Heregulin and HER2 signaling selectively activates c-Src phosphorylation at tyrosine 215

To elucidate the molecular mechanisms by which human epidermal growth factor receptor/heregulin (HER2/HRG) influence the migratory potential of breast cancer cells, we have used phospho-specific antibodies against c-Src kinase and focal adhesion kinase (FAK). This study establishes that HER2/HRG signaling selectively upregulates Tyr phosphorylation of c-Src at Tyr-215 located within the SH2 domain, increases c-Src kinase activity and selectively upregulates Tyr phosphorylation of FAK at Tyr-861. HER2-overexpressing tumors showed increased levels of c-Src phosphorylation at Tyr-215. These findings suggest that HER2/HRG influence metastasis of breast cancer cells through a novel signaling pathway involving phosphorylation of FAK tyrosine 861 via activation of c-Src tyrosine 215.     

Serum and hair levels of zinc and other elements in dogs with visceral leishmaniasis

The aim of this study was to determine the zinc, iron, copper, calcium, phosphorus, and magnesium levels in blood serum and zinc and copper levels in hair of dogs with canine visceral leishmaniasis. The serum zinc and iron levels were found to be significantly lower in diseased dogs than those of healthy controls. Serum copper levels were significantly higher, whereas no significant differences were observed for calcium, phosphorus, and magnesium. There were no significant differences in the zinc and copper levels in hair. Our results show that the serum zinc, iron, and copper levels are altered in canine leishmaniasis.     

Endocrine expression of the active form of TGF-beta1 in the TGF-beta1 null mice fails to ameliorate lethal phenotype

TGF-beta1 null mice die by 3 to 4 weeks of age due to a severe autoimmune-mediated multifocal inflammation resulting in multi-organ failure. To assess the therapeutic potential of circulating levels of active TGF-beta1, we generated mice with endocrine expression of active TGF-beta1 on a TGF-beta1 null background (TGF-beta1 (-/-/TG)) by crossing TGF-beta1(+/-) mice with transgenic mice (TG) that express recombinant TGF-beta1 specifically in the liver and secrete it in the blood. The TGF-beta1 (-/-/TG) mice exhibit a survival profile similar to the TGF-beta1 (-/-) mice indicating a failure to rescue the lethal phenotype. However, serum TGF-beta1 levels in the TGF-beta1 (-/-/TG) mice were restored to near normal levels with expression in all the tissues, notably in the kidney and spleen. Histopathology showed reduced inflammation in the target tissues, especially in the heart. Interestingly, unlike TGF-beta1 (-/-) mice, the TGF-beta1 (-/-/TG) mice have glomerulonephritis in their kidneys similar to the TG mice. Thus, the phenotype of TGF-beta1 (-/-/TG) animal model indicates the potential role of circulating active-TGF-beta1 in reducing inflammation, but its failure to rescue lethality in TGF-beta1 null mice indicates a critical autocrine role of TGF-beta1.     

Effects of trace element levels on platelet aggregation

Platelet aggregation was measured by an optical method in 32 patients with iron-deficiency anemia at the time of diagnosis and after a period of supplementation with iron. Epinephrine- and adenosine diphosphate-induced platelet aggregation were lower in anemic patients than in the controls (p<0.05). After iron-supplementation therapy, these values showed no significant differences. If induced by collagen or ristocetin, platelet aggregation was the same for patients and controls, but increased after treatment of patients (p<0.05). The plasma zinc values did not show significant differences among the subjects included in this study. These results show that iron is involved in the enzymatic systems that regulate platelet aggregation. The exact nature of this interaction is still to be determined.     

Anthranilate 4H-oxazol-5-ones: novel small molecule antibacterial acyl carrier protein synthase (AcpS) inhibitors

D-optimal design and Projection to Latent Structures (PLS) analysis were used to optimize screening hit 5 (B. subtilis AcpS IC(50): 15 microM, B. subtilis MIC: >200 microM) into a series of 4H-oxazol-5-one, small molecule, antibacterial, AcpS inhibitors. Specifically, 15, 16 and 18 show microM or sub-microM AcpS inhibition (IC(50)s: 15: 1.1 microM, 16: 1.5 microM, 18: 0.27 microM) and moderate antibacterial activity (MICs: 12.5-50 microM) against B. subtilis, E. faecalis ATCC, E. faecalis VRE and S. pneumo+.     

The effect of hyperbaric oxygen on neuroregeneration following acute thoracic spinal cord injury

AimsAlthough hyperbaric oxygen (HBO) treatment following spinal cord injury (SCI) have been studied in terms of neurological function and tissue histology, there is a limited number studies on spinal cord tissue enzyme levels.Main methodsThe effect of HBO treatment in SCI was investigated by measuring superoxide dismutase (SOD), catalase, glutathione peroxidase (GPx), nitric oxide synthase (NOS) and nitric oxide (NO) activity in the injured tissue. SCI was induced by applying an aneurysm clip extradurally at the level of T9-T11 vertebrae. Preoperative HBO (preopHBO) treatment was applied for 5 days and postoperative HBO (postopHBO) for 7 days.Key findingsIn the preopHBO group, a significant decrease was observed in NOS and NO compared to the SCI group. There was a decrease in SOD, NOS and NO in the postopHBO group when compared to the SCI group. In the pre–postHBO group SOD, GPx, NOS and NO decreased significantly. There was a decrease in SOD in postopHBO compared to preopHBO. In the prepostopHBO, SOD decreased significantly compared to that in the preopHBO group. The prepostopHBO presented a significant decrease in GPx compared to postopHBO (p < 0.05 for all parameters). No significant difference was observed for catalase for all groups. Significant improvement was found in BBB scores for both postopHBO and prepostHBO groups when compared to the SCI group (p < 0.05).SignificanceHBO treatment was found to be beneficial following SCI in terms of biochemical parameters and functional recovery in the postoperative period.     

Oxidases and oxygenases in regulation of neutrophil redox pathways in Behçet's disease patients

This study aimed to determine plasma and neutrophil oxidase activities that may contribute to vascular inflammation in Beh?et's disease (BD) patients. Cyclooxygenase (COX), NADPH oxidase and myeloperoxidase (MPO) activity was determined in neutrophils isolated from BD patients and healthy controls. Functional assay of NADPH oxidase was significantly increased in BD patients, both at basal conditions and in response to fMLP stimulation. There was a significant increase in plasma MPO activity in the disease group as compared to controls. Total COX activity was significantly increased in BD neutrophils. The increase in total COX activity was accompanied with enhanced activity of COX-2, differentiated by using the COX-1 isoform-specific inhibitor SC-560. Neutrophil nitrate/nitrite levels showed no significant difference in BD; however, plasma nitrate/nitrite contents in BD patients were significantly greater compared to controls. In conclusion, increased plasma MPO, neutrophil NADPH and COX activities may contribute to intravascular inflammation documented in BD patients.     

EGFR S1166 Phosphorylation Induced by a Combination of EGF and Gefitinib Has a Potentially Negative Impact on Lung Cancer Cell Growth

Phosphorylation of protein plays a key role in the regulation of cellular signal transduction and gene expression. In recent years, targeted mass spectrometry facilitates functional phosphoproteomics by allowing specific protein modifications of target proteins in complex samples to be characterized. In this study, we employed multiple reaction monitoring (MRM) to examine the influence of gefitinib (also known as Iressa) on the phosphorylation sites of EGFR protein before and after EGF treatment. By coupling MRM to MS/MS, 5 phosphotyrosine (Y1110, Y1172, Y1197, Y1069, and Y1092) and 1 S/T (T693) sites were identified on EGFR. Y1197 and T693 were constitutively phosphorylated. All phosphorylation sites were sensitive to gefitinib treatment except T693. Interestingly, gefitinib treatment induced phosphorylation of S1166 only in the presence of EGF. We further showed that lung cancer cells overexpressing phosphomimic S1166D EGFR mutant possessed significantly lower growth and proliferation property compared to wildtype EGFR-expressing cells. While the function and mode of regulation of S1166 remain unclear, our data supports the notion that S1166 represents a regulatory site that exerts a negative regulation on growth and proliferation of cancer cells. The data presented has implication in our understanding of dynamic drug (gefitinib)-target (EGFR) interaction and in improving the efficacy of target-directed therapeutics.     

MDR1 single nucleotide polymorphism C3435T in Turkish patients with non-small-cell lung cancer

We assessed whether single nucleotide polymorphisms (SNPs) in MDR1 gene C3435T predicted the outcome of platinum-based chemotherapies and survival in our non small cell lung cancer (NSCLC) patients. A total of 79 non-small cell lung cancer patients were enrolled to study. We determined the MDR1 C3435T single nucleotide gene polymorphisms. Median age was 60years: 91.7% male, 8.9% female. We found that CC, CT, TT genotype and T, C allele frequencies in lung cancer patients as 24.1%, 62%, 13.9% and 44.3%, 55.7%, respectively. Patients with CT genotype had a higher response rate (11.4%) than the other genotypes. However, this difference is not statistically significant (p=0.743). Cox regression analysis for overall survival showed that ECOG PS status 0 (HR PS 1 vs. 0, 5.68 p=0.002; HR of PS 2 vs. 0 is 21.579, p=0.001; HR of PS 3 vs. 0 is 35.35, p=0.001), stage ≤II (HR of stage III vs. I+II is 17.77; p=0.016, HR of stage IV vs. I+II is 26.97, p=0.006), and albumin level ≥3g/dl (HR of albumin <3g/dl vs. ≥3g/dl is 2.46, p=0.044) were the most important prognostic factors (also, time to progression was related to these factors). There was no significant association between the genotypes and clinicopathologic parameters; however, good performance status, early stage and ≥3g/dl albumin level were found to be the most important prognostic factors for overall survival and progression-free survival.