Dissecting the expression of EEF1A1/2 genes in human prostate cancer cells: the potential of EEF1A2 as a hallmark for prostate transformation and progression

High expression of eukaryotic elongation factor 1-alpha-2 in lung adenocarcinoma is associated with poor prognosis

Eukaryotic elongation factor 1 alpha 2 (eEF1A2) encodes an isoform of the alpha subunit of the elongation factor 1 complex and is responsible for the enzymatic delivery of aminoacyl tRNA to the ribosome. Our proteomic analysis has identified eEF1A2 as one of the proteins expressed during malignant progression from adenocarcinoma in situ (AIS) to early invasive lung adenocarcinoma. The expression level of eEF1A2 in 175 lung adenocarcinomas was examined by immunohistochemical staining in relation to patient prognosis and clinicopathological factors. Quantitative PCR analysis and fluorescence in situ hybridization (FISH) were performed to evaluate the amplification of the eEF1A2 gene. Relatively high expression of eEF1A2 was observed in invasive adenocarcinoma (39/144 cases) relative to minimally invasive adenocarcinoma (1/10 cases) or AIS (0/21 cases). Among invasive adenocarcinomas, solid-type adenocarcinoma (15/32 cases, 47%) showed higher expression than other histological subtypes (23/92, 25%). Patients with eEF1A2-positive tumors had a significantly poorer prognosis than those with eEF1A2-negative tumors. Of the five tumors that were eEF1A2-positive, two cases showed amplified genomic eEF1A2 DNA, which was confirmed by both qPCR and FISH. These findings indicate that eEF1A2 overexpression occurs in the course of malignant transformation of lung adenocarcinomas and is partly due to eEF1A2 gene amplification.

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.

Oncogenic activation of EEF1A2 expression: a journey from a putative to an established oncogene

Protein synthesis via translation is a central process involving several essential proteins called translation factors. Although traditionally described as cellular "housekeepers," multiple studies have now supported that protein initiation and elongation factors regulate cell growth, apoptosis, and tumorigenesis. One such translation factor is eukaryotic elongation factor 1 alpha 2 (EEF1A2), a member of the eukaryotic elongation factor family, which has a canonical role in the delivery of aminoacyl-tRNA to the A-site of the ribosome in a guanosine 5'-triphosphate (GTP)-dependent manner. EEF1A2 differs from its closely related isoform, EEF1A1, in tissue distribution. While EEF1A1 is present ubiquitously, EEF1A2 replaces it in specialized tissues. The reason why certain specialized tissues need to essentially switch EEF1A1 expression altogether with EEF1A2 remains to be answered. Abnormal "switch on" of the EEF1A2 gene in normal tissues is witnessed and is seen as a cause of oncogenic transformation in a wide variety of solid tumors. This review presents the journey of finding increased expression of EEF1A2 in multiple cancers, establishing molecular mechanism, and exploring it as a target for cancer therapy. More precisely, we have compiled studies in seven types of cancers that have reported EEF1A2 overexpression. We have discussed the effect of aberrant EEF1A2 expression on the oncogenic properties of cells, signaling pathways, and interacting partners of EEF1A2. More importantly, in the last part, we have discussed the unique potential of EEF1A2 as a therapeutic target. This review article gives an up-to-date account of EEF1A2 as an oncogene and can draw the attention of the scientific community, attracting more research.

Immunoproteasome-specific subunit PSMB9 induction is required to regulate cellular proteostasis upon mitochondrial dysfunction

Perturbed cellular protein homeostasis (proteostasis) and mitochondrial dysfunction play an important role in neurodegenerative diseases, however, the interplay between these two phenomena remains unclear. Mitochondrial dysfunction leads to a delay in mitochondrial protein import, causing accumulation of non-imported mitochondrial proteins in the cytosol and challenging proteostasis. Cells respond by increasing proteasome activity and molecular chaperones in yeast and C. elegans. Here, we demonstrate that in human cells mitochondrial dysfunction leads to the upregulation of a chaperone HSPB1 and, interestingly, an immunoproteasome-specific subunit PSMB9. Moreover, PSMB9 expression is dependent on the translation elongation factor EEF1A2. These mechanisms constitute a defense response to preserve cellular proteostasis under mitochondrial stress. Our findings define a mode of proteasomal activation through the change in proteasome composition driven by EEF1A2 and its spatial regulation, and are useful to formulate therapies to prevent neurodegenerative diseases.

The Research Advances of Aptamers in Hematologic Malignancies

Currently, research for hematological malignancies is very intensive, with many breakthroughs. Among them, aptamer-based targeted therapies could be counted. Aptamer is a targeting tool with many unique advantages (easy synthesis, low toxicity, easy modification, low immunogenicity, nano size, long stability, etc.), therefore many experts screened corresponding aptamers in various hematological malignancies for diagnosis and treatment. In this review, we try to summarize and provide the recent progress of aptamer research in the diagnosis and treatment of hematologic malignancies. Until now, 29 aptamer studies were reported in hematologic malignancies, of which 12 aptamers were tested in vivo and the remaining 17 aptamers were only tested in vitro. In this case, 11 aptamers were combined with chemotherapeutic drugs for the treatment of hematologic malignancies, 4 aptamers were used in combination with nanomaterials for the diagnosis and treatment of hematologic malignancies, and some studies used aptamers for the targeted transportation of siRNA and miRNA for targeted therapeutic effects. Their research provides multiple approaches to achieve more targeted goals. These findings show promising and encouraging future for both hematological malignancies basic and clinical trials research.

High eEF1A1 Protein Levels Mark Aggressive Prostate Cancers and the In Vitro Targeting of eEF1A1 Reveals the eEF1A1-actin Complex as a New Potential Target for Therapy

Although the eukaryotic elongation factor eEF1A1 plays a role in various tumours, there is little information on its prognosis/therapeutic value in prostate carcinoma. In high-grade and castration-resistant prostate carcinoma (CRPC), the identification of novel therapeutic markers/targets remains a priority. The expression of eEF1A1 protein was determined in formalin-fixed, paraffin-embedded prostate cancer and hyperplasia tissue by IHC. The role of eEF1A1 was investigated in a cellular model using a DNA aptamer (GT75) we previously developed. We used the aggressive CRPC cancer PC-3 and non-tumourigenic PZHPV-7 lines. Cytotoxicity was measured by the MTS assay and eEF1A1 protein levels by in-cell Western assays. The mRNA levels of eEF1A1 were measured by qPCR and ddPCR. Higher expression of eEF1A1 was found in Gleason 7-8 compared with 4-6 tissues (Gleason ≥ 7, 87% versus Gleason ≤ 6, 54%; p = 0.033). Patients with a high expression of eEF1A1 had a worse clinical outcome. In PC-3, but not in PZHPV-7, GT75 decreased cell viability and increased autophagy and cell detachment. In PC-3 cells, but not in PZHPV-7, GT75 mainly co-localised with the fraction of eEF1A1 bound to actin. Overexpression of the eEF1A1 protein can identify aggressive forms of prostate cancer. The targeting of eEF1A1 by GT75 impaired cell viability in PC-3 cancer cells but not in PZHPV-7 non-tumourigenic cells, indicating a specific role for the protein in cancer survival. The eEF1A1-actin complexes appear to be critical for the viability of PC-3 cancer cells, suggesting that eEF1A1 may be an attractive target for therapeutic strategies in advanced forms of prostate cancer.

An Overview of siRNA Delivery Strategies for Urological Cancers

The treatment of urological cancers has been significantly improved in recent years. However, for the advanced stages of these cancers and/or for those developing resistance, novel therapeutic options need to be developed. Among the innovative strategies, the use of small interfering RNA (siRNA) seems to be of great therapeutic interest. siRNAs are double-stranded RNA molecules which can specifically target virtually any mRNA of pathological genes. For this reason, siRNAs have a great therapeutic potential for human diseases including urological cancers. However, the fragile nature of siRNAs in the biological environment imposes the development of appropriate delivery systems to protect them. Thus, ensuring siRNA reaches its deep tissue target while maintaining structural and functional integrity represents one of the major challenges. To reach this goal, siRNA-based therapies require the development of fine, tailor-made delivery systems. Polymeric nanoparticles, lipid nanoparticles, nanobubbles and magnetic nanoparticles are among nano-delivery systems studied recently to meet this demand. In this review, after an introduction about the main features of urological tumors, we describe siRNA characteristics together with representative delivery systems developed for urology applications; the examples reported are subdivided on the basis of the different delivery materials and on the different urological cancers.

[EEFSEC knockdown inhibits proliferation, migration and invasion of prostate cancer cells in vitro]

OBJECTIVE

To investigate the role of selenocysteine-tRNA specific eukaryotic elongation factor (EEFSEC) in regulating the proliferation, migration, and invasion of human prostate cancer 22Rv1 cells.

METHODS

We detected EEFSEC mRNA expression levels in human normal prostate cell line RWPE1 and human prostate cancer cell lines 22Rv1, LNCaP, Vcap and PC-3 using qRT-PCR and EEFSEC protein expression in surgical specimens of prostate cancer and adjacent tissues using Western blotting. 22Rv1 cells were infected with a lentiviral vector carrying EEFSEC shRNA or a control lentivirus and the interference efficiency was determined using Western blotting. XTT assay was used to assess the changes in the viability of the infected cells, and Transwell chamber assay was used to examine the changes in cell migration and invasion. The effect of EEFSEC knockdown on cell cycle progression was determined with flow cytometry and by detecting the expressions of cell cycle proteins using qRT-PCR.

RESULTS

EEFSEC was significantly upregulated in prostate cancer cells (P < 0.05), and a high expression of EEFSEC was associated with a poor prognosis of the patients with prostate cancer. In 22Rv1 cells, EEFSEC knockdown significantly suppressed the proliferation (P < 0.001), migration (P < 0.001) and invasion (P < 0.001) of the cells, resulted in cell cycle arrest in G₀/G₁ phase, obviously inhibited the expression of C-myc and CCNB1, and significantly increased the expression of p15.

CONCLUSION

EEFSEC knockdown can inhibit the proliferation, migration, and invasion of prostate cancer cells in vitro possibly by down-regulating the expression of C-myc.

The elongation factor eEF1A2 controls translation and actin dynamics in dendritic spines

Synaptic plasticity involves structural modifications in dendritic spines that are modulated by local protein synthesis and actin remodeling. Here, we investigated the molecular mechanisms that connect synaptic stimulation to these processes. We found that the phosphorylation of isoform-specific sites in eEF1A2-an essential translation elongation factor in neurons-is a key modulator of structural plasticity in dendritic spines. Expression of a nonphosphorylatable eEF1A2 mutant stimulated mRNA translation but reduced actin dynamics and spine density. By contrast, a phosphomimetic eEF1A2 mutant exhibited decreased association with F-actin and was inactive as a translation elongation factor. Activation of metabotropic glutamate receptor signaling triggered transient dissociation of eEF1A2 from its regulatory guanine exchange factor (GEF) protein in dendritic spines in a phosphorylation-dependent manner. We propose that eEF1A2 establishes a cross-talk mechanism that coordinates translation and actin dynamics during spine remodeling.

FAT10: Function and Relationship with Cancer

Posttranslational protein modifications are known to be extensively involved in cancer, and a growing number of studies have revealed that the ubiquitin-like modifier FAT10 is directly involved in cancer development. FAT10 was found to be highly upregulated in various cancer types, such as glioma, hepatocellular carcinoma, breast cancer and gastrointestinal cancer. Protein FAT10ylation and interactions with FAT10 lead to the functional change of proteins, including proteasomal degradation, subcellular delocalization and stabilization, eventually having significant effects on cancer cell proliferation, invasion, metastasis and even tumorigenesis. In this review, we summarized the current knowledge on FAT10 and discussed its biological functions in cancer, as well as potential therapeutic strategies based on the FAT10 pathway.

Glyphosate Interaction with eEF1α1 Indicates Altered Protein Synthesis: Evidence for Reduced Spermatogenesis and Cytostatic Effect

The broad-spectrum herbicide, glyphosate, is considered safe for animals because it selectively affects the shikimate pathway that is specific to plants and microorganisms. We sought a previously unknown mechanism to explain the concerns that glyphosate exposure can negatively affect animals, including humans. Computer modeling showed a probable interaction between glyphosate and eukaryotic translation elongation factor 1 subunit alpha 1 (eEF1α1), which was confirmed by microcalorimetry. Only restricted, nondisrupted spermatogenesis in rats was observed after chronic glyphosate treatments (0.7 and 7 mg/L). Cytostatic and antiproliferative effects of glyphosate in GC-1 and SUP-B15 cells were indicated. Meta-analysis of public health data suggested a possible effect of glyphosate use on sperm count. The in silico, in vitro, and in vivo experimental results as well as the metastatistics indicate side effects of chronic glyphosate exposure. Together, these findings indicate that glyphosate delays protein synthesis through an interaction with eEF1α1, thereby suppressing spermatogenesis and cell growth.

Multifaceted control of mRNA translation machinery in cancer

The mRNA translation machinery is tightly regulated through several, at times overlapping, mechanisms that modulate its efficiency and accuracy. Due to their fast rate of growth and metabolism, cancer cells require an excessive amount of mRNA translation and protein synthesis. However, unfavorable conditions, such as hypoxia, amino acid starvation, and oxidative stress, which are abundant in cancer, as well as many anti-cancer treatments inhibit mRNA translation. Cancer cells adapt to the various internal and environmental stresses by employing specialised transcript-specific translation to survive and gain a proliferative advantage. We will highlight the major signaling pathways and mechanisms of translation that regulate the global or mRNA-specific translation in response to the intra- or extra-cellular signals and stresses that are key components in the process of tumourigenesis.

A novel immune-related gene-based prognostic signature to predict biochemical recurrence in patients with prostate cancer after radical prostatectomy

Accumulating evidences indicates that the immune landscape signature dramatically correlates with tumorigenesis and prognosis of prostate cancer (PCa). Here, we identified a novel immune-related gene-based prognostic signature (IRGPS) to predict biochemical recurrence (BCR) after radical prostatectomy. We also explored the correlation between IRGPS and tumor microenvironment. We identified an IRGPS consisting of seven immune-related genes (PPARGC1A, AKR1C2, COMP, EEF1A2, IRF5, NTM, and TPX2) that were related to the BCR-free survival of PCa patients. The high-risk patients exhibited a higher fraction of regulatory T cells and M2 macrophages than the low-risk BCR patients (P < 0.05) as well as a lower fraction of resting memory CD4 T cells and resting mast cells. These high-risk patients also had higher expression levels of CTLA4, TIGIT, PDCD1, LAG3, and TIM3. Finally, a strong correlation was detected between IRGPS and specific clinicopathological features, including Gleason scores and tumor stage. In conclusion, our study reveals the clinical significance and potential functions of the IRGPS, provides more data for predicting outcomes, and suggests more effective immunotherapeutic target strategies for PCa.

Expression of Long Non-coding RNA RGD1566344 in the Brain Cortex of Male Mice After Focal Cerebral Ischemia-Reperfusion and the Neuroprotective Effect of a Non-coding RNA RGD1566344 Inhibitor

Ischemic stroke (IS) remains a major cause of disability and death. The changes in long non-coding RNA (lncRNA) RGD1566344 expression in the mouse cerebral cortex, including the infarct and penumbra regions after IS, are not clear. Less is known about the impact and underlying mechanisms of RGD1566344 in IS. In this study, we found that RGD1566344 levels were elevated in the ischemic infarct and penumbra regions 12 h after middle cerebral artery occlusion/reperfusion (MCAO/R) in male mice and in PC12 cells with oxygen glucose deprivation/reperfusion (OGD/R). The inhibition of RGD1566344 by small interference RNA (siRNA) significantly alleviated apoptosis in OGD/R PC12 cells. In cell transfection, quantitative real-time PCR, and Western blot experiments, we demonstrated the possible interaction of non-POU domain-containing octamer-binding protein (NONO) with RGD1566344. The NONO level in OGD/R PC12 cells was obviously increased after inhibiting the RGD1566344 treatment; subsequently the protein kinase B (AKT)/mammalian target of rapamycin (mTOR) signaling pathway was activated. This demonstrated the effect of the RGD1566344-NONO-AKT axis on neural protection after IS. These results revealed a new molecular mechanism of lncRNA RGD1566344 inhibitors through targeting NONO/AKT/mTOR signaling to protect against ischemic neuronal injury, providing strong evidence for the development of promising therapeutic strategies against IS.

Targeted delivery of siRNAs against hepatocellular carcinoma-related genes by a galactosylated polyaspartamide copolymer

Given the lack of effective treatments for Hepatocellular carcinoma (HCC), the development of novel therapeutic approaches is very urgent. Here, siRNAs were delivered to HCC cells by a synthetic polymer containing α,β-poly-(N-2-hydroxyethyl)-D,L-aspartamide-(PHEA) derivatized with diethylene triamine (DETA) and bearing in the side chain galactose (GAL) linked via a polyethylene glycol (PEG) to obtain (PHEA-DETA-PEG-GAL, PDPG). The GAL residue allows the targeting to the asialo-glycoprotein receptor (ASGPR), overexpressed in HCC cells compared to normal hepatocytes. Uptake studies performed using a model siRNA or a siRNA targeted against the enhanced green fluorescence protein, demonstrated the PDPG specific delivery of siRNA to HuH7 cells, a human cellular model of HCC. GAL-free copolymer (PHEA-DETA-PEG-NH₂, PDP) or the chemical block of ASGPR, impaired PDPG targeting effectiveness in vitro. The specificity of PDPG delivery was confirmed in vivo in a mouse dorsal skinfold window chamber assay. Functional studies using siRNAs targeting the mRNAs of HCC-related genes (eEF1A1, eEF1A2 and E2F1) delivered by PDPG, significantly decreased HuH7 vitality/number and down regulated the expression of the target genes. Only minor effectiveness was in contrast observed for PDP. In IHH, a human model of normal hepatocytes with reduced ASGPR expression, PDPG barely reduced cell vitality. In a subcutaneous xenograft mouse model of HCC, PDPG-siRNAs reduced HCC tumor growth compared to controls without significant toxic effects. In conclusion, our study demonstrates the valuable potentials of PDPG for the specific delivery of siRNAs targeting HCC-related genes.

Drugs Repurposing in High-Grade Serous Ovarian Cancer

BACKGROUND

Ovary Carcinoma (OC) is the most lethal gynecological neoplasm due to the late diagnoses and to the common development of resistance to platinum-based chemotherapy. Thus, novel therapeutic approaches are urgently required. In this regard, the strategy of drug repurposing is becoming attractive. By this approach, the effectiveness of a drug originally developed for another indication is tested in a different pathology. The advantage is that data about pharmacokinetic properties and toxicity are already available. Thus, in principle, it is possible to reduce research costs and to speed up drug usage/marketing.

RESULTS

Here, some noticeable examples of repurposed drugs for OC, such as amiodarone, ruxolitinib, statins, disulfiram, ormeloxifenem, and Quinacrine, are reported. Amiodarone, an antiarrhythmic agent, has shown promising anti-OC activity, although the systemic toxicity should not be neglected. The JAK inhibitor, Ruxolitinib, may be employed particularly in coadministration with standard OC therapy as it synergistically interacts with platinum-based drugs. Particularly interesting is the use of statin which represent one of the most commonly administered drugs in aged population to treat hypercholesterolemia. Disulfiram, employed in the treatment of chronic alcoholism, has shown anti-OC properties. Ormeloxifene, commonly used for contraception, seems to be promising, especially due to the negligible side effects. Finally, Quinacrine used as an antimicrobial and anti-inflammatory drug, is able to downregulate OC cell growth and promote cell death.

CONCLUSION

Whereas further testing in patients are necessary to better clarify the therapeutic potential of repurposed drugs for OC, it is believed that their use, better if combined with OC targeted delivery systems, can significantly contribute to the development of novel and effective anti-OC treatments.

Personalized therapy design for systemic lupus erythematosus based on the analysis of protein-protein interaction networks

We analyzed protein expression data for Lupus patients, which have been obtained from publicly available databases. A combination of systems biology and statistical thermodynamics approaches was used to extract topological properties of the associated protein-protein interaction networks for each of the 291 patients whose samples were used to provide the molecular data. We have concluded that among the many proteins that appear to play critical roles in this pathology, most of them are either ribosomal proteins, ubiquitination pathway proteins or heat shock proteins. We propose some of the proteins identified in this study to be considered for drug targeting.

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.

SNX16 activates c-Myc signaling by inhibiting ubiquitin-mediated proteasomal degradation of eEF1A2 in colorectal cancer development

Sorting nexin 16 (SNX16), a member of the sorting nexin family, has been implicated in tumor development. However, the function of SNX16 has not yet been investigated in colorectal cancer (CRC). Here, we showed that SNX16 expression was significantly upregulated in CRC tissues compared with normal counterparts. Upregulated mRNA levels of SNX16 predicted poor survival of CRC patients. Functional experiments showed that SNX16 could promote CRC cells growth both in vitro and in vivo. Knockdown of SNX16 induced cell cycle arrest and apoptosis, whereas ectopic overexpression of SNX16 had the opposite effects. Mechanistically, SNX16‐eukaryotic translation elongation factor 1A2 (eEF1A2) interaction could inhibit the degradation and ubiquitination of eEF1A2, followed by activation of downstream c‐Myc signaling. Our study unveiled that the SNX16/eEF1A2/c‐Myc signaling axis could promote colorectal tumorigenesis and SNX16 might potentially serve as a novel biomarker for the diagnosis and an intervention of CRC.

A rapid and specific method to simultaneously quantify eukaryotic elongation factor 1A1 and A2 protein levels in cancer cells

BACKGROUND

The two isoforms of the eukaryotic Elongation Factor 1A (eEF1A1 and eEF1A2), sustain the progression/aggressiveness of cancer cells. Thus, they are considered promising therapeutic targets and prognostic markers. It follows that their precise quantification is of utmost relevance in research and development. The simultaneous quantification of A1 and A2 proteins in the cells helps the comprehension of cancer biology mechanisms and response to drug treatments. However, the high homology at the amino-acidic level (92%) can cause antibodies cross-reaction. Moreover, the commonly employed western blotting just gives semi-quantitative data and does not allow the detection of both protein targets within the same cell. Thus, we developed an in cell western (ICW) technique to bypass the above limitations.

METHODS

Firstly, relevant antibodies cross-reaction was excluded by immunohistochemistry on normal pancreatic tissue; then eEF1A1-A2 protein levels were quantitated by ICW in prostate and colorectal cancer cell lines in 96 well plates under different conditions, which include: 1) drug treatment, 2) siRNA silencing, 3) cell seeding density.

RESULTS

We show that: 1) eEF1A1-A2 levels vary depending on the cell type following drug treatment, 2) ICW can accurately detect eEF1A1-A2 protein levels following siRNA silencing, 3) cell seeding density influences eEF1A1-A2 levels, depending on cell type.

CONCLUSIONS

ICW is a valuable tool to specifically determine the intracellular level of eEF1A1-A2 proteins thus contributing to better define their role as potential therapeutic targets and prognostic markers in human tumors as well as for drug effects screening.

Comprehensive analysis of differentially expressed lncRNAs as diagnostic and prognostic markers for colorectal cancer

Colorectal cancer (CRC) is the third most common type of cancer worldwide. Recent studies had revealed the important roles of long non-coding RNAs (lncRNAs) in a variety of human cancers, including CRC. However, the molecular mechanisms associated with CRC remain largely undetermined. In the current study, the GSE21510 dataset was analyzed to identify differentially expressed mRNAs and lncRNAs in CRC samples. The Database for Annotation, Visualization and Integrated Discovery was used to perform Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway bioinformatics analysis. Furthermore, protein-protein interaction networks were constructed to reveal interactions among differentially expressed proteins. Kaplan-Meier analysis was subsequently performed to determine the association between key lncRNA expression and the overall survival of patients with CRC. A total of 107 upregulated lncRNAs and 43 downregulated lncRNAs were identified in CRC. A lncRNA mediated co-expression network was also constructed in CRC. Bioinformatics analysis indicated that lncRNAs were associated with a series of biological processes, including 'xenobiotic glucuronidation', 'rRNA processing', 'sister chromatid cohesion', 'cell proliferation', 'mitotic nuclear division' and 'cell cycle regulation'. Furthermore, a higher expression of small nucleolar RNA host gene 17, tetratricopeptide repeat domain 2B-antisense RNA (AS) 1, erythrocyte membrane protein band 4.1 like 4A-AS2, deleted in lymphocytic leukemia 2, and a lower expression of muscle blind like splicing regulator 1-AS1 and LOC389332 were associated with shorter overall survival time in CRC samples. The present study provides useful information that can be used in the identification of novel biomarkers for CRC.

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.

Metarrestin, a perinucleolar compartment inhibitor, effectively suppresses metastasis

Metastasis remains a leading cause of cancer mortality due to the lack of specific inhibitors against this complex process. To identify compounds selectively targeting the metastatic state, we used the perinucleolar compartment (PNC), a complex nuclear structure associated with metastatic behaviors of cancer cells, as a phenotypic marker for a high-content screen of over 140,000 structurally diverse compounds. Metarrestin, obtained through optimization of a screening hit, disassembles PNCs in multiple cancer cell lines, inhibits invasion in vitro, suppresses metastatic development in three mouse models of human cancer, and extends survival of mice in a metastatic pancreatic cancer xenograft model with no organ toxicity or discernable adverse effects. Metarrestin disrupts the nucleolar structure and inhibits RNA polymerase (Pol) I transcription, at least in part by interacting with the translation elongation factor eEF1A2. Thus, metarrestin represents a potential therapeutic approach for the treatment of metastatic cancer.

Pharmacokinetic evaluation of the PNC disassembler metarrestin in wild-type and Pdx1-Cre;LSL-KrasG12D/+;Tp53R172H/+ (KPC) mice, a genetically engineered model of pancreatic cancer

PURPOSE

Metarrestin is a first-in-class small molecule clinical candidate capable of disrupting the perinucleolar compartment, a subnuclear structure unique to metastatic cancer cells. This study aims to define the pharmacokinetic (PK) profile of metarrestin and the pharmacokinetic/pharmacodynamic relationship of metarrestin-regulated markers.

METHODS

PK studies included the administration of single or multiple dose of metarrestin at 3, 10, or 25 mg/kg via intravenous (IV) injection, gavage (PO) or with chow to wild-type C57BL/6 mice and KPC mice bearing autochthonous pancreatic tumors. Metarrestin concentrations were analyzed by UPLC-MS/MS. Pharmacodynamic assays included mRNA expression profiling by RNA-seq and qRT-PCR for KPC mice.

RESULTS

Metarrestin had a moderate plasma clearance of 48 mL/min/kg and a large volume of distribution of 17 L/kg at 3 mg/kg IV in C57BL/6 mice. The oral bioavailability after single-dose (SD) treatment was > 80%. In KPC mice treated with SD 25 mg/kg PO, plasma AUC0-∞ of 14400 ng h/mL, Cmax of 810 ng/mL and half-life (t1/2) of 8.5 h were observed. At 24 h after SD of 25 mg/kg PO, the intratumor concentration of metarrestin was high with a mean value of 6.2 µg/g tissue (or 13 µM), well above the cell-based IC50 of 0.4 µM. At multiple dose (MD) 25 mg/kg/day PO in KPC mice, mean tissue/plasma AUC0-24h ratio for tumor, spleen and liver was 37, 30 and 31, respectively. There was a good linear relationship of dosage to AUC0-24h and C24h. AUC0-24h MD to AUC0-24h SD ratios ranged from two for liver to five for tumor indicating additional accumulation in tumors. Dose-dependent normalization of FOXA1 and FOXO6 mRNA expression was observed in KPC tumors.

CONCLUSIONS

Metarrestin is an effective therapeutic candidate with a favorable PK profile achieving excellent intratumor tissue levels in a disease with known poor drug delivery.

Androgen Receptor Deregulation Drives Bromodomain-Mediated Chromatin Alterations in Prostate Cancer

Global changes in chromatin accessibility may drive cancer progression by reprogramming transcription factor (TF) binding. In addition, histone acetylation readers such as bromodomain-containing protein 4 (BRD4) have been shown to associate with these TFs and contribute to aggressive cancers including prostate cancer (PC). Here, we show that chromatin accessibility defines castration-resistant prostate cancer (CRPC). We show that the deregulation of androgen receptor (AR) expression is a driver of chromatin relaxation and that AR/androgen-regulated bromodomain-containing proteins (BRDs) mediate this effect. We also report that BRDs are overexpressed in CRPCs and that ATAD2 and BRD2 have prognostic value. Finally, we developed gene stratification signature (BROMO-10) for bromodomain response and PC prognostication, to inform current and future trials with drugs targeting these processes. Our findings provide a compelling rational for combination therapy targeting bromodomains in selected patients in which BRD-mediated TF binding is enhanced or modified as cancer progresses.

The expression profile and prognostic significance of eukaryotic translation elongation factors in different cancers

Eukaryotic translation factors, especially initiation factors have garnered much attention with regards to their role in the onset and progression of different cancers. However, the expression levels and prognostic significance of translation elongation factors remain poorly explored in different cancers. In this study, we have investigated the mRNA transcript levels of seven translation elongation factors in different cancer types using Oncomine and TCGA databases. Furthermore, we have identified the prognostic significance of these factors using Kaplan-Meier Plotter and SurvExpress databases. We observed altered expression levels of all the elongation factors in different cancers. Higher expression of EEF1A2, EEF1B2, EEF1G, EEF1D, EEF1E1 and EEF2 was observed in most of the cancer types, whereas reverse trend was observed for EEF1A1. Overexpression of many factors predicted poor prognosis in breast (EEF1D, EEF1E1, EEF2) and lung cancer (EEF1A2, EEF1B2, EEF1G, EEF1E1). However, we didn’t see any common correlation of expression levels of elongation factors with survival outcomes across cancer types. Cancer subtype stratification showed association of survival outcomes and expression levels of elongation factors in specific sub-types of breast, lung and gastric cancer. Most interestingly, we observed a reciprocal relationship between the expression levels of the two EEF1A isoforms viz. EEF1A1 and EEF1A2, in most of the cancer types. Our results suggest that translation elongation factors can have a role in tumorigenesis and affect survival in cancer specific manner. Elongation factors have potential to serve as biomarkers and therapeutic drug targets, yet further study is required. Reciprocal relationship of differential expression between EEF1A isoforms observed in multiple cancer types indicates opposing roles in cancer and needs further investigation.

The EEF1A2 gene expression as risk predictor in localized prostate cancer

Background

Besides clinical stage and Gleason score, risk-stratification of prostate cancer in the pretherapeutic setting mainly relies on the serum PSA level. Yet, this is associated with many uncertainties. With regard to therapy decision-making, additional markers are needed to allow an exact risk prediction. Eukaryotic translation elongation factor 1 alpha 2 (EEF1A2) was previously suggested as driver of tumor progression and potential biomarker. In the present study its functional and prognostic relevance in prostate cancer was investigated.

Methods

EEF1A2 expression was analyzed in two cohorts of patients (n = 40 and n = 59) with localized PCa. Additionally data from two large expression dataset (MSKCC, Cell, 2010 with n = 131 localized, n = 19 metastatic PCa and TCGA provisional data, n = 499) of PCa patients were reanalyzed. The expression of EEF1A2 was correlated with histopathology features and biochemical recurrence (BCR). To evaluate the influence of EEF1A2 on proliferation and migration of metastatic PC3 cells, siRNA interference was used. Statistical significance was tested with t-test, Mann-Whitney-test, Pearson correlation and log-rank test.

Results

qRT-PCR revealed EEF1A2 to be significantly overexpressed in PCa tissue, with an increase according to tumor stage in one cohort (p = 0.0443). In silico analyses in the MSKCC cohort confirmed the overexpression of EEF1A2 in localized PCa with high Gleason score (p = 0.0142) and in metastatic lesions (p = 0.0038). Patients with EEF1A2 overexpression had a significantly shorter BCR-free survival (p = 0.0028). EEF1A2 expression was not correlated with serum PSA levels. Similar results were seen in the TCGA cohort, where EEF1A2 overexpression only occurred in tumors with Gleason 7 or higher. Patients with elevated EEF1A2 expression had a significantly shorter BCR-free survival (p = 0.043). EEF1A2 knockdown significantly impaired the migration, but not the proliferation of metastatic PC3 cells.

Conclusion

The overexpression of EEF1A2 is a frequent event in localized PCa and is associated with histopathology features and a shorter biochemical recurrence-free survival. Due to its independence from serum PSA levels, EEF1A2 could serve as valuable biomarker in risk-stratification of localized PCa.

Potential Applications of Nanocellulose-Containing Materials in the Biomedical Field

Because of its high biocompatibility, bio-degradability, low-cost and easy availability, cellulose finds application in disparate areas of research. Here we focus our attention on the most recent and attractive potential applications of cellulose in the biomedical field. We first describe the chemical/structural composition of cellulose fibers, the cellulose sources/features and cellulose chemical modifications employed to improve its properties. We then move to the description of cellulose potential applications in biomedicine. In this field, cellulose is most considered in recent research in the form of nano-sized particle, i.e., nanofiber cellulose (NFC) or cellulose nanocrystal (CNC). NFC is obtained from cellulose via chemical and mechanical methods. CNC can be obtained from macroscopic or microscopic forms of cellulose following strong acid hydrolysis. NFC and CNC are used for several reasons including the mechanical properties, the extended surface area and the low toxicity. Here we present some potential applications of nano-sized cellulose in the fields of wound healing, bone-cartilage regeneration, dental application and different human diseases including cancer. To witness the close proximity of nano-sized cellulose to the practical biomedical use, examples of recent clinical trials are also reported. Altogether, the described examples strongly support the enormous application potential of nano-sized cellulose in the biomedical field.

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.

Proteomic Identification of eEF1A1 as a Molecular Target of Curcumol for Suppressing Metastasis of MDA-MB-231 Cells

Curcumol, a major volatile component in Rhizoma Curcumae, exhibits a potent antimetastatic effect on breast cancer cells. However, its molecular mechanism remains poorly understood. In this study, we employed two-dimensional gel electrophoresis-based proteomics to investigate the cellular targets of curcumol in MDA-MB-231 cells and identified 10 differentially expressed proteins. Moreover, Gene Ontology analysis revealed that these proteins are mainly involved in nine types of cellular components, seven different biological processes, and nine kinds of molecular functions, and 35 pathways (p < 0.05) were enriched by KEGG pathway analysis. Specially, eEF1A1, a well-characterized actin binding protein, draws our attention. Curcumol decreased eEF1A1 expression at both mRNA and protein levels. EEF1A1 expression was shown to be correlated with the invasiveness of cancer cells. Importantly, overexpression of eEF1A1 significantly reversed the inhibition of curcumol regarding the invasion and adhesion of MDA-MB-231 cells (p < 0.05). Together, our data suggest that eEF1A1 may be a potential molecular target underlying the antimetastatic effect of curcumol.

Clinical, cellular, and bioinformatic analyses reveal involvement of WRAP53 overexpression in carcinogenesis of lung adenocarcinoma

Lung cancer, of which non-small cell lung cancer accounts for 80%, remains a leading cause of cancer-related mortality and morbidity worldwide. Our study revealed that the expression of WD repeat containing antisense to P53 (WRAP53) is higher in lung-adenocarcinoma specimens than in specimens from adjacent non-tumor tissues. The prevalence of WRAP53 overexpression was significantly higher in patients with tumor larger than 3.0 cm than in patients with tumor smaller than 3.0 cm. The depletion of WRAP53 inhibits the proliferation of lung-adenocarcinoma A549 and SPC-A-1 cells via G1/S cell-cycle arrest. Several proteins interacting with WRAP53 were identified through co-immunoprecipitation and liquid chromatography/mass spectrometry. These key proteins indicated previously undiscovered functions of WRAP53. These observations strongly suggested that WRAP53 should be considered a promising target in the prevention or treatment of lung adenocarcinoma.

Exosomes from bulk and stem cells from human prostate cancer have a differential microRNA content that contributes cooperatively over local and pre-metastatic niche

The different prostate cancer (PCa) cell populations (bulk and cancer stem cells, CSCs) release exosomes that contain miRNAs that could modify the local or premetastatic niche. The analysis of the differential expression of miRNAs in exosomes allows evaluating the differential biological effect of both populations on the niche, and the identification of potential biomarkers and therapeutic targets. Five PCa primary cell cultures were established to originate bulk and CSCs cultures. From them, exosomes were purified by precipitation for miRNAs extraction to perform a comparative profile of miRNAs by next generation sequencing in an Illumina platform. 1839 miRNAs were identified in the exosomes. Of these 990 were known miRNAs, from which only 19 were significantly differentially expressed: 6 were overexpressed in CSCs and 13 in bulk cells exosomes. miR-100-5p and miR-21-5p were the most abundant miRNAs. Bioinformatics analysis indicated that differentially expressed miRNAs are highly related with PCa carcinogenesis, fibroblast proliferation, differentiation and migration, and angiogenesis. Besides, miRNAs from bulk cells affects osteoblast differentiation. Later, their effect was evaluated in normal prostate fibroblasts (WPMY-1) where transfection with miR-100-5p, miR-21-5p and miR-139-5p increased the expression of metalloproteinases (MMPs) -2, -9 and -13 and RANKL and fibroblast migration. The higher effect was achieved with miR21 transfection. As conclusion, miRNAs have a differential pattern between PCa bulk and CSCs exosomes that act collaboratively in PCa progression and metastasis. The most abundant miRNAs in PCa exosomes are interesting potential biomarkers and therapeutic targets.

The Ubiquitin-like Protein FAT10 Stabilizes eEF1A1 Expression to Promote Tumor Proliferation in a Complex Manner

Human HLA-F adjacent transcript 10 (FAT10) is the only ubiquitin-like protein that can directly target substrates for degradation by proteasomes, but it can also stabilize the expression of certain substrates by antagonizing ubiquitination, through mechanisms as yet uncharacterized. In this study, we show how FAT10 stabilizes the translation elongation factor eEF1A1, which contributes to cancer cell proliferation. FAT10 overexpression increased expression of eEF1A1, which was sufficient to promote proliferation of cancer cells. Mechanistic investigations revealed that FAT10 competed with ubiquitin (Ub) for binding to the same lysines on eEF1A1 to form either FAT10-eEF1A1 or Ub-eEF1A1 complexes, respectively, such that FAT10 overexpression decreased Ub-eEF1A1 levels and increased FAT10-eEF1A1 levels. Overall, our work establishes a novel mechanism through which FAT10 stabilizes its substrates, advancing understanding of the biological function of FAT10 and its role in cancer. Cancer Res; 76(16); 4897-907. ©2016 AACR.

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.

Eukaryotic elongation factor-1α 2 knockdown inhibits hepatocarcinogenesis by suppressing PI3K/Akt/NF-κB signaling

AIM: To assess the impact of eukaryotic elongation factor 1 alpha 2 (eEF1A2) on hepatocellular carcinoma (HCC) cell proliferation, apoptosis, migration and invasion, and determine the underlying mechanisms.

METHODS: eEF1A2 levels were detected in 62 HCC tissue samples and paired pericarcinomatous specimens, and the human HCC cell lines SK-HEP-1, HepG2 and BEF-7402, by real-time PCR and immunohistochemistry. Experimental groups included eEF1A2 silencing in BEL-7402 cells with lentivirus eEF1A2-shRNA (KD group) and eEF1A2 overexpression in SK-HEP-1 cells with eEF1A2 plasmid (OE group). Non-transfected cells (control group) and lentivirus-based empty vector transfected cells (NC group) were considered control groups. Cell proliferation (MTT and colony formation assays), apoptosis (Annexin V-APC assay), cell cycle (DNA ploidy assay), and migration and invasion (Transwell assays) were assessed. Protein levels of PI3K/Akt/NF-κB signaling effectors were evaluated by Western blot.

RESULTS: eEF1A2 mRNA and protein levels were significantly higher in HCC cancer tissue samples than in paired pericarcinomatous and normal specimens. SK-HEP-1 cells showed lower eEF1A2 mRNA levels; HepG2 and BEL-7402 cells showed higher eEF1A2 mRNA levels, with BEL-7402 cells displaying the highest amount. Efficient eEF1A2 silencing resulted in reduced cell proliferation, migration and invasion, increased apoptosis, and induced cell cycle arrest. The PI3K/Akt/NF-κB signaling pathway was notably inhibited. Inversely, eEF1A2 overexpression resulted in promoted cell proliferation, migration and invasion.

CONCLUSION: eEF1A2, highly expressed in HCC, is a potential oncogene. Its silencing significantly decreases HCC tumorigenesis, likely by inhibiting PI3K/Akt/NF-κB signaling.

Epigenetic and miRNAs Dysregulation in Prostate Cancer: The role of Nutraceuticals

The control of cancer onset and progression is recognized to benefit from specific molecular targeting. MiRNAs are increasingly being implicated in prostate cancer, and the evidence suggests they are possible targets for molecular therapy and diagnosis. In cancer cells, growing attention has been dedicated to novel molecular mechanisms linking the epigenetic scenario to miRNA dysregulation. Currently, the rising evidence shows that nutritional and natural agents, the so-called nutraceuticals, could modulate miRNAs expression, and, as a consequence, might influence cellular responses in health or diseases conditions, including cancer. Among dietary components, plant-derived polyphenols are receiving wide interest, either for their anti-aging and anti-oxidant properties, or for their more general "cell-protective" effects. Above all, their role in preventing the occurrence/recurrence of cancer and, in particular, their potentiality in nutritional intervention for modulating the functions of miRNAs and the epigenetic mechanisms, is still under active debate. This review is focused on the more recent highlights of the impact of miRNAs dysregulation on the onset and progression of prostate cancer, their interplay with epigenetic control and their modulation by natural agents.

Quantitative tissue proteomic investigation of invasive ductal carcinoma of breast with luminal B HER2 positive and HER2 enriched subtypes towards potential diagnostic and therapeutic biomarkers

Worldwide, breast cancer is one of the frequently diagnosed cancers in women with high mortality if not diagnosed at early stage. Although biomarker discoveries through various proteomic approaches have been studied in breast cancer, a limited number of studies have explored the invasive ductal carcinoma with Luminal B HER2 positive (LB) and HER2 enriched (HE) subtypes. The present study employed the complementary quantitative proteomic approaches to find a panel of markers that could discriminate LB and HE subtypes as well as early (ES) and late stages (LS) of these subtypes. A total of 67 and 68 differentially expressed proteins were identified by DIGE for the subtype and stage wise categories, respectively. Multivariate statistical analysis was employed to identify the set of most significant proteins, which could discriminate between these two subtypes and also early and late stages under study. Immunoblotting and MRM based validation in a separate cohort of samples confirmed that panel of biosignatures for LB are APOA1, GELS, HS90B, EF1A1, NHRF1 and PRDX3 and for HE are PRDX1, CATD, CALR, ATPB and CH60. For the diagnosis of early and late stages the potential markers are TPM4, CATD, PRDX3, ANXA3, HSPB1 and CALR, TRFE, GELS, CH60, CAPG, NHRF1, 1433G, GRP78 respectively.

[EEF1A2 inhibits the p53 function in hepatocellular carcinoma via PI3K/AKT/mTOR-dependent stabilization of MDM4]

Upregulation of mouse double minute 4 (MDM4) is a frequent event in human hepatocellular carcinoma (HCC) but the underlying molecular mechanisms are poorly characterized. In this study a potential role of the phosphoinositide-3-kinase/v-AKT murine thymoma viral oncogene homolog/mammalian target of rapamycin (PI3K/AKT/mTOR) cascade was investigated in the regulation of MDM4 in HCC. Inhibition of the PI3K-AKT and/or mTOR pathways lowered MDM4 protein levels in HCC cells. Mechanistic protection from proteasomal degradation resulted from de-ubiquitination by ubiquitin-specific protease 2a and AKT-mediated phosphorylation of MDM4, thus increasing MDM4 protein levels. These findings were corroborated in a chimeric AKT mouse model. Upregulation of PI3K/AKT/mTOR signaling may result from overexpression of the eukaryotic elongation factor 1A2 (EEF1A2). Finally, a strong association between the expression of EEF1A2, phosphorylated AKT and MDM4 was observed in human HCC samples. Strong activation of the EEF1A2/PI3K/AKT/mTOR/MDM4 signaling pathway was observed in HCC patients with short survival suggesting that targeting this axis might be a promising approach in a subset of HCC patients.

Mammalian translation elongation factor eEF1A2: X-ray structure and new features of GDP/GTP exchange mechanism in higher eukaryotes

Eukaryotic elongation factor eEF1A transits between the GTP- and GDP-bound conformations during the ribosomal polypeptide chain elongation. eEF1A*GTP establishes a complex with the aminoacyl-tRNA in the A site of the 80S ribosome. Correct codon–anticodon recognition triggers GTP hydrolysis, with subsequent dissociation of eEF1A*GDP from the ribosome. The structures of both the ‘GTP’- and ‘GDP’-bound conformations of eEF1A are unknown. Thus, the eEF1A-related ribosomal mechanisms were anticipated only by analogy with the bacterial homolog EF-Tu. Here, we report the first crystal structure of the mammalian eEF1A2*GDP complex which indicates major differences in the organization of the nucleotide-binding domain and intramolecular movements of eEF1A compared to EF-Tu. Our results explain the nucleotide exchange mechanism in the mammalian eEF1A and suggest that the first step of eEF1A*GDP dissociation from the 80S ribosome is the rotation of the nucleotide-binding domain observed after GTP hydrolysis.

Identification of molecular tumor markers in renal cell carcinomas with TFE3 protein expression by RNA sequencing

TFE3 translocation renal cell carcinoma (tRCC) is defined by chromosomal translocations involving the TFE3 transcription factor at chromosome Xp11.2. Genetically proven TFE3 tRCCs have a broad histologic spectrum with overlapping features to other renal tumor subtypes. In this study, we aimed for characterizing RCC with TFE3 protein expression. Using next-generation whole transcriptome sequencing (RNA-Seq) as a discovery tool, we analyzed fusion transcripts, gene expression profile, and somatic mutations in frozen tissue of one TFE3 tRCC. By applying a computational analysis developed to call chimeric RNA molecules from paired-end RNA-Seq data, we confirmed the known TFE3 translocation. Its fusion partner SFPQ has already been described as fusion partner in tRCCs. In addition, an RNA read-through chimera between TMED6 and COG8 as well as MET and KDR (VEGFR2) point mutations were identified. An EGFR mutation, but no chromosomal rearrangements, was identified in a control group of five clear cell RCCs (ccRCCs). The TFE3 tRCC could be clearly distinguished from the ccRCCs by RNA-Seq gene expression measurements using a previously reported tRCC gene signature. In validation experiments using reverse transcription-PCR, TMED6-COG8 chimera expression was significantly higher in nine TFE3 translocated and six TFE3-expressing/non-translocated RCCs than in 24 ccRCCs (P < .001) and 22 papillary RCCs (P < .05-.07). Immunohistochemical analysis of selected genes from the tRCC gene signature showed significantly higher eukaryotic translation elongation factor 1 alpha 2 (EEF1A2) and Contactin 3 (CNTN3) expression in 16 TFE3 translocated and six TFE3-expressing/non-translocated RCCs than in over 200 ccRCCs (P < .0001, both).

Roles of matrix metalloproteinases and their natural inhibitors in prostate cancer progression

Matrix metalloproteinases (MMPs), a group of zinc-dependent endopeptidases involved in the degradation of the extracellular matrix, play an important role in tissue remodeling associated with various physiological processes such as morphogenesis, angiogenesis, and tissue repair, as well as pathological processes including cirrhosis, arthritis and cancer. The MMPs are well established as mediators of tumor invasion and metastasis by breaking down connective tissue barriers. Although there has been a vast amount of literature on the role of MMPs in invasion, metastasis and angiogenesis of various cancers, the role of these endopeptidases in prostate cancer progression has not been systematically reviewed. This overview summarizes findings on the tissue and blood expression of MMPs, their function, regulation and prognostic implication in human prostate cancer, with a focus on MMP-2, -7, -9, MT1-MMP and tissue inhibitor of metalloproteinase 1 (TIMP-1). This review also summarizes the efficacy and failure of early-generation matrix metalloproteinase inhibitors (MMPIs) in the treatment of metastatic prostate cancer and highlights the lessons and challenges for next generation MMPIs.

Up-regulation of eEF1A2 promotes proliferation and inhibits apoptosis in prostate cancer

BACKGROUND

eEF1A2 is a protein translation factor involved in protein synthesis, which possesses important function roles in cancer development. This study aims at investigating the expression pattern of eEF1A2 in prostate cancer and its potential role in prostate cancer development.

METHODS

We examined the expression level of eEF1A2 in 30 pairs of prostate cancer tissues by using RT-PCR and immunohistochemical staining (IHC). Then we applied siRNA specifically targeting eEF1A2 to down-regulate its expression in DU-145 and PC-3 cells. Flow cytometer was used to explore apoptosis and Western-blot was used to detect the pathway proteins of apoptosis.

RESULTS

Our results showed that the expression level of eEF1A2 in prostate cancer tissues was significantly higher compared to their corresponding normal tissues. Reduction of eEF1A2 expression in DU-145 and PC-3 cells led to a dramatic inhibition of proliferation accompanied with enhanced apoptosis rate. Western blot revealed that apoptosis pathway proteins (caspase3, BAD, BAX, PUMA) were significantly up-regulated after suppression of eEF1A2. More importantly, the levels of eEF1A2 and caspase3 were inversely correlated in prostate cancer tissues.

CONCLUSION

Our data suggests that eEF1A2 plays an important role in prostate cancer development, especially in inhibiting apoptosis. So eEF1A2 might serve as a potential therapeutic target in prostate cancer.

EEF1A2 inactivates p53 by way of PI3K/AKT/mTOR-dependent stabilization of MDM4 in hepatocellular carcinoma

Mouse Double Minute homolog 4 (MDM4) gene up-regulation often occurs in human hepatocellular carcinoma (HCC), but the molecular mechanisms responsible for its induction remain poorly understood. Here we investigated the role of the phosphoinositide-3-kinase/v-akt murine thymoma viral oncogene homolog/mammalian target of rapamycin (PI3K/AKT/mTOR) axis in the regulation of MDM4 levels in HCC. The activity of MDM4 and the PI3K/AKT/mTOR pathway was modulated in human HCC cell lines by way of silencing and overexpression experiments. Expression of main pathway components was analyzed in an AKT mouse model and human HCCs. MDM4 inhibition resulted in growth restraint of HCC cell lines both in vitro and in vivo. Inhibition of the PI3K-AKT and/or mTOR pathways lowered MDM4 protein levels in HCC cells and reactivated p53-dependent transcription. Deubiquitination by ubiquitin-specific protease 2a and AKT-mediated phosphorylation protected MDM4 from proteasomal degradation and increased its protein stability. The eukaryotic elongation factor 1A2 (EEF1A2) was identified as an upstream inducer of PI3K supporting MDM4 stabilization. Also, we detected MDM4 protein up-regulation in an AKT mouse model and a strong correlation between the expression of EEF1A2, activated/phosphorylated AKT, and MDM4 in human HCC (each rho > 0.8, P < 0.001). Noticeably, a strong activation of this cascade was associated with shorter patient survival.

CONCLUSION

The EEF1A2/PI3K/AKT/mTOR axis promotes the protumorigenic stabilization of the MDM4 protooncogene in human HCC by way of a posttranscriptional mechanism. The activation level of the EEF1A2/PI3K/AKT/mTOR/MDM4 axis significantly influences the survival probability of HCC patients in vivo and may thus represent a promising molecular target.

Novel hepatocellular carcinoma molecules with prognostic and therapeutic potentials

Hepatocellular carcinoma (HCC), the predominant form of primary liver cancer, is the sixth most common cancer worldwide and the third leading cause of cancer-related death. The difficulty to diagnose early cancer stages, the aggressive behaviors of HCC, and the poor effectiveness of therapeutic treatments, represent the reasons for the quite similar deaths per year and incidence number. Considering the fact that the diagnosis of HCC typically occurs in the advanced stages of the disease when the therapeutic options have only modest efficacy, the possibility to identify early diagnostic markers could be of significant benefit. So far, a large number of biomarkers have been associated to HCC progression and aggressiveness, but many of them turned out not to be of practical utility. This is the reason why active investigations are ongoing in this field. Given the huge amount of published works aimed at the identification of HCC biomarkers, in this review we mainly focused on the data published in the last year, with particular attention to the role of (1) molecular and biochemical cellular markers; (2) micro-interfering RNAs; (3) epigenetic variations; and (4) tumor stroma. It is worth mentioning that a significant number of the HCC markers described in the present review may be utilized also as targets for novel therapeutic approaches, indicating the tight relation between diagnosis and therapy. In conclusion, we believe that integrated researches among the different lines of investigation indicated above should represent the winning strategies to identify effective HCC markers and therapeutic targets.

eEF1A2 promotes cell migration, invasion and metastasis in pancreatic cancer by upregulating MMP-9 expression through Akt activation

eEF1A2 is a protein translation factor involved in protein synthesis that is overexpressed in various cancers, with important functions in tumor genesis and progression. We have previously showed that the ectopic expression of eEF1A2 is correlated with lymph node metastasis and perineural invasion in pancreatic cancer. In this study, we investigated the functional role of eEF1A2 in the regulation of cell migration, invasion, and metastasis in pancreatic cancer. Furthermore, we investigated the potential molecular mechanisms involved. By evaluating the invasive ability of a panel of pancreatic cancer cell lines with different metastatic potentials, eEF1A2 expression in cells was positively associated with their invasive ability. The knockdown of eEF1A2 by siRNA decreased the migration and invasion of PANC-1 cells. By contrast, the ectopic expression of exogenous eEF1A2 significantly promoted the migration and invasion of SW1990 cells. Stable eEF1A2 overexpression in a nude mouse model of peritoneal metastasis likewise dramatically enhanced the intraperitoneal metastatic ability of SW1990 cells. In addition, eEF1A2 overexpression could upregulate MMP-9 expression and activity. A significant positive correlation between the overexpression of both eEF1A2 and MMP-9 was observed in pancreatic cancer tissues. The inhibition of MMP-9 activity reduced the promoting effect of eEF1A2 on cell migration and invasion. Furthermore, eEF1A2-mediated cell migration and invasion, as well as MMP-9 expression and upregulation, were largely dependent on the eEF1A2-induced Akt activation. The findings suggested the potentially important role of eEF1A2 in pancreatic cancer migration, invasion, and metastasis. Thus, the results provide evidence of eEF1A2 as a potential therapeutic target in the treatment of aggressive pancreatic cancer.

The more basic isoform of eEF1A relates to tumour cell phenotype and is modulated by hyper-proliferative/differentiating stimuli in normal lymphocytes and CCRF-CEM T-lymphoblasts

The elongation factor 1A proteins (eEF1A1/A2) are known to play a role in tumours. We previously found that a more basic isoform of eEF1A (MBI-eEF1A) is present in the cytoskeletal/nuclear-enriched extracts of CCRF-CEM T-lymphoblasts but not in those of normal lymphocytes. To obtain deeper knowledge about MBI-eEF1A biology, we investigate from which of the eEF1A proteins, eEF1A1 or eEF1A2, MBI-eEF1A originates and the possibility that its appearance can be modulated by the differentiated or proliferative cell status. CCRF-CEM T-lymphoblasts and normal lymphocytes were cultured with or without differentiation/pro-proliferative stimuli (Phorbol 12-Myristate 13-Acetate (PMA) alone or the combination of phytohaemagglutinin (PHA) with PMA, respectively), and the presence of MBI-eEF1A evaluated together with that of the eEF1A1/A2 mRNAs. Our data indicate that the MBI-eEF1A may derive from eEF1A1 as eEF1A2 is not expressed in CCRF-CEM and normal lymphocytes. Moreover, MBI-eEF1A is inducible in normal lymphocytes upon hyper-proliferative stimuli application; in CCRF-CEM, its presence can be abrogated by PMA-induced differentiation. Finally, MBI-eEF1A may have a functional role in hyper-proliferating/tumour cells as its disappearance reduces the growth of CCRF-CEM and that of PHA/PMA-stimulated lymphocytes. The presented data suggest that MBI-eEF1A may be related to oncogenic cell phenotype, rising the possibility to use MBI-eEF1A as target for novel therapeutic strategies.