Breast tumor kinase and extracellular signal-regulated kinase 5 mediate Met receptor signaling to cell migration in breast cancer cells

Introduction  

Breast tumor kinase (Brk/protein tyrosine kinase 6 (PTK6)) is a nonreceptor, soluble tyrosine kinase overexpressed in the majority of breast tumors. Previous work has placed Brk downstream of epidermal growth factor receptor (ErbB) activation and upstream of extracellular signal-regulated kinase 5 (ERK5) and p38 mitogen-activated protein (MAP) kinases. Herein we investigate the regulation of Brk kinase activity and cell migration in response to treatment of keratinocytes (HaCaT cells) and breast cancer cell lines (MDA-MB-231 and T47D cells) with hepatocyte growth factor (HGF) and macrophage stimulating protein (MSP), peptide ligands for Met and Ron receptors, respectively.     

Phoneutria spider toxins block ischemia‐induced glutamate release,neuronal death,and loss of neurotransmission in hippocampus

The aim of this study was to investigate the effect of spider toxins on brain injury induced by oxygen deprivation and low glucose (ODLG) insult on slices of rat hippocampus. After ODLG insult cell viabilility in hippocampal slices was assessed by confocal microscopy and epifluorescence using the live/dead kit containing calcein‐AM and ethidium homodimer and CA1 population spike amplitude recording during stimulation of Schaffer collateral fibers. Spider toxins Tx3–3 or Tx3–4 and conus toxins, ω‐conotoxin GVIA or ω‐conotoxin MVIIC are calcium channel blockers and protected against neuronal damage in slices subjected to ODLG insult. Confocal imaging of CA1 region of rat hippocampal slices subject to ischemic insult treated with Tx3–3, Tx3–4, ω‐conotoxin GVIA or ω‐conotoxin MVIIC showed a decrease in cell death that amounted to 68 ± 4.2%, 77 ± 3.8%, 32 ± 2.3%, and 46 ± 2.9%, respectively. This neuroprotective effect of Tx3–4 was corroborated by eletrophysiological recordings of population spikes amplitudes in CA1. The neuroprotection promoted on hippocampal slices by Tx3–3 or Tx3–4 was also observed when the toxins were applied 10, 20, 30, 60, 90, or 120 min after induction of the ODLG injury. During the ischemic insult, glutamate release from slices was increased by 71% (from 7.0 ± 0.3 nM/mg of protein control slices not subjected to ischemia to 12 ± 0.4 nM/mg of protein in slices exposed to ischemia). Tx3–3, Tx3–4, ω‐conotoxin GVIA or ω‐conotoxin MVIIC inhibited the ischemia‐induced increase on glutamate release by 54, 72, 60, and 70%, respectively. Thus Tx3–3 and Tx3–4 provided robust ischemic neuroprotection showing potential as a novel class of agent that exerts neuroprotection in an in vitro model of brain ischemia. © 2009 Wiley‐Liss, Inc.     

Phenotype modulation of cellular UV-sensitivity.

Mammalian cell shape is critically important to cell differentiation, apoptosis, cell division, and growth arrest. In the present study we examined the relationship among cell density, cell phenotype (which include shape and coupling) and cell survival using the human A549, H596 and H520 non-small cell lung carcinoma lines. Thus, cells from monolayers, aggregated and suspended cultures at different densities were exposed to UV-radiation and both the density and the phenotype of the cells induce shifts in cellular growth rate. Except in suspended cultures, we observed a UV-sensitivity closely related to the proliferative status of the cells. The variability of the cellular response to UV were investigated taking into account the shape and the coupling potential of the cell lines, suggesting that an intercellular-contact mechanism provides further protection against UV-radiation damage.     

Linear pemphigus vulgaris along a surgical scar.

A 64-year-old female had breast carcinoma of the right breast, and a mastectomy was performed. Three years later she developed a vesiculobullous eruption along the surgical scar. Histopathological and direct immunofluorescence findings were consistent with a diagnosis of pemphigus vulgaris. We discuss the possible pathogenesis for this striking linear distribution of the pemphigus vulgaris lesions.     

Identification of correlates of physical activity among Latino adults

127 Latino adults responded to a survey concerning physical activity. Respondents over-represented well educated and middle class Latinos. Subjects reported a mean of 48 minutes/week of walking for exercise. This sample reported less than two episodes per week of vigorous physical activity, again below the recommended 3/wk needed to insure cardiovascular fitness. We expect more representative samples to engage in less physical activity. Stepwise multiple regression analyses were conducted using 24 variables based on Social Learning Theory. A multiple R of 0.66 accounted for over 27% of the variance in walking for exercise (p<0.001). Older adults, those with a history of childhood injury, and those who reported friend support were more likely to walk for exercise. Respondents who participated in physical activity during childhood and adolescence (including formal physical education in school) and, paradoxically, those who had models for exercise in childhood were less likely to walk for exercise. A multiple R of 0.75 accounted for 43% of the variance in vigorous physical activity and reached significance (p<0.001). Self-efficacy, friends' support, childhood physical activity, and eating a heart healthy diet were positively related to vigorous activity. These results suggest that different correlates influence walking versus vigorous activity, and that correlates of physical activity are different for Latinos compared to Anglos. The findings emphasize the need for larger scale investigations of the determinants of activity within the Latino population.M. Hovell, E. Barrington, M. Hackley, J. Elder, F. Castro, Kristin Kilbourne; Division of Health Promotion, Graduate School of Public Health, San Diego State University, San Diego, CA 92182, J. Sallis; Department of Psychology, San Diego State University, San Diego, CA 92182, R. Hofstetter; Department of Political Science, San Diego State University, San Diego, CA 92182.This research was supported by grants to Drs. Hovell and Sallis: ASPH/CDC Cooperative Agreement Contract; NHLBI (40575).     

Action of a thionin isolated from nuts of Pyrularia pubera on human erythrocytes

Pyrularia thionin is a strongly basic peptide of 47 amino acids isolated from Pyrularia pubera. This peptide, a member of the thionin family, is hemolytic, cytotoxic and neurotoxic. The characteristics of the hemolytic activity on human erythrocytes are as follows: (1) the peptide does not itself have any phospholipase activity in a micellar assay system with egg yolk phosphatidylcholine, as evidenced by a lack of pH change or uptake of oxygen in the presence of lipoxidase; (2) erythrocyte membranes treated with thionin, however, show a low level of oxygen uptake in the presence of lipoxidase as a consequence of fatty acid release, and this activity is synergistic with that of bee venom phospholipase A2; (3) hemolysis caused by thionin is synergistic with added bee venom phospholipase A2; (4) kinetic analysis of the hemolytic assay reveals that the reaction follows Michaelis-Menten kinetics, being saturable with thionin with a Km of 1.6 microM; (5) binding studies with 125I-thionin show by Scatchard analysis a Kd value of 2.1 microM; (6) although iodinated thionin is inactive in the hemolysis assay, it acts as a competitive inhibitor to native thionin in the hemolytic assay; the inhibitor constant, Ki, for this reaction is 7.0 microM; and (7) Ca2+ above 1 mM inhibits the reaction. All the data are consistent with thionin binding to a receptor, most likely a protein, on the erythrocyte membrane, leading to the release of free fatty acids, most likely by activation of phospholipase A2. The release of fatty acids is itself not sufficient to explain the hemolytic reaction.     

Intravascular imaging comparison of two metallic limus-eluting stents abluminally coated with biodegradable polymers: IVUS and OCT results of the DESTINY trial

We sought to compare, by means of IVUS and OCT imaging, the performance of a novel sirolimus-eluting drug-eluting stent (DES) with biodegradable polymer (Inspiron?) to the Biomatrix? DES. From the DESTINY trial, a total of 70 randomized patients (2:1) were enrolled in the IVUS substudy (Inspiron?, n?=?46; Biomatrix?: n?=?20) while 25 patients were evaluated with OCT (Inspiron?, n?=?19; Biomatrix?: n?=?06) at 9-month follow-up. The main endpoints were % of neointimal tissue obstruction (IVUS) and neointimal stut coverage (OCT) at 9 months. Patients treated with both DES had very little NIH formation at 9 months either by IVUS (% of NIH obstruction of 4.9?±?4.1?% with Inspiron? vs. 2.7?±?2.9?% with Biomatrix?, p?=?0.03) or by OCT (neointimal thickness of 144.2?±?72.5 µm Inspiron? vs. 115.0?±?53.9 µm with Biomatrix?, p?=?0.45). Regarding OCT strut-level assessment, again both devices showed excellent 9-month performance, with high rates of strut coverage (99.49?±?1.01?% with Inspiron? vs. 97.62?±?2.21?% with Biomatrix?, p?<?0.001) and very rare malapposition (0.29?±?1.06?% with Inspiron? vs. 0.53?±?0.82?% with Biomatrix?, p?=?0.44). Patients with any uncovered struts were more frequently identified in the Biomatrix? group (9.78?±?7.13 vs. 2.29?±?3.91?%, p?<?0.001). In the present study, midterm IVUS and OCT evaluations showed that both new generation DES with biodegradable polymer were effective in terms of suppressing excessive neointimal response, with very high rates of apposed and covered struts, suggesting a consistent and benign healing pattern.     

3-[4'-bromo-(1,1'-biphenyl)-4-yl]-N,N-dimethyl-3-(2-thienyl)-2-propen-1-amine: synthesis,cytotoxicity, and leishmanicidal,trypanocidal and antimycobacterial activities

Current therapies for Chagas' disease, leishmaniasis and tuberculosis are unsatisfactory because of the failure rates, significant toxicity and/or drug resistance. In this study, the compound 3-[4'-bromo-(1,1'-biphenyl)-4-yl]-N,N-dimethyl-3-(2-thienyl)-2-propen-1-amine (IV) was synthesized and its trypanocidal, leishmanicidal and antimycobacterial activities were investigated. The cytotoxicity was determined on V79 cells with three endpoints: nucleic acid content, 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl tetrazolium bromide reduction and Neutral Red uptake. This compound was active against different species of mycobacteria and different life cycle stages of Trypanosoma cruzi. In experiments with trypomastigotes performed at 4 degrees C in the presence of blood, the activity was 8.8-fold more active than the standard drug, Crystal Violet. Higher activity was achieved against Leishmania amazonensis, with an ED(50)/24 h of 3.0 +/- 0.3 micro mol/L. The effect against trypanosomatids, which suggests high activity of compound IV against promastigotes of L. amazonensis and amastigotes of T. cruzi, stimulated further studies in vitro with amastigotes interiorized in macrophages and with in vivo models. Our results indicate that mammalian V79 cells are less susceptible to the action of compound IV than promastigotes of L. amazonensis (8.0-13.3-fold) and axenic amastigotes of T. cruzi (3.5-5.9-fold).