EIF3D promotes gallbladder cancer development by stabilizing GRK2 kinase and activating PI3K-AKT signaling pathway

eIf3a mediates malignant biological behaviors in colorectal cancer through the PI3K/AKT signaling pathway

Colorectal cancer (CRC) is among the most common gastrointestinal malignancies worldwide. eIF3a is highly expressed in a variety of cancer types, yet its role in CRC remains unclear. We introduced ectopic eIF3a expression in CRC cells to investigate its relevance to various malignant behaviors. Further, we silenced eIF3a to explore its effect on tumor growth in a nude mouse tumor xenograft model. Finally, the molecular mechanisms through which eIF3a regulates malignancy in CRC cells were explored through bioinformatics analysis combined with the use of a specific PI3K inhibitor (LY294002). eIF3a was highly expressed in the peripheral blood and cancer tissue of CRC patients. Malignancy and tumor growth were significantly inhibited by silencing eIF3a, while overexpression promoted malignant behaviors, with a positive correlation between PI3K/AKT activation and eIF3a expression. Taken together, eIF3a plays an oncogenic role in CRC by regulating PI3K/AKT signaling and is a potential biomarker for CRC diagnosis and prognostic monitoring.

N6-Methyladenosine Methylation of mRNA in Cell Apoptosis

Apoptosis, a highly controlled homeostatic mechanism that eliminates single cells without destroying tissue function, occurs during growing development and senescence. N6-methyladenosine (m6A), as the most common internal modification of eukaryotic mRNA, fine-tunes gene expression by regulating many aspects of mRNA metabolism, such as splicing, nucleation, stability, translation, and degradation. Remarkably, recent reports have indicated that aberrant methylation of m6A-related RNA may directly or indirectly influence the expression of apoptosis-related genes, thus regulating the process of cell apoptosis. In this review, we summarized the relationship between m6A modification and cell apoptosis, especially its role in the nervous system, and analyzed the limitations of the current research.

RNA splicing regulator EIF3D regulates the tumor microenvironment through immunogene-related alternative splicing in head and neck squamous cell carcinoma

Study finds that eukaryotic translation initiation factor 3 subunit D (EIF3D) may play an important role in aberrant alternative splicing (AS) events in tumors. AS possesses a pivotal role in both tumour progression and the constitution of the tumour microenvironment (TME). Regrettably, our current understanding of AS remains circumscribed especially in the context of immunogene-related alternative splicing (IGAS) profiles within Head and Neck Squamous Cell Carcinoma (HNSC). In this study, we comprehensively analyzed the function and mechanism of action of EIF3D by bioinformatics analysis combined with in vitro cellular experiments, and found that high expression of EIF3D in HNSC was associated with poor prognosis of overall survival (OS) and progression-free survival (PFS). The EIF3D low expression group had a higher degree of immune infiltration and better efficacy against PD1 and CTLA4 immunotherapy compared to the EIF3D high expression group. TCGA SpliceSeq analysis illustrated that EIF3D influenced differentially spliced alternative splicing (DSAS) events involving 105 differentially expressed immunogenes (DEIGs). We observed an induction of apoptosis and a suppression of cell proliferation, migration, and invasion in EIF3D knock-down FaDu cells. RNA-seq analysis unveiled that 531 genes exhibited differential expression following EIF3D knockdown in FaDu cells. These include 52 DEIGs. Furthermore, EIF3D knockdown influenced the patterns of 1923 alternative splicing events (ASEs), encompassing 129 IGASs. This study identified an RNA splicing regulator and revealed its regulatory role in IGAS and the TME of HNSC, suggesting that EIF3D may be a potential target for predicting HNSC prognosis and immunotherapeutic response.

EIF3D promoted cervical carcinoma through Warburg effect by interacting with GRP78

The incidence of cervical cancer ranks third among all female tumours globally and second in developing countries. However, the role of eukaryotic translation initiation factor 3 subunit D (EIF3D) in cervical carcinoma is unknown. This study investigated the effects of EIF3D on cell progression of cervical carcinoma and its underlying mechanism in vivo and vitro models. There were increases of EIF3D expression mRNA and protein expression levels in patients with cervical carcinoma. Disease-free survival (DFS) and overall surviva (OS) of EIF3D lower expression in patients with cervical carcinoma was higher than those of EIF3D higher expression. EIF3D mRNA expression levels in cervical carcinoma cell lines (AV3, Hela229, CaSki and Hela cells) were up-regulated, compared with cervical normal cell line (UVECs). EIF3D promoted cell growth and Warburg effect in vitro model of cervical carcinoma. EIF3D interacting with GRP78 to reduce the activity of GRP78 in vitro model of cervical carcinoma. The inhibition of GRP78 reduced the effects of EIF3D on Warburg effect in vitro model of cervical carcinoma.Our work identifies EIF3D promoted cell growth and Warburg effect in vitro model of cervical carcinoma and the inhibition of EIF3D represents a potential therapeutic strategy for the treatment of cervical carcinoma.IMPACT STATEMENTWhat is already known on this subject? The incidence of cervical cancer ranks third among all female tumours globally and second in developing countries.What do the results of this study add? This study investigated the effects of EIF3D on cell progression of cervical carcinoma and its underlying mechanism in vivo and vitro models.What are the implications of these findings for clinical practice and/or further research? EIF3D promoted cell growth and Warburg effect in vitro model of cervical carcinoma and the inhibition of EIF3D represents a potential therapeutic strategy for the treatment of cervical carcinoma.

eIF3d: A driver of noncanonical cap-dependent translation of specific mRNAs and a trigger of biological/pathological processes

Eukaryotic initiation factor 3d (eIF3d), a known RNA-binding subunit of the eIF3 complex, is a 66 to 68-kDa protein with an RNA-binding motif and a cap-binding domain. Compared with other eIF3 subunits, eIF3d is relatively understudied. However, recent progress in studying eIF3d has revealed a number of intriguing findings on its role in maintaining eIF3 complex integrity, global protein synthesis, and in biological and pathological processes. It has also been reported that eIF3d has noncanonical functions in regulating translation of a subset of mRNAs by binding to 5'-UTRs or interacting with other proteins independent of the eIF3 complex and additional functions in regulating protein stability. The noncanonical regulation of mRNA translation or protein stability may contribute to the role of eIF3d in biological processes such as metabolic stress adaptation and in disease onset and progression including severe acute respiratory syndrome coronavirus 2 infection, tumorigenesis, and acquired immune deficiency syndrome. In this review, we critically evaluate the recent studies on these aspects of eIF3d and assess prospects in understanding the function of eIF3d in regulating protein synthesis and in biological and pathological processes.

MYC-driven U2SURP regulates alternative splicing of SAT1 to promote triple-negative breast cancer progression

Triple-negative breast cancer (TNBC), although highly lethal, lacks validated therapeutic targets. Here, we report that U2 snRNP-associated SURP motif-containing protein (U2SURP), a poorly defined member of the serine/arginine rich protein family, was significantly upregulated in TNBC tissues, and its high expression was associated with poor prognosis of TNBC patients. MYC, a frequently amplified oncogene in TNBC tissues, enhanced U2SURP translation through an eIF3D (eukaryotic translation initiation factor 3 subunit D)-dependent mechanism, resulting in the accumulation of U2SURP in TNBC tissues. Functional assays revealed that U2SURP played an important role in facilitating tumorigenesis and metastasis of TNBC cells both in vitro and in vivo. Intriguingly, U2SURP had no significant effects on proliferative, migratory, and invasive potential of normal mammary epithelial cells. Furthermore, we found that U2SURP promoted alternative splicing of spermidine/spermine N1-acetyltransferase 1 (SAT1) pre-mRNA by removal of intron 3, resulting in an increase in the stability of SAT1 mRNA and subsequent protein expression levels. Importantly, spliced SAT1 promoted the oncogenic properties of TNBC cells, and re-expression of SAT1 in U2SURP-depleted cells partially rescued the impaired malignant phenotypes of TNBC cells caused by U2SURP knockdown both in vitro and in mice. Collectively, these findings reveal previously unknown functional and mechanism roles of the MYC-U2SURP-SAT1 signaling axis in TNBC progression and highlight U2SURP as a potential therapy target for TNBC.

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.

EIF3D promotes resistance to 5-fluorouracil in colorectal cancer through upregulating RUVBL1

BACKGROUND

As EIF3D is oncogenic in colorectal cancer (CRC) and is associated with multidrug resistance, this study aims to investigate whether and how EIF3D regulates resistance to 5-fluorouracil (5-Fu) in CRC.

METHODS

EIF3D-associated genes in CRC were predicted using bioinformatics tools. CRC cells and nude mice received 5-Fu treatment. Then, the impacts of EIF3D and the interaction between EIF3D and RUVBL1 on cell viability, colony formation, apoptosis, and DNA damage were detected through MTT, colony formation, flow cytometry, and immunofluorescence assays, and those on in vivo tumorigenesis through murine xenograft assay. IC50 value of 5-Fu for CRC cells was determined by probit regression analysis. Expressions of EIF3D, eIF4E, EIF3D-associated genes, γH2AX, Bcl-2, Bax, and Cleaved Caspase-3/Caspase-3 in CRC tissues, cells, and/or xenograft tumors were analyzed by qRT-PCR and/or Western blot.

RESULTS

EIF3D and RUVBL1 were highly expressed and positively correlated with CRC tissues/cells. In CRC cells, except for eIF4E, both EIF3D and RUVBL1 levels were upregulated by 5-Fu treatment; in addition to that, RUVBL1 level was downregulated by EIF3D silencing rather than eIF4E. Meanwhile, EIF3D silencing diminished IC50 value of 5-Fu and potentiated 5-Fu-induced viability decrease, colony formation inhibition, apoptosis promotion, Bcl-2 downregulation, and γH2AX, Bax, and Cleaved Caspase-3/Caspase-3 upregulation but reversed 5-Fu-triggered RUVBL1 upregulation. RUVBL1 overexpression offsets EIF3D silencing-induced viability decrease and apoptosis promotion of 5-Fu-treated CRC cells, and tumorigenesis suppression and apoptosis promotion in 5-Fu-treated mice.

CONCLUSION

EIF3D promotes resistance to 5-Fu in CRC through upregulating RUVBL1 level.

Computational analysis of G-protein-coupled receptor kinase family members as potential targets for colorectal cancer therapy

Background

G-protein-coupled receptor (GPCR) kinases (GRKs) interact with ligand-activated GPCR, causing intracellular phosphorylation and interfering with the intracellular signal transduction associated with the development of cancer. Colorectal cancer (CRC) is a fast-growing disease, and its molecular mechanism involves various regulatory proteins, including kinases. However, the GRK mechanism in CRC has not been explored.

Methods

We used an integrated computational approach to investigate the potential of GRK family members as targeted proteins in CRC. The GRK expression levels in tumor and normal tissues, colon adenocarcinoma samples, and metastatic colon adenocarcinoma were analyzed using ONCOMINE, GEPIA, and UALCAN, as well as TNM plots. Genetic changes in the GRK family genes were investigated using cBioportal. The prognostic value related to the gene expression of the GRK family was examined using GEPIA and UALCAN. Co-expression analysis of the GRK family was conducted using COXPRESdb. Association analysis of the Gene Ontology, KEGG pathway enrichment, and drug-gene analyses were performed using the over-representation analysis (ORA) in WebGestalt.

Results

GRK2, GRK3, and GRK5 mRNA levels increased significantly in patients with CRC and metastatic CRC. Genetic changes were detected in patients with CRC, including GRK7 (1.1%), GRK2 (1.7%), GRK4 (2.3%), GRK5 (2.5%), GRK6 (2.5%), GRK3 (2.9%), and GRK1 (4%). CRC patients with low mRNA of GRK7 levels had better disease-free and overall survival than those with high GRK7 levels. Hierarchical clustering analysis revealed significant positive correlations between GRK5 and GRK2 and between GRK2 and GRK6. KEGG pathway enrichment analysis showed that the gene network (GN) regulated several cellular pathways, such as the morphine addiction signaling and chemokine signaling pathways in cancer. The drug-gene association analysis indicated that the GN was associated with several drugs, including reboxetine, pindolol, beta-blocking agents, and protein kinase inhibitors.

Conclusion

No research has been conducted on the relation of GRK1 and GRK7 to cancer, particularly CRC. In this work, genes GRK2, GRK3, GRK5, and GRK6 were found to be oncogenes in CRC. Although inhibitors against GRK2, GRK5, and GRK6 have previously been developed, further research, particularly preclinical and clinical studies, is needed before these agents may be used to treat CRC.

Propofol produces neurotoxicity by inducing mitochondrial apoptosis

Propofol is a fast and short-acting intravenous anesthetic widely used in clinical anesthesia and intensive care unit sedation. However, its use can cause abnormal effects on the central nervous system. Thus, the purpose of this study was to investigate the mechanism of propofol on primary hippocampal neuron injury. In addition, we aimed to determine whether a correlation exists between propofol and mitochondrial apoptosis-induced neurotoxicity. Hippocampal neurons cultured for 4 days were exposed to different drugs. The treatment groups were divided according to drug exposure into propofol, a rotenone inhibitor, and a coenzyme Q10 agonist groups. The final concentrations of propofol were 1, 10 and 100 µM. The content of ATP and reactive oxygen species (ROS) in the neurons of each group were detected using commercial kits in the culture supernatant after 3 h of drug exposure. Western blotting was used to analyze the expression of apoptosis-related proteins. The JC-1 kit was used to detect the mitochondrial membrane potential. The results revealed that, compared with the non-propofol treatment groups, the expression of apoptosis-related proteins, ATP content, and mitochondrial membrane potential were significantly decreased while the ROS content was markedly increased in the propofol treatment group. In conclusion, propofol treatment promoted damage to hippocampal neuronal mitochondria in a dose-dependent manner. This damage may lead to neuronal apoptosis and neurotoxicity by inducing the inhibition of mitochondrial respiratory chain complex I.

A novel prognostic 7-methylguanosine signature reflects immune microenvironment and alternative splicing in glioma based on multi-omics analysis

Glioma is the most common type of central nervous system tumor with increasing incidence. 7-methylguanosine (m7G) is one of the diverse RNA modifications that is known to regulate RNA metabolism and its dysregulation was associated with various cancers. However, the expression pattern of m7G regulators and their roles in regulating tumor immune microenvironments (TIMEs) as well as alternative splicing events (ASEs) in glioma has not been reported. In this study, we showed that m7G regulators displayed a close correlation with each other and most of them were differentially expressed between normal and glioma tissues. Two m7G signatures were then constructed to predict the overall survival of both GBM and LGG patients with moderate predictive performance. The risk score calculated from the regression coefficient and expression level of signature genes was proved to be an independent prognostic factor for patients with LGG, thus, a nomogram was established on the risk score and other independent clinical parameters to predict the survival probability of LGG patients. We also investigated the correlation of m7G signatures with TIMEs in terms of immune scores, expression levels of HLA and immune checkpoint genes, immune cell composition, and immune-related functions. While exploring the correlation between signature genes and the ASEs in glioma, we found that EIF4E1B was a key regulator and might play dual roles depending on glioma grade. By incorporating spatial transcriptomic data, we found a cluster of cells featured by high expression of PTN exhibited the highest m7G score and may communicate with adjacent cancer cells via SPP1 and PTN signaling pathways. In conclusion, our work brought novel insights into the roles of m7G modification in TIMEs and ASEs in glioma, suggesting that evaluation of m7G in glioma could predict prognosis. Moreover, our data suggested that blocking SPP1 and PTN pathways might be a strategy for combating glioma.

The role of PI3K/AKT signaling pathway in gallbladder carcinoma

OBJECTIVES

The prognosis of gallbladder carcinoma (GBC) is poor, with a less than 5% five-year survival rate. Identifying the mechanisms underlying GBC occurrence and advancement is necessary to improve GBC patient prognosis and survival rates. The phosphatidylinositol 3-kinase (PI3K)/serine-threonine kinase (AKT) pathway is involved in cancer deterioration, tumor growth, cell proliferation, and distant metastasis. Studying the impacts of the PI3K/AKT pathway has resulted in the identification of key factors involved in GBC progression that might serve as therapeutic targets, promoting the development of new treatments.

METHODS

We reviewed recent literature exploring abnormal regulation of the PI3K/AKT pathway in gallbladder cancer, with a focus on abnormal RNA levels, protein level regulation, and drug treatment advances.

RESULTS

Further investigation of the regulation of small molecules and proteins by the PI3K/AKT pathway might ultimately provide new diagnostic or prognostic markers or cancer treatment targets. Recent studies have focused on RNA and proteins involved in the regulation of the cell cycle or cell movement in cancer progression via PI3K/AKT pathway, the use of anticancer drug combinations, or the anticancer effects of drugs not currently utilized for cancer treatment.

CONCLUSIONS

We herein review the known available molecules that affect the PI3K/AKT pathway in patients with GBC and the mechanisms of drug action associated with this pathway.

Proteomic Analysis of Potential Targets for Non-Response to Infliximab in Patients With Ulcerative Colitis

Background: Infliximab (IFX) is a potent therapeutic agent used for the treatment of conventional refractory ulcerative colitis (UC). However, the high non-response rate of IFX brings difficulties to clinical applications. In the context of proteomics research, our study of differentially expressed proteins (DEPs) is essential for non-response to IFX in UC patients and provides powerful insights into underlying drug resistance mechanisms.

Methods: A total of 12 UC patients were divided into responders to IFX (UCinfG), non-responders to IFX (UCinfL), severe UC (UCsevere) without an IFX treatment history, and mild UC (UCmild) without an IFX treatment history. Subsequently, DEPs were identified from intestinal biopsy tissue between responders and non-responders to IFX by a label-free proteomic quantitative approach, and the general principle of functional protein screening was followed to deduce the potential drug targets and predictors for non-response to IFX in UC patients. Meanwhile, these targets excluded DEPs caused by the severity of inflammation for the first time. The differential expressions of candidate protein targets were validated at the gene sequence level using GEO2R analysis of the GEO database and qRT-PCR in some independent cohorts.

Results: A total of 257 DEPs were screened out by mass spectrometry between UCinfG and UCinfL groups, excluding 22 DEPs caused by the severity of inflammation, and compared and verified at the gene sequence level in the Gene Expression Omnibus (GEO) database. Finally, five DEPs, including ACTBL2 (Q562R1), MBL2 (P11226), BPI (P17213), EIF3D (O15371), and CR1 (P17927), were identified as novel drug targets and predictive biomarkers for non-response to IFX. The drug targets were confirmed in the GEO database of the microarray results from three independent cohorts of 70 human intestinal biopsies and validated in qPCR data from 17 colonic mucosal biopsies. Among them, CR1 might affect the activation of the lectin pathway via complement-coated bacteria to play an opsonizing role in inflammation-related pathways closely associated with non-responders to IFX.

Conclusion: This is the first report of proteomics analysis for the identification of novel drug targets based on intestinal biopsy tissue, which is significant for hypotheses for mechanistic investigation that are responsible for non-response to IFX and the development of clinical new pharmaceutical drugs.

Preoperative lymphocyte to C-reactive protein ratio as a new prognostic indicator in patients with resectable gallbladder cancer

BACKGROUND

Inflammation is often related to cancer, and several inflammatory scores have been established to predict the prognosis of various types of cancer. Our study aimed to determine the prognostic value of the preoperative lymphocyte to C-reactive protein ratio (LCR) for predicting postoperative outcomes in patients with resectable gallbladder cancer (GBC).

METHODS

A retrospective analysis of 104 GBC patients who received curative surgery at Xinhua Hospital, Affiliated to Shanghai Jiao Tong University School of Medicine from January 2000 to December 2016 was performed. A time-dependent receiver operating characteristic curve was constructed to evaluate the accuracy of different markers. Univariate and multivariate Cox proportional hazard models were used to define factors associated with overall survival.

RESULTS

Among the assessed variables, the preoperative LCR showed the highest accuracy in predicting the overall survival of GBC patients (AUC: 0.736). Decreased preoperative LCR was significantly associated with advanced tumor stage, including tumor invasion (P = 0.018), lymph node metastasis (P = 0.011) and TNM stage (P = 0.022). A low preoperative LCR (cutoff threshold = 145.5) was an independent risk factor for overall survival in patients with resectable GBC (P < 0.001).

CONCLUSIONS

The preoperative LCR is a novel and valuable prognostic indicator of postoperative survival in patients with resectable GBC.

G Protein-Coupled Receptor Kinase 2 as Novel Therapeutic Target in Fibrotic Diseases

G protein-coupled receptor kinase 2 (GRK2), an important subtype of GRKs, specifically phosphorylates agonist-activated G protein-coupled receptors (GPCRs). Besides, current research confirms that it participates in multiple regulation of diverse cells via a non-phosphorylated pathway, including interacting with various non-receptor substrates and binding partners. Fibrosis is a common pathophysiological phenomenon in the repair process of many tissues due to various pathogenic factors such as inflammation, injury, drugs, etc. The characteristics of fibrosis are the activation of fibroblasts leading to myofibroblast proliferation and differentiation, subsequent aggerate excessive deposition of extracellular matrix (ECM). Then, a positive feedback loop is occurred between tissue stiffness caused by ECM and fibroblasts, ultimately resulting in distortion of organ architecture and function. At present, GRK2, which has been described as a multifunctional protein, regulates copious signaling pathways under pathophysiological conditions correlated with fibrotic diseases. Along with GRK2-mediated regulation, there are diverse effects on the growth and apoptosis of different cells, inflammatory response and deposition of ECM, which are essential in organ fibrosis progression. This review is to highlight the relationship between GRK2 and fibrotic diseases based on recent research. It is becoming more convincing that GRK2 could be considered as a potential therapeutic target in many fibrotic diseases.

Eukaryotic translation initiation factor 3 subunit B could serve as a potential prognostic predictor for breast cancer

The EIF3 gene family is essential in controlling translation initiation during the cell cycle. The significance of the EIF3 subunits as prognostic markers and therapeutic targets in breast cancer is not yet clear. We analyzed the expression of EIF3 subunits in breast cancer on the GEPIA and Oncomine databases and compared their expression in breast cancer and normal tissues using BRCA data downloaded from TCGA. Then we performed clinical survival analysis on the Kaplan–Meier Plotter database and clinicopathologic analysis on the bc-genexMiner v4.1 database. And EIF3B was chosen for mutation analysis via the Cancer SEA online tool. Meanwhile, we performed the immunohistochemical assay, real-time RT-PCR, and Western blotting to analyze EIF3B expression levels in breast cancer. An EIF3B knockdown and a negative control cell line were conducted for MTT assay and cell cycle analysis to assess cell growth. Specifically, the results of TCGA and online databases demonstrated that upregulated EIF3B was associated with poorer overall and advanced tumor progression. We also confirmed that EIF3B was more highly expressed in breast cancer cells and tissues than normal and correlated with a worse outcome. And knockdown of EIF3B expression inhibited the cell cycle and proliferation. Furthermore, EIF3B was highly mutated in breast cancer. Collectively, our results suggested EIF3B as a potential prognostic marker and therapeutic target for breast cancer.

Silencing IKBKE inhibits the migration and invasion of glioblastoma by promoting Snail1 degradation

PURPOSE

Glioblastoma multiforme (GBM) is one of the most common malignant brain tumors in adults and has high mortality and relapse rates. Over the past few years, great advances have been made in the diagnosis and treatment of GBM, but unfortunately, the five-year overall survival rate of GBM patients is approximately 5.1%. Inhibitor of nuclear factor kappa-B kinase subunit epsilon (IKBKE) is a major oncogenic protein in tumors and can promote evil development of GBM. Snail1, a key inducer of the epithelial-mesenchymal transition (EMT) transcription factor, is subjected to ubiquitination and degradation, but the mechanism by which Snail1 is stabilized in tumors remains unclear. Our study aimed to investigate the mechanism of IKBKE regulating Snail1 in GBM.

METHODS

First, we analyzed the correlation between the expression of IKBKE and the tumor grade and prognosis through public databases and laboratory specimen libraries. Second, immunohistochemistry (IHC) and western blot were used to detect the correlation between IKBKE and Snail expression in glioma samples and cell lines. Western blot and immunofluorescence (IF) experiments were used to detect the quality and distribution of IKBKE and Snail1 proteins. Third, In situ animal model of intracranial glioma to detect the regulatory effect of IKBKE on intracranial tumors.

RESULTS

In this study, Our study reveals a new connection between IKBKE and Snail1, where IKBKE can directly bind to Snail1, translocate Snail1 into the nucleus from the cytoplasm. Downregulation of IKBKE results in Snail1 destabilization and impairs the tumor cell migration and invasion capabilities.

CONCLUSION

Our studies suggest that the IKBKE-Snail1 axis may serve as a potential therapeutic target for GBM treatment.

EIF3D promotes the progression of preeclampsia by inhibiting of MAPK/ERK1/2 pathway

Preeclampsia (PE) has been recognized as one of the main reasons for neonatal and maternal mortality and morbidity. This study intended to identify certain genes that correlated with the pathogenesis of PE, and disclose the underlying mechanisms. The GSE14776 and GSE65271 datasets were obtained from the Gene Expression Omnibus database. Venn diagram analysis was performed to identify the differently expressed genes. The potential pathways were analyzed by Gene set enrichment analysis software. The expression of eukaryotic translation initiation factor 3 subunit D (EIF3D) in tissues and cells was respectively tested by immunohistochemistry and the quantitative real-time PCR. Cell transfection was utilized to alter the expression of EIF3D. Cell proliferation, invasion and migration were respectively tested by MTT, EdU, transwell and wound healing assays. Tube formation assay was utilized to determine the tube formation capacity of HTR-8/SVneo cells. ELISA was employed for determination of the concentration of Angiotensin (ANG)-1. Moreover, the expression of EIF3D, proliferation-, metastasis-, tube formation- and MAPK/ERK1/2 pathway-related proteins were measured utilizing western blot. EIF3D was selected in this study. EIF3D was upregulated in placentas tissues collected from patients with PE. EIF3D upregulation observably repressed the proliferation, invasion, migration, wound healing and tube formation of HTR-8/SVneo cells, and the expression of their associated proteins. Besides, the concentration of ANG-1, and the ratios of phosphorylated-ERK1/2 and phosphorylated-MEK1/MEK1 were also markedly lowered by EIF3D upregulation. Whereas, EIF3D knockdown exerted the opposite effects, and these effects were distinctly counteracted by ERK1/2 inhibitor SC-221593 treatment. In conclusion, these observations manifested that EIF3D upregulation might have repressed the progression of PE through modulation of MAPK/ERK1/2 pathway.

MiR-335-3p inhibits cell proliferation, induces cell cycle arrest and apoptosis in acute myeloid leukemia by targeting EIF3E

Here, we aimed to investigate the biological roles and the regulatory mechanisms of miR-335-3p in acute myeloid leukemia (AML). We first found miR-335-3p was significantly down-regulated in blood samples from leukemia patients and cell lines using reverse transcription quantitative PCR. Through CCK-8 assay and flow cytometry, we observed that miR-335-3p overexpression significantly inhibited cell proliferation, induced cell cycle G0/G1 arrest and apoptosis in AML cell lines (THP-1 and U937). Moreover, miR-335-3p directly targets EIF3E and negatively regulated its expression. More importantly, EIF3E overexpression reversed the effects of miR-335-3p on cell proliferation, G1/S transition and apoptosis. Furthermore, miR-335-3p overexpression obviously downregulated the expression of CDK4, Cyclin D1 and Bcl-2, while upregulated the expression of p21 and Bad, which were significantly rescued by the co-transfection of pcDNA3.1-EIF3E. Collectively, our study proposes that miR-335-3p/EIF3E axis could be a promising therapeutic target to mitigate the progression of AML.

Implications of protein ubiquitination modulated by lncRNAs in gastrointestinal cancers

Long non-coding RNAs (lncRNAs) are a class of RNA transcripts longer than 200 nucleotides and mostly cannot be translated into proteins. Next-generation transcriptome sequencing of various cell types has enabled the annotation of tens of thousands of lncRNAs in human genome. Varying levels of evidence supports the implications of lncRNAs in the onset and progression of cancers. Ubiquitin is an evolutionarily conserved protein and could post-translationally mark a number of proteins. The most important proteolytic role of ubiquitination is degradation of substrate proteins by the 26S proteasome. Compiling evidences demonstrated that lncRNAs are involved in the accurate execution of protein stability programs via the ubiquitin-proteasome system. In the current review, we systematically summarize the detailed mechanisms how lncRNAs modulate ubiquitination of target proteins, regulate cancerous signaling pathways and control tumorigenesis of gastrointestinal cancers. Although there are still considerable studies on unraveling the complicated interactions between lncRNAs and proteins, we believe that lncRNAs are promising but challenging molecules which may strongly facilitate precision cancer therapeutics in the future.

Unraveling the Molecular Nexus between GPCRs, ERS, and EMT

G protein-coupled receptors (GPCRs) represent a large family of transmembrane proteins that transduce an external stimulus into a variety of cellular responses. They play a critical role in various pathological conditions in humans, including cancer, by regulating a number of key processes involved in tumor formation and progression. The epithelial-mesenchymal transition (EMT) is a fundamental process in promoting cancer cell invasion and tumor dissemination leading to metastasis, an often intractable state of the disease. Uncontrolled proliferation and persistent metabolism of cancer cells also induce oxidative stress, hypoxia, and depletion of growth factors and nutrients. These disturbances lead to the accumulation of misfolded proteins in the endoplasmic reticulum (ER) and induce a cellular condition called ER stress (ERS) which is counteracted by activation of the unfolded protein response (UPR). Many GPCRs modulate ERS and UPR signaling via ERS sensors, IRE1α, PERK, and ATF6, to support cancer cell survival and inhibit cell death. By regulating downstream signaling pathways such as NF-κB, MAPK/ERK, PI3K/AKT, TGF-β, and Wnt/β-catenin, GPCRs also upregulate mesenchymal transcription factors including Snail, ZEB, and Twist superfamilies which regulate cell polarity, cytoskeleton remodeling, migration, and invasion. Likewise, ERS-induced UPR upregulates gene transcription and expression of proteins related to EMT enhancing tumor aggressiveness. Though GPCRs are attractive therapeutic targets in cancer biology, much less is known about their roles in regulating ERS and EMT. Here, we will discuss the interplay in GPCR-ERS linked to the EMT process of cancer cells, with a particular focus on oncogenes and molecular signaling pathways.

Overview of current targeted therapy in gallbladder cancer

Gallbladder cancer (GBC) is rare, but is the most malignant type of biliary tract tumor. Unfortunately, only a small population of cancer patients is acceptable for the surgical resection, the current effective regimen; thus, the high mortality rate has been static for decades. To substantially circumvent the stagnant scenario, a number of therapeutic approaches owing to the creation of advanced technologic measures (e.g., next-generation sequencing, transcriptomics, proteomics) have been intensively innovated, which include targeted therapy, immunotherapy, and nanoparticle-based delivery systems. In the current review, we primarily focus on the targeted therapy capable of specifically inhibiting individual key molecules that govern aberrant signaling cascades in GBC. Global clinical trials of targeted therapy in GBC are updated and may offer great value for novel pathologic and therapeutic insights of this deadly disease, ultimately improving the efficacy of treatment.

The Potential Roles of RNA N6-Methyladenosine in Urological Tumors

N6-methyladenosine (m⁶A) is regarded as the most abundant, prevalent and conserved internal mRNA modification in mammalian cells. M⁶A can be catalyzed by m⁶A methyltransferases METTL3, METTL14 and WTAP (writers), reverted by demethylases ALKBH5 and FTO (erasers), and recognized by m⁶A -binding proteins such as YTHDF1/2/3, IGF2BP1/2/3 and HNRNPA2B1 (readers). Emerging evidence suggests that m⁶A modification is significant for regulating many biological and cellular processes and participates in the pathological development of various diseases, including tumors. This article reviews recent studies on the biological function of m⁶A modification and the methylation modification of m⁶A in urological tumors.

PTEN in osteosarcoma: Recent advances and the therapeutic potential

Osteosarcoma is the most common primary malignant bone tumor, predominantly occurring in children and adolescents. Despite treated with surgery and neoadjuvant chemotherapy, osteosarcoma has a high potential of local recurrence and lung metastasis. Overall survival rates for osteosarcoma have plateaued in the past four decades, therefore, identification of novel targets and development of more effective treatment strategies are urgent. Phosphatase and tensin homolog (PTEN) is a tumor suppressor gene that negatively regulates the phosphatidylinositol 3-kinase (PI3K)/ protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) pathway. Over half of clinical osteosarcoma samples presented loss or low expression of PTEN, which usually indicated an advanced stage of tumor and a poor prognosis. The expression of PTEN is regulated by epigenetic silence, transcription regulation, post-translational modifications, and protein interactions in osteosarcoma. Therefore, explicating regulations to restore the anti-tumor function of PTEN might provide novel targeted therapies for osteosarcoma. Preclinical evidence suggested directly targeting the altered PTEN in osteosarcoma was promising. Current clinical application of PTEN related therapies in osteosarcoma are PI3K/mTOR inhibitors, and these drugs have shown the favorable efficacy in patients with advanced osteosarcoma.

Role of PI3K/AKT pathway in cancer: the framework of malignant behavior

Given that the PI3K/AKT pathway has manifested its compelling influence on multiple cellular process, we further review the roles of hyperactivation of PI3K/AKT pathway in various human cancers. We state the abnormalities of PI3K/AKT pathway in different cancers, which are closely related with tumorigenesis, proliferation, growth, apoptosis, invasion, metastasis, epithelial-mesenchymal transition, stem-like phenotype, immune microenvironment and drug resistance of cancer cells. In addition, we investigated the current clinical trials of inhibitors against PI3K/AKT pathway in cancers and found that the clinical efficacy of these inhibitors as monotherapy has so far been limited despite of the promising preclinical activity, which means combinations of targeted therapy may achieve better efficacies in cancers. In short, we hope to feature PI3K/AKT pathway in cancers to the clinic and bring the new promising to patients for targeted therapies.

CNDP2 Acts as an Activator for Human Ovarian Cancer Growth and Metastasis via the PI3K/AKT Pathway

Introduction:

The mechanism of tumorigenesis and metastasis of ovarian cancer has not yet been elucidated. This study aimed to investigate the role and molecular mechanism of cytosolic nonspecific dipeptidase 2 in tumorigenesis and metastasis.

Methods:

Cytosolic nonspecific dipeptidase 2 expression in human ovarian cancer tissues and cell lines was assessed with methyl thiazolyl tetrazolium (MTT), clone formation, and transwell assays performed to evaluate the ability of ovarian cancer cells to proliferate and migrate. Nude mice tumor formation experiments were also performed by subcutaneously injecting cells with stable cytosolic nonspecific dipeptidase 2 knockdown and control SKOV3 cells into BALB/c female nude mice to detect changes in PI3K/AKT pathway-related proteins by Western blotting.

Results:

Cytosolic nonspecific dipeptidase 2 was highly expressed in human ovarian cancer tissues, with its expression associated with pathological data, including ovarian cancer metastasis. A cytosolic nonspecific dipeptidase 2 stable knockdown or ectopic expression ovarian cancer cell model was established and demonstrated that cytosolic nonspecific dipeptidase 2 could promote the proliferation of ovarian cancer cells. Transwell cell migration and invasion assays confirmed that cytosolic nonspecific dipeptidase 2 enhanced cell metastasis in ovarian cancer. Furthermore, in vivo xenograft experiments demonstrated that cytosolic nonspecific dipeptidase 2 can promote the development and progression of ovarian cancer, increasing the expression of phosphorylated PI3K and AKT.

Conclusions:

Cytosolic nonspecific dipeptidase 2 promotes the occurrence and development of ovarian cancer through the PI3K/AKT signaling pathway.

Overexpression of eIF3D in Lung Adenocarcinoma Is a New Independent Prognostic Marker of Poor Survival

The eukaryotic initiation factor 3 (eIF3) is the largest and most complex translation initiation factor in mammalian cells. It consists of 13 subunits and among which several were implicated to have significant prognostic effects on multiple human cancer entities. To examine the expression profiles of eIF3 subunits and determine their prognostic value in patients with lung adenocarcinoma (LUAD), the genomic data, survival data, and related clinical information were obtained from The Cancer Genome Atlas (TCGA) project for a secondary analysis. The results showed that among ten aberrantly expressed eIF3 subunits in tumours compared with adjacent normal counterparts (p < 0.05), only upregulated eIF3D could predict poor overall survival (OS) outcome independent of multiple clinicopathological parameters (HR = 2.043, 95% CI: 1.132-3.689, p = 0.018). Chi-square analysis revealed that the highly expressed eIF3D group had larger ratios of patients with advanced pathological stage (68/40 vs. 184/206, p = 0.0046), residual tumour (13/4 vs. 163/176, p = 0.0257), and targeted molecular therapy (85/65 vs. 138/164, p = 0.0357). In silico analysis demonstrated that the altered expression of eIF3D was at least regulated by both copy number alterations (CNAs) and the hypomethylation of cg14297023 site. In conclusion, high eIF3D expression might serve as a valuable independent prognostic indicator of shorter OS in patients with LUAD.

DMBT1 suppresses progression of gallbladder carcinoma through PI3K/AKT signaling pathway by targeting PTEN

Gallbladder carcinoma (GBC) is a highly lethal malignancy of the gastrointestinal tract. Despite extensive research, the underlying molecular mechanism of GBC remains largely unclear. Deleted in malignant brain tumors 1 (DMBT1) is low-expression during cancer progression and as a potential tumor-suppressor gene in various types of cancer. However, its role in Gallbladder cancer remains poorly understood. Here, we found that DMBT1 was significantly low-expression and deletion of copy number in GBC tissues by qRT-PCR and Western blot. Overexpression of DMBT1 impaired survival, promoted apoptosis in GBC cells in vitro, and inhibited tumor progression in vivo. Further study of underlying mechanisms demonstrated that DMBT1 combined with PTEN which could stabilize PTEN protein, resulting in inhibiting the activation of PI3K/AKT signaling pathway. Our study revealed a new sight of DMBT1 as a tumor-suppressor gene on the PI3K/AKT pathway in GBC, which may be a potential therapeutic target for improving treatment.

SGO1 induces proliferation and metastasis of prostate cancer through AKT-mediated signaling pathway

Although studies have revealed some of the pathological causes associated with prostate cancer progression, further studies are still needed. Shugoshin 1 (SGO1) is a protein essential for precise chromosome segregation during mitosis and meiosis. However, the role and mechanism of SGO1 in tumors and even prostate cancer is not completely clear. In this study, expression of SGO1 in human prostate tumors were higher than that of adjacent normal tissues and were positively correlated with the poor prognosis of prostate cancer patients. SGO1 expression levels are also higher in several prostate cancer cell lines. In cell experiments, knockdown of SGO1 reduced cell proliferation, migration, and invasion in vitro and in vivo, and also inhibited cell cycle progression of prostate cancer cells. In contrast, ectopic expression of SGO1 has the opposite effects. In addition, knockdown of SGO1 induces apoptosis in prostate cancer cells by promoting cleaved caspase-3, caspase-9, and PARP. Importantly SGO1 function is dependent on AKT. Inhibition of AKT activity by AKT inhibitor abolished the role of SGO1 overexpression in promoting cell proliferation and metastasis. Therefore, SGO1 promotes the proliferation and metastasis of prostate cancer through the AKT pathway, and can be considered as an effective candidate for developing an effective prostate cancer treatment strategy.

Eukaryotic translation initiation factor 6 overexpression plays a major role in the translational control of gallbladder cancer

BACKGROUND

Gallbladder cancer (GBC) is a rare neoplasia of the biliary tract with high mortality rates and poor prognosis. Signs and symptoms of GBC are not specific and often arise at late stage of disease. For this reason, diagnosis is typically made when the cancer is already in advanced stages, and prognosis for survival is less than 5 years in 90% of cases. Biomarkers to monitor disease progression and novel therapeutic alternative targets for these tumors are strongly required. Commonly, dysregulated protein synthesis contributes to carcinogenesis and cancer progression. In this case, protein synthesis directs translation of specific mRNAs, and, in turn, promotes cell survival, invasion, angiogenesis, and metastasis of tumors. In eukaryotes, protein synthesis is regulated at its initiation, which is a rate-limiting step involving eukaryotic translation initiation factors (eIFs). We hypothesize that eIFs represent crossroads in the development of GBC, and might serve as potential biomarkers. The study focus was the role of eIF6 (an anti-association factor for the ribosomal subunits) in GBC.

METHODS

In human GBC samples, the expression of eIF6 was analyzed biochemically at the protein (immunohistochemistry, immunoblot analyses) and mRNA levels (qRT-PCR).

RESULTS

High levels of eIF6 correlated with shorter overall survival in biliary tract cancer (BTC) patients (n = 28). Immunohistochemical data from tissue microarrays (n = 114) demonstrated significantly higher expression levels of eIF6 in GBC compared to non-neoplastic tissue. Higher eIF6 expression on protein (immunoblot) and mRNA (qRT-PCR) level was confirmed by analyzing fresh frozen GBC patient samples (n = 14). Depletion of eIF6 (using specific siRNA-mediated knockdown) in Mz-ChA-2 and TFK-1 cell lines inhibited cell proliferation and induced apoptosis.

CONCLUSION

Our data indicates that eIF6 overexpression plays a major role in the translational control of GBC, and indicates its potential as a new biomarker and therapeutic target in GBC.

G protein-coupled receptor kinase 2 (GRK2) as a multifunctional signaling hub

Accumulating evidence indicates that G protein-coupled receptor kinase 2 (GRK2) is a versatile protein that acts as a signaling hub by modulating G protein-coupled receptor (GPCR) signaling and also via phosphorylation or scaffolding interactions with an extensive number of non-GPCR cellular partners. GRK2 multifunctionality arises from its multidomain structure and from complex mechanisms of regulation of its expression levels, activity, and localization within the cell, what allows the precise spatio-temporal shaping of GRK2 targets. A better understanding of the GRK2 interactome and its modulation mechanisms is helping to identify the GRK2-interacting proteins and its substrates involved in the participation of this kinase in different cellular processes and pathophysiological contexts.

EIF3D promotes sunitinib resistance of renal cell carcinoma by interacting with GRP78 and inhibiting its degradation

Background

Sunitinib is one of the multi-targeted tyrosine kinase inhibitors for the treatment of renal cell carcinoma (RCC) at present. However, its clinical efficacy is limited by chemoresistance of RCC. Our previous study found that eukaryotic translation initiation factor 3 subunit D (EIF3D) was an oncogene in the development and progression of RCC but little is known about whether EIF3D participated in sunitinib resistance of RCC.

Methods

The expression of EIF3D in the tumor tissue specimen was detected by immunohistochemistry. The effect of EIF3D on sunitinib-resistance of RCC cells was evaluated by colony formation, IC50 proliferation and in vivo tumor growth assays. The interaction between EIF3D and glucose regulated protein 78 (GRP78) was assessed by Co-IP and Western blot assays.

Finding

EIF3D expression was found higher in 786-OR and ACHN-R cells with acquired sunitinib resistance than that in 786-O and ACHN cells sunitinib to sensitive. The EIF3D level was also up-regulated in sunitinib-chemoresistant tumor tissues compared with chemosensitive tumor tissues. Functional study showed that EIF3D knockdown decreased cell viability with sunitinib treatment. Mechanistical study demonstrated that EIF3D interacted with GRP78 and enhanced protein stability through blocking the ubiquitin-mediated-proteasome degradation of GRP78. GRP78 overexpression induced sunitinib resistance of RCC cells by triggering the unfolded protein response, whereas GRP78 silencing inhibited cell viability. Forced expression of GRP78 eliminated the inhibitory effect of EIF3D silencing on cell growth in vitro and in vivo.

Interpretation

our results indicate that EIF3D played an important role in sunitinib resistance of RCC cells, suggesting that it may prove to be a potential therapeutic target for RCC.

NOP2/Sun RNA methyltransferase 2 promotes tumor progression via its interacting partner RPL6 in gallbladder carcinoma

NOP2/Sun domain family, member 2 (NSUN2) is a nuclear RNA methyl-transferase catalyzing 5-methylcytosine formation. Evidence shows that NSUN2 is correlated with cell unlimited proliferation. However, its functional role in gallbladder carcinoma (GBC), which is the most common biliary tract malignancy and has a poor prognosis, remains to be determined. Here we found that NSUN2 was highly expressed in GBC tissues as well as cell lines. NSUN2 silencing repressed GBC cell proliferation and tumorigenesis both in vitro and in vivo. Conversely, upregulation of NSUN2 enhanced GBC cell growth and colony formation. We further discovered that RPL6 was a closely interacting partner with NSUN2. Silencing RPL6 resulted in insufficient NSUN2 translational level and accumulative NSUN2 transcriptional level. Exogenous expression of NSUN2 partially rescued the effect of RPL6 in gallbladder cancer progression. Taken together, our data provided novel mechanic insights into the function of NSUN2 in GBC, thus pointing to NSUN2 as a potential and effective therapeutic approach to GBC treatment.

Inhibition of MicroRNA-15a/16 Expression Alleviates Neuropathic Pain Development through Upregulation of G Protein-Coupled Receptor Kinase 2

There is accumulating evidence that microRNAs are emerging as pivotal regulators in the development and progression of neuropathic pain. MicroRNA-15a/16 (miR-15a/16) have been reported to play an important role in various diseases and inflammation response processes. However, whether miR-15a/16 participates in the regulation of neuroinflammation and neuropathic pain development remains unknown. In this study, we established a mouse model of neuropathic pain by chronic constriction injury (CCI) of the sciatic nerves. Our results showed that both miR-15a and miR-16 expression was significantly upregulated in the spinal cord of CCI rats. Downregulation of the expression of miR-15a and miR-16 by intrathecal injection of a specific inhibitor significantly attenuated the mechanical allodynia and thermal hyperalgesia of CCI rats. Furthermore, inhibition of miR-15a and miR-16 downregulated the expression of interleukin-1β and tumor-necrosis factor-α in the spinal cord of CCI rats. Bioinformatic analysis predicted that G protein-coupled receptor kinase 2 (GRK2), an important regulator in neuropathic pain and inflammation, was a potential target gene of miR-15a and miR-16. Inhibition of miR-15a and miR-16 markedly increased the expression of GRK2 while downregulating the activation of p38 mitogen-activated protein kinase and NF-κB in CCI rats. Notably, the silencing of GRK2 significantly reversed the inhibitory effects of miR-15a/16 inhibition in neuropathic pain. In conclusion, our results suggest that inhibition of miR-15a/16 expression alleviates neuropathic pain development by targeting GRK2. These findings provide novel insights into the molecular pathogenesis of neuropathic pain and suggest potential therapeutic targets for preventing neuropathic pain development.

Reduced eIF3d accelerates HIV disease progression by attenuating CD8+ T cell function

Background

In human immunodeficiency virus (HIV) infection, 10–15% of individuals exhibit a rapid decline in CD4+ T cells and become rapid progressors (RPs). Overall, understanding the factors affecting rapid disease progression in early HIV infection (EHI) can aid in treatment initiation. Recent studies show that eIF3s, classic scaffold proteins during the translation initiation process, can directly promote or inhibit the translation of mRNA, therefore participating in the regulation of cell function. However, to our knowledge, it has not been addressed whether eIF3s are involved in the diverse prognosis of HIV infection.

Methods

Expression of eIF3s in primary cells from early or chronic HIV-infected patients was detected by real-time PCR. To investigate the potential mechanisms of eIF3d in the regulation of CD8+ T cell function, complete transcriptomes of eIF3d-inhibited Jurkat T cells were sequenced by RNA sequencing (RNA-Seq). Additionally, to examine the effect of eIF3d on CD8+ T cell function, eIF3d expression was inhibited alone or in combination with SOCS-7 knockdown by siRNA in isolated CD8+ T cells. CD8+ T cell proliferation, IFN-r secretion and apoptosis were detected by flow cytometry. Moreover, the effect of eIF3d on HIV replication was evaluated in Jurkat cells, peripheral blood mononuclear cells (PBMCs) and CD4+ T cells with eIF3d knockdown using a pNL4-3 pseudotyped virus.

Results

At approximately 100 days of infection, only eIF3d was markedly decreased in RPs compared with chronic progressors (CPs). Expression of eIF3d correlated significantly with disease progression in EHI. Based on in vitro analyses, reduced eIF3d expression led to decreased proliferation and IFN-γ secretion and increased apoptosis in CD8+ T cells. Inhibited expression of eIF3d caused enhanced expression of SOCS-7, and inhibiting SOCS-7 expression by siRNA rescued the attenuated CD8+ T cell function caused by eIF3d. Finally, when eIF3d was inhibited in Jurkat cells, PBMCs and CD4+ T cells, pNL4-3-VSV-G virus replication was enhanced.

Conclusions

The current data highlight the importance of eIF3d in HIV infection by inhibiting CD8+ T cell function and promoting viral replication. Our study provides potential targets for improved immune intervention.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-1925-0) contains supplementary material, which is available to authorized users.

SP/NK-1R promotes gallbladder cancer cell proliferation and migration

Aberrant substance P/neurokinin‐1 receptor (SP/NK‐1R) system activation plays a critical role in various disorders, however, little is known about the expression and the detailed molecular mechanism of the SP and NK‐1R in gallbladder cancer (GBC). In this study, we firstly analyzed the expression and clinical significance of them in patients with GBC. Then, cellular assays were performed to clarify their biological role in GBC cells. Moreover, we investigated the molecular mechanisms regulated by SP/NK‐1R. Meanwhile, mice xenografted with human GBC cells were analyzed regarding the effects of SP/NK1R complex in vivo. Finally, patient samples were utilized to investigate the effect of SP/NK‐1R. The results showed that SP and NK‐1R were highly expressed in GBC. We found that SP strongly induced GBC cell proliferation, clone formation, migration and invasion, whereas antagonizing NK‐1R resulted in the opposite effects. Moreover, SP significantly enhanced the expression of NF‐κB p65 and the tumor‐associated cytokines, while, Akt inhibitor could reverse these effects. Further studies indicated that decreasing activation of NF‐κB or Akt diminished GBC cell proliferation and migration. In consistent with results, immunohistochemical staining showed high levels of Akt, NF‐κB and cytokines in tumor tissues. Most importantly, the similar conclusion was obtained in xenograft mouse model. Our findings demonstrate that NK‐1R, after binding with the endogenous agonist SP, could induce GBC cell migration and spreading via modulation of Akt/NF‐κB pathway.

SLC25A22 Promotes Proliferation and Metastasis of Osteosarcoma Cells via the PTEN Signaling Pathway

Osteosarcoma is a highly malignant bone tumor. However, due to the high complexity of the occurrence and metastasis of osteosarcoma, the exact mechanism promoting its development and progression remains to be elucidated. This study highlights the causal link between solute carrier family 25 member 22 (SLC25A22) and the development, progression, and metastasis of osteosarcoma. SLC25A22 is upregulated in human osteosarcoma and predicts a poor prognosis. The upregulation of SLC25A22 in osteosarcoma tissues was significantly associated with cell proliferation, invasion, and metastasis. Studies of functional gain (overexpression) and loss (knockdown) showed that SLC25A22 significantly increases the ability of osteosarcoma cells to proliferate, as well as invade and metastasize in vitro. At the same time, the expression of SLC25A22 promoted the progression of the cellcycle of osteosarcoma cell lines and inhibited the apoptosis of osteosarcoma cells. Analysis using a mouse xenograft model showed that xenografts of SLC25A22 stable overexpressing osteosarcoma cells had a significant increase in tumor volume and weight compared to the control group. Lung metastasis models in mice showed that expression of SLC25A22 promoted lung metastasis of osteosarcoma in vivo. Furthermore, SLC25A22 inhibited phosphatase and tensin homolog expression and increased phosphorylation of protein kinase b (Akt) and Focal Adhesion Kinase (FAK) in the phosphatase and tensin homolog signaling pathway. In summary, SLC25A22 is highly expressed in osteosarcoma, promoting osteosarcoma cell proliferation and invasion by inhibiting the phosphatase and tensin homolog signaling pathway.

SLC25A22 promotes proliferation and metastasis by activating MAPK/ERK pathway in gallbladder cancer

Background

SLC25A22, a member of mitochondrial carrier system (MCS) family encoding a mitochondrial glutamate transporter, has been reported to have vital roles in promoting proliferation and migration in cancer. Gallbladder cancer (GBC) is the most common biliary tract malignancy and has a poor prognosis. We aimed to determine the expression and function of SLC25A22 in GBC.

Methods

Immunohistochemistry (IHC) staining analysis and quantitative real-time PCR (qRT-PCR) were conducted to determine the expression of SLC25A22 in GBC tissues. Human NOZ and GBC-SD cells were used to perform the experiments. The protein expression was detected by western-blot analysis. Cell viability was evaluated via CCK-8 assay and colony formation assay. Cell migration and invasion in vitro were investigated by wound healing and transwell assay. Annexin V/PI staining assay for apoptosis were measured by flow cytometry. The effect of SLC25A22 in vivo was conducted with subcutaneous xenograft.

Results

We indicated that the expression of SLC25A22 was significantly upregulated in GBC tumor tissues as well as cell lines. Downregulation of SLC25A22 inhibited GBC cell growth and proliferation in vitro and in vivo and also had an effect on metastasis of GBC cells through the EMT processes. In addition, inhibition of SLC25A22 promoted mitochondrial apoptosis via downregulating BCL-2 and upregulating cleaved PARP, Cytochrome-c, and BAX mediated by MAPK/ERK pathway.

Conclusions

Our study identified that SLC25A22 promoted development of GBC activating MAPK/ERK pathway. SLC25A22 has a potential to be used as a target for cancer diagnosis of GBC and related therapies.

GRP137 promotes cell proliferation and metastasis through regulation of the PI3K/AKT pathway in human ovarian cancer

PURPOSE

Ovarian cancer is one of the leading causes of death for women worldwide. The present study aims to investigate the role of G protein-coupled receptor 137 (GPR137) in the biological activities of ovarian cancer cells.

METHODS

(QUERY: Please supply Methods for Abstract)

RESULTS

G protein-coupled receptor 137 was highly expressed in clinical ovarian cancer tissues and exhibited the highest protein levels in SKOV3 cells and OVCAR3 cells. Knockdown of GPR137 caused significant decreases in cell proliferative rates and colony formation abilities in SKOV3 cells and OVCAR3 cells and also inhibited the in vivo tumorigenesis in a xenograft model. It was observed that knockdown of GPR137 inhibited cell motility by up to 40% in SKOV3 cells and approximately 65% in OVCAR3 cells in wound-healing assay. Cell migration abilities were consistently inhibited by 68.2% in SKOV3 cells and 59.3% in OVCAR3 cells, whereas cell invasion abilities were inhibited by 64.0% and 74.2% in SKOV3 and OVCAR3 cells, respectively, after knockdown of GPR137. When GPR137 was depleted, epithelial markers were increased, while mesenchymal markers decreased.

CONCLUSIONS

Our data suggest that GPR137 plays pro-oncogenic roles in ovarian cancer via regulation of the PI3K/AKT pathway. These observations might pave new insights into therapeutic strategies against human ovarian cancer.

Up-regulation Of EIF3e Is Associated with The Progression of Esophageal Squamous Cell Carcinoma and Poor Prognosis in Patients

Introduction: Esophageal cancer is one of the most common malignant tumors in the world. Eukaryotic translation initiation factors 3e (eIF3e) makes a notable difference in the initiation of protein synthesis and tumor progression. However, the role of eIF3e in ESCC has not been revealed yet. This study aims to investigate the bio-functional and prognostic role of eIF3e in human ESCC tissues and cells. Methods: Immunohistochemical staining and Western blot were performed to detect the eIF3e expression in ESCC patients' tissues. The Kaplan-Meier product limit method and Cox regression were conducted to analyze the association between eIF3e expression, together with other related clinical/pathological features, and patients' prognosis. In the analysis of bio-functional role of eIF3e, CCK-8 and Transwell assay were performed to compare the proliferative and migrative ability after knockdown of eIF3e. Results: Up-regulation of eIF3e were demonstrated in ESCC tissues compared with the corresponding para-cancerous tissues. Overexpression of eIF3e was associated with deep tumor depth, lymph nodes metastasis, and advanced TNM stage. Importantly, the patients with high eIF3e expression suffered shorter overall and disease-free survival. Lymph node metastasis and histological grade served as independent prognostic predictors in patients' prognosis. Knockdown of eIF3e could inhibit cell proliferation and migration, in vitro. Conclusions: The eIF3e expression, or combined with other members of eIF3 complex, might predict poor prognosis of ESCC and serve as a potential breakthrough in the multimodality therapy of ESCC.

Tea polyphenols induce S phase arrest and apoptosis in gallbladder cancer cells

Gallbladder cancer (GBC) is the most common malignancy in the biliary tract. Without effective treatment, its prognosis is notoriously poor. Tea polyphenols (TPs) have many pharmacological and health benefits, including antioxidant, anti-inflammatory, anti-tumor, anti-thrombotic, antibacterial, and vasodilatory properties. However, the anti-cancer effect of TPs in human gallbladder cancer has not yet been determined. Cell viability and colony formation assay were used to investigate the cell growth. Cell cycle and apoptosis were evaluated by flow cytometry analysis. Western blot assay was used to detect the expression of proteins related to cell cycle and apoptosis. Human tumor xenografts were used to examine the effect of TPs on gallbladder cancer cells in vivo. TPs significantly inhibited cell growth of gallbladder cancer cell lines in a dose- and time-dependent manner. Cell cycle progression in GBC cells was blocked at the S phase by TPs. TPs also induced mitochondrial-related apoptosis in GBC cells by upregulating Bax, cleaved caspase-3, and cleaved PARP expressions and downregulating Bcl-2, cyclin A, and Cdk2 expressions. The effects of TPs on GBC were further proven in vivo in a mouse xenograft model. Our study is the first to report that TPs inhibit GBC cell growth and these compounds may have potential as novel therapeutic agents for treating gallbladder cancer.

PEAK1, acting as a tumor promoter in colorectal cancer, is regulated by the EGFR/KRas signaling axis and miR-181d

PEAK1 is upregulated in multiple human malignancies and has been associated with tumor invasion and metastasis, but little is known about the role of PEAK1 in colorectal cancer (CRC) progression. We investigated the expression pattern, function and regulatory mechanisms of PEAK1 in CRC. Here, we found that PEAK1 is overexpressed in CRC tissues and that high PEAK1 expression predicts poor survival in colon cancer but not rectal cancer. Functionally, silencing PEAK1 inhibits cell proliferation, migration, and invasion in vitro and inhibits the growth of tumor xenografts in nude mice. Mechanistic studies revealed that PEAK1 is induced by epidermal growth factor receptor (EGFR) signaling and that PEAK1 is required for KRas-induced CRC cell growth and metastasis. Furthermore, we demonstrated that miR-181d directly targets PEAK1. Ectopic expression of miR-181d reduces the expression of PEAK1 and inhibits the growth and metastasis of CRC cells in vitro. Clinically, miR-181d is downregulated in CRC samples, and low miR-181d is correlated with poor patient survival. Our study demonstrates the importance of PEAK1 in CRC progression and suggests a potential mechanism by which increasing PEAK1 expression in CRC might be the result of EGFR/KRas signal activation and consequent miR-181d repression.

Embraced by eIF3: structural and functional insights into the roles of eIF3 across the translation cycle

Protein synthesis is mediated via numerous molecules including the ribosome, mRNA, tRNAs, as well as translation initiation, elongation and release factors. Some of these factors play several roles throughout the entire process to ensure proper assembly of the preinitiation complex on the right mRNA, accurate selection of the initiation codon, errorless production of the encoded polypeptide and its proper termination. Perhaps, the most intriguing of these multitasking factors is the eukaryotic initiation factor eIF3. Recent evidence strongly suggests that this factor, which coordinates the progress of most of the initiation steps, does not come off the initiation complex upon subunit joining, but instead it remains bound to 80S ribosomes and gradually falls off during the first few elongation cycles to: (1) promote resumption of scanning on the same mRNA molecule for reinitiation downstream—in case of translation of upstream ORFs short enough to preserve eIF3 bound; or (2) come back during termination on long ORFs to fine tune its fidelity or, if signaled, promote programmed stop codon readthrough. Here, we unite recent structural views of the eIF3–40S complex and discus all known eIF3 roles to provide a broad picture of the eIF3’s impact on translational control in eukaryotic cells.

eIF3: a factor for human health and disease

The eukaryotic initiation factor 3 (eIF3) is one of the most complex translation initiation factors in mammalian cells, consisting of several subunits (eIF3a to eIF3m). It is crucial in translation initiation and termination, and in ribosomal recycling. Accordingly, deregulated eIF3 expression is associated with different pathological conditions, including cancer. In this manuscript, we discuss the interactome and function of each subunit of the human eIF3 complex. Furthermore, we review how altered levels of eIF3 subunits correlate with neurodegenerative disorders and cancer onset and development; in addition, we evaluate how such misregulation may also trigger infection cascades. A deep understanding of the molecular mechanisms underlying eIF3 role in human disease is essential to develop new eIF3-targeted therapeutic approaches and thus, overcome such conditions.