NGX6 gene mediated by promoter methylation as a potential molecular marker in colorectal cancer

<p>Abstract</p> <p>Background</p> <p>Nasopharyngeal carcinoma associated gene 6 (NGX6) is down-regulated in most colon cancer cell lines and tumor tissues when compared with their normal tissue samples. As a novel suppress tumor gene, it could inhibit colon cancer cell growth and cell cycle progression. However, little is known about the transcriptional mechanisms controlling NGX6 gene expression. Recent findings suggest that epigenetic inactivation of multiple tumor suppressor genes plays an important role in the tumorigenesis of colorectal carcinoma (CRC). In this study, we explored the role of DNA methylation in regulation of NGX6 transcription.</p> <p>Methods</p> <p>In the present study, we cloned the NGX6 promoter with characteristics of a CpG island by luciferase reporter assay. Then, the CpG methylation status around the NGX6 promoter region in colon cancer cell lines and colorectal tumor tissues was examined by methylation-specific PCR and bisulfite DNA sequencing. Finally, 5-Aza-2'-deoxycytidine (5-Aza-dC) treatment was used to confirm the correlation between NGX6 promoter methylation and its gene inactivation.</p> <p>Results</p> <p>The sequence spanning positions -157 to +276 was identified as the NGX6 promoter, in which no canonical TATA boxes were found, while two CAAT boxes and GC boxes were discovered. Methylation status was observed more frequently in 40 colorectal cancer samples than in 40 adjacent normal mucosa samples (18/40 versus 7/40; P < 0.05). An analysis correlating gene methylation status with clinicopathological cancer features revealed that dense methylation of the NGX6 promoter was associated with colorectal cancer patients age (P < 0.05). Moreover, a trend was shown toward metastasis status and primary site in colorectal carcinomas with NGX6 promoter methylation (p = 0.056 and P = 0.067, respectively). In addition, 5-Aza-dC could induce NGX6 mRNA expression and NGX6 promoter demethylation in HT-29 cells.</p> <p>Conclusions</p> <p>Down-regulation of NGX6 gene is related to the promoter methylation. DNA methylation of NGX6 promoter might be a potential molecular marker for diagnosis or prognosis, or serve as a therapeutic target.</p

Promoter Hypermethylation-mediated Inactivation of LRRC4 in Gliomas

<p>Abstract</p> <p>Background</p> <p>Leucine-rich repeat C4 protein (<it>LRRC4</it>) is a new member of the leucine-rich repeat (LRR) superfamily. It is not only a brain-specific gene but also a novel candidate for tumor suppression. <it>LRRC4 </it>inactivation is commonly found in glioma cell lines and primary glioma biopsies. However, little is known about the mechanism controlling <it>LRRC4 </it>expression. In a previous study, we did not find any genetic alteration in <it>LRRC4 </it>in primary glioma, which led us to explore an alternative mechanism underlying this phenomenon.</p> <p>Methods</p> <p>In the present paper, we cloned the <it>LRRC4 </it>promoter with characteristics of a CpG island by luciferase reporter assay. Then, the CpG methylation status around the <it>LRRC4 </it>promoter region in glioma cell lines and primary gliomas was examined by methylation-specific PCR and bisulfite DNA sequencing. In order to demonstrate a functional association between <it>LRRC4 </it>promoter methylation and its gene inactivation, we performed DNA demethylation analysis with two human glioma cell lines using methylation-specific PCR and RT-PCR.</p> <p>Results</p> <p>The sequence spanning positions -835 to -293 relative to the translation start site was identified as the LRRC4 promoter; this sequence is a TATA- and CAAT- less, high GC content region. It was found that <it>LRRC4 </it>promoter activity is strongly suppressed after treatment with SssI methylase in vitro. Furthermore, LRRC4 promoter methylation was observed by methylation-specific PCR in two glioma cell lines and all 30 primary glioma specimens, but not in normal brain tissue. Bisulfite DNA sequencing showed that most of the CpG sites were located around the <it>LRRC4 </it>promoter methylated in glioma cells and tissues, but not in normal brain tissue. In addition, the methylase inhibitor 5-Aza-2'-deoxycytidine could induce <it>LRRC4 </it>mRNA expression and <it>LRRC4 </it>promoter partial demethylation in SF126 and SF767 glioma cells.</p> <p>Conclusion</p> <p>Methylation-mediated inactivation of <it>LRRC4 </it>is a frequent and glioma-specific event, and it may be a potential biomarker for diagnosis or prognosis, or serve as a therapeutic target.</p

Temperature Effects and Compensation-Control Methods

In the analysis of the effects of temperature on the performance of microgyroscopes, it is found that the resonant frequency of the microgyroscope decreases linearly as the temperature increases, and the quality factor changes drastically at low temperatures. Moreover, the zero bias changes greatly with temperature variations. To reduce the temperature effects on the microgyroscope, temperature compensation-control methods are proposed. In the first place, a BP (Back Propagation) neural network and polynomial fitting are utilized for building the temperature model of the microgyroscope. Considering the simplicity and real-time requirements, piecewise polynomial fitting is applied in the temperature compensation system. Then, an integral-separated PID (Proportion Integration Differentiation) control algorithm is adopted in the temperature control system, which can stabilize the temperature inside the microgyrocope in pursuing its optimal performance. Experimental results reveal that the combination of microgyroscope temperature compensation and control methods is both realizable and effective in a miniaturized microgyroscope prototype

Association between Virulence Factors and TRAF1/4-1BB/Bcl-xL

Objective. CagA+/vacAs1+/vacAm1+ Helicobacter pylori upregulates the expression of tumor necrosis factor receptor–associated factor 1 (TRAF1), tumor necrosis factor receptor superfamily member 9 (4-1BB), and B-cell lymphoma-extra large (Bcl-xL) in human gastric epithelial cells. We investigated the correlation between cagA/vacAs1/vacAm1 and TRAF1/4-1BB/Bcl-xL expression in gastric mucosal tissue of patients with gastric disorders. Methods. We collected gastric mucosa samples from 35 chronic, nonatrophic gastritis (CG) patients, 41 atrophic gastritis patients, 44 intestinal metaplasia with atypical hyperplasia (IM) patients, and 28 gastric carcinoma (Ca) patients. The expression of  TRAF1, 4-1BB, and Bcl-xL was determined using western blotting. The expression of cagA, vacAs1, and vacAm1 in H. pylori was examined with polymerase chain reaction. Results. The expression of TRAF1, 4-1BB, and Bcl-xL was significantly upregulated in IM and Ca patients (P<0.05 compared with CG). There were more cases of cagA+/vacAs1+/vacAm1+ H. pylori infection in samples with elevated TRAF1, 4-1BB, or Bcl-xL expression (P<0.05). Additionally, there were a remarkably large number of samples with upregulated TRAF1/4-1BB/Bcl-xL expression in cases of cagA+/vacAs1+/vacAm1+ H. pylori infection (44 cases, 67.7%; P<0.05). Conclusions. The pathogenesis of IM and Ca may be promoted by cagA+/vacAs1+/vacAm1+ H. pylori, possibly via upregulated TRAF1, 4-1BB, and Bcl-xL in gastric mucosal tissue

Development of a Prototype Miniature Silicon Microgyroscope

A miniature vacuum-packaged silicon microgyroscope (SMG) with symmetrical and decoupled structure was designed to prevent unintended coupling between drive and sense modes. To ensure high resonant stability and strong disturbance resisting capacity, a self-oscillating closed-loop circuit including an automatic gain control (AGC) loop based on electrostatic force feedback is adopted in drive mode, while, dual-channel decomposition and reconstruction closed loops are applied in sense mode. Moreover, the temperature effect on its zero bias was characterized experimentally and a practical compensation method is given. The testing results demonstrate that the useful signal and quadrature signal will not interact with each other because their phases are decoupled. Under a scale factor condition of 9.6 mV/°/s, in full measurement range of ± 300 deg/s, the zero bias stability reaches 15°/h with worse-case nonlinearity of 400 ppm, and the temperature variation trend of the SMG bias is thus largely eliminated, so that the maximum bias value is reduced to one tenth of the original after compensation from -40 °C to 80 °C

A COMPARATIVE STUDY OF ANTI-GASTRIC CANCER ACTIVITY BETWEEN AQUEOUS EXTRACT AND ETHANOL EXTRACT OF FOLIUM CORDYLINES FRUTICOSAE

The active components in Folium Cordylines Fruticosae were extracted by heat reflux method. The solvents used were distilled water and ethanol. The effects of two types of extracts on gastric cancer cells were compared; dry extract yields were calculated, as well as the inhibition rates of gastric cancer MGC-803 cell proliferation and the colony cell counts. The micro-Kjeldahl method was used to measure the cell protein contents and to make a comprehensive comparison. The results showed that the MGC-803 cell inhibition rates of three different concentrations (32.5, 75 and 150 mg/ml) of ethanol extracts increased with the increase of concentration, which was 48.9% at a concentration of 150 mg/ml; aqueous extract of Folium Cordylines Fruticosae had very low inhibitory activity at a low concentration (32.5 mg/ml), which was remained at about 20%. After being affected by two types of extracts, cells had uneven sizes, with very low brightness, while the normal cells presented a uniform full form, with high definition

Mechanical-Thermal Noise in Drive-Mode of a Silicon Micro-Gyroscope

A new closed-loop drive scheme which decouples the phase and the gain of the closed-loop driving system was designed in a Silicon Micro-Gyroscope (SMG). We deduce the system model of closed-loop driving and use stochastic averaging to obtain an approximate “slow” system that clarifies the effect of thermal noise. The effects of mechanical-thermal noise on the driving performance of the SMG, including the noise spectral density of the driving amplitude and frequency, are derived. By calculating and comparing the noise amplitude due to thermal noise both in the opened-loop driving and in the closed-loop driving, we find that the closed-loop driving does not reduce the RMS noise amplitude. We observe that the RMS noise frequency can be reduced by increasing the quality factor and the drive amplitude in the closed-loop driving system. The experiment and simulation validate the feasibility of closed-loop driving and confirm the validity of the averaged equation and its stablility criterion. The experiment and simulation results indicate the electrical noise of closed-loop driving circuitry is bigger than the mechanical-thermal noise and as the driving mass decreases, the mechanical-thermal noise may get bigger than the electrical noise of the closed-loop driving circuitry

Corylin suppresses metastasis of breast cancer cells by modulating miR-34c/LINC00963 target

Breast cancer is one of the cancers leading to most death cases among women and metastasis is the major cause of breast cancer mortality. In this study, Corylin, the flavonoid compound which is extracted and purified from Psoralea corylifolia&nbsp;L., the effect on breast cancer metastasis was investigated. Corylin showed inhibitory effect on migration and invasion abilities of breast cancer cells. Meanwhile, the epithelial–mesenchymal transition was also regulated by corylin. The long non-coding RNA LINC00963 was found to have a significantly high expression level in breast cancer while it can be down-regulated by corylin. In addition, both wound-healing assay and transwell assay showed that LINC00963 induced breast cancer cells metastasis. MiR-34c was increased by corylin treatment depending on p53, and it was firstly identified that the LINC00963 was a direct target of miR-34c. Corylin was verified here that it prohibited MCF-7 migration and invasion depending on miR-34c/LINC00963 target. In conclusion, corylin suppresses metastasis of breast cancer cells via increasing miR-34c expression, which was dependent on p53. LINC00963 was a direct target of miR-34c and the target axis was necessary for corylin function. Therefore, corylin is a promising drug candidate and LINC00963 can be seen as a promising target in breast cancer treatmen

Evaluation and optimization of ecological compensation fairness in prefecture-level cities of Anhui province

Scientific evaluation and continuous optimization of the fairness of ecological compensation are conducive to improving the effect of air pollution control. However, relevant research in this field is in its infancy. Based on the data on urban-scale PM _2.5 concentration and ecological compensation from the third quarter of 2018 to the fourth quarter of 2020, this study takes 16 prefecture-level cities in Anhui Province as the research area and uses the Granger causality test to determine the PM _2.5 overflow paths of each city. Moreover, using 2020 as an example, the PM _2.5 spillover effect of each city is calculated, and the haze Gini coefficient of Anhui Province is obtained. According to the empirical results, the ecological compensation policy for PM _2.5 control in Anhui Province is in a relatively equal fairness range (0.295). On this basis, combined with the scatter diagram of ecological compensation and spillover effect, it is suggested to reduce the ecological compensation of five cities, including Maanshan and Xuancheng, while the ecological compensation of the remaining 11 cities should be increased. Two feasible optimization schemes, i.e., annual adjustment and regular adjustment, are proposed for environmental regulators to choose