The translation elongation factor 1A in tumorigenesis, signal transduction and apoptosis: review article

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.

Immunogens in Balamuthia mandrillaris: a proteomic exploration

Balamuthia mandrillaris is the causative agent of granulomatous amoebic encephalitis, a rare and often fatal infection affecting the central nervous system. The amoeba is isolated from diverse environmental sources and can cause severe infections in both immunocompromised and immunocompetent individuals. Given the limited understanding of B. mandrillaris, our research aimed to explore its protein profile, identifying potential immunogens crucial for early granulomatous amoebic encephalitis diagnosis. Cultures of B. mandrillaris and other amoebas were grown under axenic conditions, and total amoebic extracts were obtained. Proteomic analyses, including two-dimensional electrophoresis and mass spectrometry, were performed. A 50-kDa band showed a robust recognition of antibodies from immunized BALB/c mice; peptides contained in this band were matched with elongation factor-1 alpha, which emerged as a putative key immunogen. Besides, lectin blotting revealed the presence of glycoproteins in B. mandrillaris, and confocal microscopy demonstrated the focal distribution of the 50-kDa band throughout trophozoites. Cumulatively, these observations suggest the participation of the 50-kDa band in adhesion and recognition mechanisms. Thus, these collective findings demonstrate some protein characteristics of B. mandrillaris, opening avenues for understanding its pathogenicity and developing diagnostic and therapeutic strategies.

KAT8-catalyzed lactylation promotes eEF1A2-mediated protein synthesis and colorectal carcinogenesis

Aberrant lysine lactylation (Kla) is associated with various diseases which are caused by excessive glycolysis metabolism. However, the regulatory molecules and downstream protein targets of Kla remain largely unclear. Here, we observed a global Kla abundance profile in colorectal cancer (CRC) that negatively correlates with prognosis. Among lactylated proteins detected in CRC, lactylation of eEF1A2K408 resulted in boosted translation elongation and enhanced protein synthesis which contributed to tumorigenesis. By screening eEF1A2 interacting proteins, we identified that KAT8, a lysine acetyltransferase that acted as a pan-Kla writer, was responsible for installing Kla on many protein substrates involving in diverse biological processes. Deletion of KAT8 inhibited CRC tumor growth, especially in a high-lactic tumor microenvironment. Therefore, the KAT8-eEF1A2 Kla axis is utilized to meet increased translational requirements for oncogenic adaptation. As a lactyltransferase, KAT8 may represent a potential therapeutic target for CRC.

Differential expression of genes potentially related to the callogenesis and in situ hybridization of SERK gene in macaw palm (Acrocomia aculeata Jacq.) Lodd. ex Mart

For the purpose of understanding the molecular processes triggered during callus formation in macaw palm, the expression of seven genes potentially involved in this process, identified in previous studies and from the literature, was investigated by RT-qPCR. In addition, in situ hybridization of the SERK gene was performed. Leaf tissues from adult plants from two macaw palm accession were inoculated in a medium combined with Picloram at a concentration of 450 μM to induce callus. The expression analysis was performed from leaf samples from two accessions of different origins (Municipalities of Tiros, MG, and Buriti Vermelho, DF, Brazil), which are characterized as non-responsive (NR) and responsive (R), respectively. The material was collected before callus induction (0 DAI, initial day) and 120 days after callus induction (120 DAI). Genes related to development (SERK, OASA, EF1, ANN1) and stress (LEA, CAT2, and MDAR5) were evaluated. The results obtained showed that all the genes involved with the development had their expressions downregulated at 0 DAI when the accession R was compared with the accession NR. On the other hand, it was possible to observe that these genes were upregulated at 120 DAI. The LEA stress gene showed a tendency to increase expression in the NR accession, while the R accession showed decreased expression and the CAT2 and MDAR5 genes showed upregulation in both accessions. In situ hybridization showed SERK transcripts in the vascular bundles, indicating the expression of SERK in this region, in addition to its expression in calluses. The results obtained in this study support our hypothesis that the regulation of genes involved in the control of oxidative stress and development is crucial for the formation of calluses in macaw palm.

Screening of genes encoding proteins that interact with Nrf2: Probing a cDNA library from Mytilus coruscus using a yeast two-hybrid system

The Nuclear factor Erythroid 2-related factor 2 (Nrf2) is the most important endogenous antioxidant factor in organisms, and it has been demonstrated that it exerts extensive control over the immune response by interacting with crucial innate immunity components directly or indirectly. Although Nrf2 has been widely confirmed to be involved in stress resistance in mammals and some fish, its contribution to mollusks oxidative stress resistance has not frequently been documented. In this investigation, total RNA was taken from the digestive gland of M. coruscus, and a cDNA library was constructed and screened using the GATEWAY recombination technology. The Nrf2 cDNA sequence of M. coruscus was cloned into the pGBKT7 vector to prepare the bait plasmid. Using yeast two-hybrid system, after auxotrophic medium screening, sequencing, and bioinformatics analysis, 13 binding proteins that interacted with Nrf2 were finally identified. They were QM-like protein, 40S ribosomal protein S4 (RPS4), ribosomal protein S2 (RPS2), ribosomal protein L12 (RPL12), EF1-alpha mRNA for elongation factor 1 alpha (eEF1-alpha), ferritin, alpha-amylase, trypsin, vdg3, period clock protein, cyclophilin A isoform 1 (CYP A), serine protease CFSP2, histone variant H2A.Z (H2A.Z). For a better understanding the physiological function of Nrf2 in animals and as a potential target for future research on protein roles in Nrf2 interactions, it is crucial to clarify these protein interactions.

Anticancer Small-Molecule Agents Targeting Eukaryotic Elongation Factor 1A: State of the Art

Eukaryotic elongation factor 1A (eEF1A) canonically delivers amino acyl tRNA to the ribosomal A site during the elongation stage of protein biosynthesis. Yet paradoxically, the oncogenic nature of this instrumental protein has long been recognized. Consistently, eEF1A has proven to be targeted by a wide assortment of small molecules with excellent anticancer activity, among which plitidepsin has been granted approval for the treatment of multiple myeloma. Meanwhile, metarrestin is currently under clinical development for metastatic cancers. Bearing these exciting advances in mind, it would be desirable to present a systematic up-to-date account of the title topic, which, to the best of our knowledge, has thus far been unavailable in the literature. The present review summarizes recent advances in eEF1A-targeting anticancer agents, both naturally occurring and synthetically crafted, with regard to their discovery or design, target identification, structure–activity relationship, and mode of action. Their structural diversity and differential eEF1A-targeting mechanisms warrant continuing research in pursuit of curing eEF1A-driven malignancy.

METTL13 facilitates cell growth and metastasis in gastric cancer via an eEF1A/HN1L positive feedback circuit

Although improved treatment could inhibit progression of gastric cancer (GC), the recurrence and metastasis remain challenging issues. Methyltransferase like 13 (METTL13) has been implicated in most human cancers, but its function and mechanism in GC remain elusive. In the present study, we evaluated its expression in GC samples and found it was aberrantly overexpressed in cancer tissues than that in normal stomach tissues. High expression of METTL13 was closely associated with age, tumor size and T classification. Biological experiments showed that silencing METTL13 suppressed gastric cancer cell proliferation and metastasis in vivo and vitro, whereas opposite effects were observed upon METTL13 overexpression. Further mechanistic explorations revealed that METTL13 regulated the expression of HN1L (Hematological and neurological expressed 1-like), which is reported to be an oncogene in various cancers. Knockdown of HN1L dampened gastric cancer cell growth induced by METTL13. Eukaryotic translation elongation factor-1A (eEF1A), the present sole methylation substrate of METTL13, was involved in the regulation of HN1L by METTL13 in a K55 methylation independent manner. In addition, we also found HN1L could facilitate METTL13 expression in GC cells consistent with a previous report in hepatocellular carcinoma. Thus, these findings demonstrate a METTL13/eEF1A/HN1L positive feedback circuit promoting gastric cancer development and metastasis. It will help develop promising diagnostic and therapeutic targets for this disease.

An Integrated Approach of Learning Genetic Networks From Genome-Wide Gene Expression Data Using Gaussian Graphical Model and Monte Carlo Method

Global genetic networks provide additional information for the analysis of human diseases, beyond the traditional analysis that focuses on single genes or local networks. The Gaussian graphical model (GGM) is widely applied to learn genetic networks because it defines an undirected graph decoding the conditional dependence between genes. Many algorithms based on the GGM have been proposed for learning genetic network structures. Because the number of gene variables is typically far more than the number of samples collected, and a real genetic network is typically sparse, the graphical lasso implementation of GGM becomes a popular tool for inferring the conditional interdependence among genes. However, graphical lasso, although showing good performance in low dimensional data sets, is computationally expensive and inefficient or even unable to work directly on genome-wide gene expression data sets. In this study, the method of Monte Carlo Gaussian graphical model (MCGGM) was proposed to learn global genetic networks of genes. This method uses a Monte Carlo approach to sample subnetworks from genome-wide gene expression data and graphical lasso to learn the structures of the subnetworks. The learned subnetworks are then integrated to approximate a global genetic network. The proposed method was evaluated with a relatively small real data set of RNA-seq expression levels. The results indicate the proposed method shows a strong ability of decoding the interactions with high conditional dependences among genes. The method was then applied to genome-wide data sets of RNA-seq expression levels. The gene interactions with high interdependence from the estimated global networks show that most of the predicted gene-gene interactions have been reported in the literatures playing important roles in different human cancers. Also, the results validate the ability and reliability of the proposed method to identify high conditional dependences among genes in large-scale data sets.

Glycosylating Effectors of Legionella pneumophila: Finding the Sweet Spots for Host Cell Subversion

Work over the past two decades clearly defined a significant role of glycosyltransferase effectors in the infection strategy of the Gram-negative, respiratory pathogen Legionella pneumophila. Identification of the glucosyltransferase effectors Lgt1-3, specifically modifying elongation factor eEF1A, disclosed a novel mechanism of host protein synthesis manipulation by pathogens and illuminated its impact on the physiological state of the target cell, in particular cell cycle progression and immune and stress responses. Recent characterization of SetA as a general O-glucosyltransferase with a wide range of targets including the proteins Rab1 and Snx1, mediators of membrane transport processes, and the discovery of new types of glycosyltransferases such as LtpM and SidI indicate that the vast effector arsenal might still hold more so-far unrecognized family members with new catalytic features and substrates. In this article, we review our current knowledge regarding these fascinating biomolecules and discuss their role in introducing new or overriding endogenous post-translational regulatory mechanisms enabling the subversion of eukaryotic cells by L. pneumophila.

Hepatitis B Virus DNA Polymerase Displays an Anti-Apoptotic Effect by Interacting with Elongation Factor-1 Alpha-2 in Hepatoma Cells

Hepatitis B virus (HBV) genome P-encoded protein HBV DNA polymerase (Pol) has long been known as a reverse transcriptase during HBV replication. In this study, we investigated the impact of HBV Pol on host cellular processes, mainly apoptosis, and the underlying mechanisms. We showed a marked reduction in apoptotic rates in the HBV Pol-expressed HepG2 cells compared to controls. Moreover, a series of assays, i.e., yeast two-hybrid, GST pull-down, co-immunoprecipitation, and confocal laser scanning microscopy, identified the host factor eEF1A2 to be associated with HBV Pol. Furthermore, knockdown of eEF1A2 gene by siRNA abrogated the HBV Pol-mediated anti-apoptotic effect with apoptosis induced by endoplasmatic reticulum (ER) stress-inducer thapsigargin (TG), thus suggesting that the host factor eEF1A2 is essential for HBV Pol's anti-apoptosis properties. Our findings have revealed a novel role for HBV Pol in its modulation of apoptosis through integrating with eEF1A2.

Dimethylation of eEF1A at Lysine 55 Plays a Key Role in the Regulation of eEF1A2 on Malignant Cell Functions of Acute Myeloid Leukemia

OBJECTIVE

This study aimed to explore whether eukaryotic translation elongation factor 1 alpha 2 affected cell proliferation, migration, and apoptosis via regulating the dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 in acute myeloid leukemia.

METHODS

The expressions of eukaryotic translation elongation factor 1 alpha 2 and dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 in acute myeloid leukemia cell lines and human normal bone marrow mononuclear cells (as control) were assessed. Control CRISPR-Cas9 lentivirus, eukaryotic translation elongation factor 1 alpha 2 knockout CRISPR-Cas9 lentivirus, vector plasmid, eukaryotic translation elongation factor 1 alpha 2 wild type overexpression plasmid, and eukaryotic translation elongation factor 1 alpha 2 with a K55R substitution overexpression plasmid were transfected into AML-193 and Kasumi-1 cells combined or alone, and were accordingly divided into 4 groups (Sgcontrol + vector group, SgeEF1A2 + vector group, SgeEF1A2 + eEF1A2_WT group, and SgeEFIA2 + eEF1A2_K55R group).

RESULTS

Eukaryotic translation elongation factor 1 alpha 2 and dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 expressions were higher in AML-193, Kasumi-1, and KG-1 cell lines compared to the control. In AML-193 and Kasumi-1 cells, the knockout and compensated experiments revealed that eukaryotic translation elongation factor 1 alpha 2 promoted cell proliferation and migration but repressed apoptosis. Additionally, the knockout of eukaryotic translation elongation factor 1 alpha 2 decreased dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 expression, meanwhile, eukaryotic translation elongation factor 1 alpha 2 wild type overexpression enhanced while eukaryotic translation elongation factor 1 alpha 2 with a K55R substitution overexpression did not influence the dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 expression. Furthermore, eukaryotic translation elongation factor 1 alpha 2 wild type overexpression promoted cell proliferation, enhanced migration, and decreased apoptosis, but eukaryotic translation elongation factor 1 alpha 2 with a K55R substitution overexpression did not influence these cellular functions in AML-193 and Kasumi-1 cells, suggesting the implication of dimethylation of eukaryotic translation elongation factor 1 alpha at lysine 55 in eukaryotic translation elongation factor 1 alpha 2 mediated oncogenesis of acute myeloid leukemia.

CONCLUSION

Eukaryotic translation elongation factor 1 alpha 2 and its dimethylated product may serve as therapeutic targets, and these findings may provide support for exploring novel strategies in acute myeloid leukemia treatment.

Inhibition of the antioxidant enzyme PRDX1 activity promotes MPP+-induced death in differentiated SH-SY5Y cells and may impair its colocalization with eEF1A2

AIM

eEF1A2 is highly expressed in postmitotic cells and has been reported to interact with the antioxidant enzyme peroxiredoxin 1 (PRDX1). PRDX1 is involved in motor neuron differentiation. Here, we studied the relationship between eEF1A2 and PRDX1 during dopaminergic neuron differentiation, and examined their possible association in an oxidative stress model of Parkinson's disease (PD).

MAIN METHODS

Expression of eEF1A2 and PRDX1 in SH-SY5Y cells at various durations of retinoic acid (RA) induction was detected using qRT-PCR, Western blotting and immunofluorescence. Neurons of 10-day differentiation were treated with the PRDX1 inhibitor H7, MPP⁺ and H7 plus MPP⁺. The cell viability, the amounts of apoptotic nuclei, DHE signals, and the expression of p53, p-Akt and p-mTOR were determined. The colocalization of eEF1A2 and PRDX1 was visualized using confocal microscopy.

KEY FINDINGS

eEF1A2 gradually increased after RA-induced differentiation of SH-SY5Y cells, while PRDX1 protein gradually decreased. MPP⁺ treatment increased eEF1A2 in both undifferentiated and differentiated neurons; however, PRDX1 appeared to elevate only in mature neurons. The inhibition of the PRDX1 activity with H7 promoted MPP⁺-induced cell death, as evidenced by decreased cell viability, increased apoptotic nuclei, increased the DHE signal, and increased p53. However, H7 induced the activation of the prosurvival Akt and mTOR in MPP⁺-treated cells. Besides, a colocalization of eEF1A2 and PRDX1 was evidenced in MPP⁺-treated neurons. This colocalization was possibly prevented by inhibiting the PRDX1 activity, resulting in aggravated neuronal death.

SIGNIFICANCE

Our results suggest that the possible association between eEF1A2 and PRDX1 may be a promising target for modifying neuronal death in PD.

Differences in proteomic profile between two haemocyte types, granulocytes and hyalinocytes, of the flat oyster Ostrea edulis

Haemocytes play a dominant role in shellfish immunity, being considered the main defence effector cells in molluscs. These cells are known to be responsible for many functions, including chemotaxis, cellular recognition, attachment, aggregation, shell repair and nutrient transport and digestion. There are two basic cell types of bivalve haemocytes morphologically distinguishable, hyalinocytes and granulocytes; however, functional differences and specific abilities are poorly understood: granulocytes are believed to be more efficient in killing microorganisms, while hyalinocytes are thought to be more specialised in clotting and wound healing. A proteomic approach was implemented to find qualitative differences in the protein profile between granulocytes and hyalinocytes of the European flat oyster, Ostrea edulis, as a way to evaluate functional differences. Oyster haemolymph cells were differentially separated by Percoll® density gradient centrifugation. Granulocyte and hyalinocyte proteins were separated by 2D-PAGE and their protein profiles were analysed and compared with PD Quest software; the protein spots exclusive for each haemocyte type were excised from gels and analysed by MALDI-TOF/TOF with a combination of mass spectrometry (MS) and MS/MS for sequencing and protein identification. A total of 34 proteins were identified, 20 unique to granulocytes and 14 to hyalinocytes. The results suggested differences between the haemocyte types in signal transduction, apoptosis, oxidation reduction processes, cytoskeleton, phagocytosis and pathogen recognition. These results contribute to identify differential roles of each haemocyte type and to better understand the oyster immunity mechanisms, which should help to fight oyster diseases.

Effects of eEF1A1 targeting by aptamer/siRNA in chronic lymphocytic leukaemia cells

BACKGROUND

The effectiveness of therapies for chronic lymphocytic leukemia (CLL), the most common leukemia in Western countries adults, can be improved via a deeper understanding of its molecular abnormalities. Whereas the isoforms of the eukaryotic elongation factor 1A (eEF1A1 and eEF1A2) are implicated in different tumors, no information are available in CLL.

METHODS

eEF1A1/eEF1A2 amounts were quantitated in the lymphocytes of 46 CLL patients vs normal control (real time PCR, western blotting). eEF1A1 role in CLL was investigated in a cellular (MEC-1) and animal model of CLL via its targeting by an aptamer (GT75) or a siRNA (siA1) delivered by electroporation (in vitro) or lipofection (in vivo).

RESULTS

eEF1A1/eEF1A2 were elevated in CLL lymphocytes vs control. eEF1A1 but not eEF1A2 levels were higher in patients which died during the study compared to those surviving. eEF1A1 targeting (GT75/siA1) resulted in MEC-1 viability reduction/autophagy stimulation and in vivo tumor growth down-regulation.

CONCLUSIONS

The increase of eEF1A1 in dead vs surviving patients may confer to eEF1A1 the role of a prognostic marker for CLL and possibly of a therapeutic target, given its involvement in MEC-1 survival. Specific aptamer/siRNA released by optimized delivery systems may allow the development of novel therapeutic options.

Expression of EEF1A1 Is Associated with Prognosis of Patients with Colon Adenocarcinoma

Background: The prognostic role of the translational factor, elongation factor-1 alpha 1 (EEF1A1), in colon cancer is unclear. Objectives: The present study aimed to investigate the expression of EEF1A in tissues obtained from patients with stage II and III colon cancer and analyze its association with patient prognosis. Methods: A total of 281 patients with colon cancer who underwent curative resection were analyzed according to EEF1A1 expression. Results: The five-year overall survival in the high-EEF1A1 group was 87.7%, whereas it was 65.6% in the low-EEF1A1 expression group (hazard ratio (HR) 2.47, 95% confidence interval (CI) 1.38–4.44, p = 0.002). The five-year disease-free survival of patients with high EEF1A1 expression was 82.5%, which was longer than the rate of 55.4% observed for patients with low EEF1A1 expression (HR 2.94, 95% CI 1.72–5.04, p < 0.001). Univariate Cox regression analysis indicated that age, preoperative carcinoembryonic antigen level, adjuvant treatment, total number of metastatic lymph nodes, and EEF1A1 expression level were significant prognostic factors for death. In multivariate analysis, expression of EEF1A1 was an independent prognostic factor associated with death (HR 3.01, 95% CI 1.636–5.543, p < 0.001). EEF1A1 expression was also an independent prognostic factor for disease-free survival in multivariate analysis (HR 2.54, 95% CI 1.459–4.434, p < 0.001). Conclusions: Our study demonstrated that high expression of EEF1A1 has a favorable prognostic effect on patients with colon adenocarcinoma.

Alterations in Eukaryotic Elongation Factor complex proteins (EEF1s) in cancer and their implications in epigenetic regulation

AIMS

In the cell, both transcriptional and translational processes are tightly regulated. Cancer is a multifactorial disease characterized by aberrant protein expression. Since epigenetic control mechanisms are also frequently disrupted during carcinogenesis, they have been the center of attention in cancer research within the past decades. EEF1 complex members, which are required for the elongation process in eukaryotes, have recently been implicated in carcinogenesis. This study aims to investigate genetic alterations within EEF1A1, EEF1A2, EEF1B2, EEF1D, EEF1E1 and EEF1G genes and their potential effects on epigenetic regulation mechanisms.

MATERIALS AND METHODS

In this study, we analyzed DNA sequencing and mRNA expression data available on The Cancer Genome Atlas (TCGA) across different cancer types to detect genetic alterations in EEF1 genes and investigated their potential impact on selected epigenetic modulators.

KEY FINDINGS

We found that EEF1 complex proteins were deregulated in several types of cancer. Lower EEF1A1, EEF1B2, EEF1D and EEF1G levels were correlated with poor survival in glioma, while lower EEF1B2, EEF1D and EEF1E1 levels were correlated with better survival in hepatocellular carcinoma. We detected genetic alterations within EEF1 genes in up to 35% of the patients and showed that these alterations resulted in down-regulation of histone modifying enzymes KMT2C, KMT2D, KMT2E, KAT6A and EP300.

SIGNIFICANCE

Here in this study, we showed that EEF1 deregulations might result in differential epigenomic landscapes, which affect the overall transcriptional profile, contributing to carcinogenesis. Identification of these molecular distinctions might be useful in developing targeted drug therapies and personalized medicine.

Fatty acylCoA synthetase FadD13 regulates proinflammatory cytokine secretion dependent on the NF-κB signalling pathway by binding to eEF1A1

Mycobacterium tuberculosis (Mtb) manipulates multiple host defence pathways to survive and persist in host cells. Understanding Mtb–host cell interaction is crucial to develop an efficient means to control the disease. Here, we applied the Mtb proteome chip, through separately interacting with H37Ra and H37Rv stimulated macrophage lysates, screened 283 Mtb differential proteins. Through primary screening, we focused on fatty acylCoA synthetase FadD13. Mtb FadD13 is a potential drug target, but its role in infection remains unclear. Deletion of FadD13 in Mtb reduced the production of proinflammatory cytokines IL‐1β, IL‐18, and IL‐6. Bimolecular fluorescence complementation and colocalization showed that the binding partner of FadD13 in macrophage was eEF1A1 (a translation elongation factor). Knockdown eEF1A1 expression in macrophage abrogated the promotion of proinflammatory cytokines induced by FadD13. In addition, ΔfadD13 mutant decreased the expression of the NF‐κB signalling pathway related proteins p50 and p65, so did the eEF1A1 knockdown macrophage infected with H37Rv. Meanwhile, we found that deletion of FadD13 reduced Mtb survival in macrophages during Mtb infection, and purified FadD13 proteins induced broken of macrophage membrane. Taken together, FadD13 is crucial for Mtb proliferation in macrophages, and it plays a key role in the production of proinflammatory cytokines during Mtb infection.

Styryl-cinnamate hybrid inhibits glioma by alleviating translation, bioenergetics and other key cellular responses leading to apoptosis

Gliomas are lethal and aggressive form of brain tumors with resistance to conventional radiation and cytotoxic chemotherapies; inviting continuous efforts for drug discovery and drug delivery. Interestingly, small molecule hybrids are one such pharmacophore that continues to capture interest owing to their pluripotent medicinal effects. Accordingly, we earlier reported synthesis of potent Styryl-cinnamate hybrids (analogues of Salvianolic acid F) along with its plausible mode of action (MOA). We explored iTRAQ-LC/MS-MS technique to deduce differentially expressed landscape of native & phospho-proteins in treated glioma cells. Based on this, Protein-Protein Interactome (PPI) was looked into by employing computational tools and further validated in vitro. We hereby report that the Styryl-cinnamate hybrid, an analogue of natural Salvianolic acid F, alters key regulatory proteins involved in translation, cytoskeleton development, bioenergetics, DNA repair, angiogenesis and ubiquitination. Cell cycle analysis dictates arrest at G0/G1 stage along with reduced levels of cyclin D; involved in G1 progression. We discovered that Styryl-cinnamate hybrid targets glioma by intrinsically triggering metabolite-mediated stress. Various oncological circuits alleviated by the potential drug candidate strongly supports the role of such pharmacophores as anticancer drugs. Although, further analysis of SC hybrid in treating xenografts or solid tumors is yet to be explored but their candidature has gained huge impetus through this study. This study equips us better in understanding the shift in proteomic landscape after treating glioma cells with SC hybrid. It also allows us to elicit molecular targets of this potential drug before progressing to preclinical studies.

Divergent gene expression in the gills of juvenile turbot (Psetta maxima) exposed to chronic severe hypercapnia indicates dose-dependent increase in intracellular oxidative stress and hypoxia

Elevated concentrations of carbon dioxide are a common stressor for fish and other aquatic animals. In particular, intensive aquaculture can impose prolonged periods of severe environmental hypercapnia, manifold exceeding CO₂ concentrations of natural habitats. In order to cope with this stressor, gills are essential and constitute the primary organ in the acclimatization process. Yet, despite a general understanding of changes in ion regulation, not much is known with regard to other cellular mechanisms. In this study, we apply RT-qPCR to investigate changes in the expression of several genes associated with metabolism, stress and immunity within gills of juvenile turbot (Psetta maxima) after an eight-week exposure to different concentrations of CO₂ (low = ∼3000 μatm, medium = ∼15,000 μatm and high = ∼25,000 μatm CO₂). Histological examination of the gill tissue only found a significant increase of hypertrophied secondary lamella in the highest tested treatment level. gene expression results, on the other hand, implied both, mutual and dose-dependent transcriptional adjustments. Comparable up-regulation of IL-1ß, LMP7 and Grim19 at medium and high hypercapnia indicated an increase of reactive oxygen species (ROS) within gill cells. Simultaneous increase in Akirin and PRDX transcripts at medium CO₂ indicated enhanced anti-oxidant activity and regulation of transcription, while reduced mRNA concentrations of COX, EF1α and STAT2 at high CO₂ denoted suppressed protein synthesis and reduced metabolic capacity. In addition to upregulated DFAD and ApoE expression, implying compensating repair measures, gills exposed to the highest tested treatment level seemed to operate close to or even beyond their maximum capacity. Thus, fitting the model of capacity limitation, our results provide evidence for accretive intracellular hypoxia and oxidative stress in the gills of turbot, dependent on the level of environmental hypercapnia. Further, genes, such as COX, may be valuable biomarkers when attempting to discriminate between a successful and an overpowered stress response.

Molecular Targets of Epigallocatechin-Gallate (EGCG): A Special Focus on Signal Transduction and Cancer

Green tea is a beverage that is widely consumed worldwide and is believed to exert effects on different diseases, including cancer. The major components of green tea are catechins, a family of polyphenols. Among them, epigallocatechin-gallate (EGCG) is the most abundant and biologically active. EGCG is widely studied for its anti-cancer properties. However, the cellular and molecular mechanisms explaining its action have not been completely understood, yet. EGCG is effective in vivo at micromolar concentrations, suggesting that its action is mediated by interaction with specific targets that are involved in the regulation of crucial steps of cell proliferation, survival, and metastatic spread. Recently, several proteins have been identified as EGCG direct interactors. Among them, the trans-membrane receptor 67LR has been identified as a high affinity EGCG receptor. 67LR is a master regulator of many pathways affecting cell proliferation or apoptosis, also regulating cancer stem cells (CSCs) activity. EGCG was also found to be interacting directly with Pin1, TGFR-II, and metalloproteinases (MMPs) (mainly MMP2 and MMP9), which respectively regulate EGCG-dependent inhibition of NF-kB, epithelial-mesenchimal transaction (EMT) and cellular invasion. EGCG interacts with DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), which modulates epigenetic changes. The bulk of this novel knowledge provides information about the mechanisms of action of EGCG and may explain its onco-suppressive function. The identification of crucial signalling pathways that are related to cancer onset and progression whose master regulators interacts with EGCG may disclose intriguing pharmacological targets, and eventually lead to novel combined treatments in which EGCG acts synergistically with known drugs.

Mass spectrometry-based proteomic analysis reveals the interacting partners of lipin1

As a lipin family founding member, lipin1 exerts dual functions as a phosphatidate phosphatase enzyme and/or a co-transcriptional regulator in lipid metabolism. In fact, it is also involved in many other cell processes. In this study, we utilized pull down assay coupled with mass spectrometry (MS) to unravel protein-protein interaction networks of lipin1 in 293T human embryonic kidney cells. Pull-down assay on the Ni²⁺ -chelating column was used to isolate lipin1 complexes from 293T cells transfected with 6-His tagged lipin1. The lipin1 complexes were analyzed on Q Exactive mass spectrometer. A total of 30 proteins were identified from label free quantitation of the MS data by Proteome Discoverer platform. The physical interaction between lipin1 and eEF1A1 was further affirmed in 293T cells transfected with 6-His tagged lipin1 and hepatocyte SMMC7721 cells by protein immunoprecipitation and immunofluorescence microscopy. Lipin1 also interacted with HIST1H2BK, which was confirmed in SMMC7721 cells by protein immunoprecipitation. Our proteomic analysis implicated lipin1 in novel roles in various cellular processes. © 2018 IUBMB Life, 70(8):753-762, 2018.

Eukaryotic elongation factors 2 promotes tumor cell proliferation and correlates with poor prognosis in ovarian cancer

Eukaryotic elongation factors 2 (eEF2) plays an essential role in the GTP-dependent translocation of the ribosome along mRNA. Previous studies have shown that eEF2 is overexpressed in various tumors. However, little is known about the role of eEF2 in ovarian cancer. The aim of the present study is to examine the effect of eEF2 on ovarian cancer proliferation. We first measured eEF2 protein expression by western blot using six fresh ovarian cancer tissues from G1 to G3. The results showed that eEF2 expression gradually increased from G1 to G3. Additionally, eEF2 expression correlated significantly with grade (P = 0.045), FIGO stage (P = 0.035) and Ki67 (P < 0.05). Additionally, there was a significant positive association between eEF2 expression and Ki67 (r = 0.855). Cox's proportional hazards model also showed that eEF2 (P = 0.004) and Ki67 (P < 0.001) were an independent prognostic factor of overall survival in ovarian cancer patients. In vitro, after the release of ovarian cancer cell line (HO8910) from serum starvation, the expression of eEF2, cyclinD1 and PCNA was up-regulated. Moreover, silencing eEF2 in HO8910 cells decreased cell proliferation. Finally, we hypothesize that eEF2 may be activated in a positive feedback cycle through inactivation of eEF2K via the PI3K/Akt/mTOR pathway. These data provide novel insights into developing experimental therapies for ovarian cancer.

Polymer-Mediated Delivery of siRNAs to Hepatocellular Carcinoma: Variables Affecting Specificity and Effectiveness

Despite the advances in anticancer therapies, their effectiveness for many human tumors is still far from being optimal. Significant improvements in treatment efficacy can come from the enhancement of drug specificity. This goal may be achieved by combining the use of therapeutic molecules with tumor specific effects and delivery carriers with tumor targeting ability. In this regard, nucleic acid-based drug (NABD) and particularly small interfering RNAs (siRNAs), are attractive molecules due to the possibility to be engineered to target specific tumor genes. On the other hand, polymeric-based delivery systems are emerging as versatile carriers to generate tumor-targeted delivery systems. Here we will focus on the most recent findings in the selection of siRNA/polymeric targeted delivery systems for hepatocellular carcinoma (HCC), a human tumor for which currently available therapeutic approaches are poorly effective. In addition, we will discuss the most attracting and, in our opinion, promising siRNA-polymer combinations for HCC in relation to the biological features of HCC tissue. Attention will be also put on the mathematical description of the mechanisms ruling siRNA-carrier delivery, this being an important aspect to improve effectiveness reducing the experimental work.

Identification of Eukaryotic Translation Elongation Factor 1-α 1 Gamendazole-Binding Site for Binding of 3-Hydroxy-4(1 H)-quinolinones as Novel Ligands with Anticancer Activity

Here, we have identified the interaction site of the contraceptive drug gamendazole using computational modeling. The drug was previously described as a ligand for eukaryotic translation elongation factor 1-α 1 (eEF1A1) and found to be a potential target site for derivatives of 2-phenyl-3-hydroxy-4(1 H)-quinolinones (3-HQs), which exhibit anticancer activity. The interaction of this class of derivatives of 3-HQs with eEF1A1 inside cancer cells was confirmed via pull-down assay. We designed and synthesized a new family of 3-HQs and subsequently applied isothermal titration calorimetry to show that these compounds strongly bind to eEF1A1. Further, we found that some of these derivatives possess significant in vitro anticancer activity.

Salidroside influences the cellular cross-talk of human fetal lung diploid fibroblasts: A proteomic approach

Senescence is a complex multiple factor proces, which is still poorly understood. The purpose of this study was to find the proteome of cultured human fetal lung diploid fibroblasts (2BS) of different population doubling (PD), as well as the altered proteome induced by salidroside (SAL) in 2BS cells. Proteins were identified by two-dimensional electrophoresis (2-DE) combining matrix-assisted laser desorption/ionization-time and flight mass spectrometry (MAL DI-TOF/MS). As a result, we found 16 proteins with two-fold variations in senescent cells or after SAL treatment, some being reduced such as reticulocalbin-1, heat shock protein beta-6, elongation factor 1-delta, F-actin-capping protein subunit alpha-1, and chloride intracellular channel 1. In contrast, 40S ribosomal protein SA, proteasome subunit alpha type-5, and zinc finger BED domain-containing protein 5 increased with cell age. Furthermore, heat shock protein beta-6, Zinc finger BED domain-containing protein 5 was increased in PD30 cells after 10 μM SAL treatment, whereas, elongation factor 1-delta, 6-phosphogluconolactonase, Nucleoside diphosphate kinase A, F-actin-capping protein subunit alpha-1, Probable ATP-dependent RNA helicase DDX41, Chloride intracellular channel 1, and Peroxiredoxin-6 were increased in PD50 cells after 10 μM SAL treatment. Some of these proteins were involved in the protein synthetic and degradative pathways, which emphasizes the metabolic disorder or functional impairment of cell senescence. Moreover, these proteins could be candidate biomarkers for evaluating the SAL anti-senescence effect.

Methylation of Elongation Factor 1A: Where, Who, and Why?

Eukaryotic elongation factor 1A (eEF1A) is an essential and highly conserved protein involved in diverse cellular processes, including translation, cytoskeleton organisation, nuclear export, and proteasomal degradation. Recently, nine novel and site-specific methyltransferases were discovered that target eEF1A, five in yeast and four in human, making it the eukaryotic protein with the highest number of independent methyltransferases. Some of these methyltransferases show striking evolutionary conservation. Yet, they come from diverse methyltransferase families, indicating they confer competitive advantage through independent origins. As might be expected, the first functional studies of specific methylation sites found them to have distinct effects, notably on eEF1A-related processes of translation and tRNA aminoacylation. Further functional studies of sites will likely reveal other unique roles for this interesting modification.

Transcriptomic approach: A promising tool for rapid screening nanomaterial-mediated toxicity in the marine bivalve Mytilus edulis-Application to copper oxide nanoparticles

The extensive development of nanotechnologies will inevitably lead to the release of nanomaterials (NMs) in the environment. As the aquatic environments represent the ultimate sink for various contaminants, it is highly probable that they also constitute a reservoir for NMs and hence aquatic animals represent potential targets. In a regulatory perspective, it is necessary to develop tools to rapidly screen the impact of NMs on model organisms, given that the number of NMs on the market will be increasing. In this context High Throughput Screening approaches represent relevant tools for the investigation of NM-mediated toxicity. The objective of this work was to study the effects of copper oxide nanoparticles (CuONPs) in the marine bivalve Mytilus edulis, using a transcriptomic approach. Mussels were exposed in vivo to CuONPs (10 μg·L^-1CuO NPs) for 24 h and analysis of mRNA expression levels of genes implicated in immune response, antioxidant activities, cell metabolism, cell transport and cytoskeleton was investigated by qPCR on hemocytes and gills. Results showed common effects of CuONPs and its ionic counterpart. However, greater effects of CuONPs on GST, SOD, MT, Actin, ATP synthase gene expressions were observed compared to ionic form indicating that toxicity of CuONPs is not solely due to the release of Cu²⁺. Even though M. edulis genome is not fully characterized, this study provides additional knowledge on the signaling pathways implicated in CuONP-mediated toxicity and demonstrates the reliability of using a qPCR approach to go further in the cellular aspects implicated in response to NPs in marine bivalves.

PSMB8 and PBK as potential gastric cancer subtype-specific biomarkers associated with prognosis

Gastric adenocarcinoma is a common form of cancer associated with a poor prognosis. We analyzed microarray profiling data from 48 patients with gastric adenocarcinoma to characterize gastric cancer subtypes and identify biomarkers associated with prognosis. We identified two major subtypes of gastric adenocarcinoma differentially associated with overall survival (P = 0.025). Genes that were differentially expressed were identified using specific criteria (P < 0.001 and >1.5-fold); expression of 294 and 116 genes was enriched in good and poor prognosis subtypes, respectively. Genes related to translational elongation and cell cycle were upregulated in the poor prognosis group. Of these genes, upregulation of proteasome subunit beta type 8 PSMB8 and PDZ binding kinase PBK was confirmed by real-time reverse transcription-PCR analysis. PSMB8 or PBK knockdown had no effect on gastric cancer cell proliferation but suppressed cell migration and invasion, respectively. Furthermore, immunohistochemistry analysis of 385 gastric cancer patients revealed that increased nuclear expression of PSMB8 and PBK was correlated with depth of invasion, lymph node metastasis, and lower survival rates. Taken together, two gastric adenocarcinoma subtypes were predictive of prognosis. PSMB8 and PBK were predictive of gastric cancer prognosis and could be potential gastric cancer subtype-specific biomarkers.

Elongation factor Tu is a multifunctional and processed moonlighting protein

Many bacterial moonlighting proteins were originally described in medically, agriculturally, and commercially important members of the low G + C Firmicutes. We show Elongation factor Tu (Ef-Tu) moonlights on the surface of the human pathogens Staphylococcus aureus (Sa_Ef-Tu) and Mycoplasma pneumoniae (Mpn_Ef-Tu), and the porcine pathogen Mycoplasma hyopneumoniae (Mhp_Ef-Tu). Ef-Tu is also a target of multiple processing events on the cell surface and these were characterised using an N-terminomics pipeline. Recombinant Mpn_Ef-Tu bound strongly to a diverse range of host molecules, and when bound to plasminogen, was able to convert plasminogen to plasmin in the presence of plasminogen activators. Fragments of Ef-Tu retain binding capabilities to host proteins. Bioinformatics and structural modelling studies indicate that the accumulation of positively charged amino acids in short linear motifs (SLiMs), and protein processing promote multifunctional behaviour. Codon bias engendered by an A + T rich genome may influence how positively-charged residues accumulate in SLiMs.

Protein glutaminylation is a yeast-specific posttranslational modification of elongation factor 1A

Ribosomal translation factors are fundamental for protein synthesis and highly conserved in all kingdoms of life. The essential eukaryotic elongation factor 1A (eEF1A) delivers aminoacyl tRNAs to the A-site of the translating 80S ribosome. Several studies have revealed that eEF1A is posttranslationally modified. Using MS analysis, site-directed mutagenesis, and X-ray structural data analysis of Saccharomyces cerevisiae eEF1A, we identified a posttranslational modification in which the α amino group of mono-l-glutamine is covalently linked to the side chain of glutamate 45 in eEF1A. The MS analysis suggested that all eEF1A molecules are modified by this glutaminylation and that this posttranslational modification occurs at all stages of yeast growth. The mutational studies revealed that this glutaminylation is not essential for the normal functions of eEF1A in S. cerevisiae However, eEF1A glutaminylation slightly reduced growth under antibiotic-induced translational stress conditions. Moreover, we identified the same posttranslational modification in eEF1A from Schizosaccharomyces pombe but not in various other eukaryotic organisms tested despite strict conservation of the Glu⁴⁵ residue among these organisms. We therefore conclude that eEF1A glutaminylation is a yeast-specific posttranslational modification that appears to influence protein translation.

METTL21B Is a Novel Human Lysine Methyltransferase of Translation Elongation Factor 1A: Discovery by CRISPR/Cas9 Knockout

Lysine methylation is widespread on human proteins, however the enzymes that catalyze its addition remain largely unknown. This limits our capacity to study the function and regulation of this modification. Here we used the CRISPR/Cas9 system to knockout putative protein methyltransferases METTL21B and METTL23 in K562 cells, to determine if they methylate elongation factor eEF1A. The known eEF1A methyltransferase EEF1AKMT1 was also knocked out as a control. Targeted mass spectrometry revealed the loss of lysine 165 methylation upon knockout of METTL21B, and the expected loss of lysine 79 methylation on knockout of EEF1AKMT1 No loss of eEF1A methylation was seen in the METTL23 knockout. Recombinant METTL21B was shown in vitro to catalyze methylation on lysine 165 in eEF1A1 and eEF1A2, confirming it as the methyltransferase responsible for this methylation site. Proteomic analysis by SILAC revealed specific upregulation of large ribosomal subunit proteins in the METTL21B knockout, and changes to further processes related to eEF1A function in knockouts of both METTL21B and EEF1AKMT1 This indicates that the methylation of lysine 165 in human eEF1A has a very specific role. METTL21B exists only in vertebrates, with its target lysine showing similar evolutionary conservation. We suggest METTL21B be renamed eEF1A-KMT3. This is the first study to specifically generate CRISPR/Cas9 knockouts of putative protein methyltransferase genes, for substrate discovery and site mapping. Our approach should prove useful for the discovery of further novel methyltransferases, and more generally for the discovery of sites for other protein-modifying enzymes.

Dissecting the role of the elongation factor 1A isoforms in hepatocellular carcinoma cells by liposome-mediated delivery of siRNAs

Eukaryotic elongation factor 1A (eEF1A), a protein involved in protein synthesis, has two major isoforms, eEF1A1 and eEF1A2. Despite the evidences of their involvement in hepatocellular carcinoma (HCC), the quantitative contribution of each of the two isoforms to the disease is unknown. We depleted the two isoforms by means of siRNAs and studied the effects in three different HCC cell lines. Particular care was dedicated to select siRNAs able to target each of the two isoform without affecting the other one. This is not a trivial aspect due to the high sequence homology between eEF1A1 and eEF1A2. The selected siRNAs can specifically deplete either eEF1A1 or eEF1A2. This, in turn, results in an impairment of cell vitality, growth and arrest in the G1/G0 phase of the cell cycle. Notably, these effects are quantitatively superior following eEF1A1 than eEF1A2 depletion. Moreover, functional tests revealed that the G1/G0 block induced by eEF1A1 depletion depends on the down-regulation of the transcription factor E2F1, a known player in HCC. In conclusion, our data indicate that the independent targeting of the two eEF1A isoforms is effective in reducing HCC cell growth and that eEF1A1 depletion may result in a more evident effect.

Unphosphorylated STAT1 represses apoptosis in macrophages during Mycobacteriumtuberculosis infection

In murine macrophages infected with Mycobacterium tuberculosis (Mtb), the level of phosphorylated STAT1 (P-STAT1), which drives the expression of many pro-apoptosis genes, increases quickly but then declines over a period of hours. By contrast, infection induces a continued increase in the level of unphosphorylated STAT1 that persists for several days. Here, we found that the level of unphosphorylated STAT1 correlated with the intracellular bacterial burden during the later stages of infection. To investigate the significance of a high level of unphosphorylated STAT1, we increased its concentration exogenously, and found that the apoptosis rate induced by Mtb was sufficiently decreased. Further experiments confirmed that unphosphorylated STAT1 affects the expression of several immune-associated genes and lessens the sensitivity of macrophages to CD95 (FAS)-mediated apoptosis during Mtb infection. Furthermore, we characterized 149 proteins that interacted with unphosphorylated STAT1 and the interactome network. The cooperation between unphosphorylated STAT1 and STAT3 results in downregulation of CD95 expression. Additionally, we verified that unphosphorylated STAT1 and IFIT1 competed for binding to eEF1A. Taken together, our data show that the role of unphosphorylated STAT1 differs from that of P-STAT1, and represses apoptosis in macrophages to promote immune evasion during Mtb infection.

Identification of vitamin D3 target genes in human breast cancer tissue

Multiple epidemiological studies have shown that high vitamin D₃ status is strongly associated with improved breast cancer survival. To determine the molecular pathways influenced by 1 alpha, 25-dihydroxyvitamin D₃ (1,25D) in breast epithelial cells we isolated RNA from normal human breast and cancer tissues treated with 1,25D in an ex vivo explant system. RNA-Seq revealed 523 genes that were differentially expressed in breast cancer tissues in response to 1,25D treatment, and 127 genes with altered expression in normal breast tissues. GoSeq KEGG pathway analysis revealed 1,25D down-regulated cellular metabolic pathways and enriched pathways involved with intercellular adhesion. The highly 1,25D up-regulated target genes CLMN, SERPINB1, EFTUD1, and KLK6were selected for further analysis and up-regulation by 1,25D was confirmed by qRT-PCR analysis in breast cancer cell lines and in a subset of human clinical samples from normal and cancer breast tissues. Ketoconazole potentiated 1,25D-mediated induction of CLMN, SERPINB1, and KLK6 mRNA through inhibition of 24-hydroxylase (CYP24A1) activity. Elevated expression levels of CLMN, SERPINB1, and KLK6 are associated with prolonged relapse-free survival for breast cancer patients. The major finding of the present study is that exposure of both normal and malignant breast tissue to 1,25D results in changes in cellular adhesion, metabolic pathways and tumor suppressor-like pathways, which support epidemiological data suggesting that adequate vitamin D₃ levels may improve breast cancer outcome.

Label-free LC-MS/MS shotgun proteomics to investigate the anti-inflammatory effect of rCC16

Clara cell protein (CC16) is an anti-inflammatory protein, which is expressed in the airway epithelium. It is involved in the development of airway inflammatory diseases, including chronic obstructive pulmonary disease and asthma. However, the exact molecular mechanism underlying its anti‑inflammatory action remains to be fully elucidated. The aim of the present study was to define the protein profiles of the anti‑inflammatory effect of CC16 in lipopolysaccharide (LPS)‑treated rat tracheal epithelial (RTE) cells using shotgun proteomics. Protein extracts were obtained from control RTE cells, RTE cells treated with LPS and RTE cells treated with LPS and recombinant CC16 (rCC16). Subsequent label‑free quantification and bioinformatics analyses identified 12 proteins that were differentially expressed in the three treatment groups as a cluster of five distinct groups according to their molecular functions. Five of the twelve proteins were revealed to be associated with the cytoskeleton: Matrix metalloproteinase‑9, myosin heavy chain 10, actin‑related protein‑3 homolog, elongation factor 1‑α‑1 (EF‑1‑α‑1), and acidic ribosomal phosphoprotein P0. Five of the twelve proteins were associated with cellular proliferation: DNA‑dependent protein kinase catalytic subunit, EF‑1‑α‑1, tyrosine 3‑monooxygenase, caspase recruitment domain (CARD) protein 12 and adenosylhomocysteinase (SAHH) 3. Three proteins were associated with gene regulation: EF‑1‑α‑1, SAHH 3 and acidic ribosomal phosphoprotein P0. Three proteins were associated with inflammation: Tyrosine 3‑monooxygenase, CARD protein 12 and statin‑related protein. ATPase (H+‑transporting, V1 subunit A, isoform 1) was revealed to be associated with energy metabolism, and uridine diphosphate glycosyltransferase 1 family polypeptide A8 with drug metabolism and detoxification. The identified proteins were further validated using reverse transcription‑quantitative polymerase chain reaction. These protein profiles, and their interacting protein network, may facilitate the elucidation of the molecular mechanisms underlying the anti‑inflammatory effects of CC16.

Total Syntheses of Nannocystins A and A0, Two Elongation Factor 1 Inhibitors

Asymmetric total syntheses of nannocystins A and A0 were achieved in a convergent route starting from simple materials. Nannocystin family natural products bear potent anticancer activity as elongation factor 1 inhibitors. In this synthesis, the challenging tertiary amide bond was constructed by peptide coupling between an acyl chloride and a secondary amine. A late-stage ring-closing metathesis reaction successfully rendered the macrocycle. This efficient synthetic strategy should be applicable to other nannocystins and analogues and therefore should benefit future structure-activity relationship studies.

Aptamer targeting of the elongation factor 1A impairs hepatocarcinoma cells viability and potentiates bortezomib and idarubicin effects

The high morbidity and mortality of hepatocellular carcinoma (HCC) is mostly due to the limited efficacy of the available therapeutic approaches. Here we explore the anti-HCC potential of an aptamer targeting the elongation factor 1A (eEF1A), a protein implicated in the promotion of HCC. As delivery methods, we have compared the effectiveness of cationic liposome and cholesterol-mediated approaches. A75 nucleotide long aptamer containing GT repetition (GT75) was tested in three HCC cell lines, HepG2, HuH7 and JHH6. When delivered by liposomes, GT75 was able to effectively reducing HCC cells viability in a dose and time dependent fashion. Particular sensitive were JHH6 where increased apoptosis with no effects on cell cycle were observed. GT75 effect was likely due to the interference with eEF1A activity as neither the mRNA nor the protein levels were significantly affected. Notably, cholesterol-mediated delivery of GT75 abrogated its efficacy due to cellular mis-localization as proven by fluorescence and confocal microscopic analysis. Finally, liposome-mediated delivery of GT75 improved the therapeutic index of the anticancer drugs bortezomib and idarubicin. In conclusion, liposome but not cholesterol-mediated delivery of GT75 resulted in an effective delivery of GT75, causing the impairment of the vitality of a panel of HCC derived cells.

Molecular characterization of S. japonicum exosome-like vesicles reveals their regulatory roles in parasite-host interactions

Secreted extracellular vesicles play an important role in pathogen-host interactions. Increased knowledge of schistosome extracellular vesicles could provide insights into schistosome-host interactions and enable the development of novel intervention strategies to inhibit parasitic processes and lessen disease transmission. Here, we describe biochemical characterization of Schistosoma japonicum exosome-like vesicles (S. japonicum EVs). A total of 403 proteins were identified in S. japonicum EVs, and bioinformatics analyses indicated that these proteins were mainly involved in binding, catalytic activity, and translation regulatory activity. Next, we characterized the population of small RNAs associated with S. japonicum EVs. Further studies demonstrated that mammalian cells could internalize S. japonicum EVs and transfer their cargo miRNAs to recipient cells. Additionally, we found that a specific miRNA, likely originating from a final host, ocu-miR-191–5p, is also associated with S. japonicum EVs. Overall, our findings demonstrate that S. japonicum EVs could be implicated in the pathogenesis of schistosomiasis via a mechanism involving the transfer of their cargo miRNAs to hosts. Our findings provide novel insights into the mechanisms of schistosome-host interactions.

Short-term effects on antioxidant enzymes and long-term genotoxic and carcinogenic potential of CuO nanoparticles compared to bulk CuO and ionic copper in mussels Mytilus galloprovincialis

The aim of this work was to study short-term effects on antioxidant enzyme activities and long-term genotoxic and carcinogenic potential of CuO nanoparticles (NPs) in comparison to bulk CuO and ionic copper in mussels Mytilus galloprovincialis after 21 days exposure to 10 μg Cu L(-1). Then, mussels were kept for up to 122 days in clean water. Cu accumulation depended on the form of the metal and on the exposure time. CuO NPs were localized in lysosomes of digestive cells, as confirmed by TEM and X ray microanalysis. CuO NPs, bulk CuO and ionic copper produced different effects on antioxidant enzyme activities in digestive glands, overall increasing antioxidant activities. CuO NPs significantly induced catalase and superoxide dismutase activities. Fewer effects were observed in gills. Micronuclei frequency increased significantly in mussels exposed to CuO NPs and one organism treated with CuO NPs showed disseminated neoplasia. However, transcription levels of cancer-related genes did not vary significantly. Thus, short-term exposure to CuO NPs provoked oxidative stress and genotoxicity, but further studies are needed to determine whether these early events can lead to cancer development in mussels.

New insights on the interaction between the isoforms 1 and 2 of human translation elongation factor 1A

The eukaryotic translation elongation factor 1A (eEF1A) is a moonlighting protein that besides to its canonical role in protein synthesis is also involved in many other cellular processes such as cell survival and apoptosis. In a previous work, we identified eEF1A Raf-mediated phosphorylation sites and defined their role in the regulation of eEF1A half-life and apoptosis of human cancer cells. We proposed that the phosphorylation of eEF1A by C-Raf required the presence of both eEF1A isoforms thus suggesting the formation of a potential eEF1A heterodimer owning regulatory properties. This study aimed at investigating the cellular localization and interaction between two eEF1A isoforms. To this end, we developed chimera proteins by adding at the N-terminal end of both eEF1A1 and eEF1A2 cyan fluorescence protein (mCerulean) and yellow fluorescence protein (mVenus), respectively. The fluorescent eEF1A1 and eEF1A2 chimeras were both addressed to COS-7 cells and found co-localized in the cytoplasm at the level of cellular membranes. We highlighted FRET between the labeled N-termini of eEF1A isoforms. The intra-molecular FRET of this chimera was about 17%. Our results provide novel information on the intracellular distribution and interaction of eEF1A isoforms.