB11-DIRAS2 axis is an oncogene and tumor suppressor cascade in pancreatic cancer cells.

UBE2F, a neddylation E2, neddylates CUL5 to activate cullin-RING ligase-5, upon coupling with neddylation E3 RBX2/SAG. Whether and how UBE2F controls pancreatic tumorigenesis is previously unknown. Here, we showed that UBE2F is essential for the growth of human pancreatic cancer cells with KRAS mutation. In the mouse KrasG12D pancreatic ductal adenocarcinoma (PDAC) model, Ube2f deletion suppresses cerulein-induced pancreatitis, and progression of acinar-to-ductal metaplasia (ADM) and pancreatic intraepithelial neoplasia. Mechanistically, Ube2f deletion inactivates the Mapk-c-Myc signals via blocking ubiquitylation of Diras2, a substrate of CRL5Asb11 E3 ligase. Biologically, DIRAS2 suppresses growth and survival of human pancreatic cancer cells harboring mutant KRAS, and Diras2 deletion largely rescues the phenotypes induced by Ube2f deletion. Collectively, Ube2f or Diras2 plays a tumor-promoting or tumor-suppressive role in the mouse KrasG12D PDAC model, respectively. The UBE2F-CRL5ASB11 axis could serve as a valid target for pancreatic cancer, whereas the levels of UBE2F or DIRAS2 may serve as prognostic biomarkers for PDAC patients.

UBE2C promotes the proliferation of acute myeloid leukemia cells through PI3K/AKT activation.

This study aims to investigate the role and mechanism of tubiquitin-conjugating enzyme E2 C (UBE2C) in acute myeloid leukemia (AML). Initially, UBE2C expression in leukemia was analyzed using the Cancer Genome Atlas database. Further, we silenced UBE2C expression using small-hairpin RNA (sh-RNA). UBE2C expression was detected via the quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR) and Western blot analysis. Apoptotic events and reactive oxygen species (ROS) levels were detected by flow cytometry. A xenograft model of leukemia cells were established, and the protein levels of UBE2C, KI-67, and cleaved-caspase 3 were detected by immunohistochemistry. We reported an overexpression of UBE2C in leukemia patients and cell lines (HL60, THP-1, U937, and KG-1 cells). Moreover, a high expression level of UBE2C was correlated with a dismal prognosis in AML patients. UBE2C knockdown inhibited the viability and promoted apoptosis in AML cells by regulating the phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT) signaling pathway. Furthermore, UBE2C knockdown increased cellular Fe2+ and ROS levels, and enhanced erastin-induced ferroptosis in a proteasome-dependent manner. UBE2C knockdown also suppressed the tumor formation of AML cells in the mouse model. In summary, our findings suggest that UBE2C overexpression promotes the proliferation and inhibits ferroptosis in AML cells by activating the PI3K/AKT pathway.

Echinococcus granulosus ubiquitin-conjugating enzymes (E2D2 and E2N) promote the formation of liver fibrosis in TGFß1-induced LX-2 cells.

BACKGROUND: Cystic echinococcosis (CE) is a widespread zoonosis caused by the infection with Echinococcus granulosus sensu lato (E. granulosus s.l.). CE cysts mainly develop in the liver of intermediate hosts, characterized by the fibrotic tissue that separates host organ from parasite. However, precise mechanism underlying the formation of fibrotic tissue in CE remains unclear. METHODS: To investigate the potential impact of ubiquitin-conjugating enzymes on liver fibrosis formation in CE, two members of ubiquitin-conjugating (UBC) enzyme of Echinococcus granulosus (EgE2D2 and EgE2N) were recombinantly expressed in Escherichia coli and analyzed for bioinformatics, immunogenicity, localization, and enzyme activity. In addition, the secretory pathway and their effects on the formation of liver fibrosis were also explored. RESULTS: Both rEgE2D2 and rEgE2N possess intact UBC domains and active sites, exhibiting classical ubiquitin binding activity and strong immunoreactivity. Additionally, EgE2D2 and EgE2N were widely distributed in protoscoleces and germinal layer, with differences observed in their distribution in 25-day strobilated worms. Further, these two enzymes were secreted to the hydatid fluid and CE-infected sheep liver tissues via a non-classical secretory pathway. Notably, TGFß1-induced LX-2 cells exposed to rEgE2D2 and rEgE2N resulted in increasing expression of fibrosis-related genes, enhancing cell proliferation, and facilitating cell migration. CONCLUSIONS: Our findings suggest that EgE2D2 and EgE2N could secrete into the liver and may interact with hepatic stellate cells, thereby promoting the formation of liver fibrosis.

Genome­wide identification and expression analysis of the UBC gene family in wheat (Triticum aestivum L.).

BACKGROUND: Ubiquitination is an important regulatory step of selective protein degradation in the plant UPS (ubiquitin-proteasome system), which is involved in various biological processes in eukaryotes. Ubiquitin-conjugating enzymes play an intermediate role in the process of protein ubiquitination reactions and thus play an essential role in regulating plant growth and response to adverse environmental conditions. However, a genome-wide analysis of the UBC gene family in wheat (Triticum aestivum L.) has not yet been performed. RESULTS: In this study, the number, physiochemical properties, gene structure, collinearity, and phylogenetic relationships of TaUBC family members in wheat were analyzed using bioinformatics methods. The expression pattern of TaUBC genes in different tissues/organs and developmental periods, as well as the transcript levels under abiotic stress treatment, were analyzed using RNA-Seq data and qRT-PCR. Meanwhile, favorable haplotypes of TaUBC25 were investigated based on wheat resequencing data of 681 wheat cultivars from the Wheat Union Database. The analyses identified a total of 93 TaUBC family members containing a UBC domain in wheat genome. These genes were unevenly distributed across 21 chromosomes, and numerous duplication events were observed between gene members. Based on phylogenetic analysis, the TaUBC family was divided into 13 E2 groups and a separate UEV group. We investigated the expression of TaUBC family genes under different tissue/organ and stress conditions by quantitative real-time PCR (qRT-PCR) analysis. The results showed that some TaUBC genes were specifically expressed in certain tissues/organs and that most TaUBC genes responded to NaCl, PEG6000, and ABA treatment with different levels of expression. In addition, we performed association analysis for the two haplotypes based on key agronomic traits such as thousand-kernel weight (TKW), kernel length (KL), kernel weight (KW), and kernel thickness (KT), examining 122 wheat accessions at three environmental sites. The results showed that TaUBC25-Hap II had significantly higher TKW, KL, KW, and KT than TaUBC25-Hap I. The distribution analysis of haplotypes showed that TaUBC25-Hap II was preferred in the natural population of wheat. CONCLUSION: Our results identified 93 members of the TaUBC family in wheat, and several genes involved in grain development and abiotic stress response. Based on the SNPs detected in the TaUBC sequence, two haplotypes, TaUBC25-Hap I and TaUBC25-Hap II, were identified among wheat cultivars, and their potential value for wheat breeding was validated by association analysis. The above results provide a theoretical basis for elucidating the evolutionary relationships of the TaUBC gene family and lay the foundation for studying the functions of family members in the future.

UBE2C: A pan-cancer diagnostic and prognostic biomarker revealed through bioinformatics analysis.

BACKGROUND: The diverse and complex attributes of cancer have made it a daunting challenge to overcome globally and remains to endanger human life. Detection of critical cancer-related gene alterations in solid tumor samples better defines patient diagnosis and prognosis, and indicates what targeted therapies must be administered to improve cancer patients' outcome. MATERIALS AND METHODS: To identify genes that have aberrant expression across different cancer types, differential expressed genes were detected within the TCGA datasets. Subsequently, the DEGs common to all pan cancers were determined. Furthermore, various methods were employed to gain genetic alterations, co-expression genes network and protein-protein interaction (PPI) network, pathway enrichment analysis of common genes. Finally, the gene regulatory network was constructed. RESULTS: Intersectional analysis identified UBE2C as a common DEG between all 28 types of studied cancers. Upregulated UBE2C expression was significantly correlated with OS and DFS of 10 and 9 types of cancer patients. Also, UBE2C can be a diagnostic factor in CESC, CHOL, GBM, and UCS with AUC = 100% and diagnose 19 cancer types with AUC ≥90%. A ceRNA network constructed including UBE2C, 41 TFs, 10 shared miRNAs, and 21 circRNAs and 128 lncRNAs. CONCLUSION: In summary, UBE2C can be a theranostic gene, which may serve as a reliable biomarker in diagnosing cancers, improving treatment responses and increasing the overall survival of cancer patients and can be a promising gene to be target by cancer drugs in the future.