Frequent and sex-biased deletion of SLX4IP by illegitimate V(D)J-mediated recombination in childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) accounts for ∼25% of pediatric malignancies. Of interest, the incidence of ALL is observed ∼20% higher in males relative to females. The mechanism behind the phenomenon of sex-specific differences is presently not understood. Employing genome-wide genetic aberration screening in 19 ALL samples, one of the most recurrent lesions identified was monoallelic deletion of the 5′ region of SLX4IP. We characterized this deletion by conventional molecular genetic techniques and analyzed its interrelationships with biological and clinical characteristics using specimens and data from 993 pediatric patients enrolled into trial AIEOP-BFM ALL 2000. Deletion of SLX4IP was detected in ∼30% of patients. Breakpoints within SLX4IP were defined to recurrent positions and revealed junctions with typical characteristics of illegitimate V(D)J-mediated recombination. In initial and validation analyses, SLX4IP deletions were significantly associated with male gender and ETV6/RUNX1-rearranged ALL (both overall P < 0.0001). For mechanistic validation, a second recurrent deletion affecting TAL1 and caused by the same molecular mechanism was analyzed in 1149 T-cell ALL patients. Validating a differential role by sex of illegitimate V(D)J-mediated recombination at the TAL1 locus, 128 out of 1149 T-cell ALL samples bore a deletion and males were significantly more often affected (P = 0.002). The repeatedly detected association of SLX4IP deletion with male sex and the extension of the sex bias to deletion of the TAL1 locus suggest that differential illegitimate V(D)J-mediated recombination events at specific loci may contribute to the consistent observation of higher incidence rates of childhood ALL in boys compared with girl

Effects of rising temperature on pelagic biogeochemistry in mesocosm systems: a comparative analysis of the AQUASHIFT Kiel experiments

A comparative analysis of data, obtained during four indoor-mesocosm experiments with natural spring plankton communities from the Baltic Sea, was conducted to investigate whether biogeochemical cycling is affected by an increase in water temperature of up to 6 °C above present-day conditions. In all experiments, warming stimulated in particular heterotrophic bacterial processes and had an accelerating effect on the temporal development of phytoplankton blooms. This was also mirrored in the build-up and partitioning of organic matter between particulate and dissolved phases. Thus, warming increased both the magnitude and rate of dissolved organic carbon (DOC) build-up, whereas the accumulation of particulate organic carbon (POC) and phosphorus (POP) decreased with rising temperature. In concert, the observed temperature-mediated changes in biogeochemical components suggest strong shifts in the functioning of marine pelagic food webs and the ocean’s biological carbon pump, hence providing potential feedback mechanisms to Earth’s climate system

Practical guidelines for rigor and reproducibility in preclinical and clinical studies on cardioprotection

The potential for ischemic preconditioning to reduce infarct size was first recognized more than 30 years ago. Despite extension of the concept to ischemic postconditioning and remote ischemic conditioning and literally thousands of experimental studies in various species and models which identified a multitude of signaling steps, so far there is only a single and very recent study, which has unequivocally translated cardioprotection to improved clinical outcome as the primary endpoint in patients. Many potential reasons for this disappointing lack of clinical translation of cardioprotection have been proposed, including lack of rigor and reproducibility in preclinical studies, and poor design and conduct of clinical trials. There is, however, universal agreement that robust preclinical data are a mandatory prerequisite to initiate a meaningful clinical trial. In this context, it is disconcerting that the CAESAR consortium (Consortium for preclinicAl assESsment of cARdioprotective therapies) in a highly standardized multi-center approach of preclinical studies identified only ischemic preconditioning, but not nitrite or sildenafil, when given as adjunct to reperfusion, to reduce infarct size. However, ischemic preconditioning—due to its very nature—can only be used in elective interventions, and not in acute myocardial infarction. Therefore, better strategies to identify robust and reproducible strategies of cardioprotection, which can subsequently be tested in clinical trials must be developed. We refer to the recent guidelines for experimental models of myocardial ischemia and infarction, and aim to provide now practical guidelines to ensure rigor and reproducibility in preclinical and clinical studies on cardioprotection. In line with the above guideline, we define rigor as standardized state-of-the-art design, conduct and reporting of a study, which is then a prerequisite for reproducibility, i.e. replication of results by another laboratory when performing exactly the same experiment

Sofosbuvir plus velpatasvir for 8 weeks in patients with acute hepatitis C: The HepNet acute HCV-V study

Background &amp; Aims: EASL guidelines recommend 8 weeks of treatment with sofosbuvir plus velpatasvir (SOF/VEL) for the treatment of acute or recently acquired HCV infection, but only 6- and 12-week data are available. Therefore, the aim of this study was to evaluate the safety and efficacy of a shortened 8-week SOF/VEL treatment for acute HCV monoinfection. Methods: In this investigator-initiated, prospective, multicentre, single-arm study, we recruited 20 adult patients with acute HCV monoinfection from nine centers in Germany. Patients received SOF/VEL (400/100 mg) as a fixed-dose combination tablet once daily for 8 weeks. The primary efficacy endpoint was the proportion of patients with sustained virological response 12 weeks after the end of treatment (SVR12). Results: The median HCV RNA viral load at baseline was 104,307 IU/ml; the distribution of HCV genotypes was as follows: GT1a/1b/2/3/4: n = 12/1/1/3/3. Thirteen (65%) of the 20 patients were taking medication for HIV pre-exposure prophylaxis. SVR12 was achieved in all patients who complied with the study protocol (n = 18/18 [100%], per protocol analysis), but the primary endpoint was not met in the intention-to-treat analysis (n = 18/20 [90%]) because two patients were lost to follow-up. One serious adverse event (unrelated to study drug) occurred during 12 weeks of post-treatment follow-up. Conclusions: The 8-week treatment with SOF/VEL was well tolerated and highly effective in all adherent patients with acute HCV monoinfection. Early treatment of hepatitis C might effectively prevent the spread of HCV in high-risk groups. Clinical Trial Number: NCT03818308. Impact and implications: The HepNet acute HCV-V study (NCT03818308), an investigator-initiated, single-arm, multicenter pilot study, demonstrates the efficacy and safety of 8 weeks of daily treatment with the fixed-dose combination sofosbuvir/velpatasvir (400/100 mg) in patients with acute hepatitis C virus (HCV) infection. All patients who completed therapy and were followed-up achieved sustained virologic response. Thus, early treatment with SOF/VEL which might effectively prevent the spread of HCV in high-risk groups can be recommended for patients with acute HCV monoinfection

IKZF1 deletion is an independent predictor of outcome in pediatric acute lymphoblastic leukemia treated according to the ALL-BFM 2000 protocol

IKZF1 gene deletions have been associated with a poor outcome in pediatric precursor B-cell acute lymphoblastic leukemia. To assess the prognostic relevance of IKZF1 deletions for patients treated on Berlin-Frankfurt-Munster Study Group trial ALL-BFM 2000, we screened 694 diagnostic acute lymphoblastic leukemia samples by Multiplex Ligation-Dependent Probe Amplification. Patients whose leukemic cells beared IKZF1 deletions had a lower 5-year event-free survival (0.69+/-0.05 vs. 0.85+/-0.01; p<0.0001) compared to those without, mainly due to a higher cumulative incidence of relapses (0.21+/-0.04 vs. 0.10+/-0.01; p=0.001). Although IKZF1 deletions were significantly associated with the P2RY8-CRLF2 rearrangement, their prognostic value was found independent from this association. Thus, IKZF1 deletion is an independent predictor of treatment outcome and strong candidate marker for integration in future treatment stratification strategies on ALL-BFM protocols

Enhanced reduction of myocardial infarct size by combined ACE inhibition and AT(1)-receptor antagonism

1. The effects of the angiotensin-converting-enzyme inhibitor (ACEI) ramiprilat, the angiotensin II type 1 receptor antagonist (AT(1)A) candesartan, and the combination of both drugs on infarct size (IS) resulting from regional myocardial ischaemia were studied in pigs. 2. Both ACEI and AT(1)A reduce myocardial IS by a bradykinin-mediated process. It is unclear, however, whether the combination of ACEI and AT(1)A produces a more pronounced IS reduction than each of these drugs alone. 3. Forty-six enflurane-anaesthetized pigs underwent 90 min low-flow ischaemia and 120 min reperfusion. Systemic haemodynamics (micromanometer), subendocardial blood flow (ENDO, microspheres) and IS (TTC-staining) were determined. The decreases in left ventricular peak pressure by ACEI (by 9±2 (s.e.mean) mmHg), AT(1)A (by 11±2 mmHg) or their combination (by 18±3 mmHg, P<0.05 vs ACEI and AT(1)A, respectively) were readjusted by aortic constriction prior to ischaemia. With placebo (n=10), IS averaged 20.0±3.3% of the area at risk. IS was reduced to 9.8±2.6% with ramiprilat (n=10) and 10.6±3.1% with candesartan (n=10). Combined ramiprilat and candesartan (n=10) reduced IS to 6.7±2.1%. Blockade of the bradykinin-B(2)-receptor with icatibant prior to ACEI and AT(1)A completely abolished the reduction of IS (n=6, 22.8±6.1%). The relationship between IS and ischaemic ENDO with placebo was shifted downwards by each ACEI and AT(1)A and further shifted downwards with their combination (P<0.05 vs all groups); icatibant again abolished such downward shift. 4. The combination of ACEI and AT(1)A enhances the reduction of IS following ischaemia/reperfusion compared to a monotherapy by either drug alone; this effect is mediated by bradykinin

Frequent and sex-biased deletion of SLX4IP by illegitimate V(D)J-mediated recombination in childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) accounts for ∼25% of pediatric malignancies. Of interest, the incidence of ALL is observed ∼20% higher in males relative to females. The mechanism behind the phenomenon of sex-specific differences is presently not understood. Employing genome-wide genetic aberration screening in 19 ALL samples, one of the most recurrent lesions identified was monoallelic deletion of the 5' region of SLX4IP. We characterized this deletion by conventional molecular genetic techniques and analyzed its interrelationships with biological and clinical characteristics using specimens and data from 993 pediatric patients enrolled into trial AIEOP-BFM ALL 2000. Deletion of SLX4IP was detected in ∼30% of patients. Breakpoints within SLX4IP were defined to recurrent positions and revealed junctions with typical characteristics of illegitimate V(D)J-mediated recombination. In initial and validation analyses, SLX4IP deletions were significantly associated with male gender and ETV6/RUNX1-rearranged ALL (both overall P < 0.0001). For mechanistic validation, a second recurrent deletion affecting TAL1 and caused by the same molecular mechanism was analyzed in 1149 T-cell ALL patients. Validating a differential role by sex of illegitimate V(D)J-mediated recombination at the TAL1 locus, 128 out of 1149 T-cell ALL samples bore a deletion and males were significantly more often affected (P = 0.002). The repeatedly detected association of SLX4IP deletion with male sex and the extension of the sex bias to deletion of the TAL1 locus suggest that differential illegitimate V(D)J-mediated recombination events at specific loci may contribute to the consistent observation of higher incidence rates of childhood ALL in boys compared with girls