Increasing CD44+/CD24- tumor stem cells, and upregulation of COX-2 and HDAC6, as major functions of HER2 in breast tumorigenesis

<p>Abstract</p> <p>Background</p> <p>Cancer cells are believed to arise primarily from stem cells. CD44⁺/CD24^-have been identified as markers for human breast cancer stem cells. Although, HER2 is a well known breast cancer oncogene, the mechanisms of action of this gene are not completely understood. Previously, we have derived immortal (M13SV1), weakly tumorigenic (M13SV1R2) and highly tumorigenic (M13SV1R2N1) cell lines from a breast epithelial cell type with stem cell phenotypes after successive SV40 large T-antigen transfection, X-ray irradiation and ectopic expression of HER2/C-erbB2/neu. Recently, we found that M13SV1R2 cells became non-tumorigenic after growing in a growth factor/hormone-deprived medium (R2d cells).</p> <p>Results</p> <p>In this study, we developed M13SV1R2N1 under the same growth factor/hormone-deprived condition (R2N1d cells). This provides an opportunity to analyze HER2 effect on gene expression associated with tumorigenesis by comparative study of R2d and R2N1d cells with homogeneous genetic background except HER2 expression. The results reveal distinct characters of R2N1d cells that can be ascribed to HER2: 1) development of fast-growing tumors; 2) high frequency of CD44⁺/CD24^-cells (~50% for R2N1d vs. ~10% for R2d); 3) enhanced expression of COX-2, HDAC6 mediated, respectively, by MAPK and PI3K/Akt pathways, and many genes associated with inflammation, metastasis, and angiogenesis. Furthermore, HER2 expression can be down regulated in non-adhering R2N1d cells. These cells showed longer latent period and lower rate of tumor development compared with adhering cells.</p> <p>Conclusions</p> <p>HER2 may induce breast cancer by increasing the frequency of tumor stem cells and upregulating the expression of COX-2 and HDAC6 that play pivotal roles in tumor progression.</p

A simplified stroke rehabilitation assessment of movement instrument

Background and Purpose. An efficient, reliable, and valid instrument for assessing motor function in patients with stroke is needed by both clinicians and researchers. To improve administration efficiency, we applied the multidimensional Rasch model to the 30-item, 3-subscale Stroke Rehabilitation Assessment of Movement (STREAM) instrument to produce a concise, reliable, and valid instrument (simplified STREAM [S-STREAM]) for measuring motor function in patients with stroke. Subjects and Methods. The STREAM (consisting of 3 subscales: upper-limb movements, lower-limb movements, and mobility) was administered to 351 subjects with first stroke occurrence and a median time after stroke of 19.5 months. The unidimensionality of each subscale of the STREAM first was verified with unidimensional Rasch analysis. Each subscale of the STREAM then was simplified by deleting redundant items on the basis of expert opinion and the results of the Rasch analysis. The Rasch reliability of the S-STREAM and the concurrent validity of the S-STREAM with the STREAM were examined with multidimensional Rasch analysis and the intraclass correlation coefficient (ICC), respectively. Results. After deleting the items that did not fit the Rasch model, we found that the 8-item upper-limb movement subscale, the 9-item lower-limb movement subscale, and the 10-item mobility subscale assessed single, unidimensional upper-limb movements, lower-limb movements, and mobility, respectively. We selected 5 items from each subscale to construct the S-STREAM and found that the reliability of each subscale of the resulting simplified instrument was high (Rasch reliability coefficients of [greater than or equal to] .91). The agreement between the subscale scores (Rasch estimates) of the S-STREAM and those of the STREAM was excellent (ICC of [greater than or equal to] .99, with a lower limit for the 95% confidence interval of [greater than or equal to] .985), indicating good concurrent validity of the S-STREAM with the STREAM. Discussion and Conclusion. The S-STREAM demonstrates high Rasch reliability, unidimensionality, and concurrent validity with the STREAM in patients with stroke. Furthermore, the S-STREAM is efficient to administer, as it consists of only half the number of items in the original STREAM. Additional studies to examine other psychometric properties (eg, predictive validity and responsiveness) of the S-STREAM or its psychometric properties in various recovery stages after stroke are needed to further establish its utility in both clinical and research settings.<br /

A study on Supercritical Electrolytic Polishing Process for Stainless steel substrates

The polishing technique is an important surface treatment method used in both conventional and electronic industry. Traditionally, there are three main skills included (1) mechanic polishing (2) electrolytic polishing (3) chemical polishing. However, all of them could not deal with complex parts with higher aspect ratio and serious environmental problem with labor cost. In this work, we have explored a new polishing method which applies principles of electro-chemistry and electro-physics to treat the surface of stainless substrate under the supercritical carbon dioxide fluid. It used to get rid of oxides on it and to increase its smoothness as well as brightness. The various kinds of golf head were selected as the investigated system. The roughness of sample can be upgraded to nano-metered size (~200nm) and the it’s brightness of mirror also be obtained (reflectivity > 95%). It is highlighted that the new supercritical polishing method is a green process without polluting environments and it is suitable to complex work pieces and simple operation with high efficiency

Optimization study on hardness of gold film through supercritical electroplating process by response surface methodology

A non-cyanide gold bath has been used to deposit gold film on a brass substrate through electroplating process using supercritical carbon dioxide emulsion. The hardness of deposited gold film was considered as a response variable to optimize the process parameters of electroplating operation by statistical experimental methods. Effects of current density, pressure temperature, and chemical composition of the solution were investigated to select the optimal operation factors. Scanning electron microscopy and micro-hardness tester were applied to determine the characteristics of metallic film. The screening of significant variables was examined by a 25-1 fractional factorial design with V resolution method. The experimental result showed that the significant variables affecting the deposition of gold film were current density, pressure and temperature. Based on Box-Behnken design and response surface methodology (RSM), a regression model was built by fitting the experimental results with a polynomial equation. The optimal operating variable conditions can be searched at a specified hardness for industrial hard and soft gold application ranged from 83.8 to 157.7 HV

Optimization Study on Supercritical Electrodeposition of Nickel Nanowire Arrays Using AAO Template

Highly ordered and nanometer-scaled nickel wire arrays were successfully prepared by supercritical electrodeposition method using anodized aluminum oxide (AAO) template. The results show that the well-ordered and free-standing nickel nanowire arrays can be constructed uniformly on a titanium-coated silicon wafer after removing the AAO template. The diameter and length of the nickel nanowire in the arrays can be obtained, about 100?nm and 10?um, respectively. Based on Box-Behnken design and Response Surface Methodology (RSM), a regression model was built by fitting the experimental results with a polynomial equation. The current density, pressure, and temperature are critical important factors of the growth mechanism of deposited nanowires. The optimal length of nanowires, 10.03?μm, can be achieved at the following conditions: current density 0.23?A/cm2, pressure 107?bar, and temperature 53°C