Subclonal TP53 and KRAS variants combined with poor treatment response identify ultra-high-risk pediatric T-ALL patients.

Variations in the TP53 and KRAS genes indicate a particularly adverse prognosis in relapsed pediatric T-ALL. We hypothesized that these variations might be subclonally present at disease onset and contribute to relapse risk. To test this, we examined two cohorts of children diagnosed with T-ALL: one with 81 patients who relapsed and 79 matched non-relapsing controls, and another with 226 consecutive patients, 30 of whom relapsed.

Inhibiting H3K27 Demethylases Downregulates CREB-CREBBP, Overcoming Resistance in Relapsed Acute Lymphoblastic Leukemia.

Background: CREB binding protein (CREBBP) is a key epigenetic regulator, altered in a fifth of relapsed cases of acute lymphoblastic leukemia (ALL). Selectively targeting epigenetic signaling may be an effective novel therapeutic approach to overcome drug resistance. Anti-tumor effects have previously been demonstrated for GSK-J4, a selective H3K27 histone demethylase inhibitor, in several animal models of cancers.

Serially quantifying TERT rearrangement breakpoints in circulating tumor DNA enables minimal residual disease monitoring in patients with neuroblastoma.

Telomerase is reactivated by genomic TERT rearrangements in ~30% of diagnosed high-risk neuroblastomas. Dismal patient prognosis results if the RAS/MAPK/ALK signaling transduction network also harbors mutations. We present a liquid biopsy-based monitoring strategy for this particularly vulnerable pediatric patient subgroup, for whom real-time molecular diagnostic tools are limited to date.

[Nephritic sediment - step by step].

The examination of urine and its evaluation are central components in the diagnostic pathway for kidney diseases. Essential to this process is the correct analysis and interpretation of the urine sediment. A nephritic sediment indicates glomerular kidney disease with high specificity.

Analysis of measurable residual disease by IG/TR gene rearrangements: quality assurance and updated EuroMRD guidelines.

Minimal/measurable residual disease (MRD) diagnostics using real-time quantitative PCR analysis of rearranged immunoglobulin and T-cell receptor gene rearrangements are nowadays implemented in most treatment protocols for patients with acute lymphoblastic leukemia (ALL). Within the EuroMRD Consortium, we aim to provide comparable, high-quality MRD diagnostics, allowing appropriate risk-group classification for patients and inter-protocol comparisons. To this end, we set up a quality assessment scheme, that was gradually optimized and updated over the last 20 years, and that now includes participants from around 70 laboratories worldwide.

Impact of a booster dose on SARS-CoV2 mRNA vaccine-specific humoral-, B- and T cell immunity in pediatric stem cell transplant recipients.

Stem cell transplant recipients (SCTR) are imperiled to increased risks after SARS-CoV2 infection, supporting the need for effective vaccination strategies for this vulnerable group. With respect to pediatric patients, data on immunogenicity of SARS-CoV2 mRNA-based vaccination is limited. We therefore comprehensively examined specific humoral, B- and T cell responses in a cohort of 2-19 year old SCTR after the second and third vaccine dose.

Single-cell multi-omics of mitochondrial DNA disorders reveals dynamics of purifying selection across human immune cells.

Pathogenic mutations in mitochondrial DNA (mtDNA) compromise cellular metabolism, contributing to cellular heterogeneity and disease. Diverse mutations are associated with diverse clinical phenotypes, suggesting distinct organ- and cell-type-specific metabolic vulnerabilities. Here we establish a multi-omics approach to quantify deletions in mtDNA alongside cell state features in single cells derived from six patients across the phenotypic spectrum of single large-scale mtDNA deletions (SLSMDs).

The EGR3 regulome of infant KMT2A-r acute lymphoblastic leukemia identifies differential expression of B-lineage genes predictive for outcome.

KMT2A-rearranged acute lymphoblastic infant leukemia (KMT2A-r iALL) is associated with outsize risk of relapse and relapse mortality. We previously reported strong upregulation of the immediate early gene EGR3 in KMT2A::AFF1 iALL at relapse; now we provide analyses of the EGR3 regulome, which we assessed through binding and expression target analysis of an EGR3-overexpressing t(4;11) cell culture model. Our data identify EGR3 as a regulator of early B-lineage commitment.

X-linked inhibitor of apoptosis protein represents a promising therapeutic target for relapsed/refractory ALL.

Acute lymphoblastic leukemia (ALL) represents the most frequent malignancy in children, and relapse/refractory (r/r) disease is difficult to treat, both in children and adults. In search for novel treatment options against r/r ALL, we studied inhibitor of apoptosis proteins (IAP) and Smac mimetics (SM). SM-sensitized r/r ALL cells towards conventional chemotherapy, even upon resistance against SM alone.

Minimal residual disease in BCR::ABL1-positive acute lymphoblastic leukemia: different significance in typical ALL and in CML-like disease.

Recently, we defined "CML-like" subtype of BCR::ABL1-positive acute lymphoblastic leukemia (ALL), resembling lymphoid blast crisis of chronic myeloid leukemia (CML). Here we retrospectively analyzed prognostic relevance of minimal residual disease (MRD) and other features in 147 children with BCR::ABL1-positive ALL (diagnosed I/2000-IV/2021, treated according to EsPhALL (n = 133) or other (n = 14) protocols), using DNA-based monitoring of BCR::ABL1 genomic breakpoint and clonal immunoglobulin/T-cell receptor gene rearrangements. Although overall prognosis of CML-like (n = 48) and typical ALL (n = 99) was similar (5-year-EFS 60% and 49%, respectively; 5-year-OS 75% and 73%, respectively), typical ALL presented more relapses while CML-like patients more often died in the first remission.

Supramolecular assembly of GSK3α as a cellular response to amino acid starvation.

The tolerance of amino acid starvation is fundamental to robust cellular fitness. Asparagine depletion is lethal to some cancer cells, a vulnerability that can be exploited clinically. We report that resistance to asparagine starvation is uniquely dependent on an N-terminal low-complexity domain of GSK3α, which its paralog GSK3β lacks.

A New View on Minimal Residual Disease Quantification in Acute Lymphoblastic Leukemia using Droplet Digital PCR.

Real-time quantitative PCR (qPCR) using immunoglobulin/T-cell receptor gene rearrangements has been used as the gold standard for minimal residual disease (MRD) monitoring in acute lymphoblastic leukemia (ALL) for >20 years. Recently, new PCR-based technologies have emerged, such as droplet digital PCR (ddPCR), which could offer several methodologic advances for MRD monitoring. In the current work, qPCR and ddPCR were compared in an unbiased blinded prospective study (n = 88 measurements) and in a retrospective study with selected critical low positive samples (n = 65 measurements).

Minimal Residual Disease Analysis by Monitoring Immunoglobulin and T-Cell Receptor Gene Rearrangements by Quantitative PCR and Droplet Digital PCR.

Analysis of immunoglobulin and T-cell receptor gene rearrangements by real-time quantitative polymerase chain reaction (RQ-PCR) is the gold standard for sensitive and accurate minimal residual disease (MRD) monitoring; it has been extensively standardized and guidelines have been developed within the EuroMRD consortium ( www.euromrd.org ).

Pediatric T-ALL type-1 and type-2 relapses develop along distinct pathways of clonal evolution.

The mechanisms underlying T-ALL relapse remain essentially unknown. Multilevel-omics in 38 matched pairs of initial and relapsed T-ALL revealed 18 (47%) type-1 (defined by being derived from the major ancestral clone) and 20 (53%) type-2 relapses (derived from a minor ancestral clone). In both types of relapse, we observed known and novel drivers of multidrug resistance including MDR1 and MVP, NT5C2 and JAK-STAT activators.

CXCR4 mediates leukemic cell migration and survival in the testicular microenvironment.

The testis is the second most frequent extramedullary site of relapse in pediatric acute lymphoblastic leukemia (ALL). The mechanism for B-cell (B) ALL cell migration towards and survival within the testis remains elusive. Here, we identified CXCL12-CXCR4 as the leading signaling axis for B-ALL cell migration and survival in the testicular leukemic niche.

Blinatumomab overcomes poor prognostic impact of measurable residual disease in pediatric high-risk first relapse B-cell precursor acute lymphoblastic leukemia.

Background: Blinatumomab, a CD3/CD19 BiTE (bispecific T cell engager) molecule, was superior to high-risk third course consolidation chemotherapy (HC3) in prolonging event-free survival (EFS) in children with high-risk first relapse B-cell precursor acute lymphoblastic leukemia (B-ALL). Here, we report results from a post hoc measurable residual disease (MRD) analysis of this phase 3 study (NCT02393859).

Procedure: Children >28 days and <18 years with high-risk first-relapse B-ALL in cytomorphological complete remission (M1 marrow, <5% blasts) or with M2 marrow (≥5% and <25% blasts) after induction and two cycles of high-risk consolidation chemotherapy (baseline) were enrolled in this trial.

Combining daratumumab with CD47 blockade prolongs survival in preclinical models of pediatric T-ALL.

Acute lymphoblastic leukemia (ALL) is the most common malignant disease affecting children. Although therapeutic strategies have improved, T-cell acute lymphoblastic leukemia (T-ALL) relapse is associated with chemoresistance and a poor prognosis. One strategy to overcome this obstacle is the application of monoclonal antibodies.

An alternative CYB5A transcript is expressed in aneuploid ALL and enriched in relapse.

Background: B-cell precursor acute lymphoblastic leukemia (BCP-ALL) is a genetically heterogenous malignancy with poor prognosis in relapsed adult patients. The genetic basis for relapse in aneuploid subtypes such as near haploid (NH) and high hyperdiploid (HeH) BCP-ALL is only poorly understood. Pathogenic genetic alterations remain to be identified.

Targeted Analysis of Cell-free Circulating Tumor DNA is Suitable for Early Relapse and Actionable Target Detection in Patients with Neuroblastoma.

Purpose: Treating refractory or relapsed neuroblastoma remains challenging. Monitoring body fluids for tumor-derived molecular information indicating minimal residual disease supports more frequent diagnostic surveillance and may have the power to detect resistant subclones before they give rise to relapses. If actionable targets are identified from liquid biopsies, targeted treatment options can be considered earlier.