p130Cas regulates cancer progression by driving tyrosine receptor kinase signaling. Tight regulation of p130Cas expression is necessary for survival, apoptosis, and maintenance of cell motility in ...various cell types. Several studies revealed that transcriptional and post-translational control of p130Cas are important for maintenance of its expression and activity. To explore novel regulatory mechanisms of p130Cas expression, we studied the effect of microRNAs (miRs) on p130Cas expression in human breast cancer MCF7 cells. Here, we provide experimental evidence that miR-362-3p and miR-329 perform a tumor-suppressive function and their expression is downregulated in human breast cancer. miR-362-3p and miR-329 inhibited cellular proliferation, migration, and invasion, thereby suppressing tumor growth, by downregulating p130Cas. Ectopic expression of p130Cas attenuated the inhibitory effects of the two miRs on tumor progression. Relative expression levels of miR-362-3p/329 and p130Cas between normal and breast cancer correlated inversely; miR-362-3p/329 expression was decreased, whereas that of p130Cas increased in breast cancers. Furthermore, we showed that downregulation of miR-362-3p and miR-329 was caused by differential DNA methylation of miR genes. Enhanced DNA methylation (according to methylation-specific PCR) was responsible for downregulation of miR-362-3p and miR-329 in breast cancer. Taken together, these findings point to a novel role for miR-362-3p and miR-329 as tumor suppressors; the miR-362-3p/miR-329-p130Cas axis seemingly has a crucial role in breast cancer progression. Thus, modulation of miR-362-3p/miR-329 may be a novel therapeutic strategy against breast cancer.
SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star)
. Two jets of ionized ...matter with a bulk velocity of approximately 0.26c (where c is the speed of light in vacuum) extend from the binary, perpendicular to the line of sight, and terminate inside W50, a supernova remnant that is being distorted by the jets
. SS 433 differs from other microquasars (small-scale versions of quasars that are present within our own Galaxy) in that the accretion is believed to be super-Eddington
, and the luminosity of the system is about 10
ergs per second
. The lobes of W50 in which the jets terminate, about 40 parsecs from the central source, are expected to accelerate charged particles, and indeed radio and X-ray emission consistent with electron synchrotron emission in a magnetic field have been observed
. At higher energies (greater than 100 gigaelectronvolts), the particle fluxes of γ-rays from X-ray hotspots around SS 433 have been reported as flux upper limits
. In this energy regime, it has been unclear whether the emission is dominated by electrons that are interacting with photons from the cosmic microwave background through inverse-Compton scattering or by protons that are interacting with the ambient gas. Here we report teraelectronvolt γ-ray observations of the SS 433/W50 system that spatially resolve the lobes. The teraelectronvolt emission is localized to structures in the lobes, far from the centre of the system where the jets are formed. We have measured photon energies of at least 25 teraelectronvolts, and these are certainly not Doppler-boosted, because of the viewing geometry. We conclude that the emission-from radio to teraelectronvolt energies-is consistent with a single population of electrons with energies extending to at least hundreds of teraelectronvolts in a magnetic field of about 16 microgauss.
The purpose of this study was to investigate the effects of elastic anisotropy on nanoindentation measurements in human tibial cortical bone. Nanoindentation was conducted in 12 different directions ...in three principal planes for both osteonic and interstitial lamellae. The experimental indentation modulus was found to vary with indentation direction and showed obvious anisotropy (one-way analysis of variance test,
P<0.0001). Because experimental indentation modulus in a specific direction is determined by all of the elastic constants of cortical bone, a complex theoretical model is required to analyze the experimental results. A recently developed analysis of indentation for the properties of anisotropic materials was used to quantitatively predict indentation modulus by using the stiffness matrix of human tibial cortical bone, which was obtained from previous ultrasound studies. After allowing for the effects of specimen preparation (dehydrated specimens in nanoindentation tests vs. moist specimens in ultrasound tests) and the structural properties of bone (different microcomponents with different mechanical properties), there were no statistically significant differences between the corrected experimental indentation modulus (
M
exp) values and corresponding predicted indentation modulus (
M
pre) values (two-tailed unpaired
t-test,
P>0.5). The variation of
M
pre values was found to exhibit the same trends as the corrected
M
exp data. These results show that the effects of anisotropy on nanoindentation measurements can be quantitatively evaluated.
Abstract
The Earth is bombarded by ultrarelativistic particles, known as cosmic rays (CRs). CRs with energies up to a few PeV (=10
15
eV), the knee in the particle spectrum, are believed to have a ...Galactic origin. One or more factories of PeV CRs, or PeVatrons, must thus be active within our Galaxy. The direct detection of PeV protons from their sources is not possible since they are deflected in the Galactic magnetic fields. Hundred TeV
γ
-rays from decaying
π
0
, produced when PeV CRs collide with the ambient gas, can provide the decisive evidence of proton acceleration up to the knee. Here we report the discovery by the High Altitude Water Cerenkov (HAWC) observatory of the
γ
-ray source, HAWC J1825-134, whose energy spectrum extends well beyond 200 TeV without a break or cutoff. The source is found to be coincident with a giant molecular cloud. The ambient gas density is as high as 700 protons cm
−3
. While the nature of this extreme accelerator remains unclear, CRs accelerated to energies of several PeV colliding with the ambient gas likely produce the observed radiation.
Protein crystallization still remains mostly an empirical science, as the production of crystals with the required quality for X-ray analysis is dependent on the intensive screening of the best ...protein crystallization and crystal’s derivatization conditions. Herein, this demanding step was addressed by the development of a high-throughput and low-budget microfluidic platform consisting of an ion exchange membrane (117 Nafion® membrane) sandwiched between a channel layer (stripping phase compartment) and a wells layer (feed phase compartment) forming 75 independent micro-contactors. This microfluidic device allows for a simultaneous and independent screening of multiple protein crystallization and crystal derivatization conditions, using Hen Egg White Lysozyme (HEWL) as the model protein and Hg2+ as the derivatizing agent. This microdevice offers well-regulated crystallization and subsequent crystal derivatization processes based on the controlled transport of water and ions provided by the 117 Nafion® membrane. Diffusion coefficients of water and the derivatizing agent (Hg2+) were evaluated, showing the positive influence of the protein drop volume on the number of crystals and crystal size. This microfluidic system allowed for crystals with good structural stability and high X-ray diffraction quality and, thus, it is regarded as an efficient tool that may contribute to the enhancement of the proteins’ crystals structural resolution.
The present study examined the expression pattern of oxygen (O
2) and stress-responsive gene transcripts at various preimplantation developmental stages of in vitro produced (IVP) and in vivo derived ...(IVD) bovine embryos. Embryos were produced in vitro from oocytes matured, fertilized and cultured in synthetic oviductal fluid (SOF) medium under low (5%) and high (20%) O
2 concentrations. In vivo embryos were derived from 18 superovulated and artificially inseminated cows. In IVP and IVD groups, embryos were collected at 2-, 4-, 8-, 16-cell morula and blastocyst stages at specific time points for gene expression analysis. The cleavage rates (69.8
±
4.8%) did not differ significantly, but blastocyst rates were significantly higher (28.5
±
3.7%) in low O
2 than those in high O
2 group (18.7
±
3.9%). Mean cell number in low O
2 (145
±
12) and high O
2 (121
±
73) IVP blastocyst were lower (
P
<
0.05) than those of IVD blastocyst (223
±
25). The ICM ratio of IVD blastocyst (26
±
4) was lower (
P
<
0.05) than that of IVP embryos under 5% O
2 (33
±
5) and 20% O
2 (34
±
4) concentrations, respectively. Using real time PCR, for the set of target transcripts (
Glut1, Glut5, Sox, G6PD, MnSOD, PRDX5, NADH and
Hsp 70.1) analyzed, there were differences in the mRNA expression pattern at 2-, 4-, 8-, 16-cell morula and Day 7 blastocyst stages between the two embryo sources. It can be concluded that, although in vitro bovine embryo culture in SOF medium under low (5%) O
2 concentration provided a more conducive environment in terms of blastocyst formation; differences in the total cell number and gene expression pattern between the IVP and IVD embryos reflected the effect of O
2 concentration.
Removal of the somatic DNA methylation pattern from donor cells and remodeling of embryonic status have been suggested as integral processes for successful nuclear transfer (NT) reprogramming. This ...study has investigated the effects of 5-azacytidine (5-azaC), a DNA methylation inhibitor, on global methylation changes in porcine fetal fibroblasts (PFF); this may improve NT attributable to the potential reprogramming of the methyl groups. PFF in 5th passage cultures were treated with 0, 0.5, 1.0, 2.0, and 3.0 microM 5-azaC for 96 h; 5-azaC inhibited the growth at all tested concentrations. At the higher concentrations of 5-azaC used, cells appeared to exhibit morphological changes and to become apoptotic as observed by TUNEL assay. Thus, cells were negatively affected by 5-azaC. Differences in cellular ploidy were also observed at higher concentrations. Analysis showed no considerable changes in the proportion of cells at the G1-phase of the cell cycle with 5-azaC concentrations. The fractional part of the methylated DNA of these cells was significantly reduced by 5-azaC treatment. Confocal microscopy confirmed the inhibition of methylation levels in PFF with increased concentrations of 5-azaC. Exposure to 5-azaC altered the expression of genes involved in imprinting (IGF2) or pro-apoptosis (BAX), whereas there was a reduction in the expression of the main enzyme responsible for replicating the DNA methylation pattern (DNMT1) and anti-apoptosis (BCL2L1). Therefore, 5-azaC induces a relative reduction in methylation in PFF, and cells treated with 0.5 microM 5-azaC may have enhanced potential for porcine NT.
A microfluidic device for pH gradient chromatofocusing is presented, which performs creation of a micro‐column, pH gradient generation, and fraction collection in a single device. Using a sieve ...micro‐valve, anion exchange particles were packed into a microchannel in order to realize a solid‐phase absorption column. To fractionate proteins according to their isoelectric points, elution buffer solutions with a stepwise pH gradient were prepared in 16 parallel mixing reactors and flowed through the micro‐column, wherein a protein mixture was previously loaded. The volume of the column is only 20 nL, hence it allows extremely low sample consumption and fast analysis compared with a conventional system. We demonstrated separation of two proteins, albumin–fluorescein isothiocyanate conjugate (FITC‐BSA) and R‐Phycoerythrin (R‐PE), by using a microcolumn of commercial charged polymeric particles (Source 15Q). The microfluidic device can be used as a rapid diagnostic tool to analyse crude mixtures of proteins or nucleic acids and determine adsorption/desorption characteristics of various biochemical products, which can be helpful for scientific fundamental understanding as well as instrumental in various industrial applications, especially in early stage screening and process development.
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