Peptabody-EGF: a novel apoptosis inducer targeting ErbB1 receptor overexpressing cancer cells.

The epidermal growth factor receptor (EGFR) plays a central role in cell life by controlling processes such as growth or proliferation. This receptor is commonly overexpressed in a number of epithelial malignancies and its upregulation is often associated with an aggressive phenotype of the tumor. Thus, targeting of EGFR represents a very promising challenge in oncology, and antibodies raised against this receptor have been investigated as potential antitumor agents. Various putative mechanisms of action were proposed for such antibodies, including decreased proliferation, induction of apoptosis, stimulation of the immunological response against targeted cancer cells or combinations thereof. We report here the development of an alternative high affinity molecule that is directed against EGFR. Production of this pentameric protein, named peptabody-EGF, includes expression in a bacterial expression system and subsequent refolding and multimerization of peptabody monomers. The protein complex contains 5 human EGF ligand domains, which confer specific binding towards the extracellular portion of EGFR. Receptor binding of the peptabody-EGF had a strong antiproliferative effect on different cancer cell lines overexpressing EGFR. However, cells expressing constitutive levels of the target receptor were barely affected. Peptabody-EGF treated cancer cells exhibited typical characteristics of apoptosis, which was found to be induced within 30 min after the addition of the peptabody-EGF. In vitro experiments demonstrated a significantly higher binding activity for peptabody-EGF than for the therapeutic monoclonal EGFR antibody Mab-425. Furthermore, the antitumor action provoked by the peptabody-EGF was greatly superior than antibody mediated effects when tested on EGFR overexpressing cancer cell lines. These findings suggest a potential application of this high affinity molecule as a novel tool for anti-EGFR therapy.

The impact of iron supplementation efficiency in female blood donors with a decreased ferritin level and no anaemia. Rationale and design of a randomised controlled trial: a study protocol.

ABSTRACT: BACKGROUND: There is no recommendation to screen ferritin level in blood donors, even though several studies have noted the high prevalence of iron deficiency after blood donation, particularly among menstruating females. Furthermore, some clinical trials have shown that non-anaemic women with unexplained fatigue may benefit from iron supplementation. Our objective is to determine the clinical effect of iron supplementation on fatigue in female blood donors without anaemia, but with a mean serum ferritin </= 30 ng/ml. METHODS/DESIGN: In a double blind randomised controlled trial, we will measure blood count and ferritin level of women under age 50 yr, who donate blood to the University Hospital of Lausanne Blood Transfusion Department, at the time of the donation and after 1 week. One hundred and forty donors with a ferritin level </= 30 ng/ml and haemoglobin level >/= 120 g/l (non-anaemic) a week after the donation will be included in the study and randomised. A one-month course of oral ferrous sulphate (80 mg/day of elemental iron) will be introduced vs. placebo. Self-reported fatigue will be measured using a visual analogue scale. Secondary outcomes are: score of fatigue (Fatigue Severity Scale), maximal aerobic power (Chester Step Test), quality of life (SF-12), and mood disorders (Prime-MD). Haemoglobin and ferritin concentration will be monitored before and after the intervention. DISCUSSION: Iron deficiency is a potential problem for all blood donors, especially menstruating women. To our knowledge, no other intervention study has yet evaluated the impact of iron supplementation on subjective symptoms after a blood donation. TRIAL REGISTRATION: NCT00689793.

Clinical significance of the CCR5delta32 allele in hepatitis C.

BACKGROUND: The CCR5 receptor, expressed on Th1 cells, may influence clinical outcomes of HCV infection. We explored a possible link between a CCR5 32-base deletion (CCR5delta32), resulting in the expression of a non-functioning receptor, and clinical outcomes of HCV infection. METHODS: CCR5 and HCV-related phenotypes were analysed in 1,290 chronically infected patients and 160 patients with spontaneous clearance. RESULTS: Carriage of the CCR5delta32 allele was observed in 11% of spontaneous clearers compared to 17% of chronically infected patients (OR = 0.59, 95% CI interval 0.35-0.99, P = 0.047). Carriage of this allele also tended to be observed more frequently among patients with liver inflammation (19%) compared to those without inflammation (15%, OR = 1.38, 95% CI interval 0.99-1.95, P = 0.06). The CCR5delta32 was not associated with sustained virological response (P = 0.6), fibrosis stage (P = 0.8), or fibrosis progression rate (P = 0.4). CONCLUSIONS: The CCR5delta32 allele appears to be associated with a decreased rate of spontaneous HCV eradication, but not with hepatitis progression or response to antiviral therapy.

The role of Pten in the Hematopoietic System and the Hematopoietic Stem Cells

Résumé Identification, localisation et activation des cellules souches hématopoiétiques dormantes in vivo Les cellules souches somatiques sont présentes dans la majorité des tissus régénératifs comme la peau, l'épithélium intestinal et le système hématopoiétique. A partir d'une seule cellule, elles ont les capacités de produire d'autres cellules souches du même type (auto-renouvellement) et d'engendrer un ensemble défini de cellules progénitrices différenciées qui vont maintenir ou réparer leur tissu hôte. Les cellules souches adultes les mieux caractérisées sont les cellules souches hématopoiétiques (HSC), localisées dans la moelle osseuse. Un des buts de mon travail de doctorat était de caractériser plus en profondeur la localisation des HSCs endogènes in vivo. Pour ce faire, la technique "label retaining assay", se basant sur la division peu fréquentes et sur la dormance des cellules souches, a été utilisée. Après un marquage des souris avec du BrdU (analogue à l'ADN) suivi d'une longue période sans BrdU, les cellules ayant incorporés le marquage ("label retaining cells" LCRs) ont pu être identifiées dans la moelle osseuse. Ces cellules LCRs étaient enrichies 300 fois en cellules de phenotype HSC et, en utilisant de la cytofluorométrie, il a pu être montré qu'environ 15% de toutes les HSCs d'une souris restent dormantes durant plusieures semaines. Ces HSCs dormantes à long terme ne sont probablement pas impliquées dans la maintenance de 'hématopoièse. Par contre, on assiste à l'activation rapide de ces HSCs dormantes lors d'une blessure, comme une ablation myéloide. Elles re-entrent alors en cycle cellulaire et sont essentielles pour une génération rapide des cellules progénitrices et matures qui vont remplacer les cellules perdues. De plus, la détection des LCRs, combinée avec l'utilisation du marqueur de HSCs c-kit, peut être utilisée pour la localisation des HSCs dormantes présentes dans la paroi endostéale de la cavité osseuse. De manière surprenante, les LCRs c-kit+ ont surtout étés trouvées isolées en cellule unique, suggérant que le micro-environement spécifique entourant et maintenant les HSCs, appelé niche, pourrait être très réduit et abriter une seule HSC par niche. Rôles complexes du gène supresseur de tumeur Pten dans le système hématopoiétique La phosphatase PTEN disparaît dans certains cancers héréditaires ou sporadiques humains, comme les gliomes, les cancers de l'utérus ou du sein. Pten inhibe la voie de signalisation de la PI3-kinase et joue un rôle clé dans l'apoptose, la croissance, la prolifération et la migration cellulaire. Notre but était d'étudier le rôle de Pten dans les HSC normale et durant la formation de leucémies. Pour ce faire, nous avons généré un modèle murin dans lequel le gène Pten peut être supprimé dans les cellules hématopoiétiques, incluant les HSCs. Ceci a été possible en croissant l'allèle conditionnelle ptenflox soit avec le transgène MxCre inductible par l'interféron α soit avec le transgène Scl-CreERt inductible par le tamoxifen. Ceci permet la conversion de l'allèle ptenflox en l'allèle nul PtenΔ dans les HSCs et les autres types cellulaires hématopoiétiques. Les souris mutantes Pten développent une splénomégalie massive causée par une expansion dramatiques de toutes les cellules myéloides. De manière interessante, alors que le nombre de HSCs dans la moelle osseuse diminue progressivement, le nombre des HSCs dans la rate augmente de manière proportionnelle. Etrangement, les analyses de cycle cellulaire ont montrés que Pten n'avait que peu ou pas d'effet sur la dormance des HSCs ou sur leur autorenouvellement. En revanche, une augmentation massive du niveau de la cytokine de mobilisation G-CSF a été détéctée dans le serum sanguin, suggérant que la suppression de Pten stimulerait la mobilisation et la migration des HSC de la moelle osseuse vers la rate. Finallement, la transplantation de moelle osseuse délétée en Pten dans des souris immuno-déficientes montre que Pten fonctionnerait comme un suppresseur de tumeur dans le système hématopoiétique car son absence entraîne la formation rapide de leucémies lymphocytaires. Summary Identification, localization and activation of dormant hematopoietic stun cells in vivo Somatic stem cells are present in most self-renewing tissues including the skin, the intestinal epithelium and the hematopoietic system. On a single cell basis they have the capacity to produce more stem cells of the same phenotype (self-renewal) and to give rise to a defined set of mature differentiated progeny, responsible for the maintenance or repair of the host tissue. The best characterized adult stem cell is the hematopoietic stem cell (HSC) located in the bone marrow. One goal of my thesis work was to further characterize the location of endogenous HSCs in vivo. To do this, a technique called "label retaining assay» was used which takes advantage of the fact that stem cells (including HSCs) divide very infrequently and can be dormant for months. After labeling mice with the DNA analogue BrdU followed by a long BrdU free "chase", BrdU "label retaining cells" (CRCs) could be identified in the bone marrow. These CRCs were 300-fold enriched for phenotypic HSCs and by using flow cytometry analysis it could be shown that about 15% of all HSCs in the mouse are dormant for many weeks. Our results suggest that these long-term dormant HSCs are unlikely to be involved in homeostatic maintenance. However they are rapidly activated and reenter the cell cycle in response to injury signals such as myeloid ablation. In addition, detection of LRCs in combination with the HSC marker c-Kit could be used to locate engrafted dormant HSCs close to the endosteal lining of the bone marrow cavities. Most surprisingly, c-Kit+LRCs were found predominantly as single cells suggesting that the specific stem cell maintaining microenvironment, called niche, has limited space and may house only single HSCs. Complex roles of the tumor suppressor gene Pten in the hematopoietic system. The phosphatase PTEN is lost in hereditary and sporadic forms of human cancers, including gliomas, endometrial and breast cancers. Pten inhibits the PI3-kina.se pathway and plays a key role in apoptosis, cell growth, proliferation and migration. Our aim was to study the role of Pten in normal HSCs and during leukemia formation. To do this, we generated a mouse model in which the Pten gene can be deleted in hematopoietic cells including HSCs. This was achieved by crossing the conditional ptenflox allele with either the interferona inducible MxCre or the tamoxifen inducible Scl-CreERT transgene. This allowed the conversion of the ptenflox allele into a pterr' null allele in HSCs and other hematopoietic cell types. As a result Pten mutant mice developed massive splenomegaly due to a dramatic expansion of all myeloid cells. Interestingly, while the number of bone marrow HSCs progressively decreased, the number of HSCs in the spleen increased to a similar extent. Unexpectedly, extensive cell cycle analysis showed that Pten had little or no effect on HSC dormancy or HSC self-renewal. Instead, dramatically increased levels of the mobilizing cytokine G-CSF were detected in the blood serum suggesting that loss-of Pten stimulates mobilization and migration of HSC from the BM to the spleen. Finally, transplantation of Pten deficient BM cells into immuno-compromised mice showed that Pten can function as a tumor suppressor in the hematopoietic system and that its absence leads to the rapid formation of T cell leukemia.

Tumor antigen-specific FOXP3+ CD4 T cells identified in human metastatic melanoma: peptide vaccination results in selective expansion of Th1-like counterparts.

We have previously shown that vaccination of HLA-A2 metastatic melanoma patients with the analogue Melan-A(26-35(A27L)) peptide emulsified in a mineral oil induces ex vivo detectable specific CD8 T cells. These are further enhanced when a TLR9 agonist is codelivered in the same vaccine formulation. Interestingly, the same peptide can be efficiently recognized by HLA-DQ6-restricted CD4 T cells. We used HLA-DQ6 multimers to assess the specific CD4 T-cell response in both healthy individuals and melanoma patients. We report that the majority of melanoma patients carry high frequencies of naturally circulating HLA-DQ6-restricted Melan-A-specific CD4 T cells, a high proportion of which express FOXP3 and proliferate poorly in response to the cognate peptide. Upon vaccination, the relative frequency of multimer+ CD4 T cells did not change significantly. In contrast, we found a marked shift to FOXP3-negative CD4 T cells, accompanied by robust CD4 T-cell proliferation upon in vitro stimulation with cognate peptide. A concomitant reduction in TCR diversity was also observed. This is the first report on direct ex vivo identification of antigen-specific FOXP3+ T cells by multimer labeling in cancer patients and on the direct assessment of the impact of peptide vaccination on immunoregulatory T cells.

Variation d'expression des récepteurs hormonaux et d'HER-2 dans l'évolution du cancer du sein : quelles implications en pratique clinique [Hormone receptors and HER-2 changes during breast cancer progression: clinical implications].

Breast cancer remains a major public health problem. Even if there is an increase in this cancer curability, metastatic breast cancer remains a lethal disease in the vast majority of cases. Therapeutic advances in the chemotherapeutic and targeted therapies fields induced an increase in survival, however the proportion of long survivors remains low. Phenotypic instability, an early process initiated during tumour progression, and continued on the metastatic stage of the disease, can be one of the putative hypotheses explaining these results. An increasing amount of scientific data are pledging for a reanalysis of the phenotypic profile regarding hormone receptors and HER-2 status of metastatic lesions in order to identify drugable targets and allow individualisation of the treatment of these metastatic breast cancer patients. Phenotypic changes between the primary tumour and the paired metastatic lymph nodes are a challenging pitfall, raising the question of which site has to be assessed in the adjuvant treatment decision process. This article presents a comprehensive analysis of the frequency of theses phenotypic changes altogether with new modalities to evaluate this phenotypic status.

Decreased compliance on arterial anastomoses.

The present study was undertaken to examine the cross-sectional vascular compliance at the anastomotic site. METHODS AND MATERIAL: We performed end-to-end anastomosis on the carotid artery of six pigs using continuous 6/0 polypropylene. Four carotid arteries were excised and mounted in a perfusion chamber while the remaining two were left in living animals. We used pulsed ultrasound (NIUS 02) to generate detailed longitudinal profiles of diameter and compliance in the proximity and on the anastomosis. RESULTS: On the anastomosis, the vessel diameter decreases (-1 to -2.6% of diastolic diameter) when blood pressure increases with an exponential correlation (R2 = 0.75). The arterial compliance at the anastomosis was negative: the vessel cross-section reduction for a pulse pressure of 1 up to 32 mmHg was 0.9 to 2% of diastolic vessel cross-section. CONCLUSIONS: Vessel movement generated a dynamic stenosis whose magnitude seems to depend on blood pressure level. Increasing blood pressure causes the retraction of vessel ends which causes vessel lumen reduction. These results suggest that continuous suture does not provide the continuity of mechanical properties of the artery.

Identification of MAGI1 as a tumor-suppressor protein induced by cyclooxygenase-2 inhibitors in colorectal cancer cells.

Cyclooxyganase-2 (COX-2), a rate-limiting enzyme in the prostaglandin synthesis pathway, is overexpressed in many cancers and contributes to cancer progression through tumor cell-autonomous and paracrine effects. Regular use of non-steroidal anti-inflammatory drugs or selective COX-2 inhibitors (COXIBs) reduces the risk of cancer development and progression, in particular of the colon. The COXIB celecoxib is approved for adjunct therapy in patients with Familial adenomatous polyposis at high risk for colorectal cancer (CRC) formation. Long-term use of COXIBs, however, is associated with potentially severe cardiovascular complications, which hampers their broader use as preventive anticancer agents. In an effort to better understand the tumor-suppressive mechanisms of COXIBs, we identified MAGUK with Inverted domain structure-1 (MAGI1), a scaffolding protein implicated in the stabilization of adherens junctions, as a gene upregulated by COXIB in CRC cells and acting as tumor suppressor. Overexpression of MAGI1 in CRC cell lines SW480 and HCT116 induced an epithelial-like morphology; stabilized E-cadherin and β-catenin localization at cell-cell junctions; enhanced actin stress fiber and focal adhesion formation; increased cell adhesion to matrix proteins and suppressed Wnt signaling, anchorage-independent growth, migration and invasion in vitro. Conversely, MAGI1 silencing decreased E-cadherin and β-catenin localization at cell-cell junctions; disrupted actin stress fiber and focal adhesion formation; and enhanced Wnt signaling, anchorage-independent growth, migration and invasion in vitro. MAGI1 overexpression suppressed SW480 and HCT116 subcutaneous primary tumor growth, attenuated primary tumor growth and spontaneous lung metastasis in an orthotopic model of CRC, and decreased the number and size of metastatic nodules in an experimental model of lung metastasis. Collectively, these results identify MAG1 as a COXIB-induced inhibitor of the Wnt/β-catenin signaling pathway, with tumor-suppressive and anti-metastatic activity in experimental colon cancer.

Aggregate cultures of foetal rat liver cells: development and maintenance of liver gene expression.

Rotation-mediated aggregate cultures of foetal rat liver cells were prepared and grown in a chemically defined medium. Their capacity for cellular organisation and maturation was studied over a culture period of 3 wk by using both morphologic and biochemical criteria. It was found that within each aggregate, distinct liver cell types were present and attained their normal, differentiated phenotype. Parenchymal cells formed small acini with a central lumen. Within the first 2 wk in culture, albumin and ferritin mRNA levels were maintained, while the alpha-fetoprotein mRNA levels decreased, and tyrosine aminotransferase (TAT) gene expression increased. No significant response to glucocorticoids was observed in early cultures, whereas after 3 wk a marked increase in TAT mRNA levels was elicited by dexamethasone and glucagon (additive stimulatory effects). The results show that foetal rat liver cells cultured in a chemically defined medium are able to rearrange themselves into histotypic structures, and display a developmental pattern of gene expression comparable to that of perinatal rat liver in vivo. This culture system offers therefore a useful model to study the development and function of liver cells.

Characterization of T cell clones from chagasic patients: predominance of CD8 surface phenotype in clones from patients with pathology

Human Chagas' disease, caused by the protozoan Trypanosoma cruzi, is associated with pathological processes whose mechanisms are not known. To address this question, T cell lines were developed from chronic chagasic patients peripheral blood mononuclear cells (PBMC) and cloned. These T cell clones (TCC) were analyzed phenotypically with monoclonal antibodies by the use of a fluorescence microscope. The surface phenotype of the TCC from the asymptomatic patient were predominantly CD4 positive (86%). On the contrary, the surface phenotype CD8 was predominant in the TCC from the patients suffering from cardiomegaly with right bundle branch block (83%), bradycardia with megacolon (75 %) and bradycardia (75%). Future studies will be developed in order to identify the antigens eliciting these T cell subpopulations.

Association of mutations in the NALP3/CIAS1/PYPAF1 gene with a broad phenotype including recurrent fever, cold sensitivity, sensorineural deafness, and AA amyloidosis.

OBJECTIVE: Familial cold urticaria (FCU) and Muckle-Wells syndrome (MWS) are dominantly inherited autoinflammatory disorders that cause rashes, fever, arthralgia, and in some subjects, AA amyloidosis, and have been mapped to chromosome 1q44. Sensorineural deafness in MWS, and provocation of symptoms by cold in FCU, are distinctive features. This study was undertaken to characterize the genetic basis of FCU, MWS, and an overlapping disorder in French Canadian, British, and Indian families, respectively. METHODS: Mutations in the candidate gene NALP3, which has also been named CIAS1 and PYPAF1, were sought in the study families, in a British/Spanish patient with apparent sporadic MWS, and in matched population controls. Identified variants were sought in 50 European subjects with uncharacterized, apparently sporadic periodic fever syndromes, 48 subjects with rheumatoid arthritis (RA), and 19 subjects with juvenile idiopathic arthritis (JIA). RESULTS: Point mutations, encoding putative protein variants R262W and L307P, were present in all affected members of the Indian and French Canadian families, respectively, but not in controls. The R262W variant was also present in the subject with sporadic MWS. The V200M variant was present in all affected members of the British family with MWS, in 2 of the 50 subjects with uncharacterized periodic fevers, and in 1 of 130 Caucasian and 2 of 48 Indian healthy controls. No mutations were identified among the subjects with RA or JIA. CONCLUSION: These findings confirm that mutations in the NALP3/CIAS1/PYPAF1 gene are associated with FCU and MWS, and that disease severity and clinical features may differ substantially within and between families. Analysis of this gene will improve classification of patients with inherited or apparently sporadic periodic fever syndromes.

Loss of connexin40 is associated with decreased endothelium-dependent relaxations and eNOS levels in the mouse aorta.

Upon agonist stimulation, endothelial cells trigger smooth muscle relaxation through the release of relaxing factors such as nitric oxide (NO). Endothelial cells of mouse aorta are interconnected by gap junctions made of connexin40 (Cx40) and connexin37 (Cx37), allowing the exchange of signaling molecules to coordinate their activity. Wild-type (Cx40(+/+)) and hypertensive Cx40-deficient mice (Cx40(-/-)), which also exhibit a marked decrease of Cx37 in the endothelium, were used to investigate the link between the expression of endothelial connexins (Cx40 and Cx37) and endothelial nitric oxide synthase (eNOS) expression and function in the mouse aorta. With the use of isometric tension measurements in aortic rings precontracted with U-46619, a stable thromboxane A(2) mimetic, we first demonstrate that ACh- and ATP-induced endothelium-dependent relaxations solely depend on NO release in both Cx40(+/+) and Cx40(-/-) mice, but are markedly weaker in Cx40(-/-) mice. Consistently, both basal and ACh- or ATP-induced NO production were decreased in the aorta of Cx40(-/-) mice. Altered relaxations and NO release from aorta of Cx40(-/-) mice were associated with lower expression levels of eNOS in the aortic endothelium of Cx40(-/-) mice. Using immunoprecipitation and in situ ligation assay, we further demonstrate that eNOS, Cx40, and Cx37 tightly interact with each other at intercellular junctions in the aortic endothelium of Cx40(+/+) mice, suggesting that the absence of Cx40 in association with altered Cx37 levels in endothelial cells from Cx40(-/-) mice participate to the decreased levels of eNOS. Altogether, our data suggest that the endothelial connexins may participate in the control of eNOS expression levels and function.

IL-5 and IL-5 receptor in asthma

Eosinophils, along with mast cells are key cells involved in the innate immune response against parasitic infection whereas the adaptive immune response is largely dependent on lymphocytes. In chronic parasitic disease and in chronic allergic disease, IL-5 is predominantly a T cell derived cytokine which is particularly important for the terminal differentiation, activation and survival of committed eosinophil precursors. The human IL-5 gene is located on chromosome 5 in a gene cluster that contains the evolutionary related IL-4 family of cytokine genes. The human IL-5 receptor complex is a heterodimer consisting of a unique a subunit (predominantly expressed on eosinophils) and a beta subunit which is shared between the receptors for IL-3 & GM-CSF (more widely expressed). The a subunit is required for ligand-specific binding whereas association with the beta subunit results in increased binding affinity. The alternative splicing of the alphaIL-5R gene which contains 14 exons can yield several alphaIL-5R isoforms including a membrane-anchored isoform (alphaIL-5Rm) and a soluble isoform (alphaIL-5Rs). Cytokines such as IL-5 produce specific and non-specific cellular responses through specific cell membrane receptor mediated activation of intracellular signal transduction pathways which, to a large part, regulate gene expression. The major intracellular signal transduction mechanism is activation of non-receptor associated tyrosine kinases including JAK and MAP kinases which can then transduce signals via a novel family of transcriptional factors named signal transducers and activators of transcription (STATS). JAK2, STAT1 and STAT 5 appear to be particularly important in IL-5 mediated eosinophil responses. Asthma is characterized by episodic airways obstruction, increased bronchial responsiveness, and airway inflammation. Several studies have shown an association between the number of activated T cells and eosinophils in the airways and abnormalities in FEV1, airway reactivity and clinical severity in asthma. It has now been well documented that IL-5 is highly expressed in the bronchial mucosa of atopic and intrinsic asthmatics and that the increased IL-5 mRNA present in airway tissues is predominantly T cell derived. Immunocytochemical staining of bronchial biopsy sections has confirmed that IL-5 mRNA transcripts are translated into protein in asthmatic subjects. Furthermore, the number of activated CD 4 + T cells and IL-5 mRNA positive cells are increased in asthmatic airways following antigen challenge and studies that have examined IL-5 expression in asthmatic subjects before and after steroids have shown significantly decreased expression following oral corticosteroid treatment in steroid-sensitive asthma but not in steroid resistant and chronic severe steroid dependent asthma. The link between T cell derived IL-5 and eosinophil activation in asthmatic airways is further strengthened by the demonstration that there is an increased number of alphaIL-5R mRNA positive cells in the bronchial biopsies of atopic and non-atopic asthmatic subjects and that the eosinophil is the predominant site of this increased alphaIL-5R mRNA expression. We have also shown that the subset of activated eosinophils that expressed mRNA for membrane bound alpha IL5r inversely correlated with FEV1, whereas the subset of activated eosinophils that expressed mRNA for soluble alphaIL5r directly correlated with FEV1. Hence, not only does this data suggest that the presence of eosinophils expressing alphaIL-5R mRNA contribute towards the pathogenesis of bronchial asthma, but also that the eosinophil phenotype with respect to alphaIL-5R isoform expression is of central importance. Finally, there are several animal, and more recently in vitro lung explant, models of allergen induced eosinophilia, late airway responses(LARS), and bronchial hyperresponsiveness(BHR) - all of which support a link between IL-5 and airway eosinophila and bronchial hyperresponsiveness. The most direct demonstration of T cell involvement in LARS is the finding that these physiological responses can be transferred by CD4+ but not CD8+ T cells in rats. The importance of IL-5 in animal models of allergen induced bronchial hyperresponsiveness has been further demonstrated by a number of studies which have indicated that IL-5 administration is able to induce late phase responses and BHR and that anti-IL-5 antibody can block allergen induced late phase responses and BHR. In summary, activated T lymphocytes, IL5 production and eosinophil activation are particularly important in the asthmatic response. Human studies in asthma and studies in allergic animal models have clearly emphasised the unique role of IL-5 in linking T lymphocytes and adaptive immunity, the eosinophil effector cell, and the asthma phenotype. The central role of activated lymphocytes and eosinophils in asthma would argue for the likely therapeutic success of strategies to block T cell and eosinophil activation (eg steroids). Importantly, more targeted therapies may avoid the complications associated with steroids. Such therapies could target key T cell activation proteins and cytokines by various means including blocking antibodies (eg anti-CD4, anti-CD40, anti-IL-5 etc), antisense oligonucleotides to their specific mRNAs, and/or selective inhibition of the promoter sites for these genes. Another option would be to target key eosinophil activation mechanisms including the aIL5r. As always, the risk to benefit ratio of such strategies await the results of well conducted clinical trials.

First-line temozolomide combined with bevacizumab in metastatic melanoma: a multicentre phase II trial (SAKK 50/07).

BACKGROUND: Oral temozolomide has shown similar efficacy to dacarbazine in phase III trials with median progression-free survival (PFS) of 2.1 months. Bevacizumab has an inhibitory effect on the proliferation of melanoma and sprouting endothelial cells. We evaluated the addition of bevacizumab to temozolomide to improve efficacy in stage IV melanoma. PATIENTS AND METHODS: Previously untreated metastatic melanoma patients with Eastern Cooperative Oncology Group performance status of two or more were treated with temozolomide 150 mg/m(2) days 1-7 orally and bevacizumab 10 mg/kg body weight i.v. day 1 every 2 weeks until disease progression or unacceptable toxicity. The primary end point was disease stabilisation rate [complete response (CR), partial response (PR) or stable disease (SD)] at week 12 (DSR12); secondary end points were best overall response, PFS, overall survival (OS) and adverse events. RESULTS: Sixty-two patients (median age 59 years) enrolled at nine Swiss centres. DSR12 was 52% (PR: 10 patients and SD: 22 patients). Confirmed overall response rate was 16.1% (CR: 1 patient and PR: 9 patients). Median PFS and OS were 4.2 and 9.6 months. OS (12.0 versus 9.2 months; P = 0.014) was higher in BRAF V600E wild-type patients. CONCLUSIONS: The primary end point was surpassed showing promising activity of this bevacizumab/temozolomide combination with a favourable toxicity profile. Response and OS were significantly higher in BRAF wild-type patients.