A Metabolic Shift Favoring Sphingosine 1-Phosphate at the Expense of Ceramide Controls Glioblastoma Angiogenesis

Studies in cell culture and mouse models of cancer have indicated that the soluble sphingolipid metabolite sphingosine 1-phosphate (S1P) promotes cancer cell proliferation, survival, invasiveness, and tumor angiogenesis. In contrast, its metabolic precursor ceramide is prodifferentiative and proapoptotic. To determine whether sphingolipid balance plays a significant role in glioma malignancy, we undertook a comprehensive analysis of sphingolipid metabolites in human glioma and normal gray matter tissue specimens. We demonstrate, for the first time, a systematic shift in sphingolipid metabolism favoring S1P over ceramide, which increases with increasing cancer grade. S1P content was, on average, 9-fold higher in glioblastoma tissues compared with normal gray matter, whereas the most abundant form of ceramide in the brain, C18 ceramide, was on average 5-fold lower. Increased S1P content in the tumors was significantly correlated with increased sphingosine kinase 1 (SPHK1) and decreased sphingosine phosphate phosphatase 2 (SGPP2) expression. Inhibition of S1P production by cultured glioblastoma cells, using a highly potent and selective SPHK1 inhibitor, blocked angiogenesis in cocultured endothelial cells without affecting VEGF secretion. Our findings validate the hypothesis that an altered ceramide/S1P balance is an important feature of human cancers and support the development of SPHK1 inhibitors as antiangiogenic agents for cancer therapy.     

Oleylamine-carbonyl-valinol inhibits auto-phosphorylation activity of native and T315I mutated Bcr-Abl, and exhibits selectivity towards oncogenic Bcr-Abl in SupB15 ALL cell lines

Chronic myeloid leukemia (CML) is characterized by the presence of p210^Bcr-Abl which exhibits an abnormal kinase activity. Selective Abl kinase inhibitors have been successfully established for the treatment of CML. Despite high rates of clinical response, CML patients can develop resistance against these kinase inhibitors mainly due to point mutations within the Abl protein kinase domain. Previously, we have identified oleic acid as the active component in the mushroom Daedalea gibbosa that inhibited the kinase activity of Bcr-Abl. Here, we report that the oleyl amine derivatives, S-1-(1-Hydroxymethyl-2-methyl-propyl)-3-octadec-9-enyl-urea [oleylaminocarbonyl-L-N-valinol,oroleylaminocarbonyl-S-2-isopropyl-N-ethanolamine,oleylamine-carbonyl-L-valinol] (cpd 6) and R-1-(1-Hydroxymethyl-2-methyl-propyl)-3-octadec-9-enyl-urea [oleylamineocarbonyl-D-N-valinol, oleylaminocarbonyl-R-2-isopropyl-N-ethanolamine, or oleylamine-carbonyl-D-valinol] (cpd 7), inhibited the activity of the native and T315I mutated Bcr-Abl. Furthermore, cpd 6 and 7 exhibited higher activity towards the oncogenic Bcr-Abl in comparison to native c-Abl in SupB15 Ph-positive ALL cell line.     

Mutational sensitivity of D614G in spike protein of SARS-CoV-2 in Jordan

BackgroundSpike protein is the surface glycoprotein of the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) necessary for the entry of the virus via the transmembrane receptors of the human respiratory cells causing COVID-19 disease.AimHere, we aimed to predict the three-dimensional monomer structure of spike protein of SARS-CoV-2 from 20 Jordanian nasopharyngeal samples and to determine the percentage of single amino acid variants (SAV) in the spike protein of SARS-CoV-2.MethodsThe output of the Protein Homology/analogY Recognition Engine V 2.0 (Phyre2) found four single amino acid variants in the spike gene.ResultsThe first variant represented by 5% of samples that showed tyrosine deletion at Y144 located in the N terminal domain. The second and the dominant variant, represented by 62%, showed aspartate a coil amino acid substitution to glycine an extracellular amino acid at D614G located in the spike recognition binding site. The third variant, represented by 5%, showed aspartate substitution to tyrosine at D1139Y, and the fourth variant, represented by 5% glycine substitution to serine at G1167S.ConclusionOur results have shown low mutational sensitivity in all variants except to D614G the one with the most likely neutral mutational sensitivity that all variants might not explicitly affect the function of spike glycoprotein. However, D614G might change the viral conformational plasticity and hence a potential viral fitness gain but one must be cautious about drawing any concrete conclusions about the severity of symptoms and viral transmission from genomic data only.General significanceStudying mutations such as D614G in deep is essential to control the pandemic in terms of immune systems, antibodies, or even vaccines.     

Synthesis,in vitro antitumour activity,and molecular docking study of novel 2-substituted mercapto-3-(3,4,5-trimethoxybenzyl)-4(3H)-quinazolinone analogues

A novel series of 2-substituted mercapto-3-(3,4,5-trimethoxybenzyl)-4(3H)-quinazolinones 1–20 was synthesised and evaluated for in vitro antitumour activity. N-(4-Chlorophenyl)-2-[(3-(3,4,5-trimethoxybenzyl)-4(3H)-quinazolinon-2-yl)thio)acetamide (7) and N-(3,4,5 trimethoxybenzyl)-2-[(3-(3,4,5-trimethoxybenzyl)-4(3H)-quinazolinon-2-yl)thio]propanamide (19) exhibited excellent antitumour properties, with mean growth inhibitory concentration (GI₅₀) of 17.90 and 6.33 µΜ, respectively, compared with those of 5-fluorouracil 5-FU, gefitinib, and erlotinib (mean GI₅₀: 18.60, 3.24, and 7.29 µΜ, respectively). Comparison of the GI₅₀ (µM) values of compounds 7 and 19 versus those of 5-FU, gefitinib, and erlotinib against an in vitro subpanel of tumour cells lines showed that compounds 7 and 19 have activities almost equal to or higher than that of those standard drugs, especially against lung, CNS, and breast cancer cells. However, compounds 5, 10, 14, 15, 16, 17, and 20 exhibited effective antitumour activity against the different cell lines tested, with growth inhibition percentage (MGI%) of 19, 24, 19, 17, 16, 15, and 16, respectively. A modelling study was performed for compounds 7 and 19 by docking them into the EGFR kinase enzyme to study their mode of binding with the putative binding site.     

Measurement of hydrophobic interactions of mammalian cells grown in culture

An assay was developed to measure the hydrophobic interactions of commonly used mammalian cell lines grown in culture. The assay depends on the loss of cells from an aqueous suspension following vortexing with a hydrophobic oil phase. This allowed the determination of a hydrophobicity index, which was significantly higher for Chinese Hamster Ovary (CHO) cells than either a murine hybridoma (CC9C10) or a myeloma (SP2/0). This suggests that CHO cells may have a higher intrinsic cell surface hydrophobicity. The assay was also used to study the effect of different additives on the hydrophobic interactions of the cells. A dose-dependent effect was shown for the non-ionic surfactant, Pluronic F68, in reducing the hydrophobic interaction of the CHO cells. However, the pattern of the decrease due to Pluronic F68 was different for each cell line. A higher concentration of Pluronic F68 (0.2%) was required to eliminate the hydrophobic interactions of CHO cells compared to either myelomas or hybridomas, where only 0.05% was required to reduce these interactions to a similar level. Several oils were found suitable for this assay although canola oil maximized the sensitivity of the measured changes. The assay may be useful in monitoring changes in the hydrophobic interactions of mammalian cells during growth in bioreactors. This may be important in optimizing the concentration of cell protectants such as Pluronic F68 in agitated cultures.     

LC‐MS/MS‐based serum proteomics for identification of candidate biomarkers for hepatocellular carcinoma

Associating changes in protein levels with the onset of cancer has been widely investigated to identify clinically relevant diagnostic biomarkers. In the present study, we analyzed sera from 205 patients recruited in the United States and Egypt for biomarker discovery using label‐free proteomic analysis by LC‐MS/MS. We performed untargeted proteomic analysis of sera to identify candidate proteins with statistically significant differences between hepatocellular carcinoma (HCC) and patients with liver cirrhosis. We further evaluated the significance of 101 proteins in sera from the same 205 patients through targeted quantitation by MRM on a triple quadrupole mass spectrometer. This led to the identification of 21 candidate protein biomarkers that were significantly altered in both the United States and Egyptian cohorts. Among the 21 candidates, ten were previously reported as HCC‐associated proteins (eight exhibiting consistent trends with our observation), whereas 11 are new candidates discovered by this study. Pathway analysis based on the significant proteins reveals upregulation of the complement and coagulation cascades pathway and downregulation of the antigen processing and presentation pathway in HCC cases versus patients with liver cirrhosis. The results of this study demonstrate the power of combining untargeted and targeted quantitation methods for a comprehensive serum proteomic analysis, to evaluate changes in protein levels and discover novel diagnostic biomarkers. All MS data have been deposited in the ProteomeXchange with identifier PXD001171 ( http://proteomecentral.proteomexchange.org/dataset/PXD001171 ).     

Increased hemorrhagic transformation and altered infarct size and localization after experimental stroke in a rat model type 2 diabetes

Background  

Interruption of flow through of cerebral blood vessels results in acute ischemic stroke. Subsequent breakdown of the blood brain barrier increases cerebral injury by the development of vasogenic edema and secondary hemorrhage known as hemorrhagic transformation (HT). Diabetes is a risk factor for stroke as well as poor outcome of stroke. The current study tested the hypothesis that diabetes-induced changes in the cerebral vasculature increase the risk of HT and augment ischemic injury.