MiR-155-5p affects Wilms' tumor cell proliferation and apoptosis via targeting CREB1.

The article "MiR-155-5p affects Wilms' tumor cell proliferation and apoptosis via targeting CREB1", by X.-S. Zhao, B. Han, J.-X. Zhao, N. Tao, C.-Y. Dong, published in Eur Rev Med Pharmacol Sci 2019; 23 (3): 1030-1037-DOI: 10.26355/eurrev_201902_16990-PMID: 30779069, has been retracted by the authors due to a slight deviation in the data. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/16990.

Long noncoding RNA MIAT acts as an oncogene in Wilms' tumor through regulation of DGCR8.

The article "Long noncoding RNA MIAT acts as an oncogene in Wilms' tumor through regulation of DGCR8, by X.-S. Zhao, N. Tao, C. Zhang, C.-M. Gong, C.-Y. Dong, published in Eur Rev Med Pharmacol Sci 2019; 23 (23): 10257-10263-DOI: 10.26355/eurrev_201912_19663-PMID: 31841180" has been withdrawn from the authors due to inaccuracies in the data. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/19663#:~:text=CONCLUSIONS%3A%20The%20above%20results%20suggested,and%20therapy%20of%20Wilms'%20tumor.

Long noncoding RNA SNHG16 acts as an oncogene in Wilms' tumor through sponging miR-200a-3p.

Since this article has been suspected of research misconduct and the corresponding authors did not respond to our request to prove originality of data and figures, "Long noncoding RNA SNHG16 acts as an oncogene in Wilms' tumor through sponging miR-200a-3p, by X.-S. Zhao, N. Tao, C. Zhang, C.-M. Gong, C.-Y. Dong, published in Eur Rev Med Pharmacol Sci 2020; 24 (8): 4145-4151-DOI: 10.26355/eurrev_202004_20994-PMID: 32373950" has been withdrawn. The Publisher apologizes for any inconvenience this may cause. https://www.europeanreview.org/article/20994.

Long noncoding RNA SNHG16 acts as an oncogene in Wilms' tumor through sponging miR-200a-3p.

OBJECTIVE: Recently, the role of long noncoding RNA (lncRNAs) in tumor progression has attracted much attention. The aim of this study was to investigate the role of lncRNA SNHG16 in the development of Wilms' tumor, and to explore the underlying mechanism. PATIENTS AND METHODS: Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was used to detect SNHG16 expression in Wilms' tumor patients' tissues. Function assays, including wound healing assay, and transwell assay, were conducted to detect the changes of biological behaviors in Wilms' tumor cells due to gain or loss of SNHG16. Besides, the luciferase reporter gene assay was performed to explore the underlying mechanism. RESULTS: The expression level of SNHG16 was significantly up-regulated in Wilms' tumor tissues when compared with adjacent tissues. Cell migration and invasion abilities were significantly repressed via down-regulation of SNHG16. However, opposite results were obtained after up-regulation of SNHG16 in vitro. After the down-regulation of SNHG16, the expression of miR-200a-3p increased significantly. However, the expression of miR-200a-3p was remarkably reduced via up-regulation of SNHG16 in vitro. Furthermore, SNHG16 acted as a competing endogenous RNA via sponging miR-200a-3p in Wilms' tumor. CONCLUSIONS: SNHG16 induced the metastasis of Wilms' tumor via sponging miR-200a-3p. Our findings might provide a new prospect for the diagnosis and therapy of Wilms' tumor.

Long noncoding RNA MIAT acts as an oncogene in Wilms' tumor through regulation of DGCR8.

OBJECTIVE: Recent researches have proved that long noncoding RNAs (lncRNAs) cover an important role in malignant tumors. Our study showed how lncRNA myocardial infarction-associated transcript (MIAT) functions in the development of Wilms' tumor. PATIENTS AND METHODS: Real Time-quantitative Polymerase Chain Reaction (RT-qPCR) was utilized to detect the MIAT expression in Wilms' tumor patients. The MIAT expression level and the patients' overall survival time were analyzed. Then, we conducted functional experiments to identify the changes in the biological behaviors of Wilms' tumor cells due to the loss of MIAT. Moreover, further experiments were performed to explore the potential mechanism. RESULTS: By comparing with MIAT expression in adjacent tissues, the MIAT expression level was significantly higher in Wilms' tumor samples. Moreover, the cell growth ability of Wilms' tumor cells was inhibited due to the loss of MIAT. The migrated and invaded ability of the Wilms' tumor cells was inhibited due to the loss of MIAT. Furthermore, the expression of DGCR8 was downregulated due to the loss of MIAT. In addition, it was found that the DGCR8 expression was positively correlated to MIAT expression in Wilms' tumor tissues. CONCLUSIONS: The above results suggested that MIAT could promote the cell proliferation and the metastasis of Wilms' tumor by upregulating DGCR8, which indicated that MIAT might be a potential target for the diagnosis and therapy of Wilms' tumor.

Inhibitory effects of glutaraldehyde on Geotrichum citri-aurantii and its possible mechanism.

AIMS: This study investigated the inhibitory effect of glutaraldehyde (GA) on sour rot in citrus fruit and the underlying antifungal mechanism on mycelial growth of the causative pathogen Geotrichum citri-aurantii. METHODS AND RESULTS: Glutaraldehyde exhibited a strong inhibitory effect on G. citri-aurantii, with a minimum inhibitory and fungicidal concentration (MFC) of 1·00 µl ml-1 . In addition, in vivo application of GA (1 × MFC and 5 × MFC) reduced the disease incidence of sour rot in citrus fruit by 60 and 80% respectively. Scanning electron microscopy results revealed that the morphology of G. citri-aurantii mycelia was greatly altered by GA treatment. Propidium iodide and Calcofluor White Staining revealed that the membrane permeability, rather than the cell wall integrity, of G. citri-aurantii mycelia was severely disrupted after the addition of GA. Massive accumulation of malonaldehyde and reactive oxygen species as well as an increase in lipoxygenase activity were observed. CONCLUSION: These results indicate that GA may inhibit the mycelia growth of G. citri-aurantii through a membrane damage mechanism induced by membrane peroxidation. SIGNIFICANCE AND IMPACT OF THE STUDY: Glutaraldehyde is expected to be a novel fungicide for controlling sour rot in citrus fruit.

MiR-155-5p affects Wilms' tumor cell proliferation and apoptosis via targeting CREB1.

OBJECTIVE: The aim of this study was to explore the role of microRNA-155-5p (miR-155-5p) in regulating the proliferation and apoptosis of Wilm's tumor (WT), and to investigate the possible underlying mechanism. PATIENTS AND METHODS: The expression levels of miR-155-5p in 37 pairs of WT clinical samples, as well as WT cell line (G401), were detected by quantitative reverse transcription polymerase chain reaction (qRT-PCR). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide) assay and flow cytometry assay were used to detect the effects of miR-155-5p on cell proliferation, cycle and apoptosis. Target gene prediction software was applied to screen the potential downstream target gene of miR-155-5p. QRT-PCR, Western blot (WB) and luciferase reporter gene assay proved that cAMP-response element binding protein 1 (CREB1) was the target gene of miR-155-5p. Besides, rescue experiment was conducted to further explore the effect of CREB1 on WT cells. RESULTS: The expression levels of miR-155-5p in WT tissues and cells were both significantly down-regulated. Importantly, miR-155-5p was found to be involved in the malignant behavior of WT cells. MTT assay and flow cytometry assay demonstrated that miR-155-5p significantly inhibited the proliferation, caused stagnation of cells in G0/G1 phase, and promoted cell apoptosis. CREB1 was verified as a functional target gene of miR-155-5p, which was negatively regulated by miR-155-5p. Rescue experiments indicated that restoring the expression of CREB1 could interfere with the effects of miR-155-5p on WT cells. CONCLUSIONS: MiR-155-5p could regulate the proliferation, cell cycle and apoptosis of WT cells. These effects were achieved by regulating the expression of CREB1. Furthermore, our study might provide a new theoretical basis for the basic research of WT.

Simultaneous measurement of thermal conductivity and heat capacity by flash thermal imaging methods.

Thermal properties are important for material applications involved with temperature. Although many measurement methods are available, they may not be convenient to use or have not been demonstrated suitable for testing of a wide range of materials. To address this issue, we developed a new method for the nondestructive measurement of the thermal effusivity of bulk materials with uniform property. This method is based on the pulsed thermal imaging-multilayer analysis (PTI-MLA) method that has been commonly used for testing of coating materials. Because the test sample for PTI-MLA has to be in a two-layer configuration, we have found a commonly used commercial tape to construct such test samples with the tape as the first-layer material and the bulk material as the substrate. This method was evaluated for testing of six selected solid materials with a wide range of thermal properties covering most engineering materials. To determine both thermal conductivity and heat capacity, we also measured the thermal diffusivity of these six materials by the well-established flash method using the same experimental instruments with a different system setup. This paper provides a description of these methods, presents detailed experimental tests and data analyses, and discusses measurement results and their comparison with literature values.

[Mediator effect analysis of the trait coping style on job stress and fatigue of the military personnel stationed in plateau and high cold region].

Objective: To investigate the fatigue status of military personnel stationed in plateau and high cold region, and to analyze the mediator effect of trait coping style on job stress and fatigue. Methods: In October 2010, with the method of cluster random sampling survey, 531 military personnel stationed in plateau and high cold region were chosen as subject. The fatigue status were evaluated by the Chinese version multidimensional fatigue inventory (MFI-20) , job stress were evaluated by the Job Stress Survey (JSS) , and trait coping style were evaluated by the Trait Coping Style Questionnaire (TCSQ) . Results: According to the information of different population characteristics, mean rank of physical fatigue about the urban (town) group were higher than that of rural group (Z=-2.200, P<0.05) ; mean rank of reduced motivation about the urban (town) group were higher than that of rural group (Z=-2.781, P<0.05) ; mean rank of general fatigue scores about the urban (town) group were higher than that of rural group (Z=-3.026, P<0.05) ; mean rank of physical fatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-4.045, P<0.05) ; mean rank of reduced motivation about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-2.182, P<0.05) ; mean rank of mental fatigue about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-2.879, P<0.05) ; mean rank of general fatigue scores about the up or equal 20-years old age group were higher than that of below 20-years old age group (Z=-3.647, P<0.05) ; mean rank of reduced motivation were significant statistical difference among the military officers, sergeancy and soldier group (F=18.965, P<0.05) ; mean rank of general fatigue scores were significant statistical difference among the military officers, sergeancy and soldier group (F=14.711, P<0.05) . The score of negative coping style were positively correlated with the score of physical fatigue (r(s)=0.129) , reduced activity (r(s)=0.123) , reduced motivation (r(s)=0.149) and general fatigue (r(s)=0.174) respectively, the score of organizational support lack strength were positively correlated with the score of physical fatigue (r(s)=0.090) , reduced activity (r(s)=0.098) , reduced motivation (r(s)=0.099) and general fatigue (r(s)=0.130) respectively. The mediator effect of negative coping style on the job stress and fatigue was 0.013 (P<0.01) . Conclusion: The fatigue statuses of the urban (town) group and the up or equal 20-years old age group are poor, and the negative coping style plays mediator effect on the job stress and fatigue.

Changing work stressors and coping resources influence blood pressure and hypertension incidence in a large OHSPIW cohort.

Psychosocial work environments may adversely influence blood pressure, but the benefits of altering these factors and introducing coping resources is unclear. We examined whether changing work stressors and coping resources affect the risk of hypertension and elevated BP. A total of 13,145 workers from the Occupational Health Study of Petroleum Industry Workers were included in this study. A baseline evaluation of work-related stress and coping resources was followed up in all participants after 12 years. The changes in task stressors and coping resources were measured using the Occupation Stress Inventory-Revised Edition, and changes in job control and organizational stressors were evaluated using the Instrument for Stress-Related Job Analysis (v. 6.0). Elevated hypertension incidence and BP were associated with increased task and organizational stressors, together with decreased job control and reduced coping resources. Gender-specific differences were observed in the factors influencing BP. The main risk factor was decreased self-care in males (3.11 mm Hg) and increased responsibility in females (2.84 mm Hg). The present study demonstrated that promoting such factors at the task-, individual-, and organizational level may help improve cardiovascular health.

Plasmonic Imaging of Electrochemical Reactions of Single Nanoparticles.

Electrochemical reactions are involved in many natural phenomena, and are responsible for various applications, including energy conversion and storage, material processing and protection, and chemical detection and analysis. An electrochemical reaction is accompanied by electron transfer between a chemical species and an electrode. For this reason, it has been studied by measuring current, charge, or related electrical quantities. This approach has led to the development of various electrochemical methods, which have played an essential role in the understanding and applications of electrochemistry. While powerful, most of the traditional methods lack spatial and temporal resolutions desired for studying heterogeneous electrochemical reactions on electrode surfaces and in nanoscale materials. To overcome the limitations, scanning probe microscopes have been invented to map local electrochemical reactions with nanometer resolution. Examples include the scanning electrochemical microscope and scanning electrochemical cell microscope, which directly image local electrochemical reaction current using a scanning electrode or pipet. The use of a scanning probe in these microscopes provides high spatial resolution, but at the expense of temporal resolution and throughput. This Account discusses an alternative approach to study electrochemical reactions. Instead of measuring electron transfer electrically, it detects the accompanying changes in the reactant and product concentrations on the electrode surface optically via surface plasmon resonance (SPR). SPR is highly surface sensitive, and it provides quantitative information on the surface concentrations of reactants and products vs time and electrode potential, from which local reaction kinetics can be analyzed and quantified. The plasmonic approach allows imaging of local electrochemical reactions with high temporal resolution and sensitivity, making it attractive for studying electrochemical reactions in biological systems and nanoscale materials with high throughput. The plasmonic approach has two imaging modes: electrochemical current imaging and interfacial impedance imaging. The former images local electrochemical current associated with electrochemical reactions (faradic current), and the latter maps local interfacial impedance, including nonfaradic contributions (e.g., double layer charging). The plasmonic imaging technique can perform voltammetry (cyclic or square wave) in an analogous manner to the traditional electrochemical methods. It can also be integrated with bright field, dark field, and fluorescence imaging capabilities in one optical setup to provide additional capabilities. To date the plasmonic imaging technique has found various applications, including mapping of heterogeneous surface reactions, analysis of trace substances, detection of catalytic reactions, and measurement of graphene quantum capacitance. The plasmonic and other emerging optical imaging techniques (e.g., dark field and fluorescence microscopy), together with the scanning probe-based electrochemical imaging and single nanoparticle analysis techniques, provide new capabilities for one to study single nanoparticle electrochemistry with unprecedented spatial and temporal resolutions. In this Account, we focus on imaging of electrochemical reactions at single nanoparticles.

[Effects of job content on psychological stress in young recruits].

OBJECTIVE: To explore the effects of job content on psychological stress in young recruits. METHODS: In October 2014, 625 young recruits enrolled in one troop of Xinjiang Military Command in 2014 were chosen as subjects by multi-stage stratified random sampling. The Chinese version of the job content questionnaire (JCQ)and the psychological stress self evaluation test (PEST)were used to investigate the subjects. The subjects were divided into two groups with scores higher and lower than the mean score of three subscales (job requirement, degree of autonomy, and social support)of JCQ to explore the effects of job content on psychological stress in young recruits. The correlation of psychological stress with three subscales of job content was evaluated using the Pearson' s correlation analysis. Binary logistic regression analysis was used to analyze the influencing factors for psychological stress. RESULTS: The PEST score of young recruits was 49.98±9.98. Forty-five (7.68%)out of them had scores of ≥70 points and were diagnosed with high levels of psychological stress. When the subjects were grouped based on socio-demographic characteristics, a high level of psychological stress was significantly more frequent in subjects less than 20 years of age than in those not less than 20 years of age, in smoking subjects than in non-smoking subjects, and in urban residents than in rural residents (10.42% vs 5.03%, P<0.05; 10.14% vs 5.33%, P<0.05; 10.85% vs 5.88% , P <0.05). There were no significant differences in educational level or identity before recruitment between subjects with different levels of psychological stress (P>0.05). In various job content domains that had impacts on psychological stress, subjects with a low score of social support had significantly higher PEST scores than those with a high score of social support (50.96±10.35 vs 48.49±9.22, P<0.01). The PEST score was negatively correlated with the degree of autonomy and social support (r=-0.103, P<0.05; r=-0.239, P<0.05). The results of logistic regression analysis showed that job requirement and social support were influencing factors for psychological stress (OR=0.718, 95% CI= 0.718 (0.607~0.851), P<0.05; OR=1.185, 95% CI=1.185 (1.087~1.292), P<0.05). CONCLUSION: Psychological stress of young recruits in army is not optimistic. Psychological stress is weakly negatively correlated with social support. The low scores on job requirement subscale and social support subscale may be potential protective factor and risk factor for psychological stress, respectively.

Proteomic analysis of mycelial proteins from Magnaporthe oryzae under nitrogen starvation.

Magnaporthe oryzae is an important model system in studies of plant pathogenic fungi, and nitrogen is a key nutrient source affecting microbial growth and development. In order to understand how nitrogen stress causes changes in mycelial proteins, we analyzed differentially expressed mycelial proteins from the M. oryzae virulent strain CH-63 using two-dimensional electrophoresis and mass spectrometry in complete medium or under nitrogen starvation conditions. A total of 975 ± 70 and 1169 ± 90 protein spots were detected in complete medium and under nitrogen starvation conditions, respectively. Forty-nine protein spots exhibited at least 2-fold up-regulation or down-regulation at the protein level according to PDQuest7.4. Moreover, 43 protein spots were successfully identified by matrix-assisted laser desorption/ionization-time-of-flight/time-of-flight mass spectrometry. Among these spots, 6 proteins were functionally unknown and 37 proteins were categorized into 5 groups according to their functions, including development, metabolism, biosynthesis, and biological process. These 37 proteins were further analyzed for their enriched metabolic pathways by KOBAS2.0, and 14 proteins were found to be involved in glycolysis, tricarboxylic acid cycle, and nitrogen metabolism. Taken together, the regulation of M. oryzae growth under the nitrogen starvation conditions appears to be complex because of the various proteins and enzymes involved.

Sirtuin 3 inhibits hepatocellular carcinoma growth through the glycogen synthase kinase-3ß/BCL2-associated X protein-dependent apoptotic pathway.

SIRT3 is a class III histone deacetylase that has been implicated in a variety of cancers. The role of SIRT3 in hepatocellular carcinoma (HCC) remains elusive. In this study, we found that SIRT3 expression was frequently repressed in HCC and its downregulation was closely associated with tumor grade and size. Ectopic expression of SIRT3 inhibited cell growth and induced apoptosis in HCC cells, whereas depletion of SIRT3 in immortalized hepatocyte promoted cell growth and decreased epirubicin-induced apoptosis. Mechanistic studies revealed that SIRT3 deacetylated and activated glycogen synthase kinase-3ß (GSK-3ß), which subsequently induced expression and mitochondrial translocation of the pro-apoptotic protein BCL2-associated X protein (Bax) to promote apoptosis. GSK-3ß inhibitor or gene silencing of BAX reversed SIRT3-induced growth inhibition and apoptosis. Furthermore, SIRT3 overexpression also suppressed tumor growth in vivo. Together, this study reveals a role of SIRT3/GSK-3ß/Bax signaling pathway in the suppression of HCC growth, and also suggests that targeting this pathway may represent a potential therapeutic approach for HCC treatment.

Quantification of protein interaction kinetics in a micro droplet.

Characterization of protein interactions is essential to the discovery of disease biomarkers, the development of diagnostic assays, and the screening for therapeutic drugs. Conventional flow-through kinetic measurements need relative large amount of sample that is not feasible for precious protein samples. We report a novel method to measure protein interaction kinetics in a single droplet with sub microliter or less volume. A droplet in a humidity-controlled environmental chamber is replacing the microfluidic channels as the reactor for the protein interaction. The binding process is monitored by a surface plasmon resonance imaging (SPRi) system. Association curves are obtained from the average SPR image intensity in the center area of the droplet. The washing step required by conventional flow-through SPR method is eliminated in the droplet method. The association and dissociation rate constants and binding affinity of an antigen-antibody interaction are obtained by global fitting of association curves at different concentrations. The result obtained by this method is accurate as validated by conventional flow-through SPR system. This droplet-based method not only allows kinetic studies for proteins with limited supply but also opens the door for high-throughput protein interaction study in a droplet-based microarray format that enables measurement of many to many interactions on a single chip.

A wireless hybrid chemical sensor for detection of environmental volatile organic compounds.

A hybrid sensor for monitoring volatile organic compounds (VOCs) in air is developed. The device combines two orthogonal sensing principles, selective molecular binding with a microfabricated quartz tuning fork detector and separation of analytes with a column. The tuning fork detector is functionalized with molecular imprinted polymers for selective binding to benzene, toluene, ethylbenzene, and xylenes (BTEX), and the separation column provides further discrimination of the analytes for real world complex sample analysis. The device is wireless, portable, battery-powered, and cell-phone operated, and it allows reliable detection in parts per billion (ppb) by volume-levels of BTEX in the presence of complex interferents. The hybrid device is suitable for occupational, environmental health, and epidemiological applications.

HLA DRB allele polymorphisms and risk of cervical cancer associated with human papillomavirus infection: a population study in China.

OBJECTIVE: Persistent infection with high-risk human papillomavirus (HPV) is the main cause of cervical cancer. Environmental, behavioral, and ill-defined genetic factors have also been implicated in the pathogenesis of this disease. To determine whether human leukocyte antigen (HLA) DRB alleles are associated with cervical cancer and HPV infections in the Chinese population, HLA genotypes were examined in 69 cervical cancer patients and 201 controls. MATERIALS AND METHODS: Polymorphisms in HLA-DRB genes were genotyped using oligoneucleotide arrays, and the magnitude of associations was determined by logistic regression analysis. RESULTS: HLA-DRB1*13 (OR = 4.01 95% CI, 1.703-9.442) and HLA-DRB1*3(17) (OR = 2.661 95% CI, 1.267-5.558) were associated with an increased risk of cervical cancer, and DRB1*09012 (OR = 0.182, 95% CI, 0.079-0.418 and DRB1*1201 (OR = 0.35 95% CI, 0.142-0.863 were associated with a decreased risk. The risk associations of HPV infection were increased in women carrying the HLA-DRB1*09012 (OR = 1.924; 95% CI, 1.08 -3.427) and DRB3(52)*0101 (OR = 7.527 95% CI, 0.909-62.347) alleles. Among cervical cancer patients, the risk associations differed between HPV positive and negative cases for several alleles; increased risk of cervical cancer was associated with DRB3 (52)*02/03 (OR, 12.794; 95% CI, 5.007-32.691) and DRB1*3(17) (OR = 3.48; 95% CI, 1.261-9.604), and decreased risk was associated with DRB1*09012 and DRB5(51)*01/02. Furthermore, HPV16-containing cervical cancer cases differed from non-HPV16 subjects in their positive association with DRB1*1501 (OR = 4.173; 95% CI, 1.065-16.356) and DRB5(51)*0101/0201, and their negative association with DRB4(53)*0101 (OR = 0.329; 95% CI,0.122-0.888). CONCLUSIONS: The present results provide further evidence that certain HLA class II allele polymorphisms are involved in the genetic susceptibility to cervical cancer and HPV infection in the Chinese population from an area with a high incidence of this neoplasia.

Revealing extraordinary intrinsic tensile plasticity in gradient nano-grained copper.

Nano-grained (NG) metals are believed to be strong but intrinsically brittle: Free-standing NG metals usually exhibit a tensile uniform elongation of a few percent. When a NG copper film is confined by a coarse-grained (CG) copper substrate with a gradient grain-size transition, tensile plasticity can be achieved in the NG film where strain localization is suppressed. The gradient NG film exhibits a 10 times higher yield strength and a tensile plasticity comparable to that of the CG substrate and can sustain a tensile true strain exceeding 100% without cracking. A mechanically driven grain boundary migration process with a substantial concomitant grain growth dominates plastic deformation of the gradient NG structure. The extraordinary intrinsic plasticity of gradient NG structures offers their potential for use as advanced coatings of bulk materials.

Effect of top dielectric medium on gate capacitance of graphene field effect transistors: implications in mobility measurements and sensor applications.

We have carried out Hall measurement on back-gated graphene field effect transistors (FET) with and without a top dielectric medium. The gate efficiency increases by up to 2 orders of magnitude in the presence of a high κ top dielectric medium, but the mobility does not change significantly. Our measurement further shows that the back-gate capacitance is enhanced dramatically by the top dielectric medium, and the enhancement increases with the size of the top dielectric medium. Our work strongly suggests that the previously reported top dielectric medium-induced charge transport properties of graphene FETs are possibly due to the increase of gate capacitance, rather than enhancement of carrier mobility.