The capacity to effectively label tumor cell hostones using very short pulses of [3-H]acetate and [32-P]phosphate (1 to 10 min) has been developed. Four histone fractions F3, F2a1, F2a2, and F2b are extensively acetylated in short time periods. About 70% of the acetate accumulated on the histone during a short pulse is removed with a half-life of similar to 3 min. The rest of the metabolically active acetate is removed with a half-life of 30 to 40 min. Histones F2a1, F2a2, and F1 are acetylated at the NH2 terminus and this modification is metabolically stable. In short pulses, histones are labeled with 32-P in the order F2a2 greater than F1 greater than F3 greater than F2a1 greater than F2b. All fractions have a fairly rapid turnover time (t1/2 similar 20 to 40 min) except F1 phosphate which turns over some 5 times more slowly.

The integrin family of heterodimeric cell adhesion molecules exists in both low- and high-affinity states, and integrin activation requires binding of the talin FERM (four-point-one, ezrin, radixin, moesin) domain to membrane-proximal sequences in the beta-integrin cytoplasmic domain. However, it has recently become apparent that the kindlin family of FERM domain proteins is also essential for talin-induced integrin activation. FERM domains are typically composed of F1, F2, and F3 domains, but the talin FERM domain is atypical in that it contains a large insert in F1 and is preceded by a previously unrecognized domain, F0. Initial sequence alignments showed that the kindlin FERM domain was most similar to the talin FERM domain, but the homology appeared to be restricted to the F2 and F3 domains. Based on a detailed characterization of the talin FERM domain, we have reinvestigated the sequence relationship with kindlins and now show that kindlins do indeed contain the same domain structure as the talin FERM domain. However, the kindlin F1 domain contains an even larger insert than that in talin F1 that disrupts the sequence alignment. The insert, which varies in length between different kindlins, is not conserved and, as in talin, is largely unstructured. We have determined the structure of the kindlin-1 F0 domain by NMR, which shows that it adopts the same ubiquitin-like fold as the talin F0 and F1 domains. Comparison of the kindlin-1 and talin F0 domains identifies the probable interface with the kindlin-1 F1 domain. Potential sites of interaction of kindlin F0 with other proteins are discussed, including sites that differ between kindlin-1, kindlin-2, and kindlin-3. We also demonstrate that F0 is required for the ability of kindlin-1 to support talin-induced alphaIIbbeta3 integrin activation and for the localization of kindlin-1 to focal adhesions.

NAFLD is highly prevalent but only a small subset of patients develop advanced liver fibrosis with impaired liver-related prognosis. We aimed to compare blood fibrosis tests and liver stiffness measurement (LSM) by FibroScan for the diagnosis of liver fibrosis and the evaluation of prognosis in NAFLD.

Diagnostic accuracy was evaluated in a cross-sectional study including 452 NAFLD patients with liver biopsy (NASH-CRN fibrosis stage), LSM, and eight blood fibrosis tests (BARD, NAFLD fibrosis score, FibroMeter(NAFLD), aspartate aminotransferase to platelet ratio index (APRI), FIB4, FibroTest, Hepascore, FibroMeter(V2G)). Prognostic accuracy was evaluated in a longitudinal study including 360 NAFLD patients.

LSM and FibroMeter(V2G) were the two best-performing tests in the cross-sectional study: AUROCs for advanced fibrosis (F3/4) were, respectively, 0.831±0.019 and 0.817±0.020 (p⩽0.041 vs. other tests); rates of patients with ⩾90% negative/positive predictive values for F3/4 were 56.4% and 46.7% (p<0.001 vs. other tests); Obuchowski indexes were 0.834±0.014 and 0.798±0.016 (p⩽0.036 vs. other tests). Two fibrosis classifications were developed to precisely estimate the histological fibrosis stage from LSM or FibroMeter(V2G) results without liver biopsy (diagnostic accuracy, respectively: 80.8% vs. 77.4%, p=0.190). Kaplan-Meier curves in the longitudinal study showed that both classifications categorised NAFLD patients into subgroups with significantly different prognoses (p<0.001): the higher was the class of the fibrosis classification, the worse was the prognosis.

LSM and FibroMeter(V2G) were the most accurate of nine evaluated tests for the non-invasive diagnosis of liver fibrosis in NAFLD. LSM and FibroMeter(V2G) fibrosis classifications help physicians estimate both fibrosis stage and patient prognosis in clinical practice.

The amount of liver fibrosis is the main determinant of the liver-related prognosis in patients with non-alcoholic fatty liver disease (NAFLD). We evaluated eight blood tests and FibroScan in a cross-sectional diagnostic study and found that FibroScan and the blood test FibroMeter(V2G) were the two most accurate tests for the non-invasive evaluation of liver fibrosis in NAFLD. A longitudinal prognostic study showed these two tests initially developed for the diagnosis are also prognostic markers as they allow for the stratification of NAFLD patients in several subgroups with significantly different prognosis.

The aim of this study was to analyse the electroencephalogram (EEG) background activity of Alzheimer's disease (AD) patients using multiscale entropy (MSE). MSE is a recently developed method that quantifies the regularity of a signal on different time scales. These time scales are inspected by means of several coarse-grained sequences formed from the analysed signals. We recorded the EEGs from 19 scalp electrodes in 11 AD patients and 11 age-matched controls and estimated the MSE profile for each epoch of the EEG recordings. The shape of the MSE profiles reveals the EEG complexity, and it suggests that the EEG contains information in deeper scales than the smallest one. Moreover, the results showed that the EEG background activity is less complex in AD patients than control subjects. We found significant differences between both subject groups at electrodes F3, F7, Fp1, Fp2, T5, T6, P3, P4, O1 and O2 (p-value < 0.01, Student's t-test). These findings indicate that the EEG complexity analysis performed on deeper time scales by MSE may be a useful tool in order to increase our knowledge of AD.

Virus-induced gene silencing (VIGS) is a powerful tool for functional analysis of genes in plants. A wide-host-range VIGS vector, which was developed based on the Cucumber mosaic virus (CMV), was tested for its ability to silence endogenous genes involved in flavonoid biosynthesis in soybean. Symptomless infection was established using a pseudorecombinant virus, which enabled detection of specific changes in metabolite content by VIGS. It has been demonstrated that the yellow seed coat phenotype of various cultivated soybean lines that lack anthocyanin pigmentation is induced by natural degradation of chalcone synthase (CHS) mRNA. When soybean plants with brown seed coats were infected with a virus that contains the CHS gene sequence, the colour of the seed coats changed to yellow, which indicates that the naturally occurring RNA silencing is reproduced by VIGS. In addition, CHS VIGS consequently led to a decrease in isoflavone content in seeds. VIGS was also tested on the putative flavonoid 3'-hydroxylase (F3'H) gene in the pathway. This experiment resulted in a decrease in the content of quercetin relative to kaempferol in the upper leaves after viral infection, which suggests that the putative gene actually encodes the F3'H protein. In both experiments, a marked decrease in the target mRNA and accumulation of short interfering RNAs were detected, indicating that sequence-specific mRNA degradation was induced. The present report is a successful demonstration of the application of VIGS for genes involved in flavonoid biosynthesis in plants; the CMV-based VIGS system provides an efficient tool for functional analysis of soybean genes.

The TEL-TRKC fusion is expressed as a consequence of t(12;15)(p13;q25), and is associated with two human cancers: congenital fibrosarcoma and acute myelogenous leukemia (AML). We report that the T/T(F) and T/T(L) fusion variants associated with congenital fibrosarcoma and AML, respectively, are constitutively tyrosine phosphorylated, and confer factor-independent growth to the murine hematopoietic cell line Ba/F3. Retroviral transduction of T/T(L) causes a rapidly fatal myeloproliferative disease in a murine bone marrow transplant (BMT) model, whereas T/T(F) causes a long-latency, pre-B-cell lymphoblastic lymphoma. TEL-TRKC variants are potent activators of the MAP kinase pathway, but neither variant activates Stat5 or other Stat family members. T/T(L), but not T/T(F), induces tyrosine phosphorylation of phospholipase Cgamma (PLCgamma), phosphoinositol-3 kinase and SHC. However, mutation analysis demonstrates that PLCgamma tyrosine phos phorylation by T/T(L) is dispensable for induction of the myeloproliferative phenotype by T/T(L). Collectively, these data demonstrate that the TEL-TRKC fusion variants are oncoproteins that activate the MAP kinase pathway, and do not require activation of either PLCgamma or Stat5 for efficient induction of a myeloproliferative phenotype in the murine BMT model.

A new method for quantifying irregularity of EEGs is proposed in this study. The entropy, an information measure, determines the uniformity of proportion distribution. The peakedness or flatness of the distribution of the EEG power spectrum, representing EEG rhythmicity, can be measured by the entropy, because the power spectrum consists of proportions of power at each frequency. The irregularity of the EEG was measured by the entropy of the power spectrum, called an irregularity index (II). The II was obtained from the power spectrum at F3, F4, C3, C4, P3, P4, O1 and O2 during rest and mental arithmetic in 10 normal subjects. Relative band powers of delta, theta, alpha and beta bands and alpha peak frequency were also obtained. EEGs during rest were significantly more irregular anteriorly than in the occipital areas. Alpha activity was also more irregular in the anterior region. A greater degree of EEG desynchronization during mental arithmetic was found over the left hemisphere and the right occipital area. The II was more sensitive to such desynchronization than alpha band power and alpha peak frequency. The differences in spectral structures between rest and mental arithmetic conditions, mainly over the left hemisphere, were also confirmed by the Kullback-Leibler information.

In acute myeloid leukemia (AML), two clusters of activating mutations are known in the FMS-like tyrosine kinase-3 (FLT3) gene: FLT3-internal tandem duplications (FLT3-ITDs) in the juxtamembrane (JM) domain in 20% to 25% of patients, and FLT3 point mutations in the tyrosine-kinase domain (FLT3-TKD) in 7% to 10% of patients, respectively. Here, we have characterized a new class of activating point mutations (PMs) that cluster in a 16-amino acid stretch of the juxtamembrane domain of FLT3 (FLT3-JM-PMs). Expression of 4 FLT3-JM-PMs in interleukin-3 (IL-3)-dependent Ba/F3 cells led to factor-independent growth, hyperresponsiveness to FLT3 ligand, and resistance to apoptotic cell death. FLT3-JM-PM receptors were autophosphorylated and showed a higher constitutive dimerization rate compared with the FLT3-wild-type (WT) receptor. As a molecular mechanism, we could show activation of STAT5 and up-regulation of Bcl-x(L) by all FLT3-JM-PMs. The FLT3 inhibitor PKC412 abrogated the factor-independent growth of FLT3-JM-PM-expressing cells. Compared with FLT3-ITD and FLT3-TKD mutants, the FLT3-JM-PMs showed a weaker transforming potential related to lower autophosphorylation of the receptor and its downstream target STAT5. Mapping of the FLT3-JM-PMs on the crystal structure of FLT3 showed that these mutations reduce the stability of the autoinhibitory JM domain, and provides a structural basis for the transforming capacity of this new class of gain-of-function mutations of FLT3.

JAK3 is a tyrosine kinase that associates with the common γ chain of cytokine receptors and is recurrently mutated in T-cell acute lymphoblastic leukemia (T-ALL). We tested the transforming properties of JAK3 pseudokinase and kinase domain mutants using in vitro and in vivo assays. Most, but not all, JAK3 mutants transformed cytokine-dependent Ba/F3 or MOHITO cell lines to cytokine-independent proliferation. JAK3 pseudokinase mutants were dependent on Jak1 kinase activity for cellular transformation, whereas the JAK3 kinase domain mutant could transform cells in a Jak1 kinase-independent manner. Reconstitution of the IL7 receptor signaling complex in 293T cells showed that JAK3 mutants required receptor binding to mediate downstream STAT5 phosphorylation. Mice transplanted with bone marrow progenitor cells expressing JAK3 mutants developed a long-latency transplantable T-ALL-like disease, characterized by an accumulation of immature CD8(+) T cells. In vivo treatment of leukemic mice with the JAK3 selective inhibitor tofacitinib reduced the white blood cell count and caused leukemic cell apoptosis. Our data show that JAK3 mutations are drivers of T-ALL and require the cytokine receptor complex for transformation. These results warrant further investigation of JAK1/JAK3 inhibitors for the treatment of T-ALL.

The BCR-ABL1 fusion kinase is frequently associated with chronic myeloid leukemia and B-cell acute lymphoblastic leukemia but is rare in T-cell acute lymphoblastic leukemia (T-ALL). We recently identified NUP214-ABL1 as a variant ABL1 fusion gene in 6% of T-ALL patients. Here we describe the identification of another ABL1 fusion, EML1-ABL1, in a T-ALL patient with a cryptic t(9;14)(q34;q32) associated with deletion of CDKN2A (p16) and expression of TLX1 (HOX11). Echinoderm microtubule-associated protein-like 1-Abelson 1 (EML1-ABL1) is a constitutively phosphorylated tyrosine kinase that transforms Ba/F3 cells to growth factor-independent growth through activation of survival and proliferation pathways, including extracellular signal-related kinase 1/2 (Erk1/2), signal transducers and activators of transcription 5 (Stat5), and Lyn kinase. Deletion of the coiled-coil domain of EML1 abrogated the transforming properties of the fusion kinase. EML1-ABL1 and breakpoint cluster region (BCR)-ABL1 were equally sensitive to the tyrosine kinase inhibitor imatinib. These data further demonstrate the involvement of ABL1 fusions in the pathogenesis of T-ALL and identify EML1-ABL1 as a novel therapeutic target of imatinib.

The activation of Janus kinases (JAKs) is crucial for propagation of the proliferative response initiated by many cytokines. The proliferation of various cell lines, particularly those of hematopoietic origin, is also modulated by mediators of oxidative stress such as nitric oxide and thiol redox reagents. Herein we demonstrate that nitric oxide and other thiol oxidants can inhibit the autokinase activity of rat JAK2 in vitro, presumably through oxidation of crucial dithiols to disulfides within JAK2. The reduced form of JAK2 is the most active form, and the oxidized JAK2 form is inactive. Nitric oxide pretreatment of quiescent Ba/F3 cells also inhibits the interleukin 3-triggered in vivo activation of JAK2, a phenomenon that correlates with inhibited proliferation. Furthermore, we observed that the autokinase activity of JAK3 responds in a similar fashion to thiol redox reagents in vitro and to nitric oxide donors in vivo. We suggest that the thiol redox regulation of JAKs may partially explain the generally immunosuppressive effects of nitric oxide and of other thiol oxidants.

UNASSIGNED

Nonalcoholic steatohepatitis (NASH) is projected to be the leading cause of liver transplantation by 2020. Advanced fibrosis (stage F3-F4) on liver biopsy independently predicts all-cause and liver-related mortality in NASH. There are no known efficacious treatments for advanced fibrosis related to NASH. Thiazolidinedione therapy has been extensively evaluated in NASH, and new randomized clinical trials (RCTs) of its efficacy have been completed.

UNASSIGNED

To synthesize the evidence about the association of thiazolidinedione therapy with advanced liver fibrosis in NASH.

UNASSIGNED

MEDLINE, Ovid MEDLINE In-Process, Cochrane Library, EMBASE, clinicaltrials.gov, PubMed, and Scopus databases (without language restrictions), as well as other registries and scientific meeting presentations, from database inception through August 15, 2016.

UNASSIGNED

Randomized clinical trials evaluating the effect of thiazolidinedione therapy on histologic features of the liver in biopsy-proven NASH.

UNASSIGNED

Two investigators extracted study data independently and in duplicate and rated the risk of bias using the Cochrane Risk of Bias Tool.

UNASSIGNED

The primary outcome was a dichotomous improvement in advanced fibrosis on liver biopsy, defined as an improvement in fibrosis stage from F3-F4 to F0-F2. Secondary outcomes were at least a 1-point improvement in fibrosis of any stage and NASH resolution. This meta-analysis also evaluated adverse effects of thiazolidinedione therapy, including weight gain, lower limb edema, congestive heart failure, bone fractures, cancer, and anemia. With the use of random-effects models, dichotomous variables are presented as odds ratios (ORs) with 95% CIs, and continuous variables are presented as weighted mean differences with 95% CIs.

UNASSIGNED

This study analyzed 8 RCTs (5 evaluating pioglitazone use and 3 evaluating rosiglitazone maleate use) enrolling 516 patients with biopsy-proven NASH for a duration of 6 to 24 months. Among all studies combined, thiazolidinedione therapy was associated with improved advanced fibrosis (OR, 3.15; 95% CI, 1.25-7.93; P = .01; I2 = 0%), fibrosis of any stage (OR, 1.66; 95% CI, 1.12-2.47; P = .01; I2 = 0%), and NASH resolution (OR, 3.22; 95% CI, 2.17-4.79; P < .001; I2 = 0%). Analyses restricted to RCTs enrolling patients without diabetes yielded similar results for improvement in advanced fibrosis (OR, 2.95; 95% CI, 1.04-10.90; P = .02; I2 = 0%), improvement in fibrosis of any stage (OR, 1.76; 95% CI, 1.02-3.03; P = .02; I2 = 0%), and NASH resolution (OR, 3.40; 95% CI, 1.95-5.93; P < .001; I2 = 0%). All effects were accounted for by pioglitazone use. Weight gain and lower limb edema occurred more frequently with thiazolidinedione therapy (initial body weight +2.70%; 95% CI, 1.96%-4.34%; P = .001). The small sample size of included RCTs prevented evaluation of more serious adverse effects of thiazolidinedione therapy.

UNASSIGNED

Pioglitazone use improves advanced fibrosis in NASH, even in patients without diabetes. Whether this finding translates to improvement in risk for clinical outcomes requires further study.

BACKGROUND

Individuals with an "At Risk Mental State" have a 20-30% chance of developing a psychotic disorder within two years; however it is difficult to predict which individuals will become ill on the basis of their clinical symptoms alone. We examined whether mismatch negativity (MMN) could help to identify those who are particularly likely to make a transition to psychosis.

METHODS

41 cases meeting PACE criteria for the At Risk Mental State (ARMS) and 50 controls performed a duration-deviant passive auditory oddball task whilst their electroencephalogram was recorded. The amplitude of the MMN wave was compared between groups using linear regression. The ARMS subjects were then followed for 2 years to determine their clinical outcome.

RESULTS

The MMN amplitude was significantly reduced in the ARMS group compared to controls. Of the at-risk subjects who completed followed up (n=41), ten (24% of baseline sample) subsequently developed psychosis. The MMN amplitude in this subgroup was significantly smaller across all three recording sites (FZ, F3 and F4) than in the ARMS individuals who did not become psychotic.

CONCLUSIONS

Among those with the ARMS, MMN amplitude reduction is associated with an increased likelihood of developing frank psychosis.

OBJECTIVE

to assess the accuracy of transient elastography (TE) and Acoustic Radiation Force Impulse (ARFI) for liver fibrosis assessment, as compared to percutaneous liver biopsy (LB) in patients with chronic hepatitis.

METHODS

Our study included 71 patients (P) (54 with HCV and 17 with HBV chronic hepatitis) in which we compared TE and ARFI to the LB (evaluated according to the Metavir scoring system).

RESULTS

On LB, from the 71P, 6P (8.4%) had F1, 25P (35.2%) had F2, 24P (33.8%) had F3 and 16P (22.5%) had F4. A direct, strong, linear correlation (Spearman r=0.707) was found between TE measurements and fibrosis (p<0.0001) and a weaker one, between ARFI and fibrosis (rho=0.469; p<0.0001). TE measurements were also correlated with ARFI measurements r=0.532, p<0.0001. By comparing the AUROC curves, TE and ARFI had similar predictive values for the presence of significant fibrosis (F greater or equal to 2 Metavir): AUROC ARFI=0.649, AUROC TE=0.731 (p=0.476); and cirrhosis (F=4 Metavir): AUROC ARFI=0.868, AUROC TE= 0.936 (p=0.294)

CONCLUSIONS

LS measurements assessed by means of TE correlate better than those assessed by means of ARFI to the histological fibrosis in patients with HBV and HCV chronic hepatitis. Both methods have excellent predictive values for the presence of cirrhosis.

The optimal quantity and quality of protein for low-birthweight infants is undefined. In this study, 106 well, appropriate-for-gestational age, low-birthweight infants weighing 2,100 gm or less were grouped in three gestational age categories: T1 = 28 to 30 weeks; T2 = 31 to 33 weeks; T3 = 34 to 36 weeks. Each group was assigned randomly to either banked human milk (BM) or to one of four isocaloric formulas varying in quantity and quality of protein but not in mineral content or in fat content: formula 1 = 1.5 gm of protein per 100 ml, 60 parts bovine whey proteins to 40 parts bovine caseins; formula 2 = 3.0 gm of protein per 100 ml, 60:40; formula 3 = 1.5 gm of protein per 100 ml, 18:82; formula 4 = 3.0 gm of protein per 100 ml, 18:82. Caloric intake was 117 kcal/150 ml/kg/day for the formulas. Human milk was fed at 170 ml/kg/day in order to attain a caloric intake approximately equal to that of the formulas. No significant differences were found in the rate of growth in crown-rump length, in femoral length, in head circumference, or in rate of gain in weight from time of regaining birthweight to time of discharge at 2,400 gm. Blood urea nitrogen, urine osmolarity, total serum protein, serum albumin, and serum globulin varied directly with the quantity of protein in the diet: F2, F4 greater than F1, F3 greater than BM. Blood ammonia concentration varied with both quantity and quality of protein in the diet: F2, F3, F4 greater than F1, BM. Metabolic acidosis was more frequent, more severe, and more prolonged in the infants fed the casein-predominant formulas (F3,F4) than in those fed the whey protein-predominant formulas (F1, F2).

MPL (or thrombopoietin receptor, TPO-R) 515 mutations have recently been described in 5-10% of primitive myelofibrosis (PMF) cases as decisive oncogenic events capable of triggering the disease. Here we report additional mutations located in exon 10 of MPL in PMF patients. We investigated whether these new mutations also lead to cell transformation. MPL exon 10 was systematically sequenced in 100 PMF patients. Seven different mutations were found in eight patients. We introduced each MPL mutant in Ba/F3 cells to determine whether they correspond to gain-of-function mutations. Only MPL W515 mutations induced (1) Ba/F3 proliferation independently of growth factors, (2) tumorigenesis in nude mice, (3) spontaneous activation of JAK/STAT, RAS/MAPK and PI3K transduction pathways and (4) increased S phase of cell cycle. Similar to all other myeloproliferative disorder oncogenic events identified to date, these results demonstrate that only the detected MPL W515 mutations trigger spontaneous MPL activation leading to a G(1)/S transition activation. The other mutations are devoid of significant transforming activity but may synergize with JAK2 V617F or other not yet characterized molecular events.

Oxidative stress (OS) plays a major role in chronic hepatitis C. Various OS markers have been found to be elevated in hepatitis C virus (HCV)-related liver disease. This study detected the presence of OS in serum and liver biopsy specimens of HCV patients. Reactive oxygen molecules (ROM) in sera of 54 HCV patients were compared with 23 controls. OS markers 8-hydroxydeoxyguanosine (8-OHdG), 4-hydroxy-2-nonenal, malondialdehyde, and thioredoxin were measured in liver biopsy specimens of 18 HCV patients with fibrosis staging F1 (six); F2 (two), F3 (four), and F4 (six). The interferon (IFN) response and hepatocellular carcinoma (HCC) occurrence in the presence of OS markers were also evaluated. The level of ROM in HCV patients was 318 +/- 56.7 Carr compared with 248 +/- 40.8 Carr in controls (p=0.032). Multivariate analysis found age (p=0.0236) to be the only independent variable associated with increase in ROM in sera. In liver biopsy specimens, OS markers were found mainly around the area of piecemeal necrosis or the periportal area. The presence of OS markers seemed to increase with fibrosis staging, although not significantly. The OS DNA damage marker 8-OHdG was detected in the nucleus of hepatocytes. Thirteen patients received IFN therapy. During the 4-year follow-up period, HCC developed in four nonresponders to IFN and in one untreated patient. OS markers were stained in both HCC cells and non-HCC cells in HCC patients. OS markers were found in serum and liver specimens of HCV-associated liver disease and in HCC tissue. Detection of OS markers may be important for monitoring disease progression in HCV patients. Antioxidant therapy in combination with antiviral therapy may minimize liver damage and aid in the prevention and subsequent development of HCC.

Aminopeptidase N from Escherichia coli is a major metalloprotease that participates in the controlled hydrolysis of peptides in the proteolytic pathway. Determination of the 870-aa structure reveals that it has four domains similar to the tricorn-interacting factor F3. The thermolysin-like active site is enclosed within a large cavity with a volume of 2,200 A(3), which is inaccessible to substrates except for a small opening of approximately 8-10 A. The substrate-based inhibitor bestatin binds to the protein with minimal changes, suggesting that this is the active form of the enzyme. The previously described structure of F3 had three distinct conformations that were described as "closed," "intermediate," and "open." The structure of aminopeptidase N from E. coli, however, is substantially more closed than any of these. Taken together, the results suggest that these proteases, which are involved in intracellular peptide degradation, prevent inadvertent hydrolysis of inappropriate substrates by enclosing the active site within a large cavity. There is also some evidence that the open form of the enzyme, which admits substrates, remains inactive until it adopts the closed form.

Embryonic exposure to the endocrine disruptor vinclozolin at the time of gonadal sex determination was previously found to promote transgenerational disease states. The actions of vinclozolin appear to be due to epigenetic alterations in the male germline that are transmitted to subsequent generations. Analysis of the transgenerational epigenetic effects on the male germline (i.e. sperm) identified 25 candidate DNA sequences with altered methylation patterns in the vinclozolin generation sperm. These sequences were identified and mapped to specific genes and noncoding DNA regions. Bisulfite sequencing was used to confirm the altered methylation pattern of 15 of the candidate DNA sequences. Alterations in the epigenetic pattern (i.e. methylation) of these genes/DNA sequences were found in the F2 and F3 generation germline. Therefore, the reprogramming of the male germline involves the induction of new imprinted-like genes/DNA sequences that acquire an apparent permanent DNA methylation pattern that is passed at least through the paternal allele. The expression pattern of several of the genes during embryonic development were found to be altered in the vinclozolin F1 and F2 generation testis. A number of the imprinted-like genes/DNA sequences identified are associated with epigenetic linked diseases. In summary, an endocrine disruptor exposure during embryonic gonadal sex determination was found to promote an alteration in the epigenetic (i.e. induction of imprinted-like genes/DNA sequences) programming of the male germline, and this is associated with the development of transgenerational disease states.

We describe new tools for functional analysis of the tomato genome based on insertional mutagenesis with the maize Ac/Ds transposable elements in the background of the miniature cultivar Micro-Tom. 2932 F3 families, in which Ds elements transposed and were stabilized, were screened for phenotypic mutations. Out of 10 families that had a clear mutant phenotype, only one mutant was Ds-tagged. In addition, we developed promoter trapping using the firefly luciferase reporter gene and enhancer trapping, using beta-glucuronidase (GUS). We show that luciferase can be used as a non-invasive reporter to identify, isolate and regenerate somatic sectors, to study the time course of mutant expression, and to identify inducible genes. Out of 108 families screened for luciferase activity 55% showed expression in the flower, 11% in the fruit and 4% in seedlings, suggesting a high rate of Ds insertion into genes. Preferential insertion into genes was supported by the analysis of Ds flanking sequences: 28 out of 50 sequenced Ds insertion sites were similar to known genes or to ESTs. In summary, the 2932 lines described here contain 2-3 Ds inserts per line, representing a collection of approximately 7500 Ds insertions. This collection has potential for use in high-throughput functional analysis of genes and promoter isolation in tomato.

Oncolytic virotherapy is a promising novel therapy for glioblastoma that needs to be optimized before introduced to clinic. The targeting of conditionally replicating adenoviruses (CRAds) can be improved by relying on the tumor-tropic properties of neural stem cells (NSCs). Here, we report the characterization of an FDA approved NSC, HB1.F3-CD, as a cell carrier for CRAd-S-pk7, a glioma-tropic oncolytic adenovirus. We show that NSCs replicate and release infectious CRAd-S-pk7 progeny capable of lysing glioma cell lines. Moreover, ex-vivo-loaded NSCs, injected intracranially in nude mice bearing human glioma xenografts (i) retained their tumor tropism, (ii) continued to replicate CRAd-S-pk7 for more than a week after reaching the tumor site and (iii) successfully handed off CRAd-S-pk7 to glioma cells in vivo. Delivery via carrier cells reduced non-specific adenovirus distribution in the mouse brain. Moreover, we assessed biodistribution of loaded NSCs after intracranial injection in animal models semi-permissive to adenovirus replication, the Syrian hamster and cotton rat. NSCs did not migrate to distant organs and high levels of CRAd-S-pk7 DNA were observed only in the injected hemisphere. In conclusion, this optimized carrier system, with high efficiency of adenovirus delivery and minimal systemic toxicity, poses considerable advantages for anti-glioma oncolytic virotherapy.

OBJECTIVE

Mutations associated with resistance to kinase inhibition are an important mechanism of intrinsic or acquired loss of clinical efficacy for kinase-targeted therapeutics. We report the prospective discovery of ErbB2 mutations that confer resistance to the small-molecule inhibitor lapatinib.

METHODS

We did in vitro screening using a randomly mutagenized ErbB2 expression library in Ba/F3 cells, which were dependent on ErbB2 activity for survival and growth.

RESULTS

Lapatinib resistance screens identified mutations at 16 different ErbB2 amino acid residues, with 12 mutated amino acids mapping to the kinase domain. Mutations conferring the greatest lapatinib resistance cluster in the NH2-terminal kinase lobe and hinge region. Structural computer modeling studies suggest that lapatinib resistance is caused by multiple mechanisms; including direct steric interference and restriction of conformational flexibility (the inactive state required for lapatinib binding is energetically unfavorable). ErbB2 T798I imparts the strongest lapatinib resistance effect and is analogous to the epidermal growth factor receptor T790M, ABL T315I, and cKIT T670I gatekeeper mutations that are associated with clinical drug resistance. ErbB2 mutants associated with lapatinib resistance transformed NIH-3T3 cells, including L755S and T733I mutations known to occur in human breast and gastric carcinomas, supporting a direct mechanism for lapatinib resistance in ErbB2-driven human cancers. The epidermal growth factor receptor/ErbB2/vascular endothelial growth factor receptor inhibitor EXEL-7647 was found to inhibit almost all lapatinib resistance-associated mutations. Furthermore, no ErbB2 mutations were found to be associated with EXEL-7647 resistance and lapatinib sensitivity.

CONCLUSIONS

Taken together, these data suggest potential target-based mechanisms of resistance to lapatinib and suggest that EXEL-7647 may be able to circumvent these effects.

The fibroblast growth factor receptor tyrosine kinases (FGFR1, 2, 3, and 4) represent promising therapeutic targets in a number of cancers. We have developed the first potent and selective irreversible inhibitor of FGFR1, 2, 3, and 4, which we named FIIN-1 that forms a covalent bond with cysteine 486 located in the P loop of the FGFR1 ATP binding site. We demonstrated that the inhibitor potently inhibits Tel-FGFR1-transformed Ba/F3 cells (EC(50) = 14 nM) as well as numerous FGFR-dependent cancer cell lines. A biotin-derivatized version of the inhibitor, FIIN-1-biotin, was shown to covalently label FGFR1 at Cys486. FIIN-1 is a useful probe of FGFR-dependent cellular phenomena and may provide a starting point of the development of therapeutically relevant irreversible inhibitors of wild-type and drug-resistant forms of FGFR kinases.