Expression of PAFR as Part of a Prosurvival Response to Chemotherapy: A Novel Target for Combination Therapy in Melanoma

Melanoma cells express the platelet-activating factor receptor (PAFR) and, thus, respond to PAF, a bioactive lipid produced by both tumour cells and those in the tumour microenvironment such as macrophages. Here, we show that treatment of a human melanoma SKmel37 cell line with cisplatin led to increased expression of PAFR and its accumulation. In the presence of exogenous PAF, melanoma cells were significantly more resistant to cisplatin-induced cell death. Inhibition of PAFR-dependent signalling pathways by a PAFR antagonist (WEB2086) showed chemosensitisation of melanoma cells in vitro. Nude mice were inoculated with SKmel37 cells and treated with cisplatin and WEB2086. Animals treated with both agents showed significantly decreased tumour growth compared to the control group and groups treated with only one agent. PAFR accumulation and signalling are part of a prosurvival program of melanoma cells, therefore constituting a promising target for combination therapy for melanomas.

Cediranib Plus FOLFOX/CAPOX Versus Placebo Plus FOLFOX/CAPOX in Patients With Previously Untreated Metastatic Colorectal Cancer: A Randomized, Double-Blind, Phase III Study (HORIZON II)

Purpose Cediranib is a highly potent inhibitor of vascular endothelial growth factor (VEGF) signaling with activity against all three VEGF receptors. HORIZON II [Cediranib (AZD2171, RECENTIN) in Addition to Chemotherapy Versus Placebo Plus Chemotherapy in Patients With Untreated Metastatic Colorectal Cancer] assessed infusional fluorouracil, leucovorin, and oxaliplatin/capecitabine and oxaliplatin (FOLFOX/CAPOX) with or without cediranib in patients with previously untreated metastatic colorectal cancer (mCRC). Patients and Methods Eligible patients were initially randomly assigned 1:1:1 to receive cediranib (20 or 30 mg per day) or placebo plus FOLFOX/CAPOX. In an early analysis of this and two other cediranib studies (HORIZON I [Cediranib Plus FOLFOX6 Versus Bevacizumab Plus FOLFOX6 in Patients With Previously Treated Metastatic Colorectal Cancer] and HORIZON III [Cediranib Plus FOLFOX6 Versus Bevacizumab Plus FOLFOX6 in Patients With Untreated Metastatic Colorectal Cancer]), the 20-mg dose met the predefined criteria for continuation. Subsequent patients were randomly assigned 2: 1 to the cediranib 20 mg or placebo arms. Progression-free survival (PFS) and overall survival (OS) were coprimary end points. Results In all, 860 patients received cediranib 20 mg (n = 502) or placebo (n = 358). The addition of cediranib to FOLFOX/CAPOX resulted in PFS prolongation (hazard ratio [HR], 0.84; 95% CI, 0.73 to 0.98; P = .0121; median PFS, 8.6 months for cediranib v 8.3 months for placebo) but had no impact on OS (HR, 0.94; 95% CI, 0.79 to 1.12; P = .5707; median OS, 19.7 months for cediranib v 18.9 months for placebo). There were no significant differences in the secondary end points of objective response rate, duration of response, or liver resection rate. Median chemotherapy dose-intensity was decreased by approximately 10% in patients treated with cediranib. Adverse events (AEs) associated with cediranib were manageable. Conclusion Addition of cediranib 20 mg to FOLFOX/CAPOX resulted in a modest PFS prolongation, but no significant difference in OS. The cediranib AE profile was consistent with those from previous studies. Because of the lack of improvement in OS, cediranib plus an oxaliplatin-based regimen cannot be recommended as a treatment for patients with mCRC. J Clin Oncol 30:3596-3603. (C) 2012 by American Society of Clinical Oncology

Expression of angiogenic factors in placenta of stressed rats

The aim of the present study was to analyse the influence of stress on pregnant rats, particularly in terms of maternal, placental and fetal weight, placental morphology and placental gene expression of the angiogenic factors Vegfa and Pgf and their receptors. The parameters were evaluated on gestation Day 20. Maternal, fetal and placental weights were statistically lower in stressed animals than controls, suggesting abnormalities in gestational physiology. Morphologically the placentas of rats subjected to stress were reduced in size and weight, with few glycogen cells and a significant increase in the number of apoptotic cells. Stress caused an increase in placental gene expression of Vegfa (P < 0.05) and a reduction in Pgf, Flt1 and Kdr expression (P < 0.05). It has been suggested that increased VEGF is associated with vasodilatation and hypotension, but in this model persistent hypertension was present. This study suggests that the limited hypotensive Vegfa response to stress-induced hypertension could result from reduced expression of Flt1/Kdr disrupting specific VEGF pathways. These findings may elucidate one of the multiple possible factors underlying how stress modulates placental physiology, and could aid the understanding of stress-induced gestational disorders.

Characterization of PAR1 and FGFR1 expression in invasive breast carcinomas: Prognostic significance

Breast cancer is the most common cause of cancer mortality among women worldwide. Among the several factors associated with breast cancer development, angiogenesis plays an essential role and has currently emerged as a potential diagnostic, prognostic and therapeutic target. Protease-activated receptor 1 (PAR1) and fibroblast growth factor receptor 1 (FGFR1) have important activities in tumor angiogenesis and progression. The aim of this study was to investigate the prognostic significance of these two receptors, hypothesising significant correlations between receptor expression in tumor angiogenesis and clinicopathological parameters customarily used in breast cancer prognosis and prediction. Formalin-fixed and paraffin-embedded samples of ductal invasive breast carcinomas were used to analyze the expression of PAR1 and FGFR1, in the tumor cells as well as in the tumor stroma, and further determine intratumoral microvessel density (iMVD) to quantify intratumoral angiogenesis. Correlations between PAR1 and FGFR1 expression in tumor cells and stroma, iMVD and several clinicopathological parameters and molecular markers used in breast cancer diagnosis have been addressed. The correlation between PAR1 and FGFR1 suggests an association of the two receptors with a more aggressive breast cancer phenotype and, consequently, a potential role during tumor progression. The results reported in the present study also emphasize the importance of microenvironmental factors in tumor progression, while precluding the positive association between iMVD and breast cancer aggressiveness.

Analysis of the concordance rates between core needle biopsy and surgical excision in patients with breast cancer

Objective: To evaluate whether immunohistochemical marker studies performed on core needle biopsy (CNB) specimens accurately reflect the marker status of the tumor obtained from final surgical specimen. Methods: This was a retrospective study that used the database of the Division of Mastology of the Hospital das Clinicas, Sao Paulo, Brazil. Sixty-nine patients submitted to ultrasound-guided CNB diagnosed with breast cancer were retrospectively analyzed. Immunohistochemistry (IHC) on core biopsy specimens was compared to that of excisional biopsy regarding estrogen receptor (ER), progesterone receptor (PR), human epidermal gowth factor receptor 2 gene (HER2), p53, and Ki67. The analysis of the concordance between CNB and surgical biopsy was performed using the kappa (k) coefficient (95% CI). Results: A perfect concordance between the labeling in the surgical specimens and the preoperative biopsies in p53 (k = 1.0; 95% CI: 0.76-1.0) was identified. There was an almost perfect concordance for ER (k = 0.89; 95% CI: 0.65-1.0) and a substantial concordance for PR (k = 0.70; 95% CI: 0.46-0.93). HER2 (k = 0.61; 95% CI: 0.38-0.84) and Ki-67 (k = 0.74; 95% CI: 0.58-0.98) obtained a substantial concordance this analysis. Conclusion: The results of this study indicate that the immunohistochemical analysis of ER, PR, Ki-67, and p53 from core biopsy specimens provided results that accurately reflect the marker status of the tumor. The concordance rate of HER2 was less consistent; although it produced substantial concordance, values were very close to moderate concordance.

Parathyroid hormone and phosphorus overload in uremia: impact on cardiovascular system

Background. Cardiac remodeling in uremia is characterized by left ventricular hypertrophy, interstitial fibrosis and microvascular disease. Cardiovascular disease is the leading cause of death in uremic patients, but coronary events alone are not the prevalent cause, sudden death and heart failure are. We studied the cardiac remodeling in experimental uremia, evaluating the isolated effect of parathyroid hormone (PTH) and phosphorus. Methods. Wistar rats were submitted to parathyroidectomy (PTx) and 5/6 nephrectomy (Nx); they also received vehicle (V) and PTH at normal (nPTH) or high (hPTH) doses. They were fed with a poor-phosphorus (pP) or rich-phosphorus (rP) diet and were divided into the following groups: 'Sham': G1 (V + normal-phosphorus diet (np)) and 'Nx + PTx': G2 (nPTH + pP), G3 (nPTH + rP), G4 (hPTH + pP) and G5 (hPTH + rP). After 8 weeks, biochemical analysis, myocardium morphometry and arteriolar morphological analysis were performed. In addition, using immunohistochemical analysis, we evaluated angiotensin II, alpha-actin, transforming growth factor-beta (TGF-beta) and nitrotyrosine, as well as fibroblast growth factor-23 (FGF-23), fibroblast growth factor receptor-1 (FGFR-1) and runt-related transcription factor-2 (Runx-2) expression. Results. Nx animals presented higher serum creatinine levels as well as arterial hypertension. Higher PTH levels were associated with myocardial hypertrophy and fibrosis as well as a higher coronary lesion score. High PTH animals also presented a higher myocardial expression of TGF-beta, angiotensin II, FGF-23 and nitrotyrosine and a lower expression of alpha-actin. Phosphorus overload was associated with higher serum FGF-23 levels and Runx-2, as well as myocardial hypertrophy. FGFR-1 was positive in the cardiomyocytes of all groups as well as in calcified coronaries of G4 and G5 whereas Runx-2 was positive in G3, G4 and G5. Conclusion. In uremia, PTH and phosphorus overload are both independently associated with major changes related to the cardiac remodeling process, emphasizing the need for a better control of these factors in chronic kidney disease.

Matrix metalloproteinases, tissue inhibitors of metalloproteinases, and growth factors regulate the aggressiveness and proliferative activity of keratocystic odontogenic tumors

Objective. The objective of this preliminary study was to evaluate the expression of matrix metalloproteinases (MMPs), tissue inhibitors of metalloproteinases (TIMPs) and growth factors in keratocystic odontogenic tumors (KOTs). Study Design. The expression of MMPs, TIMPs, growth factors, and the extracellular signal-regulated kinase (ERK) 1/2 signaling pathway were assessed by immunohistochemistry in 15 cases of KOT and 4 cases of calcifying cystic odontogenic tumor (CCOT). Results. KOT samples expressed significantly higher amounts of MMPs, TIMPs, growth factors, epidermal growth factor receptor (EGFR), and ERK compared with CCOT samples, with the exception of MMP-2 and TIMP-1. Conclusions. MMP-9, TIMP-2, EGF and transforming growth factor alpha act together and likely regulate the proliferation and aggressiveness of KOT. ERK-1/2 serves as the transducer of signals generated by these proteins, which signal through the common receptor, EGFR. This process may be related to the increased proliferation and aggressiveness observed in KOT. (Oral Surg Oral Med Oral Pathol Oral Radiol 2012;114:487-496)

ESMO Consensus Guidelines for management of patients with colon and rectal cancer. A personalized approach to clinical decision making

Colorectal cancer (CRC) is the most common tumour type in both sexes combined in Western countries. Although screening programmes including the implementation of faecal occult blood test and colonoscopy might be able to reduce mortality by removing precursor lesions and by making diagnosis at an earlier stage, the burden of disease and mortality is still high. Improvement of diagnostic and treatment options increased staging accuracy, functional outcome for early stages as well as survival. Although high quality surgery is still the mainstay of curative treatment, the management of CRC must be a multi-modal approach performed by an experienced multi-disciplinary expert team. Optimal choice of the individual treatment modality according to disease localization and extent, tumour biology and patient factors is able to maintain quality of life, enables long-term survival and even cure in selected patients by a combination of chemotherapy and surgery. Treatment decisions must be based on the available evidence, which has been the basis for this consensus conference-based guideline delivering a clear proposal for diagnostic and treatment measures in each stage of rectal and colon cancer and the individual clinical situations. This ESMO guideline is recommended to be used as the basis for treatment and management decisions.

Smoking cessation and bronchial epithelial remodelling in COPD: a cross-sectional study

Abstract Background Chronic Obstructive Pulmonary Disease (COPD) is associated with bronchial epithelial changes, including squamous cell metaplasia and goblet cell hyperplasia. These features are partially attributed to activation of the epidermal growth factor receptor (EGFR). Whereas smoking cessation reduces respiratory symptoms and lung function decline in COPD, inflammation persists. We determined epithelial proliferation and composition in bronchial biopsies from current and ex-smokers with COPD, and its relation to duration of smoking cessation. Methods 114 COPD patients were studied cross-sectionally: 99 males/15 females, age 62 ± 8 years, median 42 pack-years, no corticosteroids, current (n = 72) or ex-smokers (n = 42, median cessation duration 3.5 years), postbronchodilator FEV1 63 ± 9% predicted. Squamous cell metaplasia (%), goblet cell (PAS/Alcian Blue+) area (%), proliferating (Ki-67+) cell numbers (/mm basement membrane), and EGFR expression (%) were measured in intact epithelium of bronchial biopsies. Results Ex-smokers with COPD had significantly less epithelial squamous cell metaplasia, proliferating cell numbers, and a trend towards reduced goblet cell area than current smokers with COPD (p = 0.025, p = 0.001, p = 0.081, respectively), but no significant difference in EGFR expression. Epithelial features were not different between short-term quitters (<3.5 years) and current smokers. Long-term quitters (≥3.5 years) had less goblet cell area than both current smokers and short-term quitters (medians: 7.9% vs. 14.4%, p = 0.005; 7.9% vs. 13.5%, p = 0.008; respectively), and less proliferating cell numbers than current smokers (2.8% vs. 18.6%, p < 0.001). Conclusion Ex-smokers with COPD had less bronchial epithelial remodelling than current smokers, which was only observed after long-term smoking cessation (>3.5 years). Trial registration NCT00158847

Independent of ErbB1 gene copy number, EGF stimulates migration but is not associated with cell proliferation in non-small cell lung cancer

Abstract Background Lung cancer often exhibits molecular changes, such as the overexpression of the ErbB1 gene. ErbB1 encodes epidermal growth factor receptor (EGFR), a tyrosine kinase receptor, involved mainly in cell proliferation and survival. EGFR overexpression has been associated with more aggressive disease, poor prognosis, low survival rate and low response to therapy. ErbB1 amplification and mutation are associated with tumor development and are implicated in ineffective treatment. The aim of the present study was to investigate whether the ErbB1 copy number affects EGFR expression, cell proliferation or cell migration by comparing two different cell lines. Methods The copies of ErbB1 gene was evaluated by FISH. Immunofluorescence and Western blotting were performed to determine location and expression of proteins mentioned in the present study. Proliferation was studied by flow cytometry and cell migration by wound healing assay and time lapse. Results We investigated the activation and function of EGFR in the A549 and HK2 lung cancer cell lines, which contain 3 and 6 copies of ErbB1, respectively. The expression of EGFR was lower in the HK2 cell line. EGFR was activated after stimulation with EGF in both cell lines, but this activation did not promote differences in cellular proliferation when compared to control cells. Inhibiting EGFR with AG1478 did not modify cellular proliferation, confirming previous data. However, we observed morphological alterations, changes in microfilament organization and increased cell migration upon EGF stimulation. However, these effects did not seem to be consequence of an epithelial-mesenchymal transition. Conclusion EGFR expression did not appear to be associated to the ErbB1 gene copy number, and neither of these aspects appeared to affect cell proliferation. However, EGFR activation by EGF resulted in cell migration stimulation in both cell lines.

Lufaxin, a Novel Factor Xa Inhibitor From the Salivary Gland of the Sand Fly Lutzomyia longipalpis Blocks Protease-Activated Receptor 2 Activation and Inhibits Inflammation and Thrombosis In Vivo

Objective-Blood-sucking arthropods' salivary glands contain a remarkable diversity of antihemostatics. The aim of the present study was to identify the unique salivary anticoagulant of the sand fly Lutzomyia longipalpis, which remained elusive for decades. Methods and Results-Several L. longipalpis salivary proteins were expressed in human embryonic kidney 293 cells and screened for inhibition of blood coagulation. A novel 32.4-kDa molecule, named Lufaxin, was identified as a slow, tight, noncompetitive, and reversible inhibitor of factor Xa (FXa). Notably, Lufaxin's primary sequence does not share similarity to any physiological or salivary inhibitors of coagulation reported to date. Lufaxin is specific for FXa and does not interact with FX, Dansyl-Glu-Gly-Arg-FXa, or 15 other enzymes. In addition, Lufaxin blocks prothrombinase and increases both prothrombin time and activated partial thromboplastin time. Surface plasmon resonance experiments revealed that FXa binds Lufaxin with an equilibrium constant approximate to 3 nM, and isothermal titration calorimetry determined a stoichiometry of 1:1. Lufaxin also prevents protease-activated receptor 2 activation by FXa in the MDA-MB-231 cell line and abrogates edema formation triggered by injection of FXa in the paw of mice. Moreover, Lufaxin prevents FeCl3-induced carotid artery thrombus formation and prolongs activated partial thromboplastin time ex vivo, implying that it works as an anticoagulant in vivo. Finally, salivary gland of sand flies was found to inhibit FXa and to interact with the enzyme. Conclusion-Lufaxin belongs to a novel family of slow-tight FXa inhibitors, which display antithrombotic and anti-inflammatory activities. It is a useful tool to understand FXa structural features and its role in prohemostatic and proinflammatory events. (Arterioscler Thromb Vasc Biol. 2012;32:2185-2196.)

Cannabinoid CB1 receptor restrains accentuated activity of hypothalamic corticotropin-releasing factor and brainstem tyrosine hydroxylase neurons in endotoxemia-induced hypophagia in rats

It is well known that endocannabinoids play an important role in the regulation of food intake and body weight. Endocannabinoids and cannabinoid receptors are found in the hypothalamus and brainstem, which are central areas involved in the control of food intake and energy expenditure. Activation of these areas is related to hypophagia observed during inflammatory stimulus. This study investigated the effects of cannabinoid (CB1) receptor blockade on lipopolysaccharide (LPS)-induced hypophagia. Male Wistar rats were pretreated with rimonabant (10 mg/kg, by gavage) or vehicle; 30 min later they received an injection of either LPS (100 mu g/kg, intraperitoneal) or saline. Food intake, body weight, corticosterone response, CRF and CART mRNA expression, Fos-CRF and Fos-alpha-MSH immunoreactivity in the hypothalamus and Fos-tyrosine hydroxylase (TH) immunoreactivity in the brainstem were evaluated. LPS administration decreased food intake and body weight gain and increased plasma corticosterone levels and CRF mRNA expression in the PVN. We also observed an increase in Fos-CRF and Fos-TH double-labeled neurons after LPS injection in vehicle-pretreated rats, with no changes in CART mRNA or Fos-alpha-MSH immunoreactive neurons in the ARC. In saline-treated animals, rimonabant pretreatment decreased food intake and body weight gain but did not modify hormone response or Fos expression in the hypothalamus and brainstem compared with vehicle-pretreated rats. Rimonabant pretreatment potentiated LPS-induced hypophagia, body weight loss and Fos-CRF and Fos-TH expressing neurons. Rimonabant did not modify corticosterone, CRF mRNA or Fos-alpha-MSH responses in rats treated with LPS. These data suggest that the endocannabinoid system, mediated by CB1 receptors, modulates hypothalamic and brainstem circuitry underlying the hypophagic effect during endotoxemia to prevent an exaggerated food intake decrease. This article is part of a Special Issue entitled 'Central Control of Food Intake'. (C) 2011 Elsevier Ltd. All rights reserved.

Inhibition of cannabinoid CB1 receptor upregulates Slc2a4 expression via nuclear factor-kappa B and sterol regulatory element-binding protein-1 in adipocytes

Evidences have suggested that the endocannabinoid system is overactive in obesity, resulting in enhanced endocannabinoid levels in both circulation and visceral adipose tissue. The blockade of cannabinoid receptor type 1 (CB1) has been proposed for the treatment of obesity. Besides loss of body weight, CB1 antagonism improves insulin sensitivity, in which the glucose transporter type 4 (GLUT4) plays a key role. The aim of this study was to investigate the modulation of GLUT4-encoded gene (Slc2a4 gene) expression by CB1 receptor. For this, 3T3-L1 adipocytes were incubated in the presence of a highly selective CB1 receptor agonist (1 mu M arachidonyl-2'-chloroethylamide) and/or a CB1 receptor antagonist/inverse agonist (0.1, 0.5, or 1 mu M AM251, 1-(2,4-dichlorophenyl)-5-(4-iodophenyl)-4-methyl-N-1-piperidinyl-1H-pyrazole-3-carboxamide). After acute (2 and 4 h) and chronic (24 h) treatments, cells were harvested to evaluate: i) Slc2a4, Cnr1 (CB1 receptor-encoded gene), and Srebf1 type a (SREBP-1a type-encoded gene) mRNAs (real-time PCR); ii) GLUT4 protein (western blotting); and iii) binding activity of nuclear factor (NF)-kappa B and sterol regulatory element-binding protein (SREBP)-1 specifically in the promoter of Slc2a4 gene (electrophoretic mobility shift assay). Results revealed that both acute and chronic CB1 receptor antagonism greatly increased (similar to 2.5-fold) Slc2a4 mRNA and protein content. Additionally, CB1-induced upregulation of Slc2a4 was accompanied by decreased binding activity of NF-kappa B at 2 and 24 h, and by increased binding activity of the SREBP-1 at 24 h. In conclusion, these findings reveal that the blockade of CB1 receptor markedly increases Slc2a4/GLUT4 expression in adipocytes, a feature that involves NF-kappa B and SREBP-1 transcriptional regulation. Journal of Molecular Endocrinology (2012) 49, 97-106

Toll-like receptor 2 knockdown modulates Interleukin (IL)-6 and IL-8 but not Stromal Derived Factor-1 (SDF-1/CXCL12) in human periodontal ligament and gingival fibroblasts

Background: Fibroblasts are now seen as active components of the immune response because these cells express Toll-like receptors (TLRs), recognize pathogen-associated molecular patterns, and mediate the production of cytokines and chemokines during inflammation. The innate host response to lipopolysaccharide (LPS) from Porphyromonas gingivalis is unusual inasmuch as different studies have reported that it can be an agonist for Toll-like receptor 2 (TLR2) and an antagonist or agonist for Toll-like receptor 4 (TLR4). This study investigates and compares whether signaling through TLR2 or TLR4 could affect the secretion of interleukin (IL)-6, IL-8, and stromal derived factor-1 (SDF-1/CXCL12) in both human gingival fibroblasts (HGF) and human periodontal ligament fibroblasts (HPDLF). Methods: After small interfering RNA-mediated silencing of TLR2 and TLR4, HGF and HPDLF from the same donors were stimulated with P. gingivalis LPS or with two synthetic ligands of TLR2, Pam2CSK4 and Pam3CSK4, for 6 hours. IL-6, IL-8, and CXCL12 mRNA expression and protein secretion were evaluated by quantitative polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. Results: TLR2 mRNA expression was upregulated in HGF but not in HPDLF by all the stimuli applied. Knockdown of TLR2 decreased IL-6 and IL-8 in response to P. gingivalis LPS, or Pam2CSK4 and Pam3CSK4, in a similar manner in both fibroblasts subpopulations. Conversely, CXCL12 remained unchanged by TLR2 or TLR4 silencing. Conclusion: These results suggest that signaling through TLR2 by gingival and periodontal ligament fibroblasts can control the secretion of IL-6 and IL-8, which contribute to periodontal pathogenesis, but do not interfere with CXCL12 levels, an important chemokine in the repair process.