Gene expression and proliferation biomarkers for antidepressant treatment resistance

The neurotrophic hypothesis of depression suggests an association between effects on neuroplasticity and clinical response to antidepressant drug therapy. We studied individual variability in antidepressant drug effects on cell proliferation in lymphoblastoid cell lines (LCLs) from n=25 therapy-resistant patients versus n=25 first-line therapy responders from the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study. Furthermore, the variability in gene expression of genes associated with cell proliferation was analyzed for tentative candidate genes for prediction of individual LCL donor's treatment response. Cell proliferation was quantified by EdU (5-ethynyl-2'-deoxyuridine) assays after 21-day incubation of LCLs with fluoxetine (0.5 ng μl^-1) and citalopram (0.3 ng μl^-1) as developed and described earlier. Gene expression of a panel of candidate genes derived from genome-wide expression analyses of antidepressant effects on cell proliferation of LCLs from the Munich Antidepressant Response Signature (MARS) study was analyzed by real-time PCR. Significant differences in in vitro cell proliferation effects were detected between the group of LCLs from first-line therapy responders and LCLs from treatment-resistant patients. Gene expression analysis of the candidate gene panel revealed and confirmed influence of the candidate genes ABCB1, FZD7 and WNT2B on antidepressant drug resistance. The potential of these genes as tentative biomarkers for antidepressant drug resistance was confirmed. In vitro cell proliferation testing may serve as functional biomarker for individual neuroplasticity effects of antidepressants.

[Personalized drug therapy based on genetics. Possibilities and examples from clinical practice]

BACKGROUND

Pharmacogenetics are an important component in the individualization of treatment; however, pharmacogenetic diagnostics have so far not been used to any great extent in clinical practice. A consistent consideration of individual patient factors, such as pharmacogenetics may help to improve drug therapy and increase individual safety and efficacy aspects.

OBJECTIVE

A brief summary of structures and effects of genetic variations on drug efficacy is presented. Some frequently prescribed pharmaceuticals are specified. Furthermore, the feasibility of pharmacogenetic diagnostics and dose recommendations in the clinical practice are described.

CURRENT DATA

The European Medicines Agency (EMA) as the European approval authority has already extended the drug labels of more than 70 pharmaceuticals by information on pharmacogenetic biomarkers and the U.S. Food and Drug Administration (FDA) more than 150. This is a crucial step towards targeted medicine. Guidelines on dose and therapy adjustments are provided by the Clinical Pharmacogenetics Implementation Consortium of the Pharmacogenomics Research Network.

CONCLUSION

It is fundamental to consider individual patient factors for successful drug therapy. Dose and therapy recommendations based on pharmacogenetic diagnostics are highly important for individualization as well as improvement of safety and efficiency of drug therapy.

Proliferation rates and gene expression profiles in human lymphoblastoid cell lines from patients with depression characterized in response to antidepressant drug therapy

The current therapy success of depressive disorders remains in need of improvement due to low response rates and a delay in symptomatic improvement. Reliable functional biomarkers would be necessary to predict the individual treatment outcome. On the basis of the neurotrophic hypothesis of antidepressant's action, effects of antidepressant drugs on proliferation may serve as tentative individual markers for treatment efficacy. We studied individual differences in antidepressant drug effects on cell proliferation and gene expression in lymphoblastoid cell lines (LCLs) derived from patients treated for depression with documented clinical treatment outcome. Cell proliferation was characterized by EdU (5-ethynyl-2'-deoxyuridine) incorporation assays following a 3-week incubation with therapeutic concentrations of fluoxetine. Genome-wide expression profiling was conducted by microarrays, and candidate genes such as betacellulin-a gene involved in neuronal stem cell regeneration-were validated by quantitative real-time PCR. Ex vivo assessment of proliferation revealed large differences in fluoxetine-induced proliferation inhibition between donor LCLs, but no association with clinical response was observed. Genome-wide expression analyses followed by pathway and gene ontology analyses identified genes with different expression before vs after 21-day incubation with fluoxetine. Significant correlations between proliferation and gene expression of WNT2B, FZD7, TCF7L2, SULT4A1 and ABCB1 (all involved in neurogenesis or brain protection) were also found. Basal gene expression of SULT4A1 (P=0.029), and gene expression fold changes of WNT2B by ex vivo fluoxetine (P=0.025) correlated with clinical response and clinical remission, respectively. Thus, we identified potential gene expression biomarkers eventually being useful as baseline predictors or as longitudinal targets in antidepressant therapy.

LESSONS LEARNED FROM THE EURADOS SURVEY ON INDIVIDUAL MONITORING DATA AND INTERNAL DOSE ASSESSMENTS OF FOREIGNERS EXPOSED IN JAPAN FOLLOWING THE FUKUSHIMA DAIICHI NPP ACCIDENT

European Radiation Dosimetry Group e.V. (EURADOS) survey on individual monitoring data and dose assessment has been carried out for 550 foreigners returning home after being exposed in Japan to intakes of radionuclides (mainly (131)I, (132)I, (132)Te, (134)Cs and (137)Cs) as a consequence of the Fukushima Daiichi NPP accident. In vivo and in vitro measurements were performed in their respective countries at an early stage after that accident. Intakes of radionuclides were detected in 208 persons from Europe and Canada, but the committed effective dose E(50) was below the annual dose limit for the public (<1 mSv) in all the cases. Lessons learned from this EURADOS survey are presented here regarding not only internal dosimetry issues, but also the management of the emergency situation, the perception of the risk of health effects due to radiation and the communication with exposed persons who showed anxiety and lack of trust in monitoring data and dose assessments.

Cooperation of BRAF(F595L) and mutant HRAS in histiocytic sarcoma provides new insights into oncogenic BRAF signaling

Activating BRAF mutations, in particular V600E/K, drive many cancers and are considered mutually exclusive with mutant RAS, whereas inactivating BRAF mutations in the D(594)F(595)G(596) motif cooperate with RAS via paradoxical MEK/ERK activation. Due to the increasing use of comprehensive tumor genomic profiling, many non-V600 BRAF mutations are being detected whose functional consequences and therapeutic actionability are often unknown. We investigated an atypical BRAF mutation, F595L, which was identified along with mutant HRAS in histiocytic sarcoma and also occurs in epithelial cancers, melanoma and neuroblastoma, and determined its interaction with mutant RAS. Unlike other DFG motif mutants, BRAF(F595L) is a gain-of-function variant with intermediate activity that does not act paradoxically, but nevertheless cooperates with mutant RAS to promote oncogenic signaling, which is efficiently blocked by pan-RAF and MEK inhibitors. Mutation data from patients and cell lines show that BRAF(F595L), as well as other intermediate-activity BRAF mutations, frequently coincide with mutant RAS in various cancers. These data define a distinct class of activating BRAF mutations, extend the spectrum of patients with systemic histiocytoses and other malignancies who are candidates for therapeutic blockade of the RAF-MEK-ERK pathway and underscore the value of comprehensive genomic testing for uncovering the vulnerabilities of individual tumors.

Observation of low- and high-energy Gamow-Teller phonon excitations in nuclei

Gamow-Teller (GT) transitions in atomic nuclei are sensitive to both nuclear shell structure and effective residual interactions. The nuclear GT excitations were studied for the mass number A = 42, 46, 50, and 54 "f-shell" nuclei in ((3)He, t) charge-exchange reactions. In the (42)Ca → (42)Sc reaction, most of the GT strength is concentrated in the lowest excited state at 0.6 MeV, suggesting the existence of a low-energy GT phonon excitation. As A increases, a high-energy GT phonon excitation develops in the 6-11 MeV region. In the (54)Fe → (54)Co reaction, the high-energy GT phonon excitation mainly carries the GT strength. The existence of these two GT phonon excitations are attributed to the 2 fermionic degrees of freedom in nuclei.

16+ spin-gap isomer in 96Cd

A β-decaying high-spin isomer in (96)Cd, with a half-life T(1/2)=0.29(-0.10)(+0.11) s, has been established in a stopped beam rare isotope spectroscopic investigations at GSI (RISING) experiment. The nuclei were produced using the fragmentation of a primary beam of (124)Xe on a (9)Be target. From the half-life and the observed γ decays in the daughter nucleus, (96)Ag, we conclude that the β-decaying state is the long predicted 16(+) "spin-gap" isomer. Shell-model calculations, using the Gross-Frenkel interaction and the πν(p(1/2),g(9/2)) model space, show that the isoscalar component of the neutron-proton interaction is essential to explain the origin of the isomer. Core excitations across the N=Z=50 gaps and the Gamow-Teller strength, B(GT) distributions have been studied via large-scale shell-model calculations using the πν(g,d,s) model space to compare with the experimental B(GT) value obtained from the half-life of the isomer.

TCF7L2 polymorphism rs7903146 and predisposition for type 2 diabetes mellitus in obese children

Polymorphism RS7903146 in transcription factor 7-like2 gene ( TCF7L2) is associated with type 2-diabetes mellitus (T2DM) in adults. Concerned with predisposition for diabetes mellitus in obese children, we tested if risk genotypes TC and TT of rs7903146 are more common in obese children with increased homeostasis model assessment insulin resistance index (HOMA-IR) compared to obese controls with normal HOMA-IR. As exploratory analysis, we also calculated beta-cell function for these risk genotypes and measured glucagon-like peptide 1 (GLP-1) in a subgroup. The cohort was 401 obese children (BMI > 2SDS; 211 female; 59% presenting increased HOMA-IR) from two German outpatient obesity referral centers. Genotype distributions in patients presenting increased HOMA-IR (TT: 10.18%, CT: 35.65%, CC: 54.17%) and in patients with normal HOMA-IR (TT: 8.66%, CT: 42.67%, CC: 48.67%) provided no significant effect of these two risk genotypes (p > 0.2). Correction for possible confounder's gender, age, pubertal stage, and BMI revealed no association with glucose metabolism parameters including GLP-1. However, exploratory HOMA-B% index was comparatively higher in TT-homozygotes (p=0.021) as compared to CC-homozygotes. We conclude that even though TT and CT genotypes were not higher in patients presenting elevated HOMA-IR, the higher HOMA-B% index in TT-homozygotes indicates TCF7L2 to be a susceptibility gene for the development of impaired glucose tolerance in obese children as demonstrated in several adult cohort studies.

First clinical evaluation of the navigated controlled drill at the lateral skull base

Surgery on the lateral skull base puts delicate structures at risk. To support the surgeon in identifying and protecting the risk structures the principle of Navigated Control (NC) can be used for preventing iatrogenic injuries. In this paper the application of Navigated Control for surgery on the lateral skull base was investigated for the first time in clinical use. There was no risk structure damage with NC. Navigated Control in lateral skull base surgery seems to have a great potential for safe risk structure protection, a morbidity reduction and in a relief of strain for the surgeon.

Extraction of weak transition strengths via the (3He, t) reaction at 420 MeV

Differential cross sections for transitions of known weak strength were measured with the (3He, t) reaction at 420 MeV on targets of 12C, 13C, 18O, 26Mg, 58Ni, 60Ni, 90Zr, 118Sn, 120Sn, and 208Pb. Using these data, it is shown that the proportionalities between strengths and cross sections for this probe follow simple trends as a function of mass number. These trends can be used to confidently determine Gamow-Teller strength distributions in nuclei for which the proportionality cannot be calibrated via beta-decay strengths. Although theoretical calculations in the distorted-wave Born approximation overestimate the data, they allow one to understand the main experimental features and to predict deviations from the simple trends observed in some of the transitions.

Alternative interpretation of sharply rising E0 strengths in transitional regions

It is shown that strong 0(+)(2)-->0(+)(1) E0 transitions provide a clear signature of phase transitional behavior in finite nuclei. Calculations using the interacting-boson approximation (IBA) show that these transition strengths exhibit a dramatic and robust increase in spherical-deformed shape transition regions, that this rise matches well the existing data, that the predictions of these E0 transitions remain large in deformed nuclei, that they arise from the specific d-boson coherence in the wave functions, and do not necessarily require the explicit mixing of normal and intruder configurations from different IBA spaces.

Molecular cytogenetic characterization of a critical region in bands 7q35-q36 commonly deleted in malignant myeloid disorders

Loss of chromosome 7 (-7) or deletion of the long arm (7q-) are recurring chromosome abnormalities in myeloid leukemias. The association of -7/7q- with myeloid leukemia suggests that these regions contain novel tumor suppressor gene(s), whose loss of function contribute to leukemic transformation or tumor progression. Based on chromosome banding analysis, two critical regions have been identified, one in band q22 and another in bands q32-q35. Presently there are no data available on the molecular delineation of the distal critical region. In this study we analyzed bone marrow and blood samples from 13 patients with myeloid leukemia (de novo myelodysplastic syndrome [MDS], n = 3; de novo acute myeloid leukemia [AML], n = 9; therapy-related (t-) AML, n = 1) which, on chromosome banding analysis, exhibited deletions (n = 12) or in one case a balanced translocation involving bands 7q31-qter using fluorescence in situ hybridization (FISH). As probes we used representative clones from a contig map of yeast artificial chromosome (YAC) clones that spans chromosome bands 7q31.1-qter. In the 12 cases with loss of 7q material, we identified a commonly deleted region of approximately 4 to 5 megabasepairs in size encompassing the distal part of 7q35 and the proximal part of 7q36. Furthermore, the breakpoint of the reciprocal translocation from the patient with t-AML was localized to a 1,300-kb sized YAC clone that maps to the proximal boundary of the commonly deleted region. Interestingly, in this case both homologs of chromosome 7 were affected: one was lost (-7) and the second exhibited the t(7q35). The identification and delineation of translocation and deletion breakpoints provides the first step toward the identification of the gene(s) involved in the pathogenesis of 7q35-q36 aberrations in myeloid disorders.

Electrical proarrhythmia: induction of inappropriate atrial therapies due to far-field R wave oversensing in a new dual chamber defibrillator

This case report describes delivery of atrial therapies during a sinus tachycardia in a new dual chamber implantable cardioverter defibrillator inappropriately caused by far-field oversensing of ventricular beats in the atrial channel. Upon classification of the PR interval pattern, the rate criterion for an atrial tachycardia was fulfilled, and the device initiated high-frequency burst pacing as the first stage of programmed tiered atrial therapies. Atrial fibrillation subsequently was induced by high-frequency burst pacing, and eventually a programmed 10-J shock was delivered for successful termination of atrial fibrillation. The phenomenon of far-field oversensing of ventricular beats could be repeatedly observed during exercise testing and abolished by decreasing the atrial sensitivity.

Inappropriate discharge of an implantable cardioverter defibrillator during atrial flutter and intermittent ventricular antibradycardia pacing

INTRODUCTION

Inappropriate discharges of an implantable cardioverter defibrillator (ICD) are troublesome to the patient and sometimes a difficult task for the physician trying to identify and treat the cause.

METHODS AND RESULTS

For the first time, we report a mechanism of inappropriate ICD discharges during episodes of atrial flutter with a slow ventricular response and intermittent antibradycardia pacing. The episodes occurred in two patients and were triggered by the unique sensing algorithm of the Ventritex Cadence V-100 in combination with the tripolar CPI Endotak 072 transvenous defibrillation lead, which provides integrated bipolar sensing.

CONCLUSION

Besides treatment of the underlying arrhythmia, reprogramming of the device, an electrode position far away from the atria, and true bipolar sensing will enhance the performance of ICD systems with respect to the episodes described here. In addition, more flexible sensing algorithms may, in the future, prevent this overall rare complication.

Molecular cytogenetic delineation of deletions and translocations involving chromosome band 7q22 in myeloid leukemias

Loss of chromosome 7 (-7) or deletion of its long arm (7q-) are recurring chromosome abnormalities in myeloid disorders, especially in therapy-related myelodysplastic syndrome (t-MDS) and acute myeloid leukemia (t-AML). The association of -7/7q- with myeloid leukemia suggests that these regions contain a novel tumor suppressor gene(s) whose loss of function contributes to leukemic transformation or tumor progression. Based on chromosome banding analysis, two critical regions have been identified: one in band 7q22 and a second in bands 7q32-q35. We analyzed bone marrow and blood samples from 21 patients with myeloid leukemia (chronic myeloid leukemia, n = 2; de novo MDS, n = 4; de novo AML, n = 13; t-AML, n = 2) that on chromosome banding analysis exhibited deletions (n = 19) or reciprocal translocations (n = 2) of band 7q22 using fluorescence in situ hybridization. As probes, we used Alu-polymerase chain reaction products from 22 yeast artificial chromosome (YAC) clones that span chromosome bands 7q21.1-q32, including representative clones from a panel of YACs recognizing a contiguous genomic DNA fragment of 5 to 6 Mb in band 7q22. In the 19 cases with deletions, we identified two distinct commonly deleted regions: one region within band 7q22 was defined by the two CML cases; the second region encompassed a distal part of band 7q22 and the entire band 7q31 and was defined by the MDS/AML cases. The breakpoint of one of the reciprocal translocations was mapped to 7q21.3, which is centromeric to both of the commonly deleted regions. The breakpoint of the second translocation, which was present in unstimulated bone marrow and phytohemagglutinin-stimulated blood of an MDS patient, was localized to a 400-kb genomic segment in 7q22 within the deletion cluster of the MDS/AML cases. In conclusion, our data show marked heterogeneity of 7q22 deletion and translocation breakpoints in myeloid leukemias, suggesting the existence of more than one pathogenetically relevant gene.

Design and validation of DNA probe sets for a comprehensive interphase cytogenetic analysis of acute myeloid leukemia

The objective of this study was to design DNA probe sets that enable the detection of chromosome aberrations in acute myeloid leukemia (AML) by interphase cytogenetics using fluorescence in situ hybridization (FISH) and to compare the results of interphase cytogenetics with those of conventional chromosome banding analysis. One hundred five consecutive patients with adult AML entered on a multicenter treatment trial were studied with a comprehensive set of DNA probes recognizing the most relevant AML-associated structural and numerical chromosome aberrations: translocations t(8;21), t(15;17), and t(11q23); inversion inv(16);chromosomal deletions (5q-, 7q-, 9q-, 12p-, 13q-, 17p-, and 20q-); and chromosomal aneuploidies. Interphase cytogenetics was particularly sensitive for detecting the AML-specific gene fusions: 3 additional cases of inv(16) and 1 additional case of t(8;21) were identified by FISH that were missed by banding analysis, whereas equal numbers of t(11q23) and t(15;17) were detected. Five additional cases of trisomy 8q, 3 more cases of trisomy 11q, and 2 more cases of trisomies 21q and 22q were shown by FISH. These aberrations were either masked in complex karyo-types or identified in cases in which conventional banding analysis failed. On the other hand, the DNA probes selected were not informative to detect 1 case of 5q-, 9q-, and 20q-. In 5 cases, clonal aberrations were detected on banding analysis for which no FISH probes were selected. In conclusion, interphase cytogenetics proved to be more sensitive for detecting AML-specific chimeric gene fusions and some partial trisomies. Interphase cytogenetics provides a powerful technique complementary and, with further development of diagnostic DNA probes, even an alternative to chromosome banding studies for the cytogenetic analysis of AML.

High incidence of a second BCR-ABL fusion in chronic myeloid leukemia revealed by interphase cytogenetic analysis on blood and bone marrow smears

The t(9;22)(q34;q11) is the single most common chromosomal abnormality in leukemias. Recently, dual-color fluorescence in situ hybridization (FISH) protocols for the detection of the BCR-ABL fusion, which is the molecular counterpart of this translocation, have been described. In the present study, we analyzed blood or bone marrow smears of 46 patients (34 with chronic myeloid leukemia [CML] and 12 with acute lymphoblastic leukemia [ALL]) for the presence of a BCR-ABL fusion. On these clinical routine samples, hybridization was performed with high efficiency and the BCR-ABL fusion was detected reliably. This series includes one case with a Philadelphia chromosome (Ph) on banding analysis and negative reverse transcriptase polymerase chain reaction (RT-PCR) results. Surprisingly, in 13 of the 34 CML patients (4 of 17 patients with chronic phase and 9 of 17 patients with blast crisis), and in 1 of the 12 ALL patients, an additional BCR-ABL fusion was diagnosed in 4% to 72.5% of interphase cells. In 10 of these 14 patients, banding data are available; only in two cases was the additional Ph detected by metaphase analysis. The data from this interphase cytogenetic analysis indicate that an additional Ph occurs more frequently than would be assumed based on banding analysis.

[Influence of visible interferences on biochemical assays realised on Au 5231, AU 5223 (Olympus) and CL 7200 (Shimadzu)]

The impact of the major interferents (hemolysis, bilirubin, turbidity), on the quality of biochemical tests, was evaluated on multiparametric analysers (CL 7200 Shimadzu, Japan/Ciba-Corning, France; AU 5231 and AU 5223 Olympus, Japan/bioMérieux, France), according to the SFBC instructions. Interferences were detected in 33 cases upon 165 tests realized, that is to say 20% of the performed analysis. Turbidity was the most frequent cause of interference (7.8%), followed by hemolysis (8.5%) and bilirubin (3.6%). The use of a sample blank, a bireagent, the change of reagent, the change of the secondary wavelength or the modification of the measurement times, allowed us to reduce more than 80% of the interferences. Only three interferences remained: hemolysis upon the measurement of TGO and potassium, and bilirubin upon the measurement of creatinine. For these parameters, a suitable note using the Olympus factors (semi quantitative expression of the importance of the three interferents) is reported on the answer sheet.

Effect of acute resistance exercise on postexercise energy expenditure and resting metabolic rate

Two separate experiments were performed to determine the effect of acute resistive exercise on postexercise energy expenditure in male subjects previously trained in resistive exercise. In experiment 1, after measurement of their resting metabolic rate (RMR) at 0700 h and their ingestion of a standardized meal at 0800 h, seven subjects (age range 22-40 yr) beginning at 1400 h completed a 90-min weight-lifting protocol. Postexercise metabolic rate (PEMR) was measured continuously for 2 h after exercise and compared with a preexercise baseline. RMR was measured the following morning 15 h after completion of the workout. In experiment 2, six different men (age range 20-35 yr) completed a similar experimental protocol as well as a control condition on a separate day in which metabolic rate was measured for 2 h after a period of quiet sitting. For both experiments, PEMR remained elevated for the entire 2-h measured recovery period, with the average oxygen consumption for the last 6 min elevated by 11-12%. RMR measured the morning after exercise was 9.4% higher in experiment 1 and 4.7% higher in experiment 2 than on the previous day. In experiment 2, the postabsorptive respiratory exchange ratio was significantly lower the morning after the exercise bout. Strenuous resistive exercise may elevate PEMR for a prolonged period and may enhance postexercise lipid oxidation.

Autoimmune hemolytic anemia with anti Jka specificity in a patient taking aldomet

Autoimmune hemolytic anemia (hemoglobin 5.2 g, reticulocyte count 31.0 per cent) developed in a 53-year-old hypertensive woman who was taking Aldomet. Both the patient's serum and the eluate prepared from her red blood cells contained an antibody with anti-Jka specificity. Rapid sustained improvement in the anemia occurred after cessation of Aldomet and a two week course of prednisone therapy. Eight months later, anti-Jka was no longer detectable in the patient's serum and the direct antiglobulin test was nonreactive.