Humans ; Carcinoma, Hepatocellular ; Liver Neoplasms ; Ribonucleoproteins ; Eukaryotic Initiation Factor-4E

Post-stroke depression (PSD) is a serious and common complication of stroke, which seriously affects the rehabilitation of stroke patients. To date, the pathogenesis of PSD is unclear and effective treatments remain unavailable. Here, we established a mouse model of PSD through photothrombosis-induced focal ischemia. By using a combination of brain imaging, transcriptome sequencing, and bioinformatics analysis, we found that the hippocampus of PSD mice had a significantly lower metabolic level than other brain regions. RNA sequencing revealed a significant reduction of miR34b-3p, which was expressed in hippocampal neurons and inhibited the translation of eukaryotic translation initiation factor 4E (eIF4E). Furthermore, silencing eIF4E inactivated microglia, inhibited neuroinflammation, and abolished the depression-like behaviors in PSD mice. Together, our data demonstrated that insufficient miR34b-3p after stroke cannot inhibit eIF4E translation, which causes PSD by the activation of microglia in the hippocampus. Therefore, miR34b-3p and eIF4E may serve as potential therapeutic targets for the treatment of PSD.
Animals ; Mice ; Depression ; Eukaryotic Initiation Factor-4E/metabolism* ; MicroRNAs/metabolism* ; Neurons/metabolism* ; Stroke/metabolism*

OBJECTIVE: To investigate the effect of eukaryotic translation initiation factor 4E(eIF4E) on the autophagy of CD138 plasma cells in multiple myeloma(MM). METHODS: Multiple myeloma CD138 plasma cells were treated with eIF4E inhibitor 4EGI, the changes of autophagy-related factors LC3-II and Beclin1 were detected by fluorescent quantitative PCR and Western blot, the changes of cell proliferation inhibition were detected by MTT assay, and cell apoptosis was detected by flow cytometry. RESULTS: Quantitative fluorescence PCR showed that after treatment of myeloma cells with 4EGI, the expression levels of LC3-II and Beclin1 mRNA gradually increased with the enhancomer of 4EGI concentration and the prolongation of action time, and the differences were statistically significant (48 h: LC3-Ⅱ,r=0.942, Beclin1,r=0.952; 80 μg/ml: LC3-Ⅱ,r=0.966, Beclin1,r=0.998）; Western blot showed that with the enhancement of 4EGI concentration, the expression of LC3-II and Beclin1 protein gradually increased（LC3-Ⅱ,r=0.923, Beclin1,r=0.977）; CCK-8 showed that the inhibition rate of cells gradually increased （r=0.996）; the apoptotic rate of 4EGI-treated groups (23.23±4.47, 7.59±1.67, 2.03±0.19) was significantly different from that of control group (0.03±0.04) (P<0.05). CONCLUSION The inhibition of eIF4E can activate the autophagy of CD138 plasma cells in multiple myeloma and induce the death of myeloma cells.
Autophagy ; Beclin-1 ; Cell Line, Tumor ; Eukaryotic Initiation Factor-4E ; Humans ; Multiple Myeloma

OBJECTIVE: To investigate the anti-leukemia effect of total saponins of Rubus parvifolius L. (TSRP) on K562 cell xenografts in nude mice and the mechanisms of action. METHODS: The K562 cell xenografts in nude mice were established, and then randomly divided into 5 groups, the control group, the cytosine arabinoside group(Ara-c) and 3 TSRP groups (20, 40 and 100 mg/kg). The tumor volume and mass of each group of nude mice were measured and the anti-tumor rates of TSRP were calculated subsequently. The apoptosis status of tumor cells was detected by hematoxylin-eosin (HE) and terminal dexynucleotidyl transferase (TdT)-mediated dUTP nick end labeling (TUNEL) staining analysis. Finally, the activities of apoptosis related signaling of signal transducer and activator of transcription 3 (STAT3), eukaryotic initiation factor 4E (eIF4E) and B-cell lymphoma-2 (bcl-2) were determined with immunohistochemistry tests. RESULTS: Subcutaneous injection of K562 cells induced tumor formation in nude mice, and the TSRP treated group showed a signifificant inhibitory effect on tumor formation. The nude mice treated with TSRP showed a signifificant decrease in tumor growth rate and tumor weight in comparison to the control group (all P<0.05). The HE staining and TUNEL assay showed that TSRP induced cell death by apoptosis. The immunohistochemical assay showed down-regulation of the bcl-2 gene in the TSRP treated cells. The phosphorylation levels of eIF4E and STAT3 were decreased obviously after the treatment of TSRP. CONCLUSION TSRP had an excellent tumor-suppressing effect on K562 cells in the nude mice xenograft model, suggesting that TSPR can be developed as a promising anti-chronic myeloide leukemia drug.
Animals ; Apoptosis ; drug effects ; Eukaryotic Initiation Factor-4E ; physiology ; Humans ; K562 Cells ; Leukemia ; drug therapy ; pathology ; Male ; Mice ; Rubus ; chemistry ; STAT3 Transcription Factor ; physiology ; Saponins ; pharmacology ; Signal Transduction ; drug effects ; Xenograft Model Antitumor Assays

MicroRNAs (miRNAs) recruit the RNA-induced silencing complex (RISC) to repress the translation of target mRNAs. While the 5' 7-methylguanosine cap of target mRNAs has been well known to be important for miRNA repression, the underlying mechanism is not clear. Here we show that TNRC6A interacts with eIF4E2, a homologue of eIF4E that can bind to the cap but cannot interact with eIF4G to initiate translation, to inhibit the translation of target mRNAs. Downregulation of eIF4E2 relieved miRNA repression of reporter expression. Moreover, eIF4E2 downregulation increased the protein levels of endogenous IMP1, PTEN and PDCD4, whose expression are repressed by endogenous miRNAs. We further provide evidence showing that miRNA enhances eIF4E2 association with the target mRNA. We propose that miRNAs recruit eIF4E2 to compete with eIF4E to repress mRNA translation.
Autoantigens ; metabolism ; Cell Line ; Eukaryotic Initiation Factor-4E ; metabolism ; Gene Silencing ; Humans ; MicroRNAs ; genetics ; Protein Transport ; RNA, Messenger ; biosynthesis ; genetics ; RNA-Binding Proteins ; metabolism

OBJECTIVETo explore the clinical significance of eukaryotic initiation factor 4 E (eIF4E) and mammalian target of rapamycin (mTOR) expressions in esophageal squamous carcinoma tissues.

METHODSClinicopathological data and paraffin samples of resected tumor tissue from 148 patients with esophageal squamous carcinoma undergoing resection in our department between January 2010 and December 2012 were collected retrospectively. Expressions of eIF4E and mTOR were detected in above carcinoma tissues, counterpart para-carcinoma tissues (1 cm distance to carcinoma) and normal tissues (5 cm distance to carcinoma) with Western blot and immunohistochemistry. Their relevance with clinicopathological features was analyzed.

RESULTSExpression of mTOR located mainly in cytoplasm and elF4E mainly in cellular membrane, presenting as yellow grains. These two markers showed strong expression in carcinoma tissues and weak or none in para-carcinoma tissues. In esophageal squamous carcinoma tissues, counterpart para-carcinoma tissues and normal tissues, mTOR protein expression was 85.8% (127/148), 35.1% (52/148) and 3.4% (5/148), eIF4E protein expression was 93.9% (139/148), 35.1% (52/148) and 12.8% (19/148), with a downtrend respectively (all P<0.05). Expressions of mTOR and eIF4E were associated with tumor invasion depth and lymphatic metastasis (all P<0.05), while mTOR expression was associated with differentiation degree (P=0.003), but eIF4E expression was not. Both expressions were not associated with gender, age, and tumor size (all P>0.05).

CONCLUSIONSExpressions of eIF4E and mTOR are up-regulated in esophageal squamous carcinoma tissues, which may be associated with tumor malignance and lymphatic metastasis of esophageal squamous carcinoma. Combined detection of two markers may be helpful to predict the tumor malignance and the prognosis of patients.

Carcinoma, Squamous Cell ; diagnosis ; metabolism ; Esophageal Neoplasms ; diagnosis ; metabolism ; Eukaryotic Initiation Factor-4E ; metabolism ; Humans ; Immunohistochemistry ; Lymphatic Metastasis ; Prognosis ; Retrospective Studies ; TOR Serine-Threonine Kinases ; metabolism

The present study evaluated the expression of key molecules and the status of DNA in both oral squamous cell carcinoma (OSCC) and adjacent tissues to establish a molecular surgical boundary and provide a cancer progression model. Biopsy samples from 50 OSCC patients were divided into T (cancer), P1 (0-0.5 cm), P2 (0.5-1 cm), P3 (1-1.5 cm) and P4 (1.5-2 cm) groups based on the distances from the visible boundary of the primary focus. Twenty samples of normal mucosa were used as controls. We used immunohistochemical staining and flow cytometry to evaluate p53, p21(CIP1/WAF1), eIF4E and Ki-67 expression and to determine DNA status, respectively. Sub-mucosal invasion was present in the P1 and P2 groups as determined by haematoxylin and eosin staining. Mutant p53 expression decreased gradually from cancerous to normal mucosae, whereas p21(CIP1/WAF1) expression displayed an opposite trend. eIF4E expression decreased from cancerous to normal mucosae. Ki-67 expression, the heteroploidy ratio, S-phase fraction and proliferative index decreased gradually with the distance from the tumour centre. Based on these results, we suggest that the resection boundary in OSCC surgery should be beyond 2 cm from the tumour. Additionally, the adjacent tissues of the primary focus could be used as a model for assessing cancer progression.
Adult ; Aged ; Carcinoma, Squamous Cell ; metabolism ; pathology ; Cyclin-Dependent Kinase Inhibitor p21 ; metabolism ; Disease Progression ; Eukaryotic Initiation Factor-4E ; metabolism ; Female ; Humans ; Male ; Middle Aged ; Mouth Neoplasms ; metabolism ; pathology ; Tumor Suppressor Protein p53 ; metabolism

We investigated how the dual inhibition of the molecular mechanism of the mammalian target of the rapamycin (mTOR) downstreams, P70S6 kinase (P70S6K) and eukaryotic initiation factor 4E (eIF4E), can lead to a suppression of the proliferation and progression of urothelial carcinoma (UC) in an orthotopic mouse non-muscle invasive bladder tumor (NMIBT) model. A KU-7-luc cell intravesically instilled orthotopic mouse NMIBC model was monitored using bioluminescence imaging (BLI) in vivo by interfering with different molecular components using rapamycin and siRNA technology. We then analyzed the effects on molecular activation status, cell growth, proliferation, and progression. A high concentration of rapamycin (10 microM) blocked both P70S6K and elF4E phosphorylation and inhibited cell proliferation in the KU-7-luc cells. It also reduced cell viability and proliferation more than the transfection of siRNA against p70S6K or elF4E. The groups with dual p70S6K and elF4E siRNA, and rapamycin reduced tumor volume and lamina propria invasion more than the groups with p70S6K or elF4E siRNA instillation, although all groups reduced photon density compared to the control. These findings suggest that both the mTOR pathway downstream of eIF4E and p70S6K can be successfully inhibited by high dose rapamycin only, and p70S6K and Elf4E dual inhibition is essential to control bladder tumor growth and progression.
Animals ; Cell Line ; Cell Proliferation/drug effects/genetics ; Cell Survival/drug effects ; Disease Progression ; Eukaryotic Initiation Factor-4E/*antagonists & inhibitors/genetics ; Female ; Mice ; Mice, Nude ; Mucous Membrane/pathology ; Phosphorylation/drug effects ; RNA Interference ; RNA, Small Interfering ; Ribosomal Protein S6 Kinases, 70-kDa/*antagonists & inhibitors/genetics ; Signal Transduction/drug effects ; Sirolimus/*pharmacology ; TOR Serine-Threonine Kinases/*antagonists & inhibitors/metabolism ; Urinary Bladder Neoplasms/genetics/*pathology ; Urothelium/pathology

We investigated how the dual inhibition of the molecular mechanism of the mammalian target of the rapamycin (mTOR) downstreams, P70S6 kinase (P70S6K) and eukaryotic initiation factor 4E (eIF4E), can lead to a suppression of the proliferation and progression of urothelial carcinoma (UC) in an orthotopic mouse non-muscle invasive bladder tumor (NMIBT) model. A KU-7-luc cell intravesically instilled orthotopic mouse NMIBC model was monitored using bioluminescence imaging (BLI) in vivo by interfering with different molecular components using rapamycin and siRNA technology. We then analyzed the effects on molecular activation status, cell growth, proliferation, and progression. A high concentration of rapamycin (10 microM) blocked both P70S6K and elF4E phosphorylation and inhibited cell proliferation in the KU-7-luc cells. It also reduced cell viability and proliferation more than the transfection of siRNA against p70S6K or elF4E. The groups with dual p70S6K and elF4E siRNA, and rapamycin reduced tumor volume and lamina propria invasion more than the groups with p70S6K or elF4E siRNA instillation, although all groups reduced photon density compared to the control. These findings suggest that both the mTOR pathway downstream of eIF4E and p70S6K can be successfully inhibited by high dose rapamycin only, and p70S6K and Elf4E dual inhibition is essential to control bladder tumor growth and progression.
Animals ; Cell Line ; Cell Proliferation/drug effects/genetics ; Cell Survival/drug effects ; Disease Progression ; Eukaryotic Initiation Factor-4E/*antagonists & inhibitors/genetics ; Female ; Mice ; Mice, Nude ; Mucous Membrane/pathology ; Phosphorylation/drug effects ; RNA Interference ; RNA, Small Interfering ; Ribosomal Protein S6 Kinases, 70-kDa/*antagonists & inhibitors/genetics ; Signal Transduction/drug effects ; Sirolimus/*pharmacology ; TOR Serine-Threonine Kinases/*antagonists & inhibitors/metabolism ; Urinary Bladder Neoplasms/genetics/*pathology ; Urothelium/pathology

To explore the regulation of eIF4E, we screened the protein interacting with eIF4E from human cDNA library by using yeast two-hybrid system. Several clones interacting with eIF4E were identified. One of them was homologous with HUWE1 (HECT, UBA and WWE domain containing 1, also named as ARF-BP1, HECTH9 or HUWE1). Cell co-immunoprecipitation showed that eIF4E could bind to HUWE1 in mammalian cells. We also found that HUWE1 bearing the HECT domain is necessary for its association with eIF4E.
Animals ; Eukaryotic Initiation Factor-4E ; metabolism ; Humans ; Ubiquitin-Protein Ligases ; metabolism