MicroRNA-193a represses c-kit expression and functions as a methylation-silenced tumor suppressor in acute myeloid leukemia

Aberrant activation of c-kit proto-oncogene contributes to abnormal cell proliferation by altering the tyrosine kinase signaling and constitutes a crucial impetus for leukemogenesis. Epigenetic silencing of tumor-suppressive microRNAs (miRNAs) is a key oncogenic mechanism for the activation of oncogenes in tumors. In this study, several miRNAs potentially binding to the 3'-untranslated region of human c-kit mRNA were screened by luciferase reporter assays. Among these miRNAs, miR-193a was embedded in a CpG island and epigenetically repressed by promoter hypermethylation in acute myeloid leukemia (AML) cell lines and primary AML blasts, but not in normal bone marrow cells. Importantly, miR-193a levels were inversely correlated with c-kit levels measured in 9 leukemia cell lines and 27 primary AML samples. Restoring miR-193a expression in AML cells harboring c-kit mutation and/or overexpression, either by synthetic miR-193a transfection or by DNA hypomethylating agent 5-azacytidine (5-aza) treatment, resulted in a significant reduction in c-kit expression at both RNA and protein levels and inhibition of cell growth. The growth-inhibitory activity of miR-193a was associated with apoptosis and granulocytic differentiation. Moreover, 5-aza-induced c-kit reduction could be partially blocked by miR-193a inhibitor, leading to a reversal of antiproliferative and proapoptotic effects of 5-aza. These data reveal a critical role for methylation-repressed miR-193a in myeloid leukemogenesis and the therapeutic promise of upregulating miR-193a expression for c-kit-positive AML.

Notch1 and Notch2 have opposite prognostic effects on patients with colorectal cancer

BACKGROUND

Aberrantly activated Notch signaling has been shown to play a key role in carcinogenesis and progression of various human malignancies. In this study, we investigated the expression of Notch1 and Notch2 in colorectal cancer to determine whether they could serve as prognostic predictors.

PATIENTS AND METHODS

The protein expression of Notch1 and Notch2 was examined by immunohistochemistry in 1003 clinical colorectal cancer specimens. Notch1 and Notch2 protein levels were investigated by immunohistochemistry. Statistical analysis was carried out to assess their prognostic value.

RESULTS

Significantly negative correlation between Notch1 and Notch2 was found in colorectal cancer (P < 0.001). Notch1 and Notch2 were proved to be inversely correlated with tumor differentiation, depth of invasion, lymph node metastases, distant metastasis, TNM (tumor-node-metastasis) stage and survival of patients, suggesting opposite function of the two receptors. Notch1 and Notch2 were proved to be adverse independent prognostic predictors (P < 0.001). Moreover, a synergistic effect of positive Notch1 and negative Notch2 coexpression on predicting poor overall survival was proved.

CONCLUSIONS

Notch1 and Notch2 may be independent adverse prognostic predictors for patients with colorectal cancer. These results would contribute to identify more efficient prognostic predictors and therapeutic targets.

Mutations in the filaggrin gene in Han Chinese patients with atopic dermatitis

BACKGROUND

Recently, loss-of-function mutations in the filaggrin gene (FLG) have been identified as the cause of ichthyosis vulgaris (IV) and also predisposing factors for atopic dermatitis (AD) and AD-associated phenotypes. Until now, over thirty mutations in FLG have been identified in patients with IV and AD, but the FLG mutation spectrum is not clear for Chinese Han patients with AD. This study aimed to investigate the role of FLG mutations in AD and AD-associated phenotypes in a Chinese population.

METHODS

We carried out a comprehensive sequencing of the entire FLG coding region in 261 Han AD patients.

RESULTS

In our research, we identified ten novel mutations (R826X, 3222del4, R1140X, 4271delAA, Q1790X, 5757del4, 6834del5, 6950del8, S2706X and K4671X) and eight reported mutations (441delA, R501X, 3321delA, R1474X, Q2417X, E2422X, 7945delA and R4306X) in FLG. FLG mutations were present in 31.4% of our AD patients. Mutations 3321delA and K4671X, with a frequency of 14.6% and 9.2%, respectively, were two of the most common mutations in this AD cohort. FLG null alleles (compound genotypes) were significantly associated with AD (P < 0.001) and AD associated with food sensitization (P = 0.012). However, we did not observe a positive association between FLG mutations and other AD-associated phenotypes, including asthma, allergic rhinitis and elevated total serum IgE level.

CONCLUSION

Our study increases the total number of reported FLG mutations. Moreover, we further confirm that FLG mutations are strong predisposing factors for AD in Han Chinese.

Ibuprofen metabolism in the liver and gill of rainbow trout, Oncorhynchus mykiss

The presence of pharmaceuticals in the environment has become an important topic of discussion with respect to pharmaceutical absorption, metabolism and elimination in fish. This study investigates the metabolism of ibuprofen by rainbow trout (Oncorhynchus mykiss). In vitro metabolic loss of parent compound was measured in gill and liver S9 and microsomal fractions. Metabolite analysis found 2-hydroxy-ibuprofen as the major metabolite in uninduced S9 fractions. Supplementing S9 fractions with UDPGA did not significantly enhance metabolism. Additionally, assays involving the induction and inhibition of specific CYP isozymes support CYP1A2 as a possible metabolic pathway in fish.

The effect of varying footwear configurations on the peroneus longus muscle function following inversion

BACKGROUND

The ankle is one of the most commonly injured joints with inversion injury affecting its lateral ligament complex being the commonest of all. Shoes are one of the known risk factors for such an injury.

OBJECTIVE

This study seeks to examine the impact of varying shoe configurations on the protective function of the peroneus longus muscle during unanticipated foot inversion.

METHODS

The peak amplitude, latency and post-peak average amplitude of the ipsilateral peroneus longus muscle were recorded by surface electromyography following unanticipated inversion of the feet of 35 subjects in a two-footplate tilting platform from 0° to 20°. The test conditions were barefoot, standard training shoe, shoe with a sole flare, and an above the ankle laced boot.

RESULTS

Analysis revealed significant differences in peak muscle contraction between shod and unshod conditions. The standard shoe and the flared sole design showed greater statistically significant differences from the unshod condition, than the boot. The muscle was responding earlier in the shod conditions compared to the barefoot. The post-peak average amplitude with the standard shoe and the flared sole shoe were significantly different from the barefoot condition.

CONCLUSION

Albeit no marked differences could be demonstrated between the tested shoes, the inherent construct of the laced boot probably attempts to protect the ankle-subtalar joint complex evidenced by evoking a less strong peroneus longus muscle's protective response.

Blue Light Emission from Porous Silicon

Through a post treatment of light emitting porous silicon in boilingwater, a large blue shift of its photoluminescence (PL) spectrum hasbeen observed and a stable blue-green light emission at the peak wavelength down to 500 nm is achieved. The effect of boiling water treatment is suggested to be a kind of oxidation, which could reduce thesize of the Si column, fill up some micropores and strengthen the Siskeleton. The photoluminescence microscopic observation shows that the surface of blue light emitting porous silicon is composed of manysmall uniformly light-emitting domains at the size of several tens of μm. Fourier transform infrared reflection (FTIR) measurements show that the formation of Si-H bonds is not responsible for the visible luminescence in the very thin Si wires.

Quality of life and psychologic distress of recipients after adult living-donor liver transplantation (LDLT)-A study from mainland China

This cross-sectional study investigated potential factors impacting quality of life in 125 recipients after living-donor liver transplantation (LDLT). Health-related quality of life (HRQoL) was measured by using the Chinese version of Medical Outcomes Study Short Form-36 (SF-36), and psychologic symptoms by using the Symptom Checklist-90-Revised (SCL-90-R). Clinical and demographic data were collected from the records of the Chinese Liver Transplant Registry and via questionnaire. A total of 102 recipients (81.6%) completed the questionnaires. All SF-36 domain scores (except the mental health score) were lower in the study than in the general population of Sichuan. The mental quality of life was significantly lower in female than in male subjects (P = .000). Regarding the role-physical (P = .016), social functioning (P = .000), and role-emotional (P = .004) domains, recipients >1 year after transplantation scored higher than those <1 year. Bodily pain scores were lower in recipients with prior acute liver failure than those with hepatic carcinoma or hepatic cirrhosis (P = .032). Social functioning was poorer in recipients with than in those without complications (P = .039). Mental component summary scale (MCS) scores and some of physical component summary scale (PCS) significantly correlated with symptom dimension scores of the SCL-90-R (P < .05). In conclusion, gender, time since transplant, etiology of disease, complications, occupation, and some psychologic symptoms were possible factors influencing postoperative HRQoL of LDLT recipients.

Cluster Formation in Laser-Induced Ablation and Evaporation of Solids Observed by Laser Ionization Time-Offlight Mass-Spectrometry and Scanning Tunneling Microscopy

Laser ionization time-of-flight mass analysis (LIMA) used pulses (5ns) of a frequency- quadrupled Nd-YAG laser (266 nm) focused onto spots of 4–100 μm diameter to ablate material, and a reflectron time of flight tube to mass-analyze the plume. The observed mass spectra for Si, Pt, SiC, and UO2 varied in the distribution of ablation products among atoms, molecules and clusters, depending on laser power density and target material.

Cleaved surfaces of highly oriented pyrolytic graphite (HOPG) positioned at room temperature either 10 cm away from materials ablated at 10−5 Torr by 1–3 excimer laser (308 nm) pulses of 20 ns duration or 1 m away from materials vaporized at 10−8 Torr by 10 Nd-Glass laser pulses of 1 ms duration were analyzed by Scanning Tunneling Microscopy (STM) in air with Ångstrom resolution. Clusters up to 30 Å in diameter were observed.

Heating, Laser Irradiation and Passivation Study on the Light-Emitting Porous Silicon

For light-emitting porous Si there has been a severe problem with instability and degradation of the light emission. We report that a stabilization of the emission intensity and the peak energy can be achieved in air by a proper laser irradiation, In-situ photoluminescence measurements were performed to monitor the degradation and stabilization process under different conditions and parameters, such as laser power, laser wavelength and environment (ambient atmosphere of certain gas or ultra high vacuum). We found oxygen is the major cause for the emission degradation in this laser enhanced adsorption process, and the laser heating effect can be excluded. For a comparison we study the reversible thermal heating and quenching process. We also discuss microwave and ECR plasma passivation results.

Light-Emitting Porous Silicon in High Magnetic Fields

Photoluminescence from porous silicon was studied in a helium atmosphere and at high magnetic fields. In a magnetic field, the spectral peak had a negligible shift, amounting to +0.2 ±0.5 meV at B= 18T. If quantum confinement is the major effect, then the conduction electron would be confined to a diameter of less than 3.5 nm.

Oxidation Resistant Dilute Copper (Boron) Alloy Films Prepared by DC-Magnetron Cosputtering

To enhance the corrosion resistance and reliability of the proposed copper interconnections in silicon integrated circuits, alloying with small amounts thermodynamically favorable elements has been pursued. In the present investigation dilute copper (boron) alloy thin films (in boron concentration range of 0-4 at % in copper) were deposited by DC magnetron co-sputtering using a high purity copper and Cu-4 at % B targets. Films were then annealed in Ar-3% H2, pure Ar, vacuum, and air ambients in the temperature range of 200–500°C. Sheet resistance, Rutherford backscattering, x-ray diffraction measurements were made to characterize the films. The residual resistivity of the as-deposited alloy films was found to be 5.3 μΩ-cm/at %. To obtain sufficiently low working resistivity, an alloy content below 0.5 at % is suggested for application as a potential “metallization material. The addition of boron, which is the common dopant in Si, to the copper films offers considerable oxidation protection. The resulting oxidation rates are considerably lower than that for pure copper films. All this will be presented and discussed.

Characterization of a novel HLA allele, HLA-B*40:128, in a Chinese individual

Nucleotide sequence of HLA-B*40:128 has a single nucleotide difference at position 539 T>G compared with that of HLA-B*40:01:01, with an amino acid change from Leu to Arg at codon 156.

Co-adjuvant effects of retinoic acid and IL-15 induce inflammatory immunity to dietary antigens

Under physiological conditions the gut-associated lymphoid tissues not only prevent the induction of a local inflammatory immune response, but also induce systemic tolerance to fed antigens. A notable exception is coeliac disease, where genetically susceptible individuals expressing human leukocyte antigen (HLA) HLA-DQ2 or HLA-DQ8 molecules develop inflammatory T-cell and antibody responses against dietary gluten, a protein present in wheat. The mechanisms underlying this dysregulated mucosal immune response to a soluble antigen have not been identified. Retinoic acid, a metabolite of vitamin A, has been shown to have a critical role in the induction of intestinal regulatory responses. Here we find in mice that in conjunction with IL-15, a cytokine greatly upregulated in the gut of coeliac disease patients, retinoic acid rapidly activates dendritic cells to induce JNK (also known as MAPK8) phosphorylation and release the proinflammatory cytokines IL-12p70 and IL-23. As a result, in a stressed intestinal environment, retinoic acid acted as an adjuvant that promoted rather than prevented inflammatory cellular and humoral responses to fed antigen. Altogether, these findings reveal an unexpected role for retinoic acid and IL-15 in the abrogation of tolerance to dietary antigens.

Bandtail Limits to Solar Conversion Efficiencies in Amorphous Silicon Solar Cells

We describe a model for a-Si:H based pin solar cells derived primarily from valence bandtail properties. We show how hole drift-mobility measurements and measurements of the temperature-dependence of the open-circuit voltage VOC can be used to estimate the parameters, and we present VOC(T) measurements. We compared the power density under solar illumination calculated with this model with published results for as-deposited a-Si:H solar cells. The agreement is within 4% for a range of thicknesses, suggesting that the power from as-deposited cells is close to the bandtail limit.

Tissue-specific dysregulation of hexose-6-phosphate dehydrogenase and glucose-6-phosphate transporter production in db/db mice as a model of type 2 diabetes

AIMS/HYPOTHESIS

Tissue-specific amplification of glucocorticoid action through 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) affects the development of the metabolic syndrome. Hexose-6-phosphate dehydrogenase (H6PDH) mediates intracellular NADPH availability for 11β-HSD1 and depends on the glucose-6-phosphate transporter (G6PT). Little is known about the tissue-specific alterations of H6PDH and G6PT and their contributions to local glucocorticoid action in db/db mice.

METHODS

We characterised the role of H6PDH and G6PT in pre-receptor metabolism of glucocorticoids by examining the production of the hepatic 11β-HSD1-H6PDH-G6PT system in db/db mice.

RESULTS

We observed that increased production of hepatic H6PDH in db/db mice was paralleled by upregulation of hepatic G6PT production and responded to elevated circulating levels of corticosterone. Treatment of db/db mice with the glucocorticoid antagonist RU486 markedly reduced production of both H6PDH and 11β-HSD1 and improved hyperglycaemia and insulin resistance. The reduction of H6PDH and 11β-HSD1 production by RU486 was accompanied by RU486-induced suppression of hepatic G6pt (also known as Slc37a4) mRNA. Incubation of mouse primary hepatocytes with corticosterone enhanced G6PT and H6PDH production with corresponding activation of 11β-HSD1 and PEPCK: effects that were blocked by RU486. Knockdown of H6pd by small interfering RNA showed effects comparable with those of RU486 for attenuating the corticosterone-induced H6PDH production and 11ß-HSD1 reductase activity in these intact cells. Addition of the G6PT inhibitor chlorogenic acid to primary hepatocytes suppressed H6PDH production.

CONCLUSIONS/INTERPRETATION

These findings suggest that increased hepatic H6PDH and G6PT production contribute to 11β-HSD1 upregulation of local glucocorticoid action that may be related to the development of type 2 diabetes.

Comparison of the 6th and 7th editions of the UICC TNM staging system for gastric cancer: Results of a Chinese single-institution study of 1,503 patients

117

Background: To evaluate the prognostic efficacy of the 7th edition TNM classification compared to the 6th edition in gastric cancer patients.

Methods: A total of 1,503 gastric cancer patients undergoing surgical resection were staged using the 6th and 7th edition staging systems. Homogeneity, discriminatory ability, and monotonicity of gradients of the two systems were compared using linear trend X2, likelihood ratio X2 statistics, and Akaike information criterion (AIC) calculations.

Results: Significant differences in five-year survival rates were observed for the “T,” “N,” and “M” subgroups using the 7th edition system, except for stage N2 and N3 patients in the 6th edition system. There were no significant differences in survival between IB and IIA in the 7th edition system. Patients with stage IV disease due to T4/N3 in the 6th edition system who were downstaged to stage III in the 7th edition system had significantly better survival than those who remained at stage IV. The 7th edition system had higher linear trend and likelihood ratio X2 scores, and smaller AIC values compared with those for the 6th edition, which represented the optimum prognostic stratification.

Conclusions: Our study suggested that the 7th edition system performs superior to the 6th edition in several aspects.

No significant financial relationships to disclose.