Numb directs the subcellular localization of EAAT3 through binding the YxNxxF motif.

Excitatory amino acid transporter type 3 (EAAT3, also known as SLC1A1) is a high-affinity, Na(+)-dependent glutamate carrier that localizes primarily within the cell and at the apical plasma membrane. Although previous studies have reported proteins and sequence regions involved in EAAT3 trafficking, the detailed molecular mechanism by which EAAT3 is distributed to the correct location still remains elusive. Here, we identify that the YVNGGF sequence in the C-terminus of EAAT3 is responsible for its intracellular localization and apical sorting in rat hepatoma cells CRL1601 and Madin-Darby canine kidney (MDCK) cells, respectively. We further demonstrate that Numb, a clathrin adaptor protein, directly binds the YVNGGF motif and regulates the localization of EAAT3. Mutation of Y503, N505 and F508 within the YVNGGF motif to alanine residues or silencing Numb by use of small interfering RNA (siRNA) results in the aberrant localization of EAAT3. Moreover, both Numb and the YVNGGF motif mediate EAAT3 endocytosis in CRL1601 cells. In summary, our study suggests that Numb is a pivotal adaptor protein that mediates the subcellular localization of EAAT3 through binding the YxNxxF (where x stands for any amino acid) motif.

Expression of hepatocyte growth factor and c-Met is characteristic of α-fetoprotein-producing colorectal adenocarcinoma: A report of three cases.

α-fetoprotein (AFP)-producing colorectal adenocarcinoma is rare and typically not well recognized. In the present study, 3 cases of AFP-producing colorectal cancer are described. All 3 of these cases demonstrated increased levels of blood AFP associated with disease progression. Only case 2 exhibited classical histological hepatoid features. Following immunohistochemical tissue staining, all 3 cases were observed to be positive for AFP expression. In addition, the expression of hepatocyte growth factor (HGF), c-Met receptor and the transcription factor c-Myc were identified to be associated with the expression of AFP. The 3 cases demonstrated resistance to multiple drugs, including epidermal growth factor receptor inhibitors, despite the presence of wild-type Kirsten rat sarcoma viral oncogene homolog (K-RAS; codons 12 and 13), neuroblastoma-RAS (codons 12 and 13) and B-Raf proto-oncogene, serine/threonine kinase (V600E). We propose that hepatoid histological features or a positive AFP finding by immunohistochemistry are sufficient for a diagnosis of AFP-producing colorectal adenocarcinoma. Furthermore, we speculates that autocrine HGF/c-Met activation may be capable of inducing the dedifferentiation of common adenocarcinoma cells, reverting them to a cancer stem cell state and producing AFP or hepatoid differentiation. Consequently, therapy targeted to the HGF/c-Met signaling pathway may potentially be effective for the treatment of AFP-producing colorectal adenocarcinoma.

[Application of optimized parameters SVM based on photoacoustic spectroscopy method in fault diagnosis of power transformer].

In order to solve the problems such as complex operation, consumption for the carrier gas and long test period in traditional power transformer fault diagnosis approach based on dissolved gas analysis (DGA), this paper proposes a new method which is detecting 5 types of characteristic gas content in transformer oil such as CH4, C2H2, C2H4, C2H6 and H2 based on photoacoustic Spectroscopy and C2H2/C2H4, CH4/H2, C2H4/C2H6 three-ratios data are calculated. The support vector machine model was constructed using cross validation method under five support vector machine functions and four kernel functions, heuristic algorithms were used in parameter optimization for penalty factor c and g, which to establish the best SVM model for the highest fault diagnosis accuracy and the fast computing speed. Particles swarm optimization and genetic algorithm two types of heuristic algorithms were comparative studied in this paper for accuracy and speed in optimization. The simulation result shows that SVM model composed of C-SVC, RBF kernel functions and genetic algorithm obtain 97. 5% accuracy in test sample set and 98. 333 3% accuracy in train sample set, and genetic algorithm was about two times faster than particles swarm optimization in computing speed. The methods described in this paper has many advantages such as simple operation, non-contact measurement, no consumption for the carrier gas, long test period, high stability and sensitivity, the result shows that the methods described in this paper can instead of the traditional transformer fault diagnosis by gas chromatography and meets the actual project needs in transformer fault diagnosis.

Association of a pre-miR-27a polymorphism with cancer risk: an updated meta-analysis.

MicroRNA-27a is highly expressed in cancers and has been identified as an oncogenic microRNA. A genetic variant in pre-miR-27a (rs895819) with a transition of A to G has been demonstrated to be associated with cancer risk; however, the results of these studies remain conflicting rather than conclusive. Therefore, we performed a meta-analysis to derive a more precise estimation. Through searching PubMed or other databases up to March 2014 using the following MeSH terms and keywords, "miR-27a", "polymorphism" and "cancer", seventeen case-control studies were identified in this meta-analysis, including 7,813 cases and 9,602. Crude odds ratios (ORs) and corresponding 95% confidence intervals (CIs) were calculated to investigate the association strength between rs895819 and the susceptibility of cancer. The results of the overall meta-analysis did not suggest any association between rs895819 polymorphism and cancer susceptibility, and this remained in Asians as a sub- group. In Caucasians, however, the rs895819 was associated with a reduced cancer risk in heterozygous (OR, 0.83; 95%CI, 0.75-0.93) and dominant models (OR, 0.84; 95%CI, 0.76-0.93), and the [G] allele of rs895819 showed a protective effect (OR, 0.90, 95%CI, 0.84-0.97). Further studies showed a significant association between the [G] allele of rs895819 and decreased risk of breast cancer (0.91; 95%CI, 0.85-0.98), and stratified analyses indicated a protective effect of the [G] allele in Caucasians (OR, 0.89; 95%CI, 0.82-0.98), younger breast cancer cases (OR, 0.87; 95%CI, 0.79-0.96), and in the group of unilateral breast cancer patients (OR, 0.90; 95%CI, 0.83-0.97). These findings suggest an association between pre-miR-27a polymorphism rs895819 and cancer risk in Caucasians. The protective effect of rs895819 [G] allele in younger breast cancer and in the group of unilateral breast cancer patients await further confirmation since the included studies in this meta-analysis were limited.

Expression of huCdc7 in colorectal cancer.

AIM: To detect the expression of huCdc7 in colorectal cancer. METHODS: The mRNA and protein expression of huCdc7 in 39 colorectal cancer tissue specimens and matched tumor-adjacent normal colorectal tissue specimens was detected by reverse transcription-polymerase chain reaction and immunohistochemistry, respectively. RESULTS: The relative expression level of huCdc7 mRNA in colorectal cancer was significantly higher than that in tumor-adjacent normal colorectal tissues (0.03675 ± 1.00 vs 0.01199 ± 0.44, P < 0.05). huCdc7-positive cells displayed brown granules in the nucleus. Tumor tissues contained many huCdc7-positive cells, whereas normal colorectal tissues contained very few positive cells. CONCLUSION: huCdc7 may play an important role in the development and progression of colorectal cancer.

[Role of platelet in angiogenesis].

Angiogenesis is a process involving the growth of new blood vessels from pre-existing vessels though sprouting or other ways. It plays an important role in both physiological and pathological processes. Researches have found that platelets may contribute to angiogenesis as well. In this paper, we review the role of platelet in angiogenesis, especially the relationship with tumor angiogenesis, and discuss clinical implications of these findings.

Renal protective activity of Hsian-tsao extracts in diabetic rats.

OBJECTIVE: To investigate the renal protective activity of Hsian-tsao Mesona procumbens Hemsl. water extracts in diabetic rats. METHODS: Thirty Sprague-dawley female rats were randomly divided into three groups (n = 10 each), "control group" with intraperitoneal saline injection, "diabetic group" with 60 mg of intraperitoneal streptozotocin injection per kg of body weight and "Hsian-tsao group" with intragastric administration of Hsian-tsao extraction everyday for 4 weeks after intraperitoneal streptozotocin injection. The body weight and blood sugar were measured before and after model induction in the three groups. Thrombospondin-1 (TSP-1) expressions in the kidney were monitored by immunohistochemistry. Kidney ultrastructural changes were also analyzed by using transmission electron microscopy. RESULTS: Before diabetic model induction, there were no significant differences among the three groups in body weight and blood sugar. Four weeks after the induction of diabetes, the differences became statistically significant. Electron microscopy also revealed disruption of the foot processes of the podocytes and other damages in diabetic group. These damages were significantly less severe in Hsian-tsao group when compared with the diabetic group. TSP-1 expressions in the kidney were significantly increased in both the diabetic group and Hsian-tsao group, but it was relatively lower in Hsian-tsao group than in diabetic group. CONCLUSION: Our results showed that Hsian-tsao treatment in the diabetic rats effectively prevented the pathological alterations in the kidney and decreased the TSP-1 expression. It was suggested that Hsian-tsao had protective effect on the kidneys of the diabetic rats.

[Preliminary study on role of lipid rafts in receptor clustering induced by 50 Hz magnetic fields and its mechanism].

OBJECTIVE: To investigate the relationship among a 50 Hz magnetic field (MF)-induced epidermal growth factor receptor (EGFR) clustering,lipid rafts and acid sphingomyelinase (ASM), and to explore its possible mechanism. METHODS: Human amnion FL cells were exposed to 50 Hz, 0.4 mT MF for 15 min. EGF treatment was used as positive control. Nystatin was employed to study lipid rafts since it could disrupt lipid rafts structure.The EGF receptors, ASM and lipid rafts were labeled with polyclonal anti-EGFR antibody, anti-ASM antibody and FITC-Cholera toxin B, respectively. The images were observed by laser confocal scanning microscope. RESULT: Both EGF treatment and 50 Hz MF exposure could induce EGFR clustering; however, nystatin pretreatment disrupted this effect. MF exposure turned ASM (labeled with Cy3) from a diffused state in the sham exposure group to a concentrated state on the cell membrane, which co-localized with lipid rafts (labeled with FITC). CONCLUSION: The results suggest that the EGFR clustering induced by 50 Hz MF depends on intact lipid rafts on cellular membrane, and the ASM might participate in the process of EGFR clustering.

[Effects of 50 Hz magnetic fields on DNA double-strand breaks in human lens epithelial cells].

OBJECTIVE: To investigate the effects of 50 Hz magnetic fields (MF) on DNA double-strand breaks in human lens epithelial cells (hLECs). METHODS: The cultured human lens epithelial cells were exposed to 0.4 mT 50 Hz MF for 2 h, 6 h, 12 h, 24 h and 48 h. Cells exposed to 4-nitroquinoline-1-oxide, a DNA damage agent, at a final concentration of 0.1 micromol/L for 1 h were used as positive controls.After exposure, cells were fixed with 4 % paraformaldehyde and for H2AX (gamma H2AX) immunofluorescence measurement. gamma H2AX foci were detected at least 200 cells for each sample. Cells were classified as positive when more than three foci per cell were observed. Mean values of foci per cell and percentage of foci positive cells were adopted as indexes of DNA double-strand breaks. RESULT: The mean value of foci per cell and the percentage of gamma H2AX foci positive cells in 50 Hz MF exposure group for 24 h were (2.93 +/-0.43) and (27.88 +/-2.59)%, respectively, which were significantly higher than those of sham-exposure group [(1.77 +/-0.37) and (19.38+/-2.70)%, P <0.05], and the mean value of foci per cell and the percentage of gamma H2AX foci positive cells in 50 Hz MF exposure group for 48 h were (3.14 +/-0.35) and (31.00 +/-3.44)%, which were significantly higher than those of sham-exposure group (P <0.01). However there was no significant difference between 50 Hz MF exposure groups for 2 h, 6 h, 12 h and sham-exposure group for above two indexes (P >0.05). CONCLUSION: 0.4 mT 50 Hz MF exposure for longer duration might induce DNA double-strand breaks in human lens epithelial cells in vitro.

[Effects of millimeter wave on gene expression in human keratinocytes].

OBJECTIVE: To explore the effect of millimeter wave exposure at low power density on gene expression in human keratinocytes (HaCaT). METHODS: HaCaT keratinocytes were exposed to 30.16 GHz millimeter wave with power densities of 1.0 or 3.5 mW/cm2 for 30 min per day. Gene expression profiles were obtained using the Affymetrix human genome U95A GeneChip. Reverse-transcription polymerase chain reaction (RT-PCR) was performed to confirm the differential expression of genes obtained from Genechip analysis. RESULT: PAR-2 and ERGIC-53 genes in HaCaT cells were up-regulated by 3.5 mW/cm2 millimeter wave exposure for 4 times. ERGIC-53 gene was also up-regulated by 1.0 mW/cm2 millimeter wave exposure for 4 times. However, no significant change for PAR-2 expression was found after the same exposure. CONCLUSION: Millimeter wave exposure could affect gene expression in human keratinocytes, which might be related to the intensity and the times of exposure.

[Noise magnetic fields mitigates the inhibition of secretion function of primary human villous trophoblasts induced by 50 Hz magnetic fields].

OBJECTIVE: To explore the effects of 50 Hz sinusoidal magnetic fields (MF) on secretion function of primary human villous trophoblasts in vitro, and the interference effect of "noise" MF. METHODS: The trophoblasts were isolated from human villus by trypsin digestion and incubated in DMEM medium.Then the trophoblasts were exposed to 0.4 mT 50 Hz MF and/or "noise" MF respectively for different durations. Each exposure group was matched with one control group which was from the same villus and cultured with the same condition except the MF exposure. The concentrations of human chorionic gonadotropin (HCG) and progesterone in the culture medium were measured by immunofluorescence. Statistical significance of differences between means was determined by one way-ANOVA with P<0.05 considered significant. RESULT: 50 Hz MF inhibited the HCG and progesterone secretion significantly when exposure for 72 h (compared with control group, P<0.05). There was no significant change of HCG and progesterone secretion when trophoblasts were exposed to 0.4 mT "noise" MF within 72 h (compared with control group, P>0.05). However, by superimposing the "noise" MF, the inhibition of HCG and progesterone secretion of trophoblasts induced by 50 Hz MF was eliminated. CONCLUSION: The exposure to 50 Hz MF for long period could inhibit trophoblasts secreting HCG and progesterone, and the "noise" MF with the same intensity could eliminate the effects induced by 50 Hz MF.

[Effect of 1.8 GHz radiofrequency electromagnetic fields on gene expression of rat neurons].

OBJECTIVE: To investigate the changes of gene expression in rat neuron induced by 1.8 GHz radiofrequency electromagnetic fields (RF EMF) to screen for RF EMF-responsive genes and the effect of different exposure times and modes on the gene expression in neuron. METHODS: Total RNA was extracted immediately and purified from the primary culture of neurons after intermittent exposed or sham-exposed to a frequency of 1.8 GHz RF EMF for 24 hours at an average special absorption rate (SAR) of 2 W/kg. Affymetrix Rat Neurobiology U34 array was applied to investigate the changes of gene expression in rat neuron. Differentially expressed genes (Egr-1, Mbp and Plp) were further confirmed by semi-quantitative revere transcription polymerase chain reaction (RT PCR). The expression levels of Egr-1, Mbp and Plp were observed at different exposure times (6, 24 h) and modes (intermittent and continuous exposure). RESULTS: Among 1200 candidate genes, 24 up-regulated and 10 down-regulated genes were found by using Affymetrix microarray suite software 5.0 which are associated with multiple cellular functions (cytoskeleton, signal transduction pathway, metabolism, etc.) after functional classification. Under 24 h and 6 h intermittent exposure, Egr-1 and Plp in experiment groups showed statistic significance (P < 0.05) compared with the control groups, while expression of Mbp did not change significantly (P > 0.05). After 24 h continuous exposure, Egr-1 and Mbp in experiment groups showed statistic significance (P < 0.05) compared with the control group, while expression of Plp did not change significantly (P > 0.05). Under the same exposure mode 6 h, expression of all the 3 genes did not change significantly. Different times (6, 24 h) and modes (intermittent and continuous exposure) of exposure exerted remarkable different influences on the expression of Egr-1, Mbp, Plp genes (P < 0.01). CONCLUSION: The changes of many genes transcription were involved in the effect of 1.8 GHz RF EMF on rat neurons; Down-regulation of Egr-1 and up-regulation of Mbp, Plp indicated the negative effects of RF EMF on neurons; The effect of RF intermittent exposure on gene expression was more obvious than that of continuous exposure; The effect of 24 h RF exposure (both intermittent and continuous) on gene expression was more obvious than that of 6 h (both intermittent and continuous).

Effects of GSM 1800 MHz on dendritic development of cultured hippocampal neurons.

AIM: To evaluate the effects of global system for mobile communications (GSM) 1800 MHz microwaves on dendritic filopodia, dendritic arborization, and spine maturation during development in cultured hippocampal neurons in rats. METHODS: The cultured hippocampal neurons were exposed to GSM 1800 MHz microwaves with 2.4 and 0.8 W/kg, respectively, for 15 min each day from 6 days in vitro (DIV6) to DIV14. The subtle structures of dendrites were displayed by transfection with farnesylated enhanced green fluorescent protein (F-GFP) and GFP-actin on DIV5 into the hippocampal neurons. RESULTS: There was a significant decrease in the density and mobility of dendritic filopodia at DIV8 and in the density of mature spines at DIV14 in the neurons exposed to GSM 1800 MHz microwaves with 2.4 W/kg. In addition, the average length of dendrites per neuron at DIV10 and DIV14 was decreased, while the dendritic arborization was unaltered in these neurons. However, there were no significant changes found in the neurons exposed to the GSM 1800 MHz microwaves with 0.8 W/kg. CONCLUSION: These data indicate that the chronic exposure to 2.4 W/kg GSM 1800 MHz microwaves during the early developmental stage may affect dendritic development and the formation of excitatory synapses of hippocampal neurons in culture.