mTOR activation is critical for betulin treatment in renal cell carcinoma cells

Betulin, a natural product isolated from the bark of the birch trees, exhibits multiple anticancer effects. Activation of mTOR signaling pathway has been found in numerous cancers, including renal cell carcinoma (RCC). Here, we attempted to study whether mTOR signaling was essential for betulin to treat RCC. Based on cell survival and colony formation assays, we found that mTOR hyperactive RCC cell line 786-O cells were more sensitive to betulin treatment compared with mTOR-inactive Caki-2 cells. Knockdown of TSC2 in Caki-2 cells had similar results to 786-O cells, and mTOR silencing in 786-O cells rescued the inhibitory effect of betulin, indicating that betulin inhibited RCC cell proliferation in an mTOR-dependent manner. Furthermore, betulin treatment decreases the levels of glucose consumption and lactate production in 786-O cells, while minimal effects were observed in Caki-2 cells. In addition, betulin significantly inhibited the expression of PKM2 and HK2 in 786-O cells. Finally, knockdown of PKM2 or HK2 in 786-O reversed the anti-proliferative effects of betulin, and overexpression of PKM2 or HK2 in Caki-2 cells enhanced the sensitivity to betulin treatment. Taken together, these findings demonstrated the critical role of mTOR activation in RCC cells to betulin treatment, suggesting that betulin might be valuable for targeted therapies in RCC patients with mTOR activation.

Nanoplasmonic Biosensor Using Localized Surface Plasmon Resonance Spectroscopy for Biochemical Detection

Localized surface plasmon resonance (LSPR) associated with metal nanostructures has developed into a highly useful sensor technique. Optical LSPR spectroscopy of nanostructures often shows sharp absorption and scattering peaks, which can be used to probe several bio-molecular interactions. Here, we report nanoplasmonic biosensors using LSPR on nanocup arrays (nanoCA) to recognize bio-molecular binding for biochemical detection. These sensors can be modified to quantify binding of small molecules to proteins for odorant and explosive detections. Electrochemical LSPR biosensors can also be designed by coupling electrochemistry and LSPR spectroscopy measurements. Multiple sensing information can be obtained and electrochemical LSPR property can be investigated for biosensors. In some applications, the electrochemical LSPR biosensor can be used to quantify immunoreactions and enzymatic activity. The biosensors exhibit better performance than those of conventional optical LSPR measurements. With multi-transducers, the nanoplasmonic biosensor can provide a promising approach for bio-detection in environmental monitoring, healthcare diagnostics, and food quality control.

Zinc Nanoparticles-equipped Bioelectronic Nose Using a Microelectrode Array for Odorant Detection

Bioelectronic noses, such as olfactory cell- and receptor-based biosensors, have important applications for biomimetic odorant detection in various fields. Here, a nanoparticle-equipped biosensor was designed to record extracellular potentials from olfactory receptor cells effectively. In this research, a microelectrode array (MEA) was combined with olfactory epitheliums as the olfactory biosensor to record electrophysiological signals of receptor cells in the epitheliums. Zinc nanoparticles (NanoZn) were employed along with the biosensor for different kinds of odorant measurements, which improved the electrophysiological responses to odor molecules. The NanoZn-equipped biosensor showed greater performance, such as a higher sensitivity and a larger signal-to-noise ratio, than that without the nanoparticles. Thus, this approach provided a promising method to improve the detecting performance of biosensors based on olfactory cells and receptors, which would bring broad application prospects for bioelectronic noses in environmental monitoring, food analysis, and healthcare diagnosis.

Identification of therapeutic targets for Parkinson's disease via bioinformatics analysis

The present study aimed to identify molecular targets that have important roles in the progression of Parkinson's disease. The gene expression profile dataset GSE7621 and the microRNA (miRNA) expression profile dataset GSE16658 were downloaded from the Gene Expression Omnibus database. R programing software was used to identify differentially expressed genes and miRNAs. Subsequently, enriched Gene Ontology terms of differentially expressed genes were obtained using the Database for Annotation, Visualization and Integrated Discovery. Target genes of differentially expressed miRNAs were identified using the starBase database and a miRNA-gene regulatory network was constructed using Cytoscape software. A total of 391 differentially expressed genes and 88 differentially expressed miRNAs were identified. Gene Ontology terms that were associated with nervous system activity, including synapse and dopamine metabolic process, were shown to be enriched in the differentially expressed genes. A total of 620 target genes were identified from the differentially expressed miRNAs, and 10 overlaps were identified between these target genes and differentially expressed genes. Furthermore, 10 miRNA-gene regulation pairs were obtained between the overlaps and differentially expressed miRNAs. In conclusion, the present study used bioinformatics analysis of gene and miRNA expression profile datasets, and identified potential therapeutic targets for Parkinson's disease.

[Expression of Ether à go-go 1 and its molecular mechanism of regulating the malignant phenotype of osteosarcoma]

Objective: To explore the expression of ether à go-go 1 (Eag1) in human osteosarcoma and its molecular mechanisms of regulating the malignant phenotype of osteosarcoma. Methods: The expression levels of Eag1 in osteosarcoma cell lines and human osteosarcoma tissues were detected by reverse transcription polymerase chain reaction (RT-PCR), western blot analysis and immunohistochemistry. The small interfering RNA (siRNA) was used to inhibit the expression of Eag1. The abilities of proliferation and invasion in osteosarcoma cells transfected with Eag1 siRNA were determined by CCK-8, colony formation assay, transwell assay and wound healing assay. The osteosarcoma xenograft model of nude mouse was established and tumor growth curve was drawn. Western blot analysis was performed to detect the expression of vascular endothelial growth factor (VEGF) and signal transducer and activator of transcription 3 (STAT3) in osteosarcoma cells transfected with Eag1 siRNAs. Results: Eag1 was overexpressed in the osteosarcoma cells and tissues. Compared with the scrambled siRNA group, the cell survival rates of Eag1 siRNA1 and Eag1 siRNA2 groups of the two cell lines were significantly lower. [MG-63 cells: scrambled siRNA group (100.0±4.65)%, Eag1 siRNA1 group (63.57±3.89)%, and Eag1 siRNA2 group (54.13±3.70)%; Saos-2 cells: scrambled siRNA group (100.00±5.46)%, Eag1 siRNA1 group (56.70±5.34)%, and Eag1 siRNA2 group (40.27±5.28)% (P<0.001 for all)]. Similar results were obtained from colony formation assay. The colony formation rates of MG-63 cells: the scrambled siRNA group was (92.00±3.46)%, Eag1 siRNA1 group (60.00±3.06)%, and Eag1 siRNA2 group (53.67±2.40)%; the colony formation rates of Saos-2 cells: the scrambled siRNA group was (92.00±5.57)%, Eag1 siRNA1 group (52.33±5.13)%, and Eag1 siRNA2 group (41.67±2.73)%. Compared with the scrambled siRNA group, P<0.001 for all. The tumor volumes of osteosarcoma xenograft in the Eag1 siRNA1 and Eag1 siRNA2 groups were significantly smaller than that in the scrambled siRNA group after 10 days treatment (P<0.01 for all). The invasion assay data showed that MG-63 and Saos-2 cells transfected with Eag1 siRNAs exhibited the ability of cell invasion, when compared with the cells transfected with scrambled siRNA. (Invasive cell number of MG-63 cells: the scrambled siRNA group was 134.00±3.61, Eag1 siRNA1 group 105.20±2.52, and Eag1 siRNA2 group 91.00±3.01; Invasive cell number of Saos-2 cells: the scrambled siRNA group was 132.30±3.23, Eag1 siRNA1 group 114.30±3.48, and Eag1 siRNA2 group 82.67±6.33. Compared with the scrambled siRNA group, P<0.01 for all. The migration rates were (62.48±1.83)%, (35.98±1.23)% and (32.30±1.20)% in the three groups of MG-63 cells, and (70.15±1.42)%, (41.38±1.34)% and (32.40±1.92)% in the three groups of Saos-2 cells, respectively. Compared with the scrambled siRNA group, P<0.001 for all. Notably, the expression levels of VEGF decreased evidently after Eag1 siRNAs transfection, paralleled with reduction in the expression levels of STAT3. Conclusions: Eag1 may promote osteosarcoma cell proliferation and invasion by targeting STAT3-VEGF pathway and may be a potential therapeutic target for osteosarcoma.

Silencing of hERG1 Gene Inhibits Proliferation and Invasion, and Induces Apoptosis in Human Osteosarcoma Cells by Targeting the NF-κB Pathway

Recently, the human ether à go-go (eag) related gene 1 (hERG1) channel, a member of the voltage-dependent potassium channel (Kv) family, was determined to have a critical role in cancer cell proliferation, invasion, tumorigenesis and apoptosis. However, the expression levels and functions of hERG1 in osteosarcoma cells remain poorly characterized. In this study, hERG1 transcript and protein levels in osteosarcoma cells and tissues were measured using semi-quantitative real time PCR (RT-PCR), Western blot, and immunohistochemistry. The effects of hERG1 knockdown on osteosarcoma cell proliferation, apoptosis and invasion were examined using CCK-8, colony formation, flow cytometry, caspase-3 activity, wound healing and transwell based assays. Furthermore, semi-quantitative RT-PCR, Western blot and a luciferase reporter assay were used to assess the effects of hERG1 inhibition on the nuclear factor-κB (NF-κB) pathway. In addition, the effect of NF-κB p65-siRNA and NF-κB p65 expression on the survival of osteosarcoma cells was investigated. Through this work, a relationship for hERG1 with the NF-κB pathway was identified. Osteosarcoma cells and tissues were found to express high levels of hERG1. Knockdown of hERG1 significantly suppressed cellular proliferation and invasion, and induced apoptosis, while inhibition of hERG1 significantly decreased activation of NF-κB. Overall, hERG1 may stimulate nuclear translocation of p65, thus regulating the NF-κB pathway through the activation of the hERG1/beta1 integrin complex and PI3K/AKT signaling. Taken together, these results demonstrate that hERG1 is necessary for regulation of osteosarcoma cellular proliferation, apoptosis and migration. Furthermore, this regulation by hERG1 is, at least in part, through mediation of the NF-κB pathway.

Synergistic roles of p53 and HIF1α in human renal cell carcinoma-cell apoptosis responding to the inhibition of mTOR and MDM2 signaling pathways

Introduction

mTOR and MDM2 signaling pathways are frequently deregulated in cancer development, and inhibition of mTOR or MDM2 independently enhances carcinoma-cell apoptosis. However, responses to mTOR and MDM2 antagonists in renal cell carcinoma (RCC) remain unknown.

Materials and methods

A498 cells treated with MDM2 antagonist MI-319 and/or mTOR inhibitor rapamycin were employed in the present study. Cell apoptosis and Western blot analysis were performed.

Results and conclusion

We found that the MDM2 inhibitor MI-319 induced RCC cell apoptosis mainly dependent on p53 overexpression, while the mTOR antagonist rapamycin promoted RCC cell apoptosis primarily through upregulation of HIF1α expression. Importantly, strong synergistic effects of MI-319 and rapamycin combinations at relatively low concentrations on RCC cell apoptosis were observed. Depletion of p53 or HIF1α impaired both antagonist-elicited apoptoses to differential extents, corresponding to their expression changes responding to chemical treatments, and double knockdown of p53 and HIF1α remarkably hindered MI-319- or rapamycin-induced apoptosis, suggesting that both p53 and HIF1α are involved in MDM2 or mTOR antagonist-induced apoptosis. Collectively, we propose that concurrent activation of p53 and HIF1α may effectively result in cancer-cell apoptosis, and that combined MDM2 antagonists and mTOR inhibitors may be useful in RCC therapy.

Interactions of benzotriazole UV stabilizers with human serum albumin: Atomic insights revealed by biosensors, spectroscopies and molecular dynamics simulations

Benzotriazole UV stabilizers (BZTs) belong to one prominent group of ultraviolet (UV) stabilizers and are widely used in various plastics materials. Their large production volumes, frequent detections in the environment and potential toxicities have raised increasing public concern. BZTs can be transported in vivo by transport proteins in plasma and the binding association to transport proteins may serve as a significant parameter to evaluate the bioaccumulative potential. We utilized a novel HSA biosensor, circular dichroism spectroscopy, fluorescence spectroscopy to detect the dynamic interactions of six BZTs (UV-326, UV-327, UV-328, UV-329, UV-P, and BZT) with human serum albumin (HSA), and characterized the corresponding structure-activity relationships (SAR) by molecular dynamics simulations. All test BZTs potently bind at Sudlow site I of HSA with a binding constant of 10(4) L/mol at 298 K. Minor changes in the moieties of BZTs affect their interactions with HSA and differently induce conformations of HSA. Their binding reduced electrochemical impedance spectra and α-helix content of HSA, caused slight red-shifted emission, and changed fluorescence lifetime components of HSA in a concentration-dependent mode. UV-327 and UV-329 form hydrogen bonds with HSA, while UV-329, UV-P and BZT bind HSA with more favorable electrostatic interactions. Our in vitro and in silico study offered a significant framework toward the understanding of risk assessment of BZTs and provides guide for future design of environmental benign BZTs-related materials.

[Development of a New Type Elastic Syndesmosis Hook Plate]

OBJECTIVE

To design a kind of internal fixation device to treat the syndesmosis injury.

METHODS

The elastic syndesmosis hook plate is made of medical stainless steel alloy, which is consisted of locking or common screw fixing hole of the tibial side for the head, tridentate fork like arc anatomical fibula side plate for the tail and serpentine elastic connecting body. By reduction of the joint of the lower tibia and fibula, the steel plate tail is fixed at the side of the fibula and the head is fixed at the side of the tibia for fixing the symphysis.

RESULTS

The design of elastic syndesmosis hook plate is reasonable, and the operation is convenient. There is no need to penetrate the substantia ossea and the plate has elastic micro-movement feature, the problem of internal fixation breakage and loosening is avoid in huge degree, so it is safe and reliable.

CONCLUSION

The elastic syndesmosis hook plate is a new type medical apparatus of internal fixation of the symphysis, which is worthy of clinical popularization and application.

Management of combined atlas-axis fractures: a review of forty one cases

PURPOSE

To outline a management principle for the combined atlas (C1)-axis (C2) fractures and assess its therapeutic effects.

METHODS

Forty-one patients with combined C1-C2 fractures were treated according to their C2 fracture types. Non-operative external immobilization in the form of a cervical collar or halo vest was used in 22 patients. Early posterior pedicle screw fixations were performed in 19 patients whose fractures had a combination of any of the three conditions: an atlantodens interval (ADI) ≥ 5 mm, lateral mass displacement (LMD) > 7 mm, and/or C2-C3 angulation > 11°. Thirty-nine patients were followed up regularly with an average of 19.3 months (range, 12 to 45 months). Clinical and radiographic data were then collected and compared.

RESULTS

At three months following treatment, patients' visual analog scale (VAS), Neck Disability Index (NDI), American Spinal Injury Association (ASIA) scale, and Frankel grades were all significantly improved when compared to pretreatment. These results indicated that the cervical collar, halo vest, and posterior pedicle screw fixation approaches were all able to effectively treat cases of combined C1-C2 fractures. One patient in the non-surgical group developed nonunion which required late surgical treatment and one patient had pin site infection in the non-surgical group (2/22), while there were three minor complications in the surgical group.

CONCLUSION

We propose a management principle that bases the treatment of a combined C1-C2 fracture on the nature of the C2 fracture. This treatment strategy has yielded promising results as a satisfactory means for the management of combined C1-C2 fractures.

Nuclear expression and clinical significance of phosphohistidine phosphatase 1 in clear-cell renal cell carcinoma

OBJECTIVE

To explore expression and clinical relevance of phosphohistidine phosphatase 1 (PHPT1) in clear-cell renal cell carcinoma.

METHODS

Patients with clear-cell renal cell carcinoma who underwent radical or nephron-sparing nephrectomy were enrolled. Correlations between PHPT1 expression and demographic and clinical characteristics were analysed prospectively.

RESULTS

In total, 122 patients (78 male/44 female) were included. In normal kidney tissue, PHPT1 expression was observed only in the proximal tubule. High PHPT1 expression levels were associated with larger tumour size, higher Fuhrman nuclear grade and advanced pathological tumour-node-metastasis (pTNM) stage compared with low PHPT1 expression levels. Patients with low PHPT1 expression showed better overall survival and progression-free survival compared with those with high PHPT1 expression. In addition, multivariate analysis showed that nuclear grade and pTNM stage were independent predictors of progression-free survival and overall survival in patients with clear-cell renal cell carcinoma. PHPT1 expression was also an independent predictor of overall survival but not progression-free survival.

CONCLUSIONS

PHPT1 was expressed in the epithelium of proximal tubuli and nuclei of clear-cell renal cell carcinoma tissue samples. High levels of 14 kDa phosphohistidine phosphatase protein were negatively associated with overall survival and progression-free survival in patients with clear-cell renal cell carcinoma.

Peptide Functionalized Nanoplasmonic Sensor for Explosive Detection

In this study, a nanobiosensor for detecting explosives was developed, in which the peptide was synthesized with trinitrotoluene (TNT)-specific sequence and immobilized on nanodevice by Au-S covalent linkage, and the nanocup arrays were fabricated by nanoimprint and deposited with Au nanoparticles to generate localized surface plasmon resonance (LSPR). The device was used to monitor slight change from specific binding of 2,4,6-TNT to the peptide. With high refractive index sensing of ~104 nm/RIU, the nanocup device can detect the binding of TNT at concentration as low as 3.12 × 10-7 mg mL-1 by optical transmission spectrum modulated by LSPR. The nanosensor is also able to distinguish TNT from analogs of 2,4-dinitrotoluene and 3-nitrotoluene in the mixture with great selectivity. The peptide-based nanosensor provides novel approaches to design versatile biosensor assays by LSPR for chemical molecules.

Cbl-b: Roles in T Cell Tolerance, Proallergic T Cell Development, and Cancer Immunity

Cbl-b is a member of the Cbl family of RING finger E3 ubiquitin ligases and polymorphisms and mutations in Cbl-b are associated with several autoimmune/inflammatory diseases in humans. Furthermore, gene targeting experiments in mice have provided proof of the in vivo effects of Cbl-b on T cell function and its involvement with these diseases. This brief review updates our understanding of Cbl-b in T cell tolerance, proallergic T cell development, and cancer immunity in light of the most recent advances, and their impact on autoimmune-/inflammatory diseases and cancer immunotherapy.

E3 ubiquitin ligase Cbl-b in innate and adaptive immunity

Casitas B-lineage lymphoma proto-oncogene-b (Cbl-b), a RING finger E3 ubiquitin-protein ligase, has been demonstrated to play a crucial role in establishing the threshold for T-cell activation and controlling peripheral T-cell tolerance via multiple mechanisms. Accumulating evidence suggests that Cbl-b also regulates innate immune responses and plays an important role in host defense to pathogens. Understanding the signaling pathways regulated by Cbl-b in innate and adaptive immune cells is therefore essential for efficient manipulation of Cbl-b in emerging immunotherapies for human disorders such as autoimmune diseases, allergic inflammation, infections, and cancer. In this article, we review the latest developments in the molecular structural basis of Cbl-b function, the regulation of Cbl-b expression, the signaling mechanisms of Cbl-b in immune cells, as well as the biological function of Cbl-b in physiological and pathological immune responses in animal models and human diseases.

E3 ubiquitin ligase Cbl-b inhibits NLRP3 inflammasome activation by targeting NLRP3 for ubiquitination (INM6P.405)

NLRP3 inflammasome has been shown to be involved in antiviral and antibacterial innate immunity, as well as in the response to adjuvants critical for adaptive immunity. However, inappropriate activation of NLRP3 contributes to deleterious inflammatory syndromes. Although recent studies show that NLRP3 undergoes ubiquitination, the mechanisms for negatively regulating the activation of the NLRP3 inflammasome in response to PAMPs or endogenous DAMPs are largely unknown. In this study, we found that Cbl-b selectively inhibits NLRP3 inflammasome activation, leaving the other key innate response pathways. Further indication of a negative regulation by Cbl-b on NLRP3 inflammasome activity is the finding that LPS injection induces a significant mortality in Cbl-b-/- mice compared to wild-type (WT) controls, and this increased mortality in Cbl-b-/- mice is blocked by an IL-1 receptor antagonist. At the molecular levels, Cbl-b binds to NLRP3 upon LPS priming and ATP stimulation independently of ASC. NLRP3 undergoes ubiquitination in WT macrophages upon NLRP3 inflammasome stimulation, whereas its ubiquitination is impaired in Cbl-b-/- macrophages. Interestingly, NLRP3 inflammasome stimulation also induces Cbl-b tyrosine phosphorylation, which is critical for its ubiquitin ligase activity, thus initiating a negative feedback that controls NLRP3 inflammasome activity. Therefore, we provide a previously-unappreciated function for Cbl-b in regulating NLRP3 inflammasome activation.

Folic acid-conjugated glucose and dextran coated iron oxide nanoparticles as MRI contrast agents for diagnosis and treatment response of rheumatoid arthritis

Coating superparamagnetic iron oxide (SPIO) with dextran increases the stability of the magnetic nanoparticles during blood circulation, yet this is accompanied by an increase in the particle size and the vascular permeability efficiency of the SPIO nanoparticles into the joints decreases. In our study, the thickness of the dextran coated onto SPIO (dex-SPIO) was optimized without affecting the magnetic quality of iron oxide by adding a suitable amount of glucose into the crystal growth process. To further improve the signal enhancement effect of this glucose and dextran coated SPIO (glu-dex-SPIO) for the detection of the inflammatory site of arthritis, folic acid (FA) was conjugated to glu-dex-SPIO. This FA glu-dex-SPIO was used as a negative contrast agent for MRI to visualize the antigen induce arthritis (AIA) model in rats using a 7 T MR scans. MR imaging revealed more significant differences between the synovium and surrounding tissues with FA glu-dex SPIO than when using the non-targeting glu-dex-SPIO over a long period of time (24 h) after intravenous injection. Moreover, the therapeutic efficacy of the cyclooxygenase 2 (COX-2) inhibitor treatment of the inflamed joints also could be confirmed by using FA glu-dex SPIO enhanced MRI, indicating that this type of nanoparticles could also have potential as a contrast agent for measuring the treatment response of rheumatoid arthritis.