Cancers, Vol. 11, Pages 1373: Cytotoxicity and Differentiating Effect of the Poly(ADP-Ribose) Polymerase Inhibitor Olaparib in Myelodysplastic Syndromes

Cancers, Vol. 11, Pages 1373: Cytotoxicity and Differentiating Effect of the Poly(ADP-Ribose) Polymerase Inhibitor Olaparib in Myelodysplastic Syndromes Cancers doi: 10.3390/cancers11091373 Authors: Isabella Faraoni Maria Irno Consalvo Francesca Aloisio Emiliano Fabiani Manuela Giansanti Francesca Di Cristino Giulia Falconi Lucio Tentori Ambra Di Veroli Paola Curzi Luca Maurillo Pasquale Niscola Francesco Lo-Coco Grazia Graziani Maria Teresa Voso Myelodysplastic syndromes (MDS) are highly heterogeneous myeloid diseases, characterized by frequent genetic/chromosomal aberrations. Olaparib is a potent, orally bioavailable poly(ADP-ribose) polymerase 1 (PARP1) inhibitor with acceptable toxicity profile, designed as targeted therapy for DNA repair defective tumors. Here, we investigated olaparib activity in primary cultures of bone marrow mononuclear cells collected from patients with MDS (n = 28). A single treatment with olaparib induced cytotoxic effects in most samples, with median IC50 of 5.4 µM (2.0–24.8 µM), lower than plasma peak concentration reached in vivo. In addition, olaparib induced DNA damage as shown by a high proportion of γH2AX positive cells in samples with low IC50s. Olaparib preferentially killed myeloid cells causing a significant reduction of blasts and promyelocytes, paralleled by an increase in metamyelocytes and mature granulocytes while sparing lymphocytes that are not part of th...
Source: Cancers - Category: Cancer & Oncology Authors: Tags: Article Source Type: research

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nn Fabarius Popp Malignant hematopoietic cells of myelodysplastic syndromes (MDS)/chronic myelomonocytic leukemias (CMML) and acute myeloid leukemias (AML) may be vulnerable to inhibition of poly(ADP ribose) polymerase 1/2 (PARP1/2) and apurinic/apyrimidinic endonuclease 1 (APE1). PARP1/2 and APE1 are critical enzymes involved in single-strand break repair and base excision repair, respectively. Here, we investigated the cytotoxic efficacy of talazoparib and APE1 inhibitor III, inhibitors of PARP1/2 and APE1, in primary CD34+ MDS/CMML cell samples (n = 8; 4 MDS and 4 CMML) and in primary CD34+ or CD34− ...
Source: Cancers - Category: Cancer & Oncology Authors: Tags: Article Source Type: research
Publication date: Available online 3 May 2019Source: Best Practice &Research Clinical HaematologyAuthor(s): Hind Rafei, Courtney D. DiNardoAbstractMyelodysplastic syndromes and acute myeloid leukemia are sporadic for the majority of cases affecting the elderly population. Inherited cases, however, do occur. Genetic predispositions to myeloid malignancies can be classified into three categories: familial cancer syndromes associated with increased risk of various malignancies including myelodysplasia and acute myeloid leukemia such as Li-Fraumeni syndrome and constitutional mismatch repair deficiency (CMMRD); germline mu...
Source: Best Practice and Research Clinical Haematology - Category: Hematology Source Type: research
In conclusion, we showed hypermethylation of CpGs as a novel mechanism of action for DNMTi agents and identified 638 hypermethylated molecular targets (CpGs) common to decitabine and azacytidine therapy. These novel results suggest that hypermethylation of CpGs should be considered when predicting the DNMTi responses and side effects in cancer patients. Introduction DNA methyltransferase inhibitors (DNMTi) are widely used as chemical tools for hypomethylating the genome, with an aim to understand the role of DNA methylation in multiple processes (e.g., X-chromosome inactivation and DNA imprinting) and as an anti-ca...
Source: Frontiers in Pharmacology - Category: Drugs & Pharmacology Source Type: research
This study showed that potential vicious cycles underlying ARDs are quite diverse and unique, triggered by diverse and unique factors that do not usually progress with age, thus casting doubts on the possibility of discovering the single molecular cause of aging and developing the single anti-aging pill. Rather, each disease appears to require an individual approach. However, it still cannot be excluded that some or all of these cycles are triggered by fundamental processes of aging, such as chronic inflammation or accumulation of senescent cells. Nevertheless, experimental data showing clear cause and effect relationships...
Source: Fight Aging! - Category: Research Authors: Tags: Newsletters Source Type: blogs
Background:Genome instability is a hallmark of cancer. Mutations in DNA repair pathway genes are frequent in a number of solid tumors. Defects in DNA repair or damage response can weaken response to conventional chemotherapy and are frequently regarded as poor prognostic markers. However, a high tumor mutation burden (TMB, number of somatic mutations per mega base) was recently found to correlate with better response to immune checkpoint inhibitors e.g. in colon cancer. Patients with defects in the DNA mismatch repair (MMR) pathway in solid tumors are among the cases with the highest TMB. Hematological malignancies are gen...
Source: Blood - Category: Hematology Authors: Tags: 604. Molecular Pharmacology and Drug Resistance in Myeloid Diseases: Poster III Source Type: research
Recurrent somatic mutations in core components and modulators of the cohesin ring - a multimeric protein complex that forms a ring structure around DNA and provides spatial genome organization - have been identified across multiple cancer types, including acute myeloid leukemia (AML) and myelodysplastic syndrome (MDS), where they are associated with poor overall survival. Cohesin proteins are involved in sister chromatid cohesion, chromatin organization into loops, transcriptional activation, and DNA damage repair. The mechanisms underlying clonal expansion of these driver mutations are unknown and no therapies have select...
Source: Blood - Category: Hematology Authors: Tags: 636. Myelodysplastic Syndromes-Basic and Translational Studies: Disease Mechanisms and Therapeutic Implications Source Type: research
ConclusionWe found BRCC36 to be recurrently mutated in t(8;21)-positive AML Inactivation of BRCC36 was associated with impairment of the DNA damage repair pathway and thus higher sensitivity to DNA damage-inducing chemotherapy. This might be also reflected by the favorable clinical outcome of patients with BRCC36 mutated t(8;21)-positive AML, a finding which has to be confirmed in a large patient cohort.DisclosuresPaschka: Pfizer: Membership on an entity's Board of Directors or advisory committees; Takeda: Other: Travel support; Novartis: Membership on an entity's Board of Directors or advisory committees, Other: Travel su...
Source: Blood - Category: Hematology Authors: Tags: 617. Acute Myeloid Leukemia: Biology, Cytogenetics, and Molecular Markers in Diagnosis and Prognosis: Poster I Source Type: research
The first two authors and last two authors contributed equally.Genome-wide association studies (GWAS) have identified risk loci for Acute Lymphoblastic Leukemia (ALL), Chronic Lymphoblastic Leukemia (CLL) and Non-Hodgkin Lymphoma, however an Acute Myeloid Leukemia (AML) GWAS has not been published to date. We performed a GWAS to identify AML and Myelodysplastic Syndrome (MDS) risk loci using a nested case-control study design in the DISCOVeRY-BMT cohorts which includes almost 2000 AML and MDS patients as cases and 2813 unrelated donors as controls.Genotyping was performed using the Illumina Human OmniExpress BeadChip and i...
Source: Blood - Category: Hematology Authors: Tags: 617. Acute Myeloid Leukemia: Biology, Cytogenetics, and Molecular Markers in Diagnosis and Prognosis: Poster I Source Type: research
The homologous DNA repair pathway genes BRCA1 and BRCA2 are classically associated with increased susceptibility to hereditary breast and ovarian cancer due to increased vulnerability to double stranded DNA breaks (mutator phenotype). In addition to their role in breast/ovarian cancer, defects in these genes may predispose to myelodysplastic syndromes (MDS) and acute myeloid leukemia (AML). For example, in large populations of breast cancer patients, those with inherited defects in homologous repair (HR) showed a propensity to therapy-related MDS and AML; however, a relationship between BRCA gene variants and spontaneous m...
Source: Blood - Category: Hematology Authors: Tags: 636. Myelodysplastic Syndromes-Basic and Translational Studies: Poster III Source Type: research
Somatic mutations are frequently found in patients with MDS. Germline (GL) alterations are less common, in part due to sequencing panels limited to mutations seen commonly in myeloid malignancies, with further exploration only pursued in patients with a clear indication of a familiar disease. It is common to have GL cases where family history is not as informative as we expect, given unreliable recollection by patients and premature mortality of family members. The recognition of pathogenic GL variants is difficult due to the tremendous numbers of inconsequential SNPs, unclear pathologic significance of most new/rare varia...
Source: Blood - Category: Hematology Authors: Tags: 636. Myelodysplastic Syndromes-Basic and Translational Studies: Poster II Source Type: research
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