What a polyclonal antibody sees in von Willebrand factor.

INTRODUCTION: Von Willebrand factor (VWF) plays a critical role in hemostasis by carrying factor VIII (FVIII) and binding to specific ligands on the surface of blood platelets and within the blood vessel wall. MATERIALS AND METHODS: We constructed a gene-specific phage display library containing small, random VWF fragments. Using this library, we mapped the repertoire of immune epitopes recognized by a commonly used commercial rabbit antihuman VWF polyclonal antibody. RESULTS: A total of eight discrete epitopes within the VWF protein were identified, including two dominant epitopes that account for 74% of immuno selected VWF fragments. Comparison with previously mapped epitopes for mouse monoclonal antibodies reveals four overlapping regions that may identify common antigenic determinants. The distribution of these epitopes was not readily predicted from primary amino acid sequence divergence among these mammalian species or standard algorithms for the prediction of antigenicity, hydrophobicity, or surface probability. CONCLUSION: Taken together with previous monoclonal antibody epitope mapping studies, our results suggest that a limited number of exposed domains on the surface of the human VWF protein may be the primary determinants of immunogenicity.

Icotinib versus whole-brain irradiation in patients with EGFR-mutant non-small-cell lung cancer and multiple brain metastases (BRAIN): a multicentre, phase 3, open-label, parallel, randomised controlled trial.

BACKGROUND: For patients with non-small-cell lung cancer (NSCLC) and multiple brain metastases, whole-brain irradiation (WBI) is a standard-of-care treatment, but its effects on neurocognition are complex and concerning. We compared the efficacy of an epidermal growth factor receptor (EGFR)-tyrosine kinase inhibitor (TKI), icotinib, versus WBI with or without chemotherapy in a phase 3 trial of patients with EGFR-mutant NSCLC and multiple brain metastases. METHODS: We did a multicentre, open-label, parallel randomised controlled trial (BRAIN) at 17 hospitals in China. Eligible participants were patients with NSCLC with EGFR mutations, who were naive to treatment with EGFR-TKIs or radiotherapy, and had at least three metastatic brain lesions. We randomly assigned participants (1:1) to either icotinib 125 mg orally (three times per day) or WBI (30 Gy in ten fractions of 3 Gy) plus concurrent or sequential chemotherapy for 4-6 cycles, until unacceptable adverse events or intracranial disease progression occurred. The randomisation was done by the Chinese Thoracic Oncology Group with a web-based allocation system applying the Pocock and Simon minimisation method; groups were stratified by EGFR gene mutation status, treatment line (first line or second line), brain metastases only versus both intracranial and extracranial metastases, and presence or absence of symptoms of intracranial hypertension. Clinicians and patients were not masked to treatment assignment, but individuals involved in the data analysis did not participate in the treatments and were thus masked to allocation. Patients receiving icotinib who had intracranial progression only were switched to WBI plus either icotinib or chemotherapy until further progression; those receiving icotinib who had extracranial progression only were switched to icotinib plus chemotherapy. Patients receiving WBI who progressed were switched to icotinib until further progression. Icotinib could be continued beyond progression if a clinical benefit was observed by the investigators (eg, an improvement in cognition or intracranial pressure). The primary endpoint was intracranial progression-free survival (PFS), defined as the time from randomisation to either intracranial disease progression or death from any cause. We assessed efficacy and safety in the intention-to-treat population (all participants who received at least one dose of study treatment), hypothesising that intracranial PFS would be 40% longer (hazard ratio [HR] 0·60) with icotinib compared with WBI. This trial is registered with ClinicalTrials.gov, number NCT01724801. FINDINGS: Between Dec 10, 2012, and June 30, 2015, we assigned 176 participants to treatment: 85 to icotinib and 91 to WBI. 18 withdrew from the WBI group before treatment, leaving 73 for assessment. Median follow-up was 16·5 months (IQR 11·5-21·5). Median intracranial PFS was 10·0 months (95% CI 5·6-14·4) with icotinib versus 4·8 months (2·4-7·2) with WBI (equating to a 44% risk reduction with icotinib for an event of intracranial disease progression or death; HR 0·56, 95% CI 0·36-0·90; p=0·014). Adverse events of grade 3 or worse were reported in seven (8%) of 85 patients in the icotinib group and 28 (38%) of 73 patients in the WBI group. Raised concentrations of alanine aminotransferase and rash were the most common adverse events of any grade in both groups, occurring in around 20-30% of each group. At the time of final analysis, 42 (49%) patients in the icotinib group and 37 (51%) in the WBI group had died. 78 of these patients died from disease progression, and one patient in the WBI group died from thrombogenesis related to chemotherapy. INTERPRETATION: In patients with EGFR-mutant NSCLC and multiple brain metastases, icotinib was associated with significantly longer intracranial PFS than WBI plus chemotherapy, indicating that icotinib might be a better first-line therapeutic option for this patient population. FUNDING: Guangdong Provincial Key Laboratory of Lung Cancer Translational Medicine, National Health and Family Planning Commission of China, Guangzhou Science and Technology Bureau, Betta Pharmaceuticals, and the Chinese Thoracic Oncology Group.

Identification of new genes differentially expressed in coronary artery disease by expression profiling.

Genetic factors increase the risk to coronary artery disease (CAD). To date, a limited number of genes that potentially contribute to development of CAD have been identified. In this study, we have performed large-scale gene expression analysis of approximately 12,000 human genes in nine severely atherosclerotic and six nonatherosclerotic human coronary arteries using oligonucleotide microarrays. Fifty-six genes showed differential expression in atherosclerotic coronary artery tissues; expression of 55 genes was increased in atherosclerotic coronary arteries, whereas only one gene, GST, encoding a reducing agent, showed downregulated expression. The expression data of selected genes were validated by quantitative RT-PCR analysis as well as immunostaining. The associations of 49 genes with CAD appear to be novel, and they include genes encoding ICAM-2, PIM-2, ECGF1, fusin, B cell activator (BL34, GOS8), Rho GTPase activating protein-4, retinoic acid receptor responder, beta2-arrestin, membrane aminopeptidase, cathepsins K and H, MIR-7, TNF-alpha-induced protein 2 (B94), and flavocytochrome 558. In conclusion, we have identified 56 genes whose expression is associated with CAD, and 49 of them may represent new genes linked to CAD.

Therapeutic effects and adverse drug reactions are affected by icotinib exposure and CYP2C19 and EGFR genotypes in Chinese non-small cell lung cancer patients.

BACKGROUND: The aim of this study was to evaluate how CYP2C19 affects icotinib and metabolite' exposure, and to determine whether the exposure and EGFR genotype influences survival time, tumor metastasis and adverse drug reactions. MATERIALS AND METHODS: 274 NSCLC patients who accepted 125 mg icotinib/t.i.d. were chosen from a phase III study. Blood samples were obtained in 672 nd (4th week) and 1,680 th hours (10th week), and plasma was used to quantify the concentration of icotinib and blood cells were sampled to check the genotypes. Clinical data were also collected at the same time, including EGFR genotypes. Plasma concentrations were assessed by HPLC-MS/MS and genotype by sequencing. All data were analyzed through SPSS 17.0 and SAS 9.2. RESULTS: CYP 2C19 genotypes affected bio-transformation from icotinib to M24 and M26, especially in poor-metabolisers. Higher icotinib concentrations (>1000 ng/mL) not only increased patient PFS and OS but also reduced tumor metastasis. Patients with mutant EGFR experienced a higher median PFS and OS (234 and 627 days), especially those with the 19del genotype demonstrating higher PR ratio. Patients who suffered grade II skin toxicity had a higher icotinib exposure than those with grade I skin toxicity or no adverse effects. Liver toxic reactions might occur in patients with greater M20 and M23 plasma concentrations. CONCLUSIONS: CYP2C19 polymorphisms significantly affect icotinib, M24 and M26 exposure. Patients with mutant EGFR genotype and higher icotinib concentration might have increased PFS and OS and lower tumor metastasis. Liver ADR events and serious skin effects might be respectively induced by greater M20, M23 and icotinib concentrations.

Effect of BZG-4000, a novel multi-targeted kinase inhibitor with potent anticancer activity, on a hepatocellular carcinoma xenograft model.

The present study was to synthesize a novel multi-targeted kinase inhibitor and evaluated its anticancer effects on a hepatocellular carcinoma xenograft model. In our study, in vivo efficacy was determined in nude mice bearing HuH7 human HCC xenografts. The mice were randomly divided into the following five groups with the use of a randomization chart (n = 8 in each group): high-dose BZG-4000 group, medium-dose BZG-4000 group, low-dose BZG-4000 group, sorafenib group, and model group. Tumor size measurements included the length (L) and width (W) measured with calipers, and tumor volume was calculated as (LW∧2)/2. Tumor tissues slides were hematoxylin and eosin (HE) stained for histopathological examination. Immunohistochemistry detected CD31 expression, and Western blotting measured VEGF protein expression. We found that when BZG-4000 was administered orally to xenograft HuH7 nude mice, tumor growth was inhibited and significant tumor shrinkage was evident. After oral administration of BZG-4000 at 40 mg/kg/day, the tumor weight and volume were significantly lower than tumors of the sorafenib group. BZG-4000 considerably decreased the expression of CD31 and VEGF in tumors compared to tumors treated with positive control drug. It was concluded that BZG-4000 has the potential to inhibit the tumorigenesis of hepatocellular carcinoma in vivo by decreasing the expression of CD31 and VEGF.

Functional display of platelet-binding VWF fragments on filamentous bacteriophage.

von Willebrand factor (VWF) tethers platelets to sites of vascular injury via interaction with the platelet surface receptor, GPIb. To further define the VWF sequences required for VWF-platelet interaction, a phage library displaying random VWF protein fragments was screened against formalin-fixed platelets. After 3 rounds of affinity selection, DNA sequencing of platelet-bound clones identified VWF peptides mapping exclusively to the A1 domain. Aligning these sequences defined a minimal, overlapping segment spanning P1254-A1461, which encompasses the C1272-C1458 cystine loop. Analysis of phage carrying a mutated A1 segment (C1272/1458A) confirmed the requirement of the cystine loop for optimal binding. Four rounds of affinity maturation of a randomly mutagenized A1 phage library identified 10 and 14 unique mutants associated with enhanced platelet binding in the presence and absence of botrocetin, respectively, with 2 mutants (S1370G and I1372V) common to both conditions. These results demonstrate the utility of filamentous phage for studying VWF protein structure-function and identify a minimal, contiguous peptide that bind to formalin-fixed platelets, confirming the importance of the VWF A1 domain with no evidence for another independently platelet-binding segment within VWF. These findings also point to key structural elements within the A1 domain that regulate VWF-platelet adhesion.

Discovery of potent, orally active compounds of tyrosine kinase and serine/threonine-protein kinase inhibitor with anti-tumor activity in preclinical assays.

Traditional medicines have become the most productive source of leads for drugs development, particularly as anti-cancer agents. Various screening approaches are being applied. Sorafenib, a multikinase inhibitor, is used to treat primary kidney cancer (advanced renal cell carcinoma) and advanced primary liver cancer. A small library of compounds analogous to sorafenib were designed and screened for the treatment of liver cancer. Multiple members of the family in an assay panel of tyrosine kinase family and serine/threonine-protein kinase family, including VEGFR, Abl, Aurora A, p 38, Lck, Src, PDGFR, Flt3, c-RAF, c-KIT, MEK(MAPKK) were selected to test these compounds. Analysis of the selectivity patterns for these compounds shows specificity for many kinase families. IC50 were measured for the selected compounds. Multiple compounds have very similar kinase inhibition profiles of VEGFR, Flt3, FGFR to that of sorafenib. The IC50 of c-RAF of BB1 is lower than sorafenib. The IC50 of c-RAF of BB3-12 is higher than that of sorafenib. For Flt3, IC50 of BB1-4 is less than sorafenib. The IC50 value of KDR of BB1-10 is less than sorafenib. especially against c-RAF, PDGFR, c-KIT, KDR compared to sorafenib. These compounds are potent Raf1 and Flt4 kinase inhibitors.

Phase I trial of icotinib, a novel epidermal growth factor receptor tyrosine kinase inhibitor, in Chinese patients with non-small cell lung cancer.

BACKGROUND: The preclinical experiments and studies of congener drugs show icotinib, a new epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, can specifically bind to the tyrosine kinase domain of the EGFR, block the EGFR related signal, thereby inhibit the growth of tumor cell. The objective of this study was to investigate the safety, tolerability and dose-related biologic effects of icotinib in patients with non-small cell lung cancer (NSCLC) in a Chinese patient population. METHODS: This was an open-label, phase I, dose escalation, safety/tolerability trial of oral icotinib (100 to 400 mg), administered twice per day for 28-continuous-day cycles until disease progression or undue toxicity. RESULTS: Forty patients with stage IIIB (15%) or IV (85%) NSCLC were included in the study. They had mainly adenocarcinoma (85%), with a performance status (PS) of 0 (45%) or 1 (55%) and less than half the patients (45%) had histories of smoking and all were pretreated by at least one regimen of chemotherapy. Patients were assigned to three dose levels of 150 mg b.i.d, 200 mg b.i.d, or 125 mg t.i.d. The follow-up periods ranged from 5 to 80 weeks. Adverse events were found in 35% patients, most of which were mild and reversible. The adverse events mainly occurred in the first 4 weeks and included rash (25%), diarrhea, nausea and abdominal distention. One definite interstitial lung disease (ILD) was found in a patient in the dose of 200 mg b.i.d. According to an 8-week assessment, one (2.5%) patient receiving 150 mg gained complete response (CR) that persisted for 44 weeks, seven (17.50%) patients had partial remission (PR), and 18 (45%) patients had stable disease (SD). The objective response including CR + PR was 20%. The median time of progression-free survival for the 40 patients was 20 weeks (range: 12 to 32 weeks). The response was not affected by pathological type, history of smoking, or numbers of previous therapeutic regimens. No relationship between dose, response, adverse effect, or duration of the study was observed. CONCLUSIONS: Icotinib, given as oral twice daily, showed favorable safety and tolerability. Mild and reversible rash, diarrhea, and nausea were the main adverse events. Antitumor activity was obvious at each dose in heavily pretreated patients. Pharmacodynamic evaluations and further phase II/III trials are in progress.

Intregrated analysis of the human cardiac transcriptome, proteome and phosphoproteome.

Altered expression of different classes of genes has been shown to differentiate between failing and nonfailing human hearts. However, characterization of proteins and the post-translational modifications that regulate their functions is required for understanding both the physiology of cardiac muscle and the mechanisms leading to pathological states associated with cardiac diseases. We present in this paper, an analysis of the human cardiac transcriptome, proteome and phosphoproteome. Data from two sources (i) experiments performed in our laboratory and (ii) bioinformatics searches of public databases (SWISS-PROT, NCBI, Cardiac Gene Expression Knowledge Base, Gene Ontology Consortium and Affymetrix) are reported in a relational database that allows user-designed specific queries. Microarray experiments were performed with Affymetrix Hu95Av2. Cardiac proteins were digested with trypsin. An 11 step cation exchange procedure produced fractions for analysis in separate reversed phase high-performance liquid chromatography-tandem mass spectrometry (MS/MS) experiments. Immobilized metal affinity chromatography was used to select the phosphopeptides from the same tryptic peptide mixture. They were then further investigated by MS/MS. Gel-free approaches were used to detect 267 proteins and 47 phosphopeptides. Our human cardiac database contains 447 entries. We propose the use of this platform, built with data derived from nonfailing hearts, as a template for initiating the effort to characterize the human cardiac proteome and its associated post-translational modifications.

The gene expression fingerprint of human heart failure.

Multiple pathways are responsible for transducing mechanical and hormonal stimuli into changes in gene expression during heart failure. In this study our goals were (i) to develop a sound statistical method to establish a comprehensive cutoff point for identification of differentially expressed genes, (ii) to identify a gene expression fingerprint for heart failure, (iii) to attempt to distinguish different etiologies of heart failure by their gene expression fingerprint, and (iv) to identify gene clusters that show coordinated up- or down-regulation in human heart failure. We used oligonucleotide microarrays to profile seven nonfailing (NF) and eight failing (F) human hearts with a diagnosis of end-stage dilated cardiomyopathy. Biological and experimental variability of the hybridization data were analyzed, and then a statistical analysis procedure was developed, including Student's t test after log-transformation and Wilcoxon Mann-Whitney test. A comprehensive cutoff point composed of fold change, average difference, and absolute call was then established and validated by TaqMan PCR. Of 6,606 genes on the GeneChip, 103 genes in 10 functional groups were differentially expressed between F and NF hearts. A dendrogram identified a gene expression fingerprint of F and NF hearts and also distinguished two F hearts with distinct etiologies (familial and alcoholic cardiomyopathy, respectively) with different expression patterns. K means clustering also revealed two potentially novel pathways associated with up-regulation of atrial natriuretic factor and brain natriuretic peptide and with increased expression of extracellular matrix proteins. Gene expression fingerprints may be useful indicators of heart failure etiologies.