Inhibition of Fatty Acid Synthase Decreases Expression of Stemness Markers in Glioma Stem Cells

Cellular metabolic changes, especially to lipid metabolism, have recently been recognized as a hallmark of various cancer cells. However, little is known about the significance of cellular lipid metabolism in the regulation of biological activity of glioma stem cells (GSCs). In this study, we examined the expression and role of fatty acid synthase (FASN), a key lipogenic enzyme, in GSCs. In the de novo lipid synthesis assay, GSCs exhibited higher lipogenesis than differentiated non-GSCs. Western blot and immunocytochemical analyses revealed that FASN is strongly expressed in multiple lines of patient-derived GSCs (G144 and Y10), but its expression was markedly reduced upon differentiation. When GSCs were treated with 20 μM cerulenin, a pharmacological inhibitor of FASN, their proliferation and migration were significantly suppressed and de novo lipogenesis decreased. Furthermore, following cerulenin treatment, expression of the GSC markers nestin, Sox2 and fatty acid binding protein (FABP7), markers of GCSs, decreased while that of glial fibrillary acidic protein (GFAP) expression increased. Taken together, our results indicate that FASN plays a pivotal role in the maintenance of GSC stemness, and FASN-mediated de novo lipid biosynthesis is closely associated with tumor growth and invasion in glioblastoma.     

The tumor suppressor p53 is bound to RNA by a stable covalent linkage.

We have previously shown that the carboxyl-terminal tryptic peptide of the tumor suppressor p53 coeluted from reverse-phase high-performance liquid chromatography (HPLC) with ribonucleotides, suggesting the possible linkage of RNA to p53. In this report, we establish that p53 is covalently linked to RNA, using biochemical criteria at the levels of both tryptic peptide and intact protein: the electrophoretic properties of a tryptic peptide containing phosphorylated Ser-389 and the HPLC chromatographic properties of p53 depend on the linked RNA, p53, purified through urea-sodium dodecyl sulfate-polyacrylamide gel electrophoresis and HPLC, copurifies with RNA, and Ser-389 liberates ribonucleotides upon RNase or alkali treatment. Wild-type and mutant p53s from both simian virus 40 (SV40)-transformed and SV40-nontransformed cells are RNA linked, indicating that RNA linkage may be a general property of p53. The RNA is labeled in vivo with 3H-uridine and in vitro by RNA ligase, suggesting that the RNA is bound by a 5' linkage. The RNA is a long-lived, integral component of p53 rather than a transient reaction intermediate. RNA linkage occurs at an evolutionarily conserved site on p53. We propose that RNA-linked p53 is a major biologically active form of p53 and that its interaction with RNA-linked SV40 T antigen reflects a role in RNA metabolism.     

Ultraviolet inactivation and photoreactivation of the cholera phage ‘Kappa’

Summary The lysogenic cholera phage, Kappa is some ten to twenty folds more resistant to UV (254 nm) than are most of the T. phages ofE. coli, or the cholera phage PL 163/10, or the hostV. cholerae strain H218 Sm^r, the 37% (D ₃₇) and 10% (D ₁₀) survival doses being 255.8 J/m² and 633.6 J/m² respectively. The UV-irradiated Kappa phages could be photoreactivated in the hostV. cholerae strain H218 Sm^r to a maximum extent of 40%. The removal of the number of lethal hits per phage by the survival-enhancement treatment (photoreactivation) with time followed an exponential relation, the constant probability of removal of lethal hit per unit time being 2.8 × 10^–2 min^–1. The UV-irradiated phages could also be Weigle reactivated in the host strain H218 Sm^r by a small degree, the maximum reactivation factor (ratio of survivals in UV-irradiated and non-irradiated hosts) being 1.50.     

A simple enzymeimmunoassay of milk progesterone for monitoring fertility in dairy buffaloes

A simple, sensitive, direct (without extraction) enzymeimmunoassay (EIA) was usec to determine progesterone levels in whole milk samples of 400 Nili-Ravi dairy buffaloes. The mean progesterone values 22 d after A.I. were significantly higher in pregnant (16.6 +/- 9.2 ng/ml) than nonpregnant (below 5 ng/ml) animals. The mean progesterone values were below 0.34 +/- 0.12 (the detection limit) both at estrus and in cases of clinically diagnosed inactive ovaries, 3.18 +/- 1.9 at proestrus, 2.25 +/- 1.2 postestrus and 13.22 +/- 6.74 at Day 10 of the estrous cycle. Twenty buffaloes confirmed pregnant for 2 to 3 mo, had a mean value of 20.3 +/- 4.5 ng/ml. The EIA test is very reliable in the selection of nonpregnant buffaloes (100 %) and the confirmation of inactive ovaries and of estrus. Differential diagnosis of inactive or active ovaries can be made by analyzing two milk samples at a 7-d interval.     

Freeze Thaw: A Simple Approach for Prediction of Optimal Cryoprotectant for Freeze Drying

The present study evaluates freeze thaw as a simple approach for screening the most appropriate cryoprotectant. Freeze–thaw study is based on the principle that an excipient, which protects nanoparticles during the first step of freezing, is likely to be an effective cryoprotectant. Nanoparticles of rifampicin with high entrapment efficiency were prepared by the emulsion-solvent diffusion method using dioctyl sodium sulfosuccinate (AOT) as complexing agent and Gantrez AN-119 as polymer. Freeze–thaw study was carried out using trehalose and fructose as cryoprotectants. The concentration of cryoprotectant, concentration of nanoparticles in the dispersion, and the freezing temperature were varied during the freeze–thaw study. Cryoprotection increased with increase in cryoprotectant concentration. Further, trehalose was superior to fructose at equivalent concentrations and moreover permitted use of more concentrated nanosuspensions for freeze drying. Freezing temperature did not influence the freeze–thaw study. Freeze-dried nanoparticles revealed good redispersibility with a size increase that correlated well with the freeze–thaw study at 20% w/v trehalose and fructose. Transmission electron microscopy revealed round particles with a size ∼400 nm, which correlated with photon correlation spectroscopic measurements. Differential scanning calorimetry and X-ray diffraction suggested amorphization of rifampicin. Fourier transfer infrared spectroscopy could not confirm interaction of drug with AOT. Nanoparticles exhibited sustained release of rifampicin, which followed diffusion kinetics. Nanoparticles of rifampicin were found to be stable for 12 months. The good correlation between freeze thaw and freeze drying suggests freeze–thaw study as a simple and quick approach for screening optimal cryoprotectant for freeze drying.     

Prevalence and detection of metallo-β-lactamase (MBL)-producingPseudomonas aeruginosa strains from clinical isolates in Iran

Of the 126 isolates obtained from clinical specimens, seventy strains were selected because of resistance or reduced susceptibilities to imipenem and/or ceftazidime. Screening for detection of MBL-producing strains was performed in latter isolates by the Etest MBL strips. Isolates that were positive to Etest MBL strips were analysed by PCR. PCR was performed with specific DNA probes for detection of genes coding IMP or VIM enzymes and positive controls (MBL-producing strains). Finally, eight isolates ofPseudomonas aeruginosa were detected to carry a bla_VIM gene.     

Dictyostelium myosin II G680V suppressors exhibit overlapping spectra of biochemical phenotypes including facilitated phosphate release.

We have biochemically characterized 13 intragenic suppressors of the G680V mutation of Dictyostelium myosin II. In the absence of the G680V mutation, the suppressors result in a number of deviant behaviors, most commonly an increase in the basal (actin-independent) ATPase of the motor. This phenotype is complementary to that of the G680V mutant and supports our proposal that the latter impairs phosphate release. Different subsets of the mutants also suffer from poor ATPase enhancement by 1 mg/ml actin, failure to release from actin in the presence of ATPgammaS (or ADP and salt), and excessive release from actin in the presence of ADP. The patterns of suppressor behaviors suggest that, in general, they are facilitating P(i)-releasing state(s) of the motor, but that different individual suppressors may secondarily perturb other states or actions of the motor.     

Neuropathological and genomic characterization of glioblastoma-induced rat model: How similar is it to humans for targeted therapy?

Glioblastoma multiforme (GBM) is a unique aggressive tumor and mostly develops in the brain, while rarely spreading out of the central nervous system. It is associated with a high mortality rate; despite tremendous efforts having been made for effective therapy, tumor recurrence occurs with high prevalence. To elucidate the mechanisms that lead to new drug discovery, animal models of tumor progression is one of the oldest and most beneficial approaches to not only investigating the aggressive nature of the tumor, but also improving preclinical research. It is also a useful tool for predicting novel therapies' effectiveness as well as side effects. However, there are concerns that must be considered, such as the heterogeneity of tumor, biological properties, pharma dynamic, and anatomic shapes of the models, which have to be similar to humans as much as possible. Although several methods and various species have been used for this approach, the real recapitulation of the human tumor has been left under discussion. The GBM model, which has been verified in this study, has been established by using the Rat C6 cell line. By exploiting bioinformatic tools, the similarities between aberrant gene expression and pathways have been predicted. In this regard, 610 common genes and a number of pathways have been detected. Moreover, while magnetic resonance imaging analysis enables us to compare tumor features between these two specious, pathological findings provides most of the human GBM characteristics. Therefore, the present study provides genomics, pathologic, and imaging evidence for showing the similarities between human and rat GBM models.     

Targeted drug delivery of magnetic microbubble for abdominal aortic aneurysm: an in silico study

Biomechanics and Modeling in Mechanobiology - Targeted drug delivery (TDD) to abdominal aortic aneurysm (AAA) using a controlled and efficient approach has recently been a significant challenge. In...