Nucleo-cytoplasmic shuttling of 14-3-3 epsilon carrying hnRNP C promotes autophagy.

Translocation of 14-3-3 protein epsilon (14-3-3ε) was found to be involved in Triptolide (Tp)-induced inhibition of colorectal cancer (CRC) cell proliferation. However, the form of cell death induced by 14-3-3ε translocation and mechanisms underlying this effect remain unclear. This study employed label-free LC-MS/MS to identify 14-3-3ε-associated proteins in CRC cells treated with or without Tp. Our results confirmed that heterogeneous nuclear ribonucleoproteins C1/C2 (hnRNP C) were exported out of the nucleus by 14-3-3ε and degraded by ubiquitination. The nucleo-cytoplasmic shuttling of 14-3-3ε carrying hnRNP C mediated Tp-induced proliferation inhibition, cell cycle arrest and autophagic processes. These findings have broad implications for our understanding of 14-3-3ε function, provide an explanation for the mechanism of nucleo-cytoplasmic shuttling of hnRNP C and provide new insights into the complex regulation of autophagy.

Microwave-enhanced hydrogen production: a review.

Currently, the massive use of fossil fuels, which still serve as the dominant global energy, has led to the release of large amounts of greenhouse gases. Providing abundant, clean, and safe renewable energy is one of the major technical challenges for humankind. Nowadays, hydrogen-based energy is widely considered a potentially ideal energy carrier that could provide clean energy in the fields of transportation, heat and power generation, and energy storage systems, almost without any impact on the environment after consumption. However, a smooth energy transition from fossil-fuel-based energy to hydrogen-based energy must overcome a number of key challenges that require scientific, technological, and economic support. To accelerate the hydrogen energy transition, advanced, efficient, and cost-effective methods for producing hydrogen from hydrogen-rich materials need to be developed. Therefore, in this study, a new alternative method based on the use of microwave (MW) heating technology in enhanced hydrogen production pathways from plastic, biomass, low-carbon alcohols, and methane pathways compared with conventional heating methods is discussed. Furthermore, the mechanisms of MW heating, MW-assisted catalysis, and MW plasma are also discussed. MW-assisted technology usually has the advantages of low energy consumption, easy operation, and good safety practices, which make it a promising solution to supporting the future hydrogen society.

Microstructures and Mechanical Properties of an AlCoCrNiFe HEA/WC Reinforcing Particle Composite Coating Prepared by Laser Cladding.

In this study, an AlCoCrFeNi HEA coating with a 10% mass fraction of WC particles was fabricated on the surface of 316L stainless steel by laser cladding technology. WC powders were formed by the partial or total dissolution of the initial WC particles with different sizes in the AlCoCrFeNi HEA coating. Micron WC particles were dispersed in the coating homogeneously, and millimeter WC particles were deposited on the bottom of coating because of their high density. The addition of the WC powers prompted Columnar dendritic and cellular grains, observed in the bottom and top regions of the coating, respectively. Additionally, this led to a higher micro-hardness and better corrosion resistance than that of the pure HEA coating.

Network meta-analysis of curative efficacy of different acupuncture methods on obesity combined with insulin resistance.

Objective: This study aims to systematically evaluate the curative efficacy of different acupuncture methods in the treatment of obesity combined with insulin resistance in randomized clinical trials (RCTs) by network meta-analysis. Methods: Four Chinese databases (CNKI, WanFang Data, VIP, and SinoMed) and four English databases (PubMed, Embase, the Cochrane Library, and www.clinicaltrial.gov) were electronically searched to identify qualified studies. Two reviewers independently screened the literature in accordance with the inclusion/exclusion criteria by EndNote 20 software and extracted data by ADDIS1.16.8 software, and then the risk of bias of the included studies were evaluated by the Cochrane tool. Network meta-analysis was performed by Stata 15.1 software. The primary outcomes included fasting blood glucose (FBG), fasting serum insulin (FINS), homeostasis model assessment-insulin resistance (HOMA-IR), and body mass index (BMI). The secondary outcomes included waistline, waist-hip ratio, triglyceride (TG), total cholesterol (TC), high-density lipoprotein (HDL), and low-density lipoprotein (LDL). Results: Five RCTs with a total of 410 patients with obesity combined with insulin resistance were included. The results of the network meta-analysis showed that, compared with the control group, three kinds of acupuncture methods (electropuncture, acupoint catgut embedding, and acupuncture point patch) had significant efficacy in reducing FBG [electropuncture (MD = -0.44, 95% CI: -0.83, -0.05) and acupoint catgut embedding (MD = -0.36, 95% CI: -0.51, -0.21)], FINS [electropuncture (MD = -6.17, 95% CI: -9.69, -2.65), acupoint catgut embedding (MD = -5.87, 95% CI: -6.92, -4.82), and acupuncture point patch (MD = -5.86, 95% CI: -11.40, -0.32)], HOMA-IR [electropuncture (MD = -1.59, 95% CI: -2.73, -0.45) and acupoint catgut embedding (MD =-0.91, 95% CI: -1.07, -0.75)], BMI [electropuncture (MD = -1.68, 95% CI: -2.70, -0.66), acupoint catgut embedding (MD = -3.39, 95% CI: -4.38, -2.40), and acupuncture point patch [MD = -2.90, 95%CI: -4.93, -0.87)], and waistline [electropuncture (MD = -5.49, 95% CI: -8.56, -2.42) and acupoint catgut embedding (MD = -4.91, 95% CI: -7.51, -2.31)] in obese patients with insulin resistance, suggesting that their efficacy was better than that of the western medicine group in some of the outcome indicators. For the index related to blood lipid, the efficacy of electropuncture was significantly better than behavioral therapy and western medicine. Except that acupoint catgut embedding was superior to electroacupuncture in reducing the BMI, there was no statistically significant difference in efficacy among the three acupuncture methods. Conclusions: The results showed that the therapeutic effect of acupuncture methods was superior to conventional western treatment alone. Acupuncture methods could serve as an alternative or adjunctive treatment in obese patients with insulin resistance. Systematic Review Registration: https://inplasy.com, identifier 202280075.

Flipping the Switch: Reverse-Demand Voltage-Sensitive Fluorophores.

Fluorescence microscopy with fluorescent reporters that respond to environmental cues is a powerful method for interrogating biochemistry and biophysics in living systems. Photoinduced electron transfer (PeT) is commonly used as a trigger to modulate fluorescence in response to changes in the biological environment. PeT-based indicators rely on PeT either into the excited state (acceptor PeT) or out of the excited state (donor PeT). Our group has been developing voltage-sensitive fluorophores (VF dyes) that respond to changes in biological membrane potential (Vm). We hypothesize that the mechanism of voltage sensitivity arises from acceptor PeT (a-PeT) from an electron-rich aniline-containing molecular wire into the excited-state fluorophore, resulting in decreased fluorescence at negative Vm. In this work, we reversed the direction of electron flow to access donor-excited PeT (d-PeT) VF dyes by introducing electron-withdrawing rather than electron-rich molecular wires. VF dyes containing electron-withdrawing groups show voltage-sensitive fluorescence, but with the opposite polarity: hyperpolarizing Vm now gives fluorescence increases. We used a combination of computation and experiment to design and synthesize five d-PeT VF targets, two of which are voltage-sensitive.

Status Quo and Research Trends of Neurosurgical Departments in China: Bibliometric and Scientometric Analyses.

BACKGROUND: Modern neurosurgery is a relatively young discipline characterized by finesse and complexity. In recent years, neurosurgery in China has made continuous developments, with long-term progress and outstanding discoveries in many aspects of the field. OBJECTIVE: This scientometric investigation aimed to comprehensively provide insight into the development trends of neurosurgery in China, to demonstrate how the field has evolved. METHODS: PubMed database was searched to retrieve relevant papers published between 1988 and 2018 from neurosurgery institutions in China. The database of the National Natural Science Foundation of China was also retrieved for funding information. Information (eg, year of publication, journal, institute of origin) and keywords were collected from each paper after removing duplicates and filtering unintentional words. Co-word analysis was performed on the papers' keywords, and a time distribution matrix of coexisting keywords in a given paper (ie, termed co-words) was established. Co-words were clustered according to their growth rate within years and visually presented with a mountain plot and a heatmap. Trends and potential subspecialties were identified, and each topic, represented either by a co-word from publications or funding from the National Natural Science Foundation of China during the period from 2011 to 2018, was collected and analyzed. RESULTS: Within 15,972 publications on neurosurgery from institutions in China, diagnostic image was found to coexist the most with other keywords. Cluster 0, represented by diagnostic image with retrospective study, contained emerging topics with great developmental potential and demonstrated high growth rates in recent years. This finding suggests that the topics represented in Cluster 0 may represent future areas of important neurosurgical research. We also found that the developmental trend of China's neurosurgical research is highly correlated with National Natural Science Foundation of China funding acquisition. CONCLUSIONS: Co-word analysis and visualization results provided insight into the emerging research topics that are of vital importance, which can be used as a reference by neurosurgeons and researchers for future investigations. In this study, our analysis strategy based on co-word biclustering was able to clearly demonstrate current academic subject development; therefore, co-word biclustering is a reliable bibliometric analysis strategy.

Biomass-derived carbon from Ganoderma lucidum spore as a promising anode material for rapid potassium-ion storage.

The design and preparation of powerful anode materials are key to developing potassium-ion batteries. A biomass-based potassium anode material with a distinct hollow-cage structure was prepared by one-step carbonization. The target carbon exhibited a specific surface area of 104.4 m2 g-1 and mesopores/macropores distributed materials. When used as the negative electrode of a potassium-ion battery, the cage-like porous carbon (CPC) showed a reversible capacity of 407 mAh g-1 after 50 cycles at 50 mA g-1 current density. After 100 cycles, at a current density of 200 mA g-1, the reversible capacity was 163.8 mAh g-1. It still exhibits an extremely long cycle stability at high current densities (discharge capacity of 124.6 mAh g-1 after 700 cycles at a current density of 1 A g-1). The excellent performance is attributed to the stable cage-like carbon scaffold and uniform continuous distribution of mesopores/macropores to improve ion diffusion kinetics and electronic conductivity. These results indicate that a properly designed CPC can effectively increase the capacity and cycle stability of a potassium-ion battery.

Si@SnS2 -Reduced Graphene Oxide Composite Anodes for High-Capacity Lithium-Ion Batteries.

Invited for this month's cover is the group of Weitang Yao at the Southwest University of Science and Technology. The image shows that developing low-cost and high-energy-density batteries is important for powering our city. The Si@SnS2 -rGO composites are good electrode materials for Li-ion batteries. The Full Paper itself is available at 10.1002/cssc.201902839.

Si@SnS2 -Reduced Graphene Oxide Composite Anodes for High-Capacity Lithium-Ion Batteries.

One of the key challenges for the development of lithium-ion batteries is the preparation of high-performance anode materials. In this paper, a micro/nanostructured Si@SnS2 -rGO composite is reported in which Si nanoparticles with a particle size of 30 nm are electrostatically anchored on a 3D reduced graphene oxide (rGO) network and mixed with SnS2 . The step-wise lithiation/delithiation of SnS2 provided space-constraining effects to accommodate volume expansion and particle aggregation, thereby alleviating the volume expansion of Si during cycling as well as enhancing the structural stability, whereas the rGO in the 3D network stabilized the composite. The composite had a high specific capacity of 1480.1 mAh g-1 after 200 cycles at a current density of 200 mA g-1 and a high stability at rates of 200-3000 mA g-1 . The capacity attenuation after cycling was only 89.18 %. A stable specific capacity (425.5 mAh g-1 ) was achieved after 600 cycles at a current density of 3000 mA g-1 . Therefore, the micro/nanostructured Si@SnS2 -rGO composite is a promising anode material for use in lithium-ion batteries.

Marek's Disease Virus Activates the PI3K/Akt Pathway Through Interaction of Its Protein Meq With the P85 Subunit of PI3K to Promote Viral Replication.

It is known that viruses can active the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway in host cells to support cell survival and viral replication; however, the role of PI3K/Akt signaling in the pathogenic mechanisms induced by Marek's disease virus (MDV) which causes a neoplastic Marek's disease in poultry, remains unknown. In this study, we showed that MDV activated the PI3K/Akt pathway in chicken embryo fibroblasts (CEFs) at the early phase of infection, whereas treatment with a PI3K inhibitor LY294002 prior to MDV infection decreased viral replication and DNA synthesis. Flow cytometry analysis showed that inhibition of the PI3K/Akt pathway could significantly increase apoptosis in MDV-infected host cells, indicating that activation of PI3K/Akt signaling could facilitate viral replication through support of cell survival during infection. Evaluation of the underlying molecular mechanism by co-immunoprecipitation and laser confocal microscopy revealed that a viral protein Meq interacted with both p85α and p85ß regulatory subunits of PI3K and could induce PI3K/Akt signaling in Meq-overexpressing chicken fibroblasts. Our results showed, for the first time, that MDV activated PI3K/Akt signaling in host cells through interaction of its Meq protein with the regulatory p85 subunit of PI3K to delay cell apoptosis and promote viral replication. This study provides clues for further studies of the molecular mechanisms underlying MDV infection and pathogenicity for the host.

Identification of Key Candidate Proteins and Pathways Associated with Temozolomide Resistance in Glioblastoma Based on Subcellular Proteomics and Bioinformatical Analysis.

TMZ resistance remains one of the main reasons why treatment of glioblastoma (GBM) fails. In order to investigate the underlying proteins and pathways associated with TMZ resistance, we conducted a cytoplasmic proteome research of U87 cells treated with TMZ for 1 week, followed by differentially expressed proteins (DEPs) screening, KEGG pathway analysis, protein-protein interaction (PPI) network construction, and validation of key candidate proteins in TCGA dataset. A total of 161 DEPs including 65 upregulated proteins and 96 downregulated proteins were identified. Upregulated DEPs were mainly related to regulation in actin cytoskeleton, focal adhesion, and phagosome and PI3K-AKT signaling pathways which were consistent with our previous studies. Further, the most significant module consisted of 28 downregulated proteins that were filtered from the PPI network, and 9 proteins (DHX9, HNRNPR, RPL3, HNRNPA3, SF1, DDX5, EIF5B, BTF3, and RPL8) among them were identified as the key candidate proteins, which were significantly associated with prognosis of GBM patients and mainly involved in ribosome and spliceosome pathway. Taking the above into consideration, we firstly identified candidate proteins and pathways associated with TMZ resistance in GBM using proteomics and bioinformatic analysis, and these proteins could be potential biomarkers for prevention or prediction of TMZ resistance in the future.

Antitumor Activity and Mechanism of a Reverse Transcriptase Inhibitor, Dapivirine, in Glioblastoma.

ETHNOPHARMACOLOGICAL RELEVANCE: Dapivirine is one of reverse transcriptase inhibitors (RTIs). It is the prototype of diarylpyrimidines (DAPY), formerly known as TMC120 or DAPY R147681 (IUPAC name: 4- [[4-(2, 4, 6-trimethylphenyl) amino]-2-pyrimidinyl] amino]-benzonitrile; CAS no.244767-67-7). AIM: The purpose of this study is to investigate the antitumor activity of dapivirine, one of the RTIs, on U87 glioblastoma (GBM) cells in vitro and in vivo. MATERIALS AND METHODS: U87 GBM cells were cultured and treated with or without dapivirine. Cell viability was evaluated by CCK-8 (Cell Counting Kit 8, CCK-8) assay; apoptosis was analyzed by flow cytometry; cell migration was evaluated by Boyden Chamber assay; Western blotting was performed to detect proteins related to apoptosis, epithelial-to-mesenchymal transition and autophagy. PathScan intracellular signaling array kit was used to detect important and well-characterized signaling molecules. Tumor xenograft model in nude mice was used to evaluate the antitumorigenic effect in vivo. RESULTS: Dapivirine weakened proliferation of glioma cells and induced the apoptosis of U87 glioblastoma cells. Furthermore, dapivirine regulated autophagy and induced Akt, Bad and SAPK/JNK activations. Moreover, the inhibition of glioma cell growth by dapivirine was also observed in nude mice in vivo. CONCLUSION: In summary, in our study dapivirine exposure induces stress, resulting in JNK and PI3K/Akt pathway activation through diminished inhibition of the apoptosis and autophagy cascade in U87 GBM cells, which inhibits cell growth in vitro and in vivo.

[MACF1 knockdown in glioblastoma multiforme cells increases temozolomide-induced cytotoxicity].

OBJECTIVE: To investigate the role of microtubule-actin crosslinking factor 1 (MACF1) in the response of glioma cells to temozolomide (TMZ). METHODS: TMZ was applied to a human gliomablastoma cell line (U87) and changes in the protein expression and cellular localization were determined with Western blot, RT-PCR, and immunofluorescence. The responses of the cells with MACF1 expression knockdown by RNA interference to TMZ were assessed. TMZ-induced effects on MACF1 expression were also assessed by immunohistochemistry in a nude mouse model bearing human glioblastoma xenografts. RESULTS: TMZ resulted in significantly increased MACF1 expression (by about 2 folds) and changes in its localization in the gliomablastoma cells both in vitro and in vivo (P<0.01). Knockdown of MACF1 reduced the proliferation (by 45%) of human glioma cell lines treated with TMZ (P<0.01). TMZ-induced changes in MACF1 expression was accompanied by cytoskeletal rearrangement. CONCLUSION: MACF1 may be a potential therapeutic target for glioblastoma.

Expression of dynein, cytoplasmic 2, heavy chain 1 (DHC2) associated with glioblastoma cell resistance to temozolomide.

Temozolomide (TMZ) is the main chemotherapeutic drug utilized for the treatment of glioblastoma multiforme (GMB), however, drug resistance often leads to tumor recurrence and poor outcomes. GMB cell lines were treated with TMZ for up to two weeks and then subjected to proteomics analysis to identify the underlying molecular pathology that is associated with TMZ resistance. Proteomics data showed that TMZ altered expression of proteins that related to cytoskeleton structure and function, such as DHC2 and KIF2B. qRT-PCR and immunofluorescence were used to verify expression of DHC2 and KIF2B in these cells. Immunohistochemistry was used to verify expression of these two proteins in xenografts of a nude mouse model, and ex vivo GBM tissue samples. Their expression was knocked down using siRNA to confirm their role in the regulation of GBM cell sensitivity to TMZ. Knockdown of DHC2 expression enhanced sensitivity of U87 cells to TMZ treatment. Ex vivo data showed that DHC2 expression in GBM tissue samples was associated with tumor recurrence after TMZ chemotherapy. These results indicated cytoskeleton related protein DHC2 reduced sensitivity of GBM cells to TMZ treatment. Further studies should assess DHC2 as a novel target in GBM for TMZ combination treatment.

AGE/RAGE/Akt pathway contributes to prostate cancer cell proliferation by promoting Rb phosphorylation and degradation.

Metabolomic research has revealed that metabolites play an important role in prostate cancer development and progression. Previous studies have suggested that prostate cancer cell proliferation is induced by advanced glycation end products (AGEs) exposure, but the mechanism of this induction remains unknown. This study investigated the molecular mechanisms underlying the proliferative response of prostate cancer cell to the interaction of AGEs and the receptor for advanced glycation end products (RAGE). To investigate this mechanism, we used Western blotting to evaluate the responses of the retinoblastoma (Rb), p-Rb and PI3K/Akt pathway to AGEs stimulation. We also examined the effect of knocking down Rb and blocking the PI3K/Akt pathway on AGEs induced PC-3 cell proliferation. Our results indicated that AGE-RAGE interaction enhanced Rb phosphorylation and subsequently decreased total Rb levels. Bioinformatics analysis further indicated a negative correlation between RAGE and RB1 expression in prostate cancer tissue. Furthermore, we observed that AGEs stimulation activated the PI3K/Akt signaling pathway and that blocking PI3K/Akt signaling abrogated AGEs-induced cell proliferation. We report, for the first time, that AGE-RAGE interaction enhances prostate cancer cell proliferation by phosphorylation of Rb via the PI3K/Akt signaling pathway.

Proteomic analysis on effectors involved in BMP-2-induced osteogenic differentiation of beagle bone marrow mesenchymal stem cells.

OBJECTIVE: To identify the protein regulation profile of recombinant human bone morphogenetic protein-2 (rhBMP-2)-induced osteogenic differentiation in beagle bone marrow stem cells (BMSCs). METHODS: Beagle BMSCs were isolated and cultured with or without rhBMP-2. Two-dimensional gel electrophoresis was used to determine the differences in protein expression in rhBMP-2-induced and non-induced BMSCs. Real-time PCR and western blotting analyses were used to verify the expression patterns of selected proteins. RESULTS: After the induction, the osteogenic differentiation of beagle BMSCs was activated successfully. Nine and 11 proteins were found to be down- and up-regulated by rhBMP-2, respectively. The increase in Lim and SH3 domain protein 1(LASP1) and the decrease in ferritin were verified by real-time PCR and western blotting analyses. CONCLUSIONS: Among the 20 rhBMP-2-regulated factors, there is empirical evidence supporting the involvement of LASP1 and ferritin in osteogenic differentiation. LASP1 plays an important role in the regulation of the activity of the cytoskeleton, and ferritin is an important molecule in cellular iron homeostasis. Further studies focused on these 20 proteins will help elucidate the molecular mechanism(s) through which rhBMP-2 induces osteogenic differentiation of BMSCs.

[Recombinant human bone morphogenetic protein-2 down-regulates LASP1 and up-regulates ferritin during osteogenic differentiation of beagle dog bone marrow mesenchymal stem cells].

OBJECTIVE: To identify the proteins involved in osteogenic differentiation of beagle dog bone marrow mesenchymal stem cells (BMSCs) and explore its possible regulation mechanism of osteogenic differentiation of BMSCs. METHODS: Cultured beagle dog BMSCs were induced by recombinant human bone morphogenetic protein-2 (rhBMP-2) for 7 days. The differentially expressed proteins between cells with osteogenic differentiation and control cells were identified by proteomics analysis based on two-dimensional gel electrophoresis. Q-PCR and Western blotting were used to verify the interested protein of LASP1, ferritin light chain and heavy chain. RESULTS: Osteogenic differentiation was induced successfully in the BMSCs. Twenty differentially expressed proteins were identified by proteomic analysis, including 9 down-regulated and 11 up-regulated ones. Q-PCR and Western blotting demonstrated a significant reduction of LASP1 expression and significant up-regulation of ferritin in the BMSCs after a 7-day induction with rhBMP-2. CONCLUSION: LASP1, which plays an important role in the regulation of the activity of the cytoskeleton, and ferritin, an important molecule in cellular iron homeostasis, can be critical in the osteogenic differentiation of beagle dog BMSCs induced by rhBMP-2.

Down-regulation of miR-200b-3p by low p73 contributes to the androgen-independence of prostate cancer cells.

BACKGROUND: An increasing body of evidence indicates that microRNAs play critical roles in androgen-independent prostate cancer (AIPC) growth. However, the regulation of the expression of microRNAs in AIPC is not very clear. In this study, we investigated the role that the interaction between miR-200b-3p and p73 plays in the proliferation of AIPC. METHODS: We compared several relevant microRNAs and cancer related genes between the androgen-dependent prostate cancer (ADPC) cell line and the AIPC cell line using quantitative real-time PCR (Q-PCR) and Western blot. Then we examined the effect of p73 and miR-200b-3p on the proliferation of AIPC and ADPC using CCK-8. Furthermore we investigated the regulation of miR-200b-3p by p73. RESULTS: p73 and miR-200b-3p were both downregulated in the PC3 cell line (AIPC). Down-regulation of both p73 and miR-200b-3p increased the proliferation of ADPC cells cultured with androgen-free medium, while up-regulation of p73 and miR-200b-3p decreased the proliferation of AIPC cells. When p73 was over-expressed in the AIPC cell subline, miR-200b-3p expression increased accordingly, while p73 was inhibited in ADPC cells cultured with androgen-free medium and miR-200b-3p expression decreased significantly. CONCLUSION: miR-200b-3p is down-regulated by low expression of p73 in AIPC cells, and this interaction contributes to the proliferation of AIPC.

Derepression of c-Fos caused by microRNA-139 down-regulation contributes to the metastasis of human hepatocellular carcinoma.

This study investigates whether the anti-metastasis effect of microRNA-139 (miR-139) on hepatocellular carcinoma (HCC) is mediated through regulating c-fos expression. The expression levels of miR-139 and c-fos in human HCC cell sublines with high (MHCC97H) and low (MHCC97L) spontaneous metastatic potentials were quantified using QPCR or Western blot. miR-139 mimics was transfected into MHCC97H cells to overexpress miR-139, and miR-139 inhibitor was transfected into MHCC97L cells to down-express miR-139. The effect of overexpression or down-expression of miR-139 on c-fos expression of MHCC97H and MHCC97L cells was evaluated using QPCR and Western blot. The 3' untranslated region segments of FOS containing the miR-139 binding sites were amplified by PCR, and the luciferase activity in the transfected cells was assayed. In comparison with the expression level of miR-139 in MHCC97L cells, the expression level in MHCC97H cells was significantly decreased, whereas c-Fos was significantly up-regulated in MHCC97H. The overexpression of miR-139 significantly inhibited the expression of c-fos in MHCC97H cells, and the down-expression of miR-139 significantly promoted the expression of c-fos in MHCC97L cells. miR-139 suppressed the luciferase activity of the pGL-FOS by approximately 40% compared with the negative control. In vitro cell migration analysis demonstrated that depletion of c-fos or overexpression of miR-139 in MHCC97H cells reduced cell migration, whereas overexpression of c-fos or depletion of miR-139 in MHCC97L cells increased cell migration. Thus, we got the conclusion that miR-139 expression is down-regulated in human HCC cell sublines with high spontaneous metastatic potentials (MHCC97H). Derepression of c-Fos caused by miR-139 down-regulation contributes to the metastasis of HCC.

Nix protein positively regulates NF-κB activation in gliomas.

Previous reports indicate that the NIX/BNIP3L gene acts as a pro-apoptotic factor by interacting with BCL2 and BCL-XL, playing an important role in hypoxia-dependent cell death and acting as a tumor suppressor. However, many studies also showed that NIX is linked to a protective role and cell survival in cancer cells. Nuclear factor-κB (NF-κB) can attenuate apoptosis in human cancers in response to chemotherapeutic agents and ionizing radiation. We observed an absence of i-κBα (NF-κB activation inhibitor) expression, but a greater expression of Nix and p-NF-κB proteins in the Nix-wt U251 cells, which was not observed in the Nix-kn cells under hypoxic conditions. Using electrophoretic mobility shift assay (EMSA) and luciferase detection, the activation of NF-κB was detected only in the Nix-wt U251 cells with hypoxia. These data imply that Nix protein might play a role in the positive regulation of the NF-κB pathway. Moreover, 46 cases of glioma also showed high levels of Nix protein expression, which was always accompanied by high p-NF-κB expression. Patients with Nix (+) showed less tissue apoptosis behavior in glioblastoma (GBM), unlike that observed in the Nix-negative patients (-). The same apoptotic tendency was also identified in anaplastic astrocytoma (AA) groups, but not in astrocytoma (AS). On analyzing the Kaplan-Meier curve, better tumor-free survival was observed only in cases of astrocytoma, and not in AA and GBM. Thus, our study indicates that Nix protein might have multiple functions in regulating glioma behaviors. In the low-grade gliomas (astrocytoma) with low expression of NF-κB, the cell death-inducing function that occurs through a Bax mechanism might predominate and act as a tumor suppressor. While in the malignant gliomas (AA and GBM), with higher expression of the NIX gene and with activity of the NF-κB pathway, the oncogene function of Nix was predominant.