Tripartite motif-containing 14 (TRIM14) promotes epithelial-mesenchymal transition via ZEB2 in glioblastoma cells

m6A-Mediated Upregulation of lncRNA CHASERR Promotes the Progression of Glioma by Modulating the miR-6893-3p/TRIM14 Axis

Long noncoding RNAs (lncRNAs) play crucial roles in tumor progression and are dysregulated in glioma. However, the functional roles of lncRNAs in glioma remain largely unknown. In this study, we utilized the TCGA (the Cancer Genome Atlas database) and GEPIA2 (Gene Expression Profiling Interactive Analysis 2) databases and observed the overexpression of lncRNA CHASERR in glioma tissues. We subsequently investigated this phenomenon in glioma cell lines. The effects of lncRNA CHASERR on glioma proliferation, migration, and invasion were analyzed using in vitro and in vivo experiments. Additionally, the regulatory mechanisms among PTEN/p-Akt/mTOR and Wnt/β-catenin, lncRNA CHASERR, Micro-RNA-6893-3p(miR-6893-3p), and tripartite motif containing14 (TRIM14) were investigated via bioinformatics analyses, quantitative real-time PCR (qRT-PCR), western blot (WB), RNA immunoprecipitation (RIP), dual luciferase reporter assay, fluorescence in situ hybridization (FISH), and RNA sequencing assays. RIP and RT-qRCR were used to analyze the regulatory effect of N6-methyladenosine(m6A) on the aberrantly expressed lncRNA CHASERR. High lncRNA CHASERR expression was observed in glioma tissues and was associated with unfavorable prognosis in glioma patients. Further functional assays showed that lncRNA CHASERR regulates glioma growth and metastasis in vitro and in vivo. Mechanistically, lncRNA CHASERR sponged miR-6893-3p to upregulate TRIM14 expression, thereby facilitating glioma progression. Additionally, the activation of PTEN/p-Akt/mTOR and Wnt/β-catenin pathways by lncRNA CHASERR, miR-6893-3p, and TRIM14 was found to regulate glioma progression. Moreover, the upregulation of lncRNA CHASERR was observed in response to N6-methyladenosine modification, which was facilitated by METTL3/YTHDF1-mediated RNA transcripts. This study elucidates the m6A/lncRNACHASERR/miR-6893-3p/TRIM14 pathway that contributes to glioma progression and underscores the potential of lncRNA CHASERR as a novel prognostic indicator and therapeutic target for glioma.

Role of Non-coding RNAs in the Response of Glioblastoma to Temozolomide

Chemotherapy and radiotherapy are widely used in clinical practice across the globe as cancer treatments. Intrinsic or acquired chemoresistance poses a significant problem for medical practitioners and researchers, causing tumor recurrence and metastasis. The most dangerous kind of malignant brain tumor is called glioblastoma multiforme (GBM) that often recurs following surgery. The most often used medication for treating GBM is temozolomide chemotherapy; however, most patients eventually become resistant. Researchers are studying preclinical models that accurately reflect human disease and can be used to speed up drug development to overcome chemoresistance in GBM. Non-coding RNAs (ncRNAs) have been shown to be substantial in regulating tumor development and facilitating treatment resistance in several cancers, such as GBM. In this work, we mentioned the mechanisms of how different ncRNAs (microRNAs, long non-coding RNAs, circular RNAs) can regulate temozolomide chemosensitivity in GBM. We also address the role of these ncRNAs encapsulated inside secreted exosomes.

IKBKE promotes the ZEB2-mediated EMT process by phosphorylating HMGA1a in glioblastoma

IKBKE (Inhibitor of Nuclear Factor Kappa-B Kinase Subunit Epsilon) is an important oncogenic protein in a variety of tumors, which can promote tumor growth, proliferation, invasion and drug resistance, and plays a critical regulatory role in the occurrence and progression of malignant tumors. HMGA1a (High Mobility Group AT-hook 1a) functions as a cofactor for proper transcriptional regulation and is highly expressed in multiple types of tumors. ZEB2 (Zinc finger E-box Binding homeobox 2) exerts active functions in epithelial mesenchymal transformation (EMT). In our current study, we confirmed that IKBKE can increase the proliferation, invasion and migration of glioblastoma cells. We then found that IKBKE can phosphorylate HMGA1a at Ser 36 and/or Ser 44 sites and inhibit the degradation process of HMGA1a, and regulate the nuclear translocation of HMGA1a. Crucially, we observed that HMGA1a can regulate ZEB2 gene expression by interacting with ZEB2 promoter region. Hence, HMGA1a was found to promote the ZEB2-related metastasis. Consequently, we demonstrated that IKBKE can exert its oncogenic functions via the IKBKE/HMGA1a/ZEB2 signalling axis, and IKBKE may be a prominent biomarker for the treatment of glioblastoma in the future.

The construction of a novel prognostic prediction model for glioma based on GWAS-identified prognostic-related risk loci

Backgrounds

Glioma is a highly malignant brain tumor with a grim prognosis. Genetic factors play a role in glioma development. While some susceptibility loci associated with glioma have been identified, the risk loci associated with prognosis have received less attention. This study aims to identify risk loci associated with glioma prognosis and establish a prognostic prediction model for glioma patients in the Chinese Han population.

Methods

A genome-wide association study (GWAS) was conducted to identify risk loci in 484 adult patients with glioma. Cox regression analysis was performed to assess the association between GWAS-risk loci and overall survival as well as progression-free survival in glioma. The prognostic model was constructed using LASSO Cox regression analysis and multivariate Cox regression analysis. The nomogram model was constructed based on the single nucleotide polymorphism (SNP) classifier and clinical indicators, enabling the prediction of survival rates at 1-year, 2-year, and 3-year intervals. Additionally, the receiver operator characteristic (ROC) curve was employed to evaluate the prediction value of the nomogram. Finally, functional enrichment and tumor-infiltrating immune analyses were conducted to examine the biological functions of the associated genes.

Results

Our study found suggestive evidence that a total of 57 SNPs were correlated with glioma prognosis (p < 5 × 10-5). Subsequently, we identified 25 SNPs with the most significant impact on glioma prognosis and developed a prognostic model based on these SNPs. The 25 SNP-based classifier and clinical factors (including age, gender, surgery, and chemotherapy) were identified as independent prognostic risk factors. Subsequently, we constructed a prognostic nomogram based on independent prognostic factors to predict individualized survival. ROC analyses further showed that the prediction accuracy of the nomogram (AUC = 0.956) comprising the 25 SNP-based classifier and clinical factors was significantly superior to that of each individual variable.

Conclusion

We identified a SNP classifier and clinical indicators that can predict the prognosis of glioma patients and established a prognostic prediction model in the Chinese Han population. This study offers valuable insights for clinical practice, enabling improved evaluation of patients' prognosis and informing treatment options.

L-theanine regulates the immune function of SD rats fed high-protein diets through the FABP5/IL-6/STAT3/PPARα pathway

The protein levels in a diet are correlated with immunity but the long-term intake of excessive protein can compromise various aspects of health. L-theanine regulates immunity and protein metabolism; however, how its regulatory immunity effects under a high-protein diet are unclear. We used proteomics, metabonomics, and western blotting to analyze the effects of diets with different protein levels on immune function in rats to determine the role of L-theanine in immunity under a high-protein diet. The long-term intake of high-protein diets (≥40% protein) promoted oxidative imbalance and inflammation. These were alleviated by L-theanine. High-protein diets inhibited peroxisome proliferator-activated receptor (PPAR)α expression through the interleukin (IL)-6/signal transducer and activator of transcription (STAT)3 pathway and mediated inflammation. L-theanine downregulated anti-fatty acid-binding protein 5 (FABP5), inhibited the IL-6/STAT3 axis, and reduced high-protein diet-induced PPARα inhibition. Therefore, L-theanine alleviates the adverse effects of high-protein diets via the FABP5/IL-6/STAT3/PPARα pathway and regulates the immunity of normally fed rats through the epoxide hydrolase (EPHX)2/nuclear factor-kappa B inhibitor (IκB)α/triggering receptor expressed on myeloid cells (TREM)1 axis.

Tripartite motif‑containing 14 may aggravate cardiac hypertrophy via the AKT signalling pathway in neonatal rat cardiomyocytes and transgenic mice

Tripartite motif‑containing 14 (TRIM14) is an E3 ubiquitin ligase that primarily participates in the natural immune response and in tumour development via ubiquitination. However, the role of TRIM14 in cardiac hypertrophy is not currently clear. The present study examined the role of TRIM14 in cardiac hypertrophy and its potential molecular mechanism. TRIM14 was overexpressed in neonatal rat cardiomyocytes using adenovirus and cardiomyocyte hypertrophy was induced using phenylephrine (PE). Cardiomyocyte hypertrophy was assessed by measuring cardiomyocyte surface area and markers of hypertrophy. In addition, TRIM14‑transgenic (TRIM14‑TG) mice were created and cardiac hypertrophy was induced using transverse aortic constriction (TAC). Cardiac function, heart weight‑to‑body weight ratio (HW/BW), cardiomyocyte cross‑sectional area, cardiac fibrosis and hypertrophic markers were further examined. The expression of AKT signalling pathway‑related proteins was detected. TRIM14 overexpression in cardiomyocytes promoted PE‑induced increases in cardiomyocyte surface area and hypertrophic markers. TRIM14‑TG mice developed worse cardiac function, greater HW/BW, cross‑sectional area and cardiac fibrosis, and higher levels of hypertrophic markers in response to TAC. TRIM14 overexpression also increased the phosphorylation levels of AKT, GSK‑3β, mTOR and p70S6K in vivo and in vitro. To the best our knowledge, the present study was the first to reveal that overexpression of TRIM14 aggravated cardiac hypertrophy in vivo and in vitro, which may be related to activation of the AKT signalling pathway.

Systematic Review of Molecular Targeted Therapies for Adult-Type Diffuse Glioma: An Analysis of Clinical and Laboratory Studies

Gliomas are the most common brain tumor in adults, and molecularly targeted therapies to treat gliomas are becoming a frequent topic of investigation. The current state of molecular targeted therapy research for adult-type diffuse gliomas has yet to be characterized, particularly following the 2021 WHO guideline changes for classifying gliomas using molecular subtypes. This systematic review sought to characterize the current state of molecular target therapy research for adult-type diffuse glioma to better inform scientific progress and guide next steps in this field of study. A systematic review was conducted in accordance with PRISMA guidelines. Studies meeting inclusion criteria were queried for study design, subject (patients, human cell lines, mice, etc.), type of tumor studied, molecular target, respective molecular pathway, and details pertaining to the molecular targeted therapy-namely the modality, dose, and duration of treatment. A total of 350 studies met the inclusion criteria. A total of 52 of these were clinical studies, 190 were laboratory studies investigating existing molecular therapies, and 108 were laboratory studies investigating new molecular targets. Further, a total of 119 ongoing clinical trials are also underway, per a detailed query on clinicaltrials.gov. GBM was the predominant tumor studied in both ongoing and published clinical studies as well as in laboratory analyses. A few studies mentioned IDH-mutant astrocytomas or oligodendrogliomas. The most common molecular targets in published clinical studies and clinical trials were protein kinase pathways, followed by microenvironmental targets, immunotherapy, and cell cycle/apoptosis pathways. The most common molecular targets in laboratory studies were also protein kinase pathways; however, cell cycle/apoptosis pathways were the next most frequent target, followed by microenvironmental targets, then immunotherapy pathways, with the wnt/β-catenin pathway arising in the cohort of novel targets. In this systematic review, we examined the current evidence on molecular targeted therapy for adult-type diffuse glioma and discussed its implications for clinical practice and future research. Ultimately, published research falls broadly into three categories-clinical studies, laboratory testing of existing therapies, and laboratory identification of novel targets-and heavily centers on GBM rather than IDH-mutant astrocytoma or oligodendroglioma. Ongoing clinical trials are numerous in this area of research as well and follow a similar pattern in tumor type and targeted pathways as published clinical studies. The most common molecular targets in all study types were protein kinase pathways. Microenvironmental targets were more numerous in clinical studies, whereas cell cycle/apoptosis were more numerous in laboratory studies. Immunotherapy pathways are on the rise in all study types, and the wnt/β-catenin pathway is increasingly identified as a novel target.

TRIM67 drives tumorigenesis in oligodendrogliomas through Rho GTPase-dependent membrane blebbing

BACKGROUND

IDH mutant gliomas are grouped into astrocytomas or oligodendrogliomas depending on the codeletion of chromosome arms 1p and 19q. Although the genomic alterations of IDH mutant gliomas have been well described, transcriptional changes unique to either tumor type have not been fully understood. Here, we identify Tripartite Motif Containing 67 (TRIM67), an E3 ubiquitin ligase with essential roles during neuronal development, as an oncogene distinctly upregulated in oligodendrogliomas.

METHODS

We used several cell lines, including patient-derived oligodendroglioma tumorspheres, to knock down or overexpress TRIM67. We coupled high-throughput assays, including RNA sequencing, total lysate-mass spectrometry (MS), and coimmunoprecipitation (co-IP)-MS with functional assays including immunofluorescence (IF) staining, co-IP, and western blotting (WB) to assess the in vitro phenotype associated with TRIM67. Patient-derived oligodendroglioma tumorspheres were orthotopically implanted in mice to determine the effect of TRIM67 on tumor growth and survival.

RESULTS

TRIM67 overexpression alters the abundance of cytoskeletal proteins and induces membrane bleb formation. TRIM67-associated blebbing was reverted with the nonmuscle class II myosin inhibitor blebbistatin and selective ROCK inhibitor fasudil. NOGO-A/Rho GTPase/ROCK2 signaling is altered upon TRIM67 ectopic expression, pointing to the underlying mechanism for TRIM67-induced blebbing. Phenotypically, TRIM67 expression resulted in higher cell motility and reduced cell adherence. In orthotopic implantation models of patient-derived oligodendrogliomas, TRIM67 accelerated tumor growth, reduced overall survival, and led to increased vimentin expression at the tumor margin.

CONCLUSIONS

Taken together, our results demonstrate that upregulated TRIM67 induces blebbing-based rounded cell morphology through Rho GTPase/ROCK-mediated signaling thereby contributing to glioma pathogenesis.

Circular RNA circ_0000741/miR-379-5p/TRIM14 signaling axis promotes HDAC inhibitor (SAHA) tolerance in glioblastoma

BACKGROUND

Histone deacetylase (HDAC) inhibitor-based therapeutic drug tolerance is a major obstacle to glioblastoma (GBM) treatment. Meanwhile, non-coding RNAs have been reported to be involved in the regulation of HDAC inhibitor (SAHA) tolerance in some human tumors. However, the relationship between circular RNAs (circRNAs) and SAHA tolerance is still unknown. Herein, we explored the role and mechanism of circ_0000741 on SAHA tolerance in GBM.

METHODS

Circ_0000741, microRNA-379-5p (miR-379-5p), and tripartite motif-containing 14 (TRIM14) level were detected by real-time quantitative polymerase chain reaction (RT-qPCR). (4-5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Colony formation, flow cytometry, and transwell assays were used to detect SAHA tolerance, proliferation, apoptosis, and invasion in SAHA-tolerant GBM cells. Western blot analysis of protein levels of E-cadherin, N-cadherin, and TRIM14. After Starbase2.0 analysis, the binding between miR-379-5p and circ_0000741 or TRIM14 was proved using a dual-luciferase reporter. The role of circ_0000741 on drug tolerance was assessed using a xenograft tumor model in vivo.

RESULTS

Circ_0000741 and TRIM14 were upregulated, and miR-379-5p was reduced in SAHA-tolerant GBM cells. Furthermore, circ_0000741 absence reduced SAHA tolerance, suppressed proliferation, invasion, and induced apoptosis in SAHA-tolerant GBM cells. Mechanistically, circ_0000741 might affect TRIM14 content via sponging miR-379-5p. Besides, circ_0000741 silencing enhanced the drug sensitivity of GBM in vivo.

CONCLUSION

Circ_0000741 might accelerate SAHA tolerance by regulating the miR-379-5p/TRIM14 axis, which provided a promising therapeutic target for GBM treatment.

Hypoxia-circular RNA crosstalk to promote breast cancer

The expression of hypoxia-inducible factors (HIFs), particularly HIF-1, plays a major role in the adaptation of solid tumors to hypoxic conditions. The activation of the HIF pathway results in an expression of genes involved in the promotion of cell growth, proliferation, vascularization, metastasis, and therapeutic resistance. Circular RNA (CircRNA) is considered as a major regulator of gene expression. CircRNAs could regulate the HIF-1 pathway in cancer cells. In addition, they might be regulated by the HIF-1 pathway to promote cancer progression. Therefore, the crosstalk between hypoxia and circRNA might be involved in the pathogenesis of cancers, including breast cancer. In this review, we discussed the function of HIF-related circRNAs in the progression, angiogenesis, metabolic reprogramming, and stemness maintenance of breast cancer. In addition, the correlation between HIF-related circRNAs and clinical features of breast cancer is reviewed.

TRIM8: a double-edged sword in glioblastoma with the power to heal or hurt

Glioblastoma multiforme (GBM) is an aggressive primary brain tumor and one of the most lethal central nervous system tumors in adults. Despite significant breakthroughs in standard treatment, only about 5% of patients survive 5 years or longer. Therefore, much effort has been put into the search for identifying new glioma-associated genes. Tripartite motif-containing (TRIM) family proteins are essential regulators of carcinogenesis. TRIM8, a member of the TRIM superfamily, is abnormally expressed in high-grade gliomas and is associated with poor clinical prognosis in patients with glioma. Recent research has shown that TRIM8 is a molecule of duality (MoD) that can function as both an oncogene and a tumor suppressor gene, making it a "double-edged sword" in glioblastoma development. This characteristic is due to its role in selectively regulating three major cellular signaling pathways: the TP53/p53-mediated tumor suppression pathway, NFKB/NF-κB, and the JAK-STAT pathway essential for stem cell property support in glioma stem cells. In this review, TRIM8 is analyzed in detail in the context of GBM and its involvement in essential signaling and stem cell-related pathways. We also discuss the basic biological activities of TRIM8 in macroautophagy/autophagy, regulation of bipolar spindle formation and chromosomal stability, and regulation of chemoresistance, and as a trigger of inflammation.

Development of a novel glycolysis-related genes signature for isocitrate dehydrogenase 1-associated glioblastoma multiforme

Background

The significant difference in prognosis between IDH1 wild-type and IDH1 mutant glioblastoma multiforme (GBM) may be attributed to their metabolic discrepancies. Hence, we try to construct a prognostic signature based on glycolysis-related genes (GRGs) for IDH1-associated GBM and further investigate its relationships with immunity.

Methods

Differentially expressed GRGs between IDH1 wild-type and IDH1 mutant GBM were screened based on the TCGA database and the Molecular Signature Database (MSigDB). Consensus Cluster Plus analysis and KEGG pathway analyses were used to establish a new GRGs set. WGCNA, univariate Cox, and LASSO regression analyses were then performed to construct the prognostic signature. Then, we evaluated association of the prognostic signature with patients’ survival, clinical characteristics, tumor immunogenicity, immune infiltration, and validated one hub gene.

Results

956 differentially expressed genes (DEGs) between IDH1 wild-type and mutant GBM were screened out and six key prognostically related GRGs were rigorously selected to construct a prognostic signature. Further evaluation and validation showed that the signature independently predicted GBM patients’ prognosis with moderate accuracy. In addition, the prognostic signature was also significantly correlated with clinical traits (sex and MGMT promoter status), tumor immunogenicity (mRNAsi, EREG-mRNAsi and HRD-TAI), and immune infiltration (stemness index, immune cells infiltration, immune score, and gene mutation). Among six key prognostically related GRGs, CLEC5A was selected and validated to potentially play oncogenic roles in GBM.

Conclusion

Construction of GRGs prognostic signature and identification of close correlation between the signature and immune landscape would suggest its potential applicability in immunotherapy of GBM in the future.

TRIM family contribute to tumorigenesis, cancer development, and drug resistance

The tripartite-motif (TRIM) family represents one of the largest classes of putative single protein RING-finger E3 ubiquitin ligases. TRIM family is involved in a variety of cellular signaling transductions and biological processes. TRIM family also contributes to cancer initiation, progress, and therapy resistance, exhibiting oncogenic and tumor-suppressive functions in different human cancer types. Moreover, TRIM family members have great potential to serve as biomarkers for cancer diagnosis and prognosis. In this review, we focus on the specific mechanisms of the participation of TRIM family members in tumorigenesis, and cancer development including interacting with dysregulated signaling pathways such as JAK/STAT, PI3K/AKT, TGF-β, NF-κB, Wnt/β-catenin, and p53 hub. In addition, many studies have demonstrated that the TRIM family are related to tumor resistance; modulate the epithelial–mesenchymal transition (EMT) process, and guarantee the acquisition of cancer stem cells (CSCs) phenotype. In the end, we havediscussed the potential of TRIM family members for cancer therapeutic targets.

Chrysomycin A Inhibits the Proliferation, Migration and Invasion of U251 and U87-MG Glioblastoma Cells to Exert Its Anti-Cancer Effects

Chrysomycin A (Chr-A), an antibiotic from Streptomyces, is reported to have anti-tumor and anti-tuberculous activities, but its anti-glioblastoma activity and possible mechanism are not clear. Therefore, the current study was to investigate the mechanism of Chr-A against glioblastoma using U251 and U87-MG human cells. CCK8 assays, EdU-DNA synthesis assays and LDH assays were carried out to detect cell viability, proliferation and cytotoxicity of U251 and U87-MG cells, respectively. Transwell assays were performed to detect the invasion and migration abilities of glioblastoma cells. Western blot was used to validate the potential proteins. Chr-A treatment significantly inhibited the growth of glioblastoma cells and weakened the ability of cell migration and invasion by down regulating the expression of slug, MMP2 and MMP9. Furthermore, Chr-A also down regulated Akt, p-Akt, GSK-3β, p-GSK-3β and their downstream proteins, such as β-catenin and c-Myc in human glioblastoma cells. In conclusion, Chr-A may inhibit the proliferation, migration and invasion of glioblastoma cells through the Akt/GSK-3β/β-catenin signaling pathway.

Emerging Roles of TRIM Family Proteins in Gliomas Pathogenesis

Simple Summary

Gliomas remain challenging tumors due to their increased heterogeneity, complex molecular profile, and infiltrative phenotype that are often associated with a dismal prognosis. In a constant search for molecular changes and associated mechanisms, the TRIM protein family has emerged as an important area of investigation because of the regulation of vital cellular processes involved in brain pathophysiology that may possibly lead to brain tumor development. Herein, we discuss the diverse role of TRIM proteins in glioma progression, aiming to detect potential targets for future intervention.

Abstract

Gliomas encompass a vast category of CNS tumors affecting both adults and children. Treatment and diagnosis are often impeded due to intratumor heterogeneity and the aggressive nature of the more malignant forms. It is therefore essential to elucidate the molecular mechanisms and explore the intracellular signaling pathways underlying tumor pathology to provide more promising diagnostic, prognostic, and therapeutic tools for gliomas. The tripartite motif-containing (TRIM) superfamily of proteins plays a key role in many physiological cellular processes, including brain development and function. Emerging evidence supports the association of TRIMs with a wide variety of cancers, exhibiting both an oncogenic as well as a tumor suppressive role depending on cancer type. In this review, we provide evidence of the pivotal role of TRIM proteins in gliomagenesis and exploit their potential as prognostic biomarkers and therapeutic targets.

TRIM7 modulates NCOA4-mediated ferritinophagy and ferroptosis in glioblastoma cells

Objective

Glioblastoma is one of the most common intracranial malignant tumors with an unfavorable prognosis, and iron metabolism as well as ferroptosis are implicated in the pathogenesis of glioblastoma. The present study aims to decipher the role and mechanisms of tripartite motif-containing protein 7 (TRIM7) in ferroptosis and glioblastoma progression.

Methods

Stable TRIM7-deficient or overexpressing human glioblastoma cells were generated with lentiviral vectors, and cell survival, lipid peroxidation and iron metabolism were evaluated. Immunoprecipitation, protein degradation and ubiquitination assays were performed to demonstrate the regulation of TRIM7 on its candidate proteins.

Results

TRIM7 expression was elevated in human glioblastoma cells and tissues. TRIM7 silence suppressed growth and induced death, while TRIM7 overexpression facilitated growth and inhibited death of human glioblastoma cells. Meanwhile, TRIM7-silenced cells exhibited increased iron accumulation, lipid peroxidation and ferroptosis, which were significantly reduced by TRIM7 overexpression. Mechanistically, TRIM7 directly bound to and ubiquitinated nuclear receptor coactivator 4 (NCOA4) using K48-linked chains, thereby reducing NCOA4-mediated ferritinophagy and ferroptosis of human glioblastoma cells. Moreover, we found that TRIM7 deletion sensitized human glioblastoma cells to temozolomide therapy.

Conclusion

We for the first time demonstrate that TRIM7 modulates NCOA4-mediated ferritinophagy and ferroptosis in glioblastoma cells, and our findings provide a novel insight into the progression and treatment for human glioblastoma.

TRIM36 suppresses cell growth and promotes apoptosis in human esophageal squamous cell carcinoma cells by inhibiting Wnt/β-catenin signaling pathway

Our recent study has shown that TRIM36, a member of tripartite motif-containing (TRIM) family proteins and tumor suppressor and β-catenin may serve as a prognostic biomarker for esophageal squamous cell carcinoma (ESCC). Here, we sought to examine functional roles of TRIM36 and β-catenin in ESCC cells. TRIM36 was overexpressed or silenced by lentivirus transduction. Cell proliferation was examined by Cell Counting Kit (CCK)-8 assay, while cell cycle distribution and cell apoptosis was assessed via flow cytometry analysis. Xenograft mouse model was applied for in vivo analysis. Overexpression of TRIM36 inhibited cell proliferation in human ESCC cells, and silencing of TRIM36 led to opposite effects. We also found that ectopic expression of TRIM36 enhanced the ratio of G0/G1 phase cells and induced apoptosis in ESCC cells. Our data further revealed that TRIM36 stimulated the ubiquitination of β-catenin, and in turn, its inactivation. Finally, we confirmed these in vitro results in a xenograft mouse model and clinical specimens post-operatively obtained from patients of ESCC. In summary, these data support that TRIM36 can effectively inhibit tumorigenesis of ESCC by repressing Wnt/β-catenin signaling pathway, which suggest that selectively repressing this signaling pathway in ESCC may lead to development of a novel therapeutic approach for controlling this disease.

TRIM46 upregulates Wnt/β-catenin signaling by inhibiting Axin1 to mediate hypoxia-induced epithelial-mesenchymal transition in HK2 cells

Hypoxia can cause Epithelial-mesenchymal transition (EMT) in renal tubular cells, and in turn, renal fibrosis. We tested the expression of TRIM46, a member of tripartite motif-containing (TRIM) family proteins, and mesenchymal markers under hypoxia. Our results showed that hypoxia significantly enhanced expression of TRIM46 in HK2 human renal proximal tubular epithelial cells. Our data further showed that hypoxia led to upregulated expression of mesenchymal markers including α-smooth muscle actin, vimentin, and Snail, and downregulated expression of epithelial marker E-cadherin, coupled with an increased abundance of nuclear β-catenin. However, such effects were reversed when TRIM46 expression was knocked down. TRIM46 overexpression had similar effects as hypoxia exposure, and such effects were reversed when cells were treated with XAV-939, a selective inhibitor for β-catenin. Furthermore, we found that TRIM46 promoted ubiquitination and proteasomal degradation of Axin1 protein, a robust negative regulator of Wnt/β-catenin signaling activity. Finally, increased TRIM46 coupled with decreased Axin1 was observed in a rat renal fibrosis model. These data suggest a novel mechanism contributing to EMT that mediates hypoxia-induced renal fibrosis. Our results suggest that selectively inhibiting this pathway that activates fibrosis in human kidney may lead to development of a novel therapeutic approach for managing this disease.

Epithelial–mesenchymal transition: The history, regulatory mechanism, and cancer therapeutic opportunities

Epithelial–mesenchymal transition (EMT) is a program wherein epithelial cells lose their junctions and polarity while acquiring mesenchymal properties and invasive ability. Originally defined as an embryogenesis event, EMT has been recognized as a crucial process in tumor progression. During EMT, cell–cell junctions and cell–matrix attachments are disrupted, and the cytoskeleton is remodeled to enhance mobility of cells. This transition of phenotype is largely driven by a group of key transcription factors, typically Snail, Twist, and ZEB, through epigenetic repression of epithelial markers, transcriptional activation of matrix metalloproteinases, and reorganization of cytoskeleton. Mechanistically, EMT is orchestrated by multiple pathways, especially those involved in embryogenesis such as TGFβ, Wnt, Hedgehog, and Hippo, suggesting EMT as an intrinsic link between embryonic development and cancer progression. In addition, redox signaling has also emerged as critical EMT modulator. EMT confers cancer cells with increased metastatic potential and drug resistant capacity, which accounts for tumor recurrence in most clinic cases. Thus, targeting EMT can be a therapeutic option providing a chance of cure for cancer patients. Here, we introduce a brief history of EMT and summarize recent advances in understanding EMT mechanisms, as well as highlighting the therapeutic opportunities by targeting EMT in cancer treatment.

TRIM22 inhibits osteosarcoma progression through destabilizing NRF2 and thus activation of ROS/AMPK/mTOR/autophagy signaling

Osteosarcoma (OS) is a malignant bone tumor that mainly occurs in adolescents. It is accompanied by a high rate of lung metastasis, and high mortality. Recent studies have suggested the important roles of tripartite motif-containing (TRIM) family proteins in regulating various substrates and signaling pathways in different tumors. However, the detailed functional role of TRIM family proteins in the progression of OS is still unknown and requires further investigations. In this study, we found that tripartite motif-containing 22 (TRIM22) was downregulated in OS tissues and was hence associated with better prognosis. In vitro and in vivo functional analysis demonstrated that TRIM22 inhibits proliferation and metastasis of OS cells. Nuclear factor erythroid 2-related factor 2 (NRF2), a redox regulator, was identified as a novel target for TRIM22. TRIM22 interacts with and accelerates the degradation of NRF2 by inducing its ubiquitination dependent on its E3 ligase activity but independent of Kelch-like ECH-associated protein 1 (KEAP1). Further, a series of gain- and loss-of-function experiments showed that knockdown or overexpression of NRF2 reversed the functions of knockdown or overexpression of TRIM22 in OS. Mechanistically, TRIM22 inhibited OS progression through NRF2-mediated intracellular reactive oxygen species (ROS) imbalance. ROS production was significantly promoted and mitochondrial potential was remarkably inhibited when overexpressing TRIM22, thus activating AMPK/mTOR signaling. Moreover, TRIM22 was also found to inhibit Warburg effect in OS cells. Autophagy activation was found in OS cells which were overexpressed TRIM22, thus leading to autophagic cell death. Treatment with N-Acetylcysteine (NAC), a ROS scavenger or the autophagy inhibitor 3-Methyladenine (3-MA) abolished the decreased malignant phenotypes in TRIM22 overexpressing OS cells. In conclusion, our study indicated that TRIM22 inhibits OS progression by promoting proteasomal degradation of NRF2 independent of KEAP1, thereby activating ROS/AMPK/mTOR/Autophagy signaling that leads to autophagic cell death in OS. Therefore, our findings indicated that targeting TRIM22/NRF2 could be a promising therapeutic target for treating OS.

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TRIM22 inhibits proliferation and metastasis of OS cells.

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TRIM22 interacts with and accelerates NRF2 degradation by inducing its ubiquitination dependent on E3 ligase activity.

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TRIM22 inhibited OS progression through NRF2-mediated intracellular ROS imbalance.

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TRIM22 inhibits OS progression by promoting NRF2 degradation, thereby activating ROS/AMPK/mTOR/Autophagy signaling.

Identification of a tripartite motif family gene signature for predicting the prognosis of patients with glioma

Objectiove: The tripartite motif (TRIM) family genes, which encode a protein subfamily of the RING type E3 ubiquitin ligases, function as important regulators of oncogenesis and development. It is thus of great importance to investigate the potential value of the TRIM family genes for prognostic prediction in glioma.

METHODS

The gene expression RNA-Seq data and corresponding clinical information of glioma patients were obtained from The Cancer Genome Atlas (TCGA) dataset and the Chinese Glioma Genome Atlas (CGGA) dataset. LASSO regression and multivariate Cox regression analyses were performed to construct a risk signature of the TRIM family genes. The accuracy of the risk signature in predicting the prognosis of glioma patients was evaluated. The effects of TRIM17 on glioma cell proliferation were further explored.

RESULTS

We constructed a prognostic signature based on eight TRIMs for the prediction of overall survival of glioma patients. Internal and external cohorts confirmed the satisfactory accuracy and generalizability of the signature in predicting the prognosis of glioma patients. Of the eight TRIMs, TRIM17 was significantly downregulated in glioma, and decreased with an increase in the tumor grade. Moreover, low expression of TRIM17 predicted poor prognosis in glioma. CCK-8 and colony formation assays indicated that TRIM17 overexpression significantly inhibited cell proliferation. Conversely, silencing of TRIM17 had the opposite effects.

CONCLUSION

Our eight-gene signature based on the TRIM gene family is a novel and clinically useful biomarker, which may be helpful for clinical decision-making. Additionally, TRIM17 might be a therapeutic target for glioma.

TRIM58 Inactivates p53/p21 to Promote Chemoresistance via Ubiquitination of DDX3 in Breast Cancer

Chemotherapy resistance is that the most important reason behind of carcinoma treatment failure but the underlying molecular mechanisms are unclear. Members of the tripartite motifcontaining protein (TRIM) family play crucial roles in the carcinogenesis and development of resistance against chemotherapy. Herein, we first confirmed that TRIM58 is highly expressed in triple-negative breast cancer tissues and drug-resistant MCF7/ADR cells. Furthermore, TRIM58 knockdown resulted in increased sensitivity of MCF7/ADR cells toward doxorubicin in vitro and in vivo. In contrast, TRIM58 overexpression in breast cancer cells increased doxorubicin resistance. TRIM58 was found to interact with DDX3, a protein recently reported to modulate resistance against chemotherapy. We found that TRIM58 negatively regulates DDX3 expression downstream of the P53/P21 pathway, and that DDX3 is degraded by TRIM58-mediated ubiquitination. Knockdown of DDX3 reversed doxorubicin chemotherapy sensitivity induced by TRIM58 knockdown via the P53/P21 pathway.Our study reveals that TRIM58 mediates a novel mechanism underlying the development of resistance against chemotherapy in breast cancer and provides potential targets for developing novel therapeutic targets for breast cancer.

The Emerging Roles of Tripartite Motif Proteins (TRIMs) in Acute Lung Injury

Acute lung injury (ALI) is an inflammatory disorder of the lung that causes high mortality and lacks any pharmacological intervention. Ubiquitination plays a critical role in the pathogenesis of ALI as it regulates the alveolocapillary barrier and the inflammatory response. Tripartite motif (TRIM) proteins are one of the subfamilies of the RING-type E3 ubiquitin ligases, which contains more than 80 distinct members in humans involved in a broad range of biological processes including antivirus innate immunity, development, and tumorigenesis. Recently, some studies have shown that several members of TRIM family proteins play important regulatory roles in inflammation and ALI. Herein, we integrate emerging evidence regarding the roles of TRIMs in ALI. Articles were selected from the searches of PubMed database that had the terms "acute lung injury," "ubiquitin ligases," "tripartite motif protein," "inflammation," and "ubiquitination" using both MeSH terms and keywords. Better understanding of these mechanisms may ultimately lead to novel therapeutic approaches by targeting TRIMs for ALI treatment.

Human mesenchymal stem cells derived exosomes inhibit the growth of acute myeloid leukemia cells via regulating miR-23b-5p/TRIM14 pathway

Background

Acute myeloid leukemia (AML) is a malignancy commonly seen in adults. Previous studies indicated that TRIM14 played a tumorigenic role in various types of cancer and miR-23b-5p was down-regulated in human mesenchymal stem cell-derived exosomes (HMSC-exos) of AML patients. However, their roles in AML remains unclear. Our study aims to investigate the role of TRIM14 and miR-23b-5p in the pathogenesis of AML.

Materials and methods

The blood specimen was collected from de novo AML patients and healthy donators. Exosomes were extracted from the culture medium of human mesenchymal stem cells under ultracentrifugation. Then exosomes were co-cultured with AML cells to determine the effect of their contents. The cell proliferation was detected by cell counting kit-8 assay, whereas the cell apoptosis was detected by flow cytometry. The expression of miR-23b-5p and TRIM14 was silenced or overexpressed to explore their biological functions in AML. Luciferase reporter assay was conducted to validate the interaction between miR-23b-5p and TRIM14. Gene expression was determined by quantitative real-time PCR and immunoblots.

Results

TRIM14 was significantly increased in AML patients and cell lines. The inhibition of TRIM14 significantly reduced the proliferation and induced the apoptosis of AML cells via activating PI3K/AKT pathway, whereas its overexpression exhibited reversed effects. HMSC-exos could suppress the proliferation of AML cells through the delivery of miR-23b-5p. Moreover, miR-23b-5p inhibited the transcription of TRIM14 by binding on its 3’UTR region. Overexpression of TRIM14 exhibited reversed effect against the function of miR-23b-5p mimic.

Conclusion

TRIM14 could promote the proliferation of AML cells via activating PI3K/AKT pathway, which was reversed by HMSC-exos through delivering miR-23b-5p. These findings indicated that miR-23b-5p and TRIM14 could be applied as potential targets for the treatment of AML.

Supplementary Information

The online version contains supplementary material available at 10.1186/s10020-021-00393-1.

TRIM37 orchestrates renal cell carcinoma progression via histone H2A ubiquitination-dependent manner

Background

Ubiquitylation modification is one of the multiple post-transcriptional process to regulate cellular physiology, including cell signaling, cycle regulation, DNA repair and transcriptional regulation. Members of TRIM family proteins could be defined as E3 ubiquitin ligases as they contain a RING-finger domain, and alterations of TRIM proteins are involved into a broad range of diverse disorders including cancer. TRIM37 is a novel discovered E3 ubiquitin ligase and acts as a oncoprotein in multiple human neoplasms, however its biological role in RCC still remains elusive.

Methods

RCC microarray chips and public datasets were screened to identify novel TRIMs member as TRIM37, which was dysregulated in RCC. Gain or loss of functional cancer cell models were constructed, and in vitro and in vivo assays were performed to elucidate its tumorigenic phenotypes. Interactive network analyses were utilized to define intrinsic mechanism.

Results

We identified TRIM37 was upregulated in RCC tumors, and its aberrant function predicted aggressive neoplastic phenotypes, poorer survival endings. TRIM37 promoted RCC cells EMT and malignant progression via TGF-β1 signaling activation, as a consequence of directly mediated by ubiquitinating-H2A modifications.

Conclusions

Our findings identified a previously unappreciated role of TRIM37 in RCC progression and prognostic prediction. Importantly, we declared a novel ubiquitination-dependent link between TRIM ubiquitin ligases and TGF-β1 signaling in regulating cancerous malignancies.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13046-021-01980-0.

miR-637 Prevents Glioblastoma Progression by Interrupting ZEB2/WNT/β-catenin Cascades

Glioblastomas (GBMs) are the most frequent primary malignancies in the central nervous system. Aberrant activation of WNT/β-catenin signaling pathways is critical for GBM malignancy. However, the regulation of WNT/β-catenin signaling cascades remains unclear. Presently, we observed the increased expression of ZEB2 and the decreased expression of miR-637 in GBM. The expression of miR-637 was negatively correlated with ZEB2 expression. miR-637 overexpression overcame the ZEB2-enhanced cell proliferation and G1/S phase transition. Besides, miR-637 suppressed the canonical WNT/β-catenin pathways by targeting WNT7A directly. Gain- and loss-of-function experiments with U251 mice demonstrated that miR-637 inhibited cell proliferation and arrested the G1/S phase transition, leading to tumor growth suppression. The collective findings suggest that ZEB2 and WNT/β-catenin cascades merge at miR-637, and the ectopic expression of miR-637 disturbs ZEB2/WNT/β-catenin-mediated GBM growth. The findings provide new clues for improving β-catenin-targeted therapy against GBM.

TRIM14 regulates melanoma malignancy via PTEN/PI3K/AKT and STAT3 pathways

Melanoma is one of the most aggressive cancers with poor overall survival. To date, there are still few effective methods for the treatment of melanoma. TRIM14 was previously reported to be an important oncogene in many tumors. Nevertheless, the roles of TRIM14 in melanoma remain unknown. In this study, we found that TRIM14 was abnormally upregulated in melanoma cell lines. Knockdown of TRIM14 suppressed melanoma cell proliferation, migration, invasion, epithelial-mesenchymal transition, and melanin synthesis. Overexpression of TRIM14 had opposite effects on the cellular functions of melanoma cell lines. Further study revealed that TRIM14 knockdown increased PTEN protein levels, which in turn inactivated AKT and STAT3 pathways. Moreover, blocking AKT or STAT3 pathway with a specific inhibitor could partially reverse the promotion of melanoma malignancy mediated by TRIM14 overexpression. In addition, in vivo assay also supported the above findings. These results indicated that TRIM14 might be a promising target for melanoma treatment.

Human TRIM14 protects transgenic mice from influenza A viral infection without activation of other innate immunity pathways

TRIM14 is an important component of innate immunity that defends organism from various viruses. It was shown that TRIM14 restricted influenza A virus (IAV) infection in cell cultures in an interferon-independent manner. However, it remained unclear whether TRIM14 affects IAV reproduction and immune system responses upon IAV infection in vivo. In order to investigate the effects of TRIM14 at the organismal level we generated transgenic mice overexpressing human TRIM14 gene. We found that IAV reproduction was strongly inhibited in lungs of transgenic mice, resulting in the increased survival of transgenic animals. Strikingly, upon IAV infection, the transcription of genes encoding interferons, IL-6, IL-1β, and TNFα was notably weaker in lungs of transgenic animals than that in control mice, thus indicating the absence of significant induction of interferon and inflammatory responses. In spleen of transgenic mice, where TRIM14 was unexpectedly downregulated, upon IAV infection the transcription of genes encoding interferons was oppositely increased. Therefore, we demonstrated the key role of TRIM14 in anti-IAV protection in the model organism that is realized without noticeable activation of other innate immune system pathways.

The translational values of TRIM family in pan-cancers: From functions and mechanisms to clinics

Cancer is the second leading cause of human death across the world. Tripartite motif (TRIM) family, with E3 ubiquitin ligase activities in majority of its members, is reported to be involved in multiple cellular processes and signaling pathways. TRIM proteins have critical effects in the regulation of biological behaviors of cancer cells. Here, we discussed the current understanding of the molecular mechanism of TRIM proteins regulation of cancer cells. We also comprehensively reviewed published studies on TRIM family members as oncogenes or tumor suppressors in the oncogenesis, development, and progression of a variety of types of human cancers. Finally, we highlighted that certain TRIM family members are potential molecular biomarkers for cancer diagnosis and prognosis, and potential therapeutic targets.

C3G downregulation induces the acquisition of a mesenchymal phenotype that enhances aggressiveness of glioblastoma cells

Glioblastoma (GBM) is the most aggressive tumor from the central nervous system (CNS). The current lack of efficient therapies makes essential to find new treatment strategies. C3G, a guanine nucleotide exchange factor for some Ras proteins, plays a dual role in cancer, but its function in GBM remains unknown. Database analyses revealed a reduced C3G mRNA expression in GBM patient samples. C3G protein levels were also decreased in a panel of human GBM cell lines as compared to astrocytes. Based on this, we characterized C3G function in GBM using in vitro and in vivo human GBM models. We report here that C3G downregulation promoted the acquisition of a more mesenchymal phenotype that enhanced the migratory and invasive capacity of GBM cells. This facilitates foci formation in anchorage-dependent and -independent growth assays and the generation of larger tumors in xenografts and chick chorioallantoic membrane (CAM) assays, but with a lower cell density, as proliferation was reduced. Mechanistically, C3G knock-down impairs EGFR signaling by reducing cell surface EGFR through recycling inhibition, while upregulating the activation of several other receptor tyrosine kinases (RTKs) that might promote invasion. In particular, FGF2, likely acting through FGFR1, promoted invasion of C3G-silenced GBM cells. Moreover, ERKs mediate this invasiveness, both in response to FGF2- and serum-induced chemoattraction. In conclusion, our data show the distinct dependency of GBM tumors on C3G for EGF/EGFR signaling versus other RTKs, suggesting that assessing C3G levels may discriminate GBM patient responders to different RTK inhibition protocols. Hence, patients with a low C3G expression might not respond to EGFR inhibitors.

Inhibition of TRIM14 protects cerebral ischemia/reperfusion injury through regulating NF-κB/NLRP3 pathway-mediated inflammation and apoptosis

PURPOSE

Many proteins in tripartite motif (TRIM) family have been reported to play an important role in cerebral ischemia/reperfusion (I/R) injury. This study was designed to investigate the effect of TRIM14 on the cerebral I/R injury in rats.

METHODS

The rat model was constructed through inserting thread into the middle cerebral artery. The expression of TRIM14 was measured by qRT-PCR, immunoblotting, and immunofluorescence. The hippocampal sections were stained with 2,3,5-triphenyltetrazolium chloride (TTC) to determine infarct volume and used for measuring the neurologic deficit score and brain water content. The H&E staining was used for immunohistochemical (IHC) staining. The number of apoptotic cells was measured by fluorescence microscopy. The levels of IL-6, IL-1β, and TNFα were detected by qRT-PCR and ELISA. The swimming speed, latency time, and number of platform crossings were measured by the water maze test.

RESULTS

TRIM14 was significantly enhanced in rats with cerebral I/R injury compared to Sham rats, showing its highest level at 24 h after I/R. TRIM14 inhibition reduced ischemic brain injury, suppressed neuron apoptosis, suppressed inflammation, and improved cognitive dysfunction in rats with cerebral I/R injury. TRIM14 inhibition also suppressed the activation of NF-κB/NLRP3 pathway in rats with cerebral I/R injury.

CONCLUSION

In conclusion, the expression of TRIM14 was increased in rats with cerebral I/R injury, the protective effect of TRIM14 inhibitor on cerebral I/R injury in rats depends on its anti-apoptotic and anti-inflammatory effect. The underlying mechanism was, at least partially, through regulating NF-κB/NLRP3 pathway.

Circ_0005198 enhances temozolomide resistance of glioma cells through miR-198/TRIM14 axis

Circular RNAs (circRNAs) are associated with chemoresistance in many cancers. However, the function of circ_0005198 in the temozolomide (TMZ) resistance of glioma has not been well elucidated. Here, we demonstrated that circ_0005198 was considerably up-regulated in glioma tissues, serum samples and TMZ-resistant glioma cells. Silencing of circ_0005198 restrained TMZ resistance, restricted the proliferation and facilitated the apoptosis of TMZ-resistant glioma cells. MiR-198 could be sponged by circ_0005198, and we demonstrated that the effect of circ_0005198 on the progression of TMZ-resistant glioma cells was attributed to the inhibition of miR-198 activity. Moreover, TRIM14 was a target of miR-198 and silencing of TRIM14 hindered TMZ resistance and suppressed the progression of TMZ-resistant glioma cells, while TRIM14 over-expression rescued the inhibiting effect of miR-198 over-expression. We conclude that circ_0005198-miR-198-TRIM14 regulatory pathway is critical to TMZ resistance of glioma.

Targeting the Ubiquitin System in Glioblastoma

Glioblastoma is the most common primary brain tumor in adults with poor overall outcome and 5-year survival of less than 5%. Treatment has not changed much in the last decade or so, with surgical resection and radio/chemotherapy being the main options. Glioblastoma is highly heterogeneous and frequently becomes treatment-resistant due to the ability of glioblastoma cells to adopt stem cell states facilitating tumor recurrence. Therefore, there is an urgent need for novel therapeutic strategies. The ubiquitin system, in particular E3 ubiquitin ligases and deubiquitinating enzymes, have emerged as a promising source of novel drug targets. In addition to conventional small molecule drug discovery approaches aimed at modulating enzyme activity, several new and exciting strategies are also being explored. Among these, PROteolysis TArgeting Chimeras (PROTACs) aim to harness the endogenous protein turnover machinery to direct therapeutically relevant targets, including previously considered "undruggable" ones, for proteasomal degradation. PROTAC and other strategies targeting the ubiquitin proteasome system offer new therapeutic avenues which will expand the drug development toolboxes for glioblastoma. This review will provide a comprehensive overview of E3 ubiquitin ligases and deubiquitinating enzymes in the context of glioblastoma and their involvement in core signaling pathways including EGFR, TGF-β, p53 and stemness-related pathways. Finally, we offer new insights into how these ubiquitin-dependent mechanisms could be exploited therapeutically for glioblastoma.

Long non-coding RNA HOTAIRM1 promotes proliferation and inhibits apoptosis of glioma cells by regulating the miR-873-5p/ZEB2 axis

Background

Glioblastoma is one of the most common malignant brain tumors. Conventional clinical treatment of glioblastoma is not sufficient, and the molecular mechanism underlying the initiation and development of this disease remains unclear. Our study aimed to explore the expression and function of miR-873a-5p in glioblastoma and related molecular mechanism.

Methods

We analyzed the most dysregulated microRNAs from the Gene Expression Omnibus (GEO) database and examined the expression of miR-873-5p in 20 glioblastoma tissues compared with ten normal brain tissues collected in the Zhejiang Tongde Hospital. We then overexpressed or inhibited miR-873-5p expression in U87 glioblastoma cell lines and analyzed the phenotype using the cell counting kit-8 assay, wound healing assay, and apoptosis. In addition, we predicted upstream and downstream genes of miR-873-5p in glioblastoma using bioinformatics analysis and tested our hypothesis in U87 cells using the luciferase reporter gene assay and Western blotting assay. The differences between two groups were analyzed by Student's t test. The Kruskal-Wallis test was used for the comparison of multiple groups. A P < 0.05 was considered to be significant.

Results

The miR-873-5p was downregulated in glioblastoma tissues compared with that in normal brain tissues (normal vs. tumor, 0.762 ± 0.231 vs. 0.378 ± 0.114, t = 4.540, P < 0.01). Overexpression of miR-873-5p inhibited cell growth (t = 6.095, P < 0.01) and migration (t = 3.142, P < 0.01) and promoted cell apoptosis (t = 4.861, P < 0.01), while inhibition of miR-873-5p had the opposite effect. Mechanistically, the long non-coding RNA HOTAIRM1 was found to act as a sponge of miR-873-5p to activate ZEB2 expression in U87 cells.

Conclusions

We uncovered a novel HOTAIRM1/miR-873-5p/ZEB2 axis in glioblastoma cells, providing new insight into glioblastoma progression and a theoretical basis for the treatment of glioblastoma.

USP18 deubiquitinates and stabilizes Twist1 to promote epithelial-mesenchymal transition in glioblastoma cells

Aberrant activation of epithelial-mesenchymal transition (EMT) pathway drives the invasion and migration of multiple cancers including glioblastoma (GBM). Clinical interventions focused on inhibiting EMT are of increasing interest in the treatment of GBM. In the present study, we discovered that glioma tissues and cells, especially GBMs show significantly up-modulated ubiquitin-specific protease 18 (USP18) expression. Functionally, decreased USP18 expression attenuated GBM cell invasion and migration through repressing EMT. Moreover, a critical EMT-inducing transcription factor Twist1 that activates EMT, was identified as a downstream target of USP18. Mechanistically, USP18 interacts with Twist1, removes its ubiquitination off, and subsequently stabilizes it. Short hairpin RNA-mediated downregulation of USP18 accelerates Twist1 degradation, resulting in the inhibition of GBM cell invasion and migration in vitro and in a nude mouse model. Importantly, reconstituted expression of Twist1 almost completely rescues the inhibitory effect of USP18 depletion on GBM cell invasion, migration and tumor formation. Clinically, the expression levels of USP18 and Twist1 are positively relevant in GBM specimens, and high expression of USP18 correlates with patient's poor outcome. Finally, our findings unveil the crucial role of USP18 on GBM malignancy. Targeting USP18-Twist1 regulatory axis may open a novel avenue for GBM treatment.

The Tripartite Nexus: Autophagy, Cancer, and Tripartite Motif-Containing Protein Family Members

Autophagy is a cellular degradative process that has multiple important actions in cancer. Autophagy modulation is under consideration as a promising new approach to cancer therapy. However, complete autophagy dysregulation is likely to have substantial undesirable side effects. Thus, more targeted approaches to autophagy modulation may prove clinically beneficial. One potential avenue to achieving this goal is to focus on the actions of tripartite motif-containing protein family members (TRIMs). TRIMs have key roles in an array of cellular processes, and their dysregulation has been extensively linked to cancer risk and prognosis. As detailed here, emerging data shows that TRIMs can play important yet context-dependent roles in controlling autophagy and in the selective targeting of autophagic substrates. This review covers how the autophagy-related actions of TRIM proteins contribute to cancer and the possibility of targeting TRIM-directed autophagy in cancer therapy.

A twelve-gene signature for survival prediction in malignant melanoma patients

Background

Melanoma is defined as a highly mutational heterogeneous disease containing numerous alternations of the molecule. However, due to the phenotypically and genetically heterogeneity of malignant melanoma, conventional clinical characteristics remain restricted or limited in the ability to accurately predict individual outcomes and survival. This study aimed to establish an accurate gene expression signature to predict melanoma prognosis.

Methods

In this study, we established an RNA sequencing-based 12-gene signature data of melanoma patients obtained from 2 independent databases: the Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) database. We evaluated the quality of each gene to predict survival conditions in each database by employing univariate and multivariate regression models. A prognostic risk score based on a prognostic signature was determined. This prognostic gene signature further classified patients into low-risk and high-risk groups.

Results

Based on a prognostic signature, a prognostic risk score was determined. This prognostic gene signature further divided the patients into low-risk and high-risk groups. In the chemotherapy and radiotherapy groups of the TCGA cohort and V-raf murine sarcoma viral oncogene homolog B1 (BRAF) expression group in the GEO cohort, patients in the low-risk group had a longer survival duration compared to patients in the high-risk group. Nevertheless, the immunotherapy group in the TCGA database and neuroblastoma RAS viral oncogene homolog (NRAS) expression group in the GEO database had no significant differences in statistics. Moreover, this gene signature was associated with patient prognosis regardless of whether the Breslow depth was greater than or less than 3.75 mm. Stratified gene set enrichment analysis (GSEA) revealed that certain immune-related pathways, such as the T-cell signaling pathway, chemokine signaling pathway, and primary immunodeficiency, were significantly enriched in the low-risk group of both TCGA and GEO cohorts. This information implied the immune-related properties of the 12-gene signature.

Conclusions

Our study emphasizes the significance of the gene expression signature in that it may be an indispensable prognostic predictor in melanoma and has great potential for application in personalized treatment.

Overexpression of tripartite motif containing 26 inhibits non-small cell lung cancer cell growth by suppressing PI3K/AKT signaling

It has been reported that tripartite motif containing 26 (TRIM26) is involved in the tumorigenesis of some cancers, but its function in non-small cell lung cancer (NSCLC) is still unclear. In this study, we found that TRIM26 was markedly down-regulated in both of NSCLC tumor tissues and cell lines. Additionally, high expression of TRIM26 in NSCLC patients predicted a positive index for patients' overall survival. What is more, overexpression of TRIM26 significantly suppressed NSCLC cell growth. Our further studies indicated that overexpression of TRIM26 inhibited the phosphorylation of PI3K p85 and AKT. And overexpressed TRIM26 regulated cell cycle-related genes' expression, including downregulating CDK4, Cyclin A, Cyclin D1, Cyclin D3, and Cyclin E, and upregulating p27 expression. Finally, we found that TRIM26 up-regulated PTEN expression by stabilizing PTEN protein in NSCLC cells. Collectively, our present study indicated that TRIM26 was decreased in NSCLC and overexpression of TRIM26 inhibited NSCLC cell growth by suppressing PI3K/AKT pathway, which suggested that TRIM26 could be as a potential target for the treatment of NSCLC in the future.

A Novel Gene Signature-Based Model Predicts Biochemical Recurrence-Free Survival in Prostate Cancer Patients after Radical Prostatectomy

Abstract: Currently, decision-making regarding biochemical recurrence (BCR) following prostatectomy relies solely on clinical parameters. We therefore attempted to develop an integrated prediction model based on a molecular signature and clinicopathological features, in order to forecast the risk for BCR and guide clinical decision-making for postoperative therapy. Using high-throughput screening and least absolute shrinkage and selection operator (LASSO) in the training set, a novel gene signature for biochemical recurrence-free survival (BCRFS) was established. Validation of the prognostic value was performed in five other independent datasets, including our patient cohort. Multivariate Cox regression analysis was performed to evaluate the importance of risk for BCR. Time-dependent receiver operating characteristic (tROC) was used to evaluate the predictive power. In combination with relevant clinicopathological features, a decision tree was built to improve the risk stratification. The gene signature exhibited a strong capacity for identifying high-risk BCR patients, and multivariate Cox regression analysis demonstrated that the gene signature consistently acted as a risk factor for BCR. The decision tree was successfully able to identify the high-risk subgroup. Overall, the gene signature established in the present study is a powerful predictor and risk factor for BCR after radical prostatectomy.

Overexpression of Tripartite Motif-Containing 48 (TRIM48) Inhibits Growth of Human Glioblastoma Cells by Suppressing Extracellular Signal Regulated Kinase 1/2 (ERK1/2) Pathway

BACKGROUND Herein, we found that tripartite motif-containing 48 (TRIM48) was reduced in human glioblastoma (GBM) cell lines. We investigated whether and how TRIM48 functions in human GBM in vitro. MATERIAL AND METHODS Human GBM cells (U87 MG and U138 MG) were infected with lentivirus to overexpress TRIM48, and 1 human GBM cell line (T98G) was infected with siRNAs to knock down TRIM48 expression. Techniques used included cell proliferation assay, measured by CCK-8 and BrdU-ELISA method, and cell cycle assay, determined using flow cytometry. Curcumin, a specific activator of extracellular signal regulated kinases (ERK1/2), or PD98059, a specific inhibitor of ERK1/2, was used to activate or block the ERK1/2 pathway, respectively. Expression of phosphorylated (p)-ERK1/2, and its downstream targets (Cyclin D1) were measured to assess the mechanism. RESULTS Our data suggest that overexpression of TRIM48 reduces the viability of U87 MG and U138 MG and leads to cell cycle arrest (in G0-G1 phase), which is associated with blockade of the ERK1/2 pathway and reduction of Cyclin D1. In contrast, knockdown of TRIM48 resulted in the opposite effects. Interestingly, the inhibitory effect of TRIM48 overexpression on human GBM cell growth and the inactivation of ERK1/2 were significantly alleviated with additional curcumin treatment, while it the promoted the effect of siTRIM48 on human GBM cell growth, and the activation of ERK1/2 was significantly alleviated with additional PD98059 treatment. CONCLUSIONS TRIM48 suppressed the growth of human GBM cell via the prevention of ERK1/2 activation.

E3 Ubiquitin Ligase TRIM Proteins, Cell Cycle and Mitosis

The cell cycle is a series of events by which cellular components are accurately segregated into daughter cells, principally controlled by the oscillating activities of cyclin-dependent kinases (CDKs) and their co-activators. In eukaryotes, DNA replication is confined to a discrete synthesis phase while chromosome segregation occurs during mitosis. During mitosis, the chromosomes are pulled into each of the two daughter cells by the coordination of spindle microtubules, kinetochores, centromeres, and chromatin. These four functional units tie chromosomes to the microtubules, send signals to the cells when the attachment is completed and the division can proceed, and withstand the force generated by pulling the chromosomes to either daughter cell. Protein ubiquitination is a post-translational modification that plays a central role in cellular homeostasis. E3 ubiquitin ligases mediate the transfer of ubiquitin to substrate proteins determining their fate. One of the largest subfamilies of E3 ubiquitin ligases is the family of the tripartite motif (TRIM) proteins, whose dysregulation is associated with a variety of cellular processes and directly involved in human diseases and cancer. In this review we summarize the current knowledge and emerging concepts about TRIMs and their contribution to the correct regulation of cell cycle, describing how TRIMs control the cell cycle transition phases and their involvement in the different functional units of the mitotic process, along with implications in cancer progression.