Increased expression of elongation factor-1α is significantly correlated with poor prognosis of human prostate cancer

The proteomic landscape of diffuse midline glioma highlights the therapeutic potential of non-histone protein methyltransferases

BACKGROUND

Diffuse Midline Glioma (DMG) is a highly aggressive pediatric brain tumor with limited treatment options despite extensive genomic characterization. The aim of this study was to investigate the proteomic landscape of DMG to identify potential therapeutic targets.

METHODS

We conducted a comprehensive proteomic analysis using LC-MS3, along with DNA methylation and DNA/RNA sequencing in 55 DMG patients' samples. PTM profiling (phosphoproteome and methylproteome) was conducted in 30 patient samples. We then investigated the effects of modulating key protein targets on protein methylation, protein synthesis, and DMG cell growth in vitro and in vivo.

RESULTS

DMGs exhibited high global protein methylation, with significant enrichment of translation machinery proteins and factors involved in apoptosis regulation. Surprisingly, while targets of key kinases were highly phosphorylated, overall protein phosphorylation was lower in DMG compared to normal brain tissues. Non-histone methyltransferases METTL13 and METTL21B, along with protein kinases PAK2, PRKACA, and AKT1, were identified as key players in DMG methylproteome and phosphoproteome, respectively. METTL13 knockdown led to reduced EEF1A1 protein methylation, a shift in oncoprotein synthesis, and inhibited DMG cell growth in vitro and in vivo.

CONCLUSIONS

Our findings highlight the dependency of DMG on methyl-signaling pathways, particularly involving METTL13, which regulates EEF1A1 protein methylation and oncoprotein synthesis. Targeting the non-histone methyltransferases offers a promising therapeutic strategy for DMG. This study underscores the potential of post-translational modifications, specifically methyl-signaling pathways, as novel therapeutic targets for DMG and possibly other currently incurable cancers.

The eEF1A protein in cancer: Clinical significance, oncogenic mechanisms, and targeted therapeutic strategies

Eukaryotic elongation factor 1A (eEF1A) is among the most abundant proteins in eukaryotic cells. Evolutionarily conserved across species, eEF1A is in charge of translation elongation for protein biosynthesis as well as a plethora of non-translational moonlighting functions for cellular homeostasis. In malignant cells, however, eEF1A becomes a pleiotropic driver of cancer progression via a broad diversity of pathways, which are not limited to hyperactive translational output. In the past decades, mounting studies have demonstrated the causal link between eEF1A and carcinogenesis, gaining deeper insights into its multifaceted mechanisms and corroborating its value as a prognostic marker in various cancers. On the other hand, an increasing number of natural and synthetic compounds were discovered as anticancer eEF1A-targeting inhibitors. Among them, plitidepsin was approved for the treatment of multiple myeloma whereas metarrestin was currently under clinical development. Despite significant achievements in these two interrelated fields, hitherto there lacks a systematic examination of the eEF1A protein in the context of cancer research. Therefore, the present work aims to delineate its clinical implications, molecular oncogenic mechanisms, and targeted therapeutic strategies as reflected in the ever expanding body of literature, so as to deepen mechanistic understanding of eEF1A-involved tumorigenesis and inspire the development of eEF1A-targeted chemotherapeutics and biologics.

The SARS-CoV-2 targeted human RNA binding proteins network biology to investigate COVID-19 associated manifestations

The global coronavirus disease 2019 (COVID-19) pandemic caused by the SARS-CoV-2 virus has had unprecedented social and economic ramifications. Identifying targets for drug repurposing could be an effective means to present new and fast treatments. Furthermore, the risk of morbidity and mortality from COVID-19 goes up when there are coexisting medical conditions, however, the underlying mechanisms remain unclear. In the current study, we have adopted a network-based systems biology approach to investigate the RNA binding proteins (RBPs)-based molecular interplay between COVID-19, various human cancers, and neurological disorders. The network based on RBPs commonly involved in the three disease conditions consisted of nine RBPs connecting 10 different cancer types, 22 brain disorders, and COVID-19 infection, ultimately hinting at the comorbidities and complexity of COVID-19. Further, we underscored five miRNAs with reported antiviral properties that target all of the nine shared RBPs and are thus therapeutically valuable. As a strategy to improve the clinical conditions in comorbidities associated with COVID-19, we propose perturbing the shared RBPs by drug repurposing. The network-based analysis presented hereby contributes to a better knowledge of the molecular underpinnings of the comorbidities associated with COVID-19.

Proteomic Characterization of Normal and Woody Breast Meat from Broilers of Five Genetic Strains

Woody breast (WB) is an emergent broiler myopathy that is macroscopically characterized by hardened areas of the Pectoralis major muscle. Five genetic strains (strains 1–5) of mixed-sex broilers were fed either a control or an amino acid (AA)-reduced diet (20% reduction of digestible lysine, total sulfur AAs, and threonine) for 8 wk. Differences between whole-muscle proteome profiles of normal breast (NB; n = 6 gels) and WB tissue (n = 6 gels) were characterized for (1) broiler strains 1–5 that were fed with a control diet and collected at 0 min; (2) strain 5 (control diet) that were collected at 15 min, 4 h, and 24 h; (3) strain 5 (0 min) that were fed with a control and an AA-reduced diet. Birds that yielded WB were heavier and had a greater pH at death (pH0min) than normal birds. Results indicated that 21 proteins were more abundant (P < 0.05) and 3 proteins were less abundant (P < 0.05) in WB compared with NB. The differentially abundant proteins in each comparison were consistently upregulated or downregulated in WB tissue although the different protein profiles were noticed for each comparison. Strains 2 and 5 had more protein profile differences between WB and NB meat than strains 1, 3, and 4, which potentially indicates a stronger genetic component for strains 2 and 5 with respect to WB formation. The proteins that were more abundant in WB compared to NB are involved in carbohydrate metabolism, oxidative stress, cytoskeleton structure, and transport and signaling. Ingenuity Pathway Analysis indicated that regulated pathways in WB were mainly related to carbohydrate metabolism, cellular repair, cellular organization and maintenance, and cell death and survival. The results support the potential causes of WB myopathy, including the presence of hypoxia, oxidative stress, increased apoptosis, misfolded proteins, and inflammation.

Recombinant elongation factor 1 alpha of Haemonchus contortus affects the functions of goat PBMCs

Excretory/secretory proteins of Haemonchus contortus (HcESPs) intermingle comprehensively with host immune cells and modulate host immune responses. In this study, H contortus ES antigen named as elongation factor 1 alpha (HcEF‐1α) was cloned and expressed. The influences of recombinant HcEF‐1α on multiple functions of goat peripheral blood mononuclear cells (PBMCs) were observed in vitro. Immunoblot analysis revealed that rHcEF‐1α was recognized by the serum of goat infected with H contortus. Immunofluorescence analysis indicated that rHcEF‐1α was bound on surface of PBMCs. Moreover, the productions of IL‐4, TGF‐β1, IFN‐γ and IL‐17 of cells were significantly modulated by the incubation with rHcEF‐1α. The production of interleukin IL‐10 was decreased. Cell migration, cell proliferation and cell apoptosis were significantly increased; however, nitric oxide production (NO) was significantly decreased. The MHC II molecule expression of cells incubated with rHcEF‐1α was increased significantly, whereas MHC‐I was not changed as compared to the control groups (PBS control and pET32a). These findings indicated that rHcEF‐1α protein might play essential roles in functional regulations of HcESPs on goat PBMC and mediate the immune responses of the host during host‐parasite relationship.

Microgravity-induced hepatogenic differentiation of rBMSCs on board the SJ-10 satellite

Bone marrow-derived mesenchymal stem cells (BMSCs) are able to differentiate into functional hepatocytelike cells, which are expected to serve as a potential cell source in regenerative medicine, tissue engineering, and clinical treatment of liver injury. Little is known about whether and how space microgravity is able to direct the hepatogenic differentiation of BMSCs in the actual space microenvironment. In this study, we examined the effects of space microgravity on BMSC hepatogenic differentiation on board the SJ-10 Recoverable Scientific Satellite. Rat BMSCs were cultured and induced in hepatogenic induction medium for 3 and 10 d in custom-made space cell culture hardware. Cell growth was monitored periodically in orbit, and the fixed cells and collected supernatants were retrieved back to the Earth for further analyses. Data indicated that space microgravity improves the differentiating capability of the cells by up-regulating hepatocyte-specific albumin and cytokeratin 18. The resulting cells tended to be maturated, with an in-orbit period of up to 10 d. In space, mechanosensitive molecules of β1-integrin, β-actin, α-tubulin, and Ras homolog gene family member A presented enhanced expression, whereas those of cell-surface glycoprotein CD44, intercellular adhesion molecule 1, vascular cell adhesion molecule 1, vinculin, cell division control protein 42 homolog, and Rho-associated coiled-coil kinase yielded reduced expression. Also observed in space were the depolymerization of actin filaments and the accumulation of microtubules and vimentin through the altered expression and location of focal adhesion complexes, Rho guanosine 5'-triphosphatases, as well as the enhanced exosome-mediated mRNA transfer. This work furthers the understanding of the underlying mechanisms of space microgravity in directing hepatogenic differentiation of BMSCs.-Lü, D., Sun, S., Zhang, F., Luo, C., Zheng, L., Wu, Y., Li, N., Zhang, C., Wang, C., Chen, Q., Long, M. Microgravity-induced hepatogenic differentiation of rBMSCs on board the SJ-10 satellite.

[Eukaryotic translation elongation factor 1A1 positively regulates NOB1 expression to promote invasion and metastasis of hepatocellular carcinoma cells in vitro]

OBJECTIVE

To explore the role of eukaryotic translation elongation factor 1A1 (eEF1A1) in regulating the invasion and metastasis of hepatocellular carcinoma (HCC) cells and the possible mechanism.

METHODS

qRT-PCR and Western blotting were used to detect the mRNA and protein expression of eEF1A1 and NOB1 in different HCC cell lines and normal liver cells. The invasion and migration abilities of HCC cells with eEF1A1 knockdown or overexpression were examined using Transwell chamber assay and RTCA assay, and the changes in NOB1 mRNA and protein expressions in the cells were detected. The effects of increasing NOB1 expression in HCCLM3-sheEF1A1 cells and decreasing NOB1 expression in eEF1A1-overexpressing MHCC97h cells on eEF1A1 expression and cell invasion and migration abilities were analyzed using Western blotting, Transwell chamber assay and RTCA assay.

RESULTS

The expressions of eEF1A1 and NOB1 were significantly increased in positive correlation in HCC cells as compared with normal hepatocytes. Knockdown of eEF1A1 significantly decreased the invasion and migration of HCC cells and reduced the mRNA and protein expression of NOB1 (P < 0.01). Overexpression of eEF1A1 significantly enhanced invasion and migration of HCC cells and increased NOB1 mRNA and protein expressions (P < 0.01). Increasing NOB1 expression in HCCLM3-sheEF1A1 cells led to the restoration of NOB1 expression and cell invasion and migration abilities (P < 0.01), whereas decreasing NOB1 in MHCC97h-eEF1A1 cells resulted in inhibition of NOB1 expression and cell invasion and migration (P < 0.01).

CONCLUSIONS

eEF1A1 positively regulates the expression of NOB1 to promote the invasion and migration of HCC cells in vitro.

Er:YAG Laser and Cyclosporin A Effect on Cell Cycle Regulation of Human Gingival Fibroblast Cells

Introduction: Periodontitis is a set of inflammatory disorders characterized by periodontal attachment loss and alveolar bone resorption. Because of deficiency in periodontitis mechanical therapy, this study was aimed to explore the molecular influence of the erbiumdoped: yttrium aluminum garnet (Er:YAG) laser and cyclosporin A (CsA) on human gingival fibroblasts (HGFs) for improvement in periodontal diseases therapy. Methods: We focused on articles that studied the proteome profiles of HGFs after treatment with laser irradiation and application of CsA. The topological features of differentially expressed proteins were analyzed using Cytoscape Version 3.4.0 followed by module selection from the protein-protein interaction (PPI) network using Cluster ONE plugin. In addition, we performed gene ontology (GO) enrichment analysis for the densely connected region and key proteins in both PPI networks. Results: Analysis of PPI network of Er:YAG laser irradiation on HGFs lead to introducing YWHAZ, VCP, HNRNPU, YWHAE, UBA52, CLTC, FUS and IGHG1 as key proteins while similar analysis revealed that ACAT1, CTSD, ALDOA, ANXA2, PRDX1, LGALS3, ARHGDI and EEF1A1 are the crucial proteins related to the effect of drug. GO enrichment analysis of hubbottleneck proteins of the 2 networks showed the different significant biological processes and cellular components. The functional enrichments of module of Er:YAG laser network are included as fatty acid transmembrane transport, cytokinesis, regulation of RNA splicing and asymmetric protein localization. There are not any significant clusters in network of HGF treated by CsA. Conclusion: The results indicate that there are 2 separate biomarker panels for the 2 treatment methods.

Translational connection of TGFβ signaling: Phosphorylation of eEF1A1 by TβR-I inhibits protein synthesis

Transforming growth factor-β (TGFβ) signaling pathways regulate a wide array of cellular activities that are crucial for cell proliferation, apoptosis, migration and differentiation. TGFβ signaling pathways are initiated by ligand-activated TGFβ receptors, with type I TGFβ receptors (TβR-I) kinase being essential for phosphorylation of downstream targets. Until now, a prevalent view was that the TGFβ intracellular signaling targets would regulate transcription. Recently, we uncovered a novel TGFβ signaling pathway that exerts a direct regulatory effect on mRNA translation and protein synthesis. Eukaryotic elongation factor eEF1A1 is a GTP-binding protein that plays a central role in protein synthesis. By using a screening method for kinase substrate that was developed in our laboratory, we identified eEF1A1 as a novel substrate of TβR-I. This shed a new light on the convergence of TGFβ signaling and protein synthesis. We also showed phosphorylation of eEF1A1 at Ser300 by TβR-I prevents aa-tRNA binding to eEF1A1. As a consequence, TGFβ-dependent phosphorylation of eEF1A1 has an inhibitory effect on protein synthesis and cell proliferation. Therefore, we unveiled a novel regulatory mechanism of cellular proliferation by TGFβ at the translational level. Here we discuss this finding in the context of its potential role in the multiplicity of TGFβ signaling, and in the regulation of fundamental cellular functions, such as proliferation.

Chemical proteomics identifies heterogeneous nuclear ribonucleoprotein (hnRNP) A1 as the molecular target of quercetin in its anti-cancer effects in PC-3 cells

Quercetin, a flavonoid abundantly present in plants, is widely used as a phytotherapy in prostatitis and prostate cancer. Although quercetin has been reported to have a number of therapeutic effects, the cellular target(s) responsible for its anti-cancer action has not yet been clearly elucidated. Here, employing affinity chromatography and mass spectrometry, we identified heterogeneous nuclear ribonucleoprotein A1 (hnRNPA1) as a direct target of quercetin. A specific interaction between quercetin and hnRNPA1 was validated by immunoblotting and in vitro binding experiments. We found that quercetin bound the C-terminal region of hnRNPA1, impairing the ability of hnRNPA1 to shuttle between the nucleus and cytoplasm and ultimately resulting in its cytoplasmic retention. In addition, hnRNPA1 was recruited to stress granules after treatment of cells with quercetin for up to 48 h, and the levels of cIAP1 (cellular inhibitor of apoptosis), an internal ribosome entry site translation-dependent protein, were reduced by hnRNPA1 regulation. This is the first report that anti-cancer effects of quercetin are mediated, in part, by impairing functions of hnRNPA1, insights that were obtained using a chemical proteomics strategy.