Cytogenetic and molecular predictors of response in patients with myeloid malignancies without del[5q] treated with lenalidomide

<p>Abstract</p> <p>Background</p> <p>While lenalidomide (LEN) shows high efficacy in myelodysplastic syndromes (MDS) with del[5q], responses can be also seen in patients presenting without del[5q]. We hypothesized that improved detection of chromosomal abnormalities with new karyotyping tools may better predict response to LEN.</p> <p>Design and methods</p> <p>We have studied clinical, molecular and cytogenetic features of 42 patients with MDS, myeloproliferative neoplasms (MPN), MDS/MPN overlap syndromes and secondary acute myeloid leukemia (sAML) without del[5q] by metaphase cytogenetics (MC) who underwent therapy with LEN.</p> <p>Results</p> <p>Fluorescence in situ hybridization (FISH) or single nucleotide polymorphism array (SNP-A)-based karyotyping marginally increased the diagnostic yield over MC, detecting 2/42 (4.8%) additional cases with del[5q], one of whom were responded to LEN. Responses were more often observed in patients with a normal karyotype by MC (60% vs abnormal MC; 17%, <it>p </it>= .08) and those with gain of chromosome 8 material by either of all 3 karyotyping methods (83% vs all other chromosomal abnormalities; 44% <it>p </it>= .11). However, 5 out of those 6 patients received combined LEN/AZA therapy and it may also suggest those with gain of chromosome 8 material respond well to AZA. The addition of FISH or SNP-A did not improve the predictive value of normal cytogenetics by MC. Mutational analysis of <it>TET2, UTX, CBL, EZH2, ASXL1, TP53, RAS, IDH1/2</it>, and <it>DNMT-3A </it>was performed on 21 of 41 patients, and revealed 13 mutations in 11 patients, but did not show any molecular markers of responsiveness to LEN.</p> <p>Conclusions</p> <p>Normal karyotype and gain of chromosome 8 material was predictive of response to LEN in non-del[5q] patients with myeloid malignancies.</p

Conjunctive input processing drives feature selectivity in hippocampal CA1 neurons

Feature-selective firing allows networks to produce representations of the external and internal environments. Despite its importance, the mechanisms generating neuronal feature selectivity are incompletely understood. In many cortical microcircuits the integration of two functionally distinct inputs occurs nonlinearly through generation of active dendritic signals that drive burst firing and robust plasticity. To examine the role of this processing in feature selectivity, we recorded CA1 pyramidal neuron membrane potential and local field potential in mice running on a linear treadmill. We found that dendritic plateau potentials were produced by an interaction between properly timed input from entorhinal cortex and hippocampal CA3. These conjunctive signals positively modulated the firing of previously established place fields and rapidly induced new place field formation to produce feature selectivity in CA1 that is a function of both entorhinal cortex and CA3 input. Such selectivity could allow mixed network level representations that support context-dependent spatial maps.Howard Hughes Medical InstituteRikagaku Kenkyūjo (Japan

A randomized, controlled trial of 3.0 mg of liraglutide in weight management

BACKGROUND Obesity is a chronic disease with serious health consequences, but weight loss is difficult to maintain through lifestyle intervention alone. Liraglutide, a glucagonlike peptide-1 analogue, has been shown to have potential benefit for weight management at a once-daily dose of 3.0 mg, injected subcutaneously. METHODS We conducted a 56-week, double-blind trial involving 3731 patients who did not have type 2 diabetes and who had a body-mass index (BMI; the weight in kilograms divided by the square of the height in meters) of at least 30 or a BMI of at least 27 if they had treated or untreated dyslipidemia or hypertension. We randomly assigned patients in a 2:1 ratio to receive once-daily subcutaneous injections of liraglutide at a dose of 3.0 mg (2487 patients) or placebo (1244 patients); both groups received counseling on lifestyle modification. The coprimary end points were the change in body weight and the proportions of patients losing at least 5% and more than 10% of their initial body weight. RESULTS At baseline, the mean (±SD) age of the patients was 45.1±12.0 years, the mean weight was 106.2±21.4 kg, and the mean BMI was 38.3±6.4; a total of 78.5% of the patients were women and 61.2% had prediabetes. At week 56, patients in the liraglutide group had lost a mean of 8.4±7.3 kg of body weight, and those in the placebo group had lost a mean of 2.8±6.5 kg (a difference of -5.6 kg; 95% confidence interval, -6.0 to -5.1; P&lt;0.001, with last-observation-carried-forward imputation). A total of 63.2% of the patients in the liraglutide group as compared with 27.1% in the placebo group lost at least 5% of their body weight (P&lt;0.001), and 33.1% and 10.6%, respectively, lost more than 10% of their body weight (P&lt;0.001). The most frequently reported adverse events with liraglutide were mild or moderate nausea and diarrhea. Serious events occurred in 6.2% of the patients in the liraglutide group and in 5.0% of the patients in the placebo group. CONCLUSIONS In this study, 3.0 mg of liraglutide, as an adjunct to diet and exercise, was associated with reduced body weight and improved metabolic control. (Funded by Novo Nordisk; SCALE Obesity and Prediabetes NN8022-1839 ClinicalTrials.gov number, NCT01272219.)

Prioritizing multiple therapeutic targets in parallel using automated DNA-encoded library screening

AbstractThe identification and prioritization of chemically tractable therapeutic targets is a significant challenge in the discovery of new medicines. We have developed a novel method that rapidly screens multiple proteins in parallel using DNA-encoded library technology (ELT). Initial efforts were focused on the efficient discovery of antibacterial leads against 119 targets from Acinetobacter baumannii and Staphylococcus aureus. The success of this effort led to the hypothesis that the relative number of ELT binders alone could be used to assess the ligandability of large sets of proteins. This concept was further explored by screening 42 targets from Mycobacterium tuberculosis. Active chemical series for six targets from our initial effort as well as three chemotypes for DHFR from M. tuberculosis are reported. The findings demonstrate that parallel ELT selections can be used to assess ligandability and highlight opportunities for successful lead and tool discovery.</jats:p

Identification of genetic variants associated with Huntington's disease progression: a genome-wide association study

Background Huntington's disease is caused by a CAG repeat expansion in the huntingtin gene, HTT. Age at onset has been used as a quantitative phenotype in genetic analysis looking for Huntington's disease modifiers, but is hard to define and not always available. Therefore, we aimed to generate a novel measure of disease progression and to identify genetic markers associated with this progression measure. Methods We generated a progression score on the basis of principal component analysis of prospectively acquired longitudinal changes in motor, cognitive, and imaging measures in the 218 indivduals in the TRACK-HD cohort of Huntington's disease gene mutation carriers (data collected 2008–11). We generated a parallel progression score using data from 1773 previously genotyped participants from the European Huntington's Disease Network REGISTRY study of Huntington's disease mutation carriers (data collected 2003–13). We did a genome-wide association analyses in terms of progression for 216 TRACK-HD participants and 1773 REGISTRY participants, then a meta-analysis of these results was undertaken. Findings Longitudinal motor, cognitive, and imaging scores were correlated with each other in TRACK-HD participants, justifying use of a single, cross-domain measure of disease progression in both studies. The TRACK-HD and REGISTRY progression measures were correlated with each other (r=0·674), and with age at onset (TRACK-HD, r=0·315; REGISTRY, r=0·234). The meta-analysis of progression in TRACK-HD and REGISTRY gave a genome-wide significant signal (p=1·12 × 10−10) on chromosome 5 spanning three genes: MSH3, DHFR, and MTRNR2L2. The genes in this locus were associated with progression in TRACK-HD (MSH3 p=2·94 × 10−8 DHFR p=8·37 × 10−7 MTRNR2L2 p=2·15 × 10−9) and to a lesser extent in REGISTRY (MSH3 p=9·36 × 10−4 DHFR p=8·45 × 10−4 MTRNR2L2 p=1·20 × 10−3). The lead single nucleotide polymorphism (SNP) in TRACK-HD (rs557874766) was genome-wide significant in the meta-analysis (p=1·58 × 10−8), and encodes an aminoacid change (Pro67Ala) in MSH3. In TRACK-HD, each copy of the minor allele at this SNP was associated with a 0·4 units per year (95% CI 0·16–0·66) reduction in the rate of change of the Unified Huntington's Disease Rating Scale (UHDRS) Total Motor Score, and a reduction of 0·12 units per year (95% CI 0·06–0·18) in the rate of change of UHDRS Total Functional Capacity score. These associations remained significant after adjusting for age of onset. Interpretation The multidomain progression measure in TRACK-HD was associated with a functional variant that was genome-wide significant in our meta-analysis. The association in only 216 participants implies that the progression measure is a sensitive reflection of disease burden, that the effect size at this locus is large, or both. Knockout of Msh3 reduces somatic expansion in Huntington's disease mouse models, suggesting this mechanism as an area for future therapeutic investigation

Chromosomal lesions and uniparental disomy detected by SNP arrays in MDS, MDS/MPD, and MDS-derived AML

Using metaphase cytogenetics (MC), chromosomal abnormalities are found in only a proportion of patients with myelodysplastic syndrome (MDS). We hypothesized that with new precise methods more cryptic karyotypic lesions can be uncovered that may show important clinical implications. We have applied 250K single nucleotide polymorphisms (SNP) arrays (SNP-A) to study chromosomal lesions in samples from 174 patients (94 MDS, 33 secondary acute myeloid leukemia [sAML], and 47 myelodysplastic/myeloproliferative disease [MDS/MPD]) and 76 controls. Using SNP-A, aberrations were found in around three-fourths of MDS, MDS/MPD, and sAML (vs 59%, 37%, 53% by MC; in 8% of patients MC was unsuccessful). Previously unrecognized lesions were detected in patients with normal MC and in those with known lesions. Moreover, segmental uniparental disomy (UPD) was found in 20% of MDS, 23% of sAML, and 35% of MDS/MPD patients, a lesion resulting in copy-neutral loss of heterozygosity undetectable by MC. The potential clinical significance of abnormalities detected by SNP-A, but not seen on MC, was demonstrated by their impact on overall survival. UPD involving chromosomes frequently affected by deletions may have prognostic implications similar to the deletions visible by MC. SNP-A–based karyotyping shows superior resolution for chromosomal defects, including UPD. This technique further complements MC to improve clinical prognosis and targeted therapies

SNP-A Karyotyping Provides Clinically Relevant Results In Myeloid Hematologic Disorders with Unsuccessful Routine Cytogenetic Testing

Abstract Abstract 3374 Metaphase spreads have an established value in the routine diagnostic workup of myeloid malignancies and bone marrow failure disorders. In myelodysplastic syndrome (MDS) abnormal karyotypes play a large role in scoring systems and may greatly impact prognosis, or even predict responsiveness to certain therapies. In aplastic anemia (AA) cytogenetic abnormalities detected by metaphase karyotyping may rule out hypoplastic MDS. In myeloproliferative neoplasia (MPN), an abnormal karyotype may distinguish between reactive or malignant proliferation. Due to technical problems, including specimen quality, viability, hypocellularity or a failure of growth, this routine test may fail to yield conclusive results in some patients. With the advent of SNP-A karyotyping, which only requires extracted DNA, non-informative cases can be resolved. As a cytogenetic test, single nucleotide polymorphism array (SNP-A) analysis can provide an opportunity to improve risk assessment and selection of proper treatment modalities. The advantages of SNP-A include excellent resolution, detection of copy neutral loss of heterozygosity (also known as uniparental disomy or UPD), and perhaps most importantly, the ability to test archived DNA samples, rather than actively dividing cells. However, unlike metaphase cytogenetics, this technology cannot detect subsets of abnormal populations or certain classes of genomic rearrangements, such as balanced translocation, inversion or ring chromosomes. In this study, we examined the prognosis and disease characterization for patients with non-informative cytogenetics (N=144) collected over the last 8 years. SNP-A-based karyotyping has been performed for a representative subset of these patients (N=60) to assess whether this technique could provide clinically relevant information. These patients included patients with MDS (N=20), AA (N=20), AML (N=12) and MDS/MPN (N=3). Bone marrow obtained following induction chemotherapy was excluded. We have detected 27 somatic microdeletions and 33 microduplications (<10Mb) after eliminating germ line copy number variants seen in an internal control cohort (N=1355), publicly available databases or those present in paired non-clonal samples. However, for the purpose of subsequent analysis, somatic microdeletions and duplications were not included, as their prognostic significance has not been validated in large cohorts. (These microalterations may indicate edges of balanced translocations or true clonal pathogenic lesions.) None of these microdeletions were recurrent. Based on these criteria, SNP-A analysis revealed an abnormal karyotype in 14 (23%) patients; 3 with AA and 11 with myeloid disorders. The most common recurrent abnormalities included deletion 5q (N=5) and del7/7q (N=3) but other lesions including13q-, del20, +8p were also seen. Of note we have also detected somatic UPD (regions >25Mb) in 2 cases, including 22q11.23qter and 14q12-q22.1. In 4/60 (7%) a complex karyotype was detected, while 10 had sole lesions (>10Mb). In presumed AA patients, we have identified 2 patients with monosomy 7, prompting a change of diagnosis to MDS and thereby altering their clinical management. In MDS, when cytogenetic prognostic groupings were applied in previously unscored patients, 10/20 had IPSS scores of 3 or greater. The presence of chromosomal abnormalities detected by SNP-At indictated the presence of advanced risk disease and thereby contributed into poorer survival as predicted by IPSS. Disclosures: No relevant conflicts of interest to declare