Unveiling the dynamics and molecular landscape of a rare chronic lymphocytic leukemia subpopulation driving refractoriness: insights from single-cell RNA sequencing.

Early identification of resistant cancer cells is currently a major challenge, as their expansion leads to refractoriness. To capture the dynamics of these cells, we made a comprehensive analysis of disease progression and treatment response in a chronic lymphocytic leukemia (CLL) patient using a combination of single-cell and bulk genomic methods. At diagnosis, the patient presented with unfavorable genetic markers, including notch receptor 1 (NOTCH1) mutation and loss(11q).

Circulating free DNA and its potential in the diagnostics and therapy of malignant lymphoma.

Background: Malignant lymphomas represent a highly heterogeneous group of tumors with varied clinical behavior - from indolent to very aggressive forms with survival in the order of months. From the very beginning, these diseases are considered systemic, often occurring in several anatomical locations simultaneously. However, diagnosis and exact classification are usually inferred from a bio-psy of a single pathological lymph node or infiltrate, even though clinical experience shows that the bio-logical behavior of lymphoma is not necessarily identical across anatomical locations.

Integrative NGS testing reveals clonal dynamics of adverse genomic defects contributing to a natural progression in treatment-naïve CLL patients.

Large-scale next-generation sequencing (NGS) studies revealed extensive genetic heterogeneity, driving a highly variable clinical course of chronic lymphocytic leukaemia (CLL). The evolution of subclonal populations contributes to diverse therapy responses and disease refractoriness. Besides, the dynamics and impact of subpopulations before therapy initiation are not well understood.

Very rare near-haploid acute lymphoblastic leukemia resistant to immunotherapy and CAR-T therapy in 19-year-old male patient.

Near-haploid acute lymphoblastic leukemia is rare subgroup of the disease, which is very important due to very poor prognosis and resistance to treatment including novel monoclonal antibodies and CAR-T therapy.

Evolution of TP53 abnormalities during CLL disease course is associated with telomere length changes.

Background: Telomeres are protective structures at chromosome ends which shorten gradually with increasing age. In chronic lymphocytic leukemia (CLL), short telomeres have been associated with unfavorable disease outcome, but the link between clonal evolution and telomere shortening remains unresolved.

Methods: We investigated relative telomere length (RTL) in a well-characterized cohort of 198 CLL patients by qPCR and focused in detail on a subgroup 26 patients who underwent clonal evolution of TP53 mutations (evolTP53).

LYmphoid NeXt-Generation Sequencing (LYNX) Panel: A Comprehensive Capture-Based Sequencing Tool for the Analysis of Prognostic and Predictive Markers in Lymphoid Malignancies.

B-cell neoplasms represent a clinically heterogeneous group of hematologic malignancies with considerably diverse genomic architecture recently endorsed by next-generation sequencing (NGS) studies. Because multiple genetic defects have a potential or confirmed clinical impact, a tendency toward more comprehensive testing of diagnostic, prognostic, and predictive markers is desired. This study introduces the design, validation, and implementation of an integrative, custom-designed, capture-based NGS panel titled LYmphoid NeXt-generation sequencing (LYNX) for the analysis of standard and novel molecular markers in the most common lymphoid neoplasms (chronic lymphocytic leukemia, acute lymphoblastic leukemia, diffuse large B-cell lymphoma, follicular lymphoma, and mantle cell lymphoma).

Bioinformatic strategies for the analysis of genomic aberrations detected by targeted NGS panels with clinical application.

Molecular profiling of tumor samples has acquired importance in cancer research, but currently also plays an important role in the clinical management of cancer patients. Rapid identification of genomic aberrations improves diagnosis, prognosis and effective therapy selection. This can be attributed mainly to the development of next-generation sequencing (NGS) methods, especially targeted DNA panels.

Genomic landscape of B-other acute lymphoblastic leukemia in an adult retrospective cohort with a focus on -like subtype.

Introduction: -like acute lymphoblastic leukemia (ALL) is a high-risk disease with a complex genomic background. Though extensively studied, data on the frequency and mutual associations of present mutations are still incomplete in adult patients. This retrospective study aims to map the genomic landscape of B-other ALL in a cohort of adult patients with a focus on the -like ALL subtype.

The Effect of Mutation on the DNA Damage Response and Nonsense-Mediated mRNA Decay in Cancer.

Recurrent mutations in splicing factor 3B subunit 1 () have been identified in several malignancies and are associated with an increased expression of 3' cryptic transcripts as a result of alternative branchpoint recognition. A large fraction of cryptic transcripts associated with mutations is expected to be sensitive for RNA degradation nonsense-mediated mRNA decay (NMD). Several studies indicated alterations in various signaling pathways in SF3B1-mutated cells, including an impaired DNA damage response (DDR) in chronic lymphocytic leukemia (CLL).

EGR2 mutations define a new clinically aggressive subgroup of chronic lymphocytic leukemia.

Recurrent mutations within EGR2 were recently reported in advanced-stage chronic lymphocytic leukemia (CLL) patients and associated with a worse outcome. To study their prognostic impact, 2403 CLL patients were examined for mutations in the EGR2 hotspot region including a screening (n=1283) and two validation cohorts (UK CLL4 trial patients, n=366; CLL Research Consortium (CRC) patients, n=490). Targeted deep-sequencing of 27 known/postulated CLL driver genes was also performed in 38 EGR2-mutated patients to assess concurrent mutations.

[Molecular Prognostic Markers and Their Clinical Relevance in Chronic Lymphocytic Leukemia].

Chronic lymphocytic leukemia is the most common leukemia in Western countries affecting particularly elderly adults. Despite the constantly improving therapy options, chronic lymphocytic leukemia is still an incurable disease owing to considerable clinical and bio-logical heterogeneity. Pathogenesis of chronic lymphocytic leukemia is not fully understood; however, aberrant antigenic stimulation, apoptosis deregulation and microenvironmental interactions play a crucial role in disease development.

Assessment of p53 and ATM functionality in chronic lymphocytic leukemia by multiplex ligation-dependent probe amplification.

The ATM-p53 DNA-damage response (DDR) pathway has a crucial role in chemoresistance in CLL, as indicated by the adverse prognostic impact of genetic aberrations of TP53 and ATM. Identifying and distinguishing TP53 and ATM functional defects has become relevant as epigenetic and posttranscriptional dysregulation of the ATM/p53 axis is increasingly being recognized as the underlying cause of chemoresistance. Also, specific treatments sensitizing TP53- or ATM-deficient CLL cells are emerging.

Targeted next-generation sequencing in chronic lymphocytic leukemia: a high-throughput yet tailored approach will facilitate implementation in a clinical setting.

Next-generation sequencing has revealed novel recurrent mutations in chronic lymphocytic leukemia, particularly in patients with aggressive disease. Here, we explored targeted re-sequencing as a novel strategy to assess the mutation status of genes with prognostic potential. To this end, we utilized HaloPlex targeted enrichment technology and designed a panel including nine genes: ATM, BIRC3, MYD88, NOTCH1, SF3B1 and TP53, which have been linked to the prognosis of chronic lymphocytic leukemia, and KLHL6, POT1 and XPO1, which are less characterized but were found to be recurrently mutated in various sequencing studies.

The impact of SF3B1 mutations in CLL on the DNA-damage response.

Mutations or deletions in TP53 or ATM are well-known determinants of poor prognosis in chronic lymphocytic leukemia (CLL), but only account for approximately 40% of chemo-resistant patients. Genome-wide sequencing has uncovered novel mutations in the splicing factor sf3b1, that were in part associated with ATM aberrations, suggesting functional synergy. We first performed detailed genetic analyses in a CLL cohort (n=110) containing ATM, SF3B1 and TP53 gene defects.

Recurrent mutations refine prognosis in chronic lymphocytic leukemia.

Through the European Research Initiative on chronic lymphocytic leukemia (CLL) (ERIC), we screened 3490 patients with CLL for mutations within the NOTCH1 (n=3334), SF3B1 (n=2322), TP53 (n=2309), MYD88 (n=1080) and BIRC3 (n=919) genes, mainly at diagnosis (75%) and before treatment (>90%). BIRC3 mutations (2.5%) were associated with unmutated IGHV genes (U-CLL), del(11q) and trisomy 12, whereas MYD88 mutations (2.

Identification of novel sequence variations in microRNAs in chronic lymphocytic leukemia.

MicroRNA (miRNA) expression is deregulated in many tumors including chronic lymphocytic leukemia (CLL). Although the particular mechanism(s) responsible for their aberrant expression is not well characterized, the presence of mutations and single-nucleotide polymorphisms (SNPs) in miRNA genes, possibly affecting their secondary structure and expression, has been described. In CLL; however, the impact and frequency of such variations have yet to be elucidated.

ATM mutations uniformly lead to ATM dysfunction in chronic lymphocytic leukemia: application of functional test using doxorubicin.

ATM abnormalities are frequent in chronic lymphocytic leukemia and represent an important prognostic factor. Sole 11q deletion does not result in ATM inactivation by contrast to biallelic defects involving mutations. Therefore, the analysis of ATM mutations and their functional impact is crucial.