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1.
Hemasphere ; 8(9): e149, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39233904

RESUMEN

Pediatric classic Hodgkin lymphoma (cHL) patients have a high survival rate but suffer from severe long-term side effects induced by chemo- and radiotherapy. cHL tumors are characterized by the low fraction (0.1%-10%) of malignant Hodgkin and Reed-Sternberg (HRS) cells in the tumor. The HRS cells depend on the surrounding immune cells for survival and growth. This dependence is leveraged by current treatments that target the PD-1/PD-L1 axis in cHL tumors. The development of more targeted therapies that are specific for the tumor and are therefore less toxic for healthy tissue compared with conventional chemotherapy could improve the quality of life of pediatric cHL survivors. Here, we applied single-cell RNA sequencing (scRNA-seq) on isolated HRS cells and the immune cells from the same cHL tumors. Besides TNFRSF8 (CD30), we identified other genes of cell surface proteins that are consistently overexpressed in HRS cells, such as NRXN3 and LRP8, which can potentially be used as alternative targets for antibody-drug conjugates or CAR T cells. Finally, we identified potential interactions by which HRS cells inhibit T cells, among which are the galectin-1/CD69 and HLA-II/LAG3 interactions. RNAscope was used to validate the enrichment of CD69 and LAG3 expression on T cells near HRS cells and indicated large variability of the interaction strength with the corresponding ligands between patients and between tumor tissue regions. In conclusion, this study identifies new potential therapeutic targets for cHL and highlights the importance of studying heterogeneity when identifying therapy targets, specifically those that target tumor-immune cell interactions.

2.
DNA Repair (Amst) ; 142: 103755, 2024 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-39216121

RESUMEN

By replicating damaged nucleotides, error-prone DNA translesion synthesis (TLS) enables the completion of replication, albeit at the expense of fidelity. TLS of helix-distorting DNA lesions, that usually have reduced capacity of basepairing, comprises insertion opposite the lesion followed by extension, the latter in particular by polymerase ζ (Pol ζ). However, little is known about involvement of Pol ζ in TLS of non- or poorly-distorting, but miscoding, lesions such as O6-methyldeoxyguanosine (O6-medG). Using purified Pol ζ we describe that the enzyme can misincorporate thymidine opposite O6-medG and efficiently extend from terminal mismatches, suggesting its involvement in the mutagenicity of O6-medG. Surprisingly, O6-medG lesions induced by the methylating agent N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) appeared more, rather than less, mutagenic in Pol ζ-deficient mouse embryonic fibroblasts (MEFs) than in wild type MEFs. This suggested that in vivo Pol ζ participates in non-mutagenic TLS of O6-medG. However, we found that the Pol ζ-dependent misinsertions at O6-medG lesions are efficiently corrected by DNA mismatch repair (MMR), which masks the error-proneness of Pol ζ. We also found that the MNNG-induced mutational signature is determined by the adduct spectrum, and modulated by MMR. The signature mimicked single base substitution signature 11 in the catalogue of somatic mutations in cancer, associated with treatment with the methylating drug temozolomide. Our results unravel the individual roles of the major contributors to methylating drug-induced mutagenesis. Moreover, these results warrant caution as to the classification of TLS as mutagenic or error-free based on in vitro data or on the analysis of mutations induced in MMR-proficient cells.


Asunto(s)
Reparación de la Incompatibilidad de ADN , ADN Polimerasa Dirigida por ADN , Metilnitronitrosoguanidina , Animales , ADN Polimerasa Dirigida por ADN/metabolismo , ADN Polimerasa Dirigida por ADN/genética , Ratones , Metilnitronitrosoguanidina/toxicidad , Mutagénesis , Guanina/análogos & derivados , Guanina/metabolismo , Daño del ADN , Metilación de ADN , Fibroblastos/metabolismo , Fibroblastos/efectos de los fármacos , Replicación del ADN , ADN/metabolismo , Síntesis Translesional de ADN
3.
Nat Commun ; 15(1): 6025, 2024 Jul 17.
Artículo en Inglés | MEDLINE | ID: mdl-39019934

RESUMEN

Therapy-related myeloid neoplasms (t-MN) arise as a complication of chemo- and/or radiotherapy. Although t-MN can occur both in adult and childhood cancer survivors, the mechanisms driving therapy-related leukemogenesis likely vary across different ages. Chemotherapy is thought to induce driver mutations in children, whereas in adults pre-existing mutant clones are selected by the exposure. However, selective pressures induced by chemotherapy early in life are less well studied. Here, we use single-cell whole genome sequencing and phylogenetic inference to show that the founding cell of t-MN in children starts expanding after cessation of platinum exposure. In patients with Li-Fraumeni syndrome, characterized by a germline TP53 mutation, we find that the t-MN already expands during treatment, suggesting that platinum-induced growth inhibition is TP53-dependent. Our results demonstrate that germline aberrations can interact with treatment exposures in inducing t-MN, which is important for the development of more targeted, patient-specific treatment regimens and follow-up.


Asunto(s)
Mutación de Línea Germinal , Síndrome de Li-Fraumeni , Neoplasias Primarias Secundarias , Proteína p53 Supresora de Tumor , Humanos , Proteína p53 Supresora de Tumor/genética , Síndrome de Li-Fraumeni/genética , Niño , Neoplasias Primarias Secundarias/genética , Masculino , Femenino , Compuestos de Platino/uso terapéutico , Adulto , Adolescente , Secuenciación Completa del Genoma , Filogenia , Preescolar , Antineoplásicos/uso terapéutico , Análisis de la Célula Individual
4.
STAR Protoc ; 5(3): 103189, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-39003744

RESUMEN

Isogenic disease models, such as genetically engineered organoids, provide insight into the impact of genetic variants on organ function. Here, we present a protocol to create isogenic disease models from adult stem cell-derived organoids using next-generation CRISPR tools. We describe steps for single guide RNA (sgRNA) design and cloning, electroporation, and selecting electroporated cells. We then detail procedures for clonal line generation. Next-generation CRISPR tools do not require double-stranded break (DSB) induction for their function, thus simplifying in vitro disease model generation. For complete details on the use and execution of this protocol, please refer to Geurts et al.1,2.

5.
Nat Genet ; 56(7): 1420-1433, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38956208

RESUMEN

Mismatch repair (MMR)-deficient cancer evolves through the stepwise erosion of coding homopolymers in target genes. Curiously, the MMR genes MutS homolog 6 (MSH6) and MutS homolog 3 (MSH3) also contain coding homopolymers, and these are frequent mutational targets in MMR-deficient cancers. The impact of incremental MMR mutations on MMR-deficient cancer evolution is unknown. Here we show that microsatellite instability modulates DNA repair by toggling hypermutable mononucleotide homopolymer runs in MSH6 and MSH3 through stochastic frameshift switching. Spontaneous mutation and reversion modulate subclonal mutation rate, mutation bias and HLA and neoantigen diversity. Patient-derived organoids corroborate these observations and show that MMR homopolymer sequences drift back into reading frame in the absence of immune selection, suggesting a fitness cost of elevated mutation rates. Combined experimental and simulation studies demonstrate that subclonal immune selection favors incremental MMR mutations. Overall, our data demonstrate that MMR-deficient colorectal cancers fuel intratumor heterogeneity by adapting subclonal mutation rate and diversity to immune selection.


Asunto(s)
Neoplasias Colorrectales , Reparación de la Incompatibilidad de ADN , Inestabilidad de Microsatélites , Humanos , Neoplasias Colorrectales/genética , Reparación de la Incompatibilidad de ADN/genética , Proteínas de Unión al ADN/genética , Mutación , Proteína 3 Homóloga de MutS/genética , Tasa de Mutación , Mutación del Sistema de Lectura/genética
6.
Cancer Res ; 84(16): 2720-2733, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-38885294

RESUMEN

Leukemia is characterized by oncogenic lesions that result in a block of differentiation, whereas phenotypic plasticity is retained. A better understanding of how these two phenomena arise during leukemogenesis in humans could help inform diagnosis and treatment strategies. Here, we leveraged the well-defined differentiation states during T-cell development to pinpoint the initiation of T-cell acute lymphoblastic leukemia (T-ALL), an aggressive form of childhood leukemia, and study the emergence of phenotypic plasticity. Single-cell whole genome sequencing of leukemic blasts was combined with multiparameter flow cytometry to couple cell identity and clonal lineages. Irrespective of genetic events, leukemia-initiating cells altered their phenotypes by differentiation and dedifferentiation. The construction of the phylogenies of individual leukemias using somatic mutations revealed that phenotypic diversity is reflected by the clonal structure of cancer. The analysis also indicated that the acquired phenotypes are heritable and stable. Together, these results demonstrate a transient period of plasticity during leukemia initiation, where phenotypic switches seem unidirectional. Significance: A method merging multicolor flow cytometry with single-cell whole genome sequencing to couple cell identity with clonal lineages uncovers differentiation-state plasticity in leukemia, reconciling blocked differentiation with phenotypic plasticity in cancer.


Asunto(s)
Diferenciación Celular , Humanos , Análisis de la Célula Individual/métodos , Ratones , Citometría de Flujo , Animales , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/metabolismo , Mutación , Secuenciación Completa del Genoma , Plasticidad de la Célula/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/patología , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Fenotipo , Linaje de la Célula/genética
7.
J Pathol ; 263(2): 217-225, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38551073

RESUMEN

Environmental factors like the pathogenicity island polyketide synthase positive (pks+) Escherichia coli (E. coli) could have potential for risk stratification in colorectal cancer (CRC) screening. The association between pks+ E. coli measured in fecal immunochemical test (FIT) samples and the detection of advanced neoplasia (AN) at colonoscopy was investigated. Biobanked FIT samples were analyzed for both presence of E. coli and pks+ E. coli and correlated with colonoscopy findings; 5020 CRC screening participants were included. Controls were participants in which no relevant lesion was detected because of FIT-negative results (cut-off ≥15 µg Hb/g feces), a negative colonoscopy, or a colonoscopy during which only a nonadvanced polyp was detected. Cases were participants with AN [CRC, advanced adenoma (AA), or advanced serrated polyp (ASP)]. Existing DNA isolation and quantitative polymerase chain reaction (qPCR) procedures were used for the detection of E. coli and pks+ E. coli in stool. A total of 4542 (90.2%) individuals were E. coli positive, and 1322 (26.2%) were pks+ E. coli positive. The prevalence of E. coli in FIT samples from individuals with AN was 92.9% compared to 89.7% in FIT samples of controls (p = 0.010). The prevalence of pks+ E. coli in FIT samples from individuals with AN (28.6%) and controls (25.9%) was not significantly different (p = 0.13). The prevalences of pks+ E. coli in FIT samples from individuals with CRC, AA, or ASP were 29.6%, 28.3%, and 32.1%, respectively. In conclusion, the prevalence of pks+ E. coli in a screening population was 26.2% and did not differ significantly between individuals with AN and controls. These findings disqualify the straightforward option of using a snapshot measurement of pks+ E. coli in FIT samples as a stratification biomarker for CRC risk. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Asunto(s)
Neoplasias Colorrectales , Detección Precoz del Cáncer , Escherichia coli , Heces , Sintasas Poliquetidas , Humanos , Neoplasias Colorrectales/microbiología , Neoplasias Colorrectales/diagnóstico , Heces/microbiología , Heces/enzimología , Escherichia coli/aislamiento & purificación , Escherichia coli/enzimología , Escherichia coli/genética , Masculino , Detección Precoz del Cáncer/métodos , Femenino , Persona de Mediana Edad , Anciano , Sintasas Poliquetidas/genética , Colonoscopía , Factores de Riesgo , Adenoma/microbiología , Adenoma/diagnóstico , Medición de Riesgo , Biomarcadores de Tumor , Estudios de Casos y Controles
8.
BMJ Open ; 14(3): e081833, 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38548357

RESUMEN

INTRODUCTION: Around 1 in 1000-2000 pregnancies are affected by a cancer diagnosis. Previous studies have shown that chemotherapy during pregnancy has reassuring cognitive and cardiac neonatal outcomes, and hence has been proposed as standard of care. However, although these children perform within normal ranges for their age, subtle differences have been identified. Given that chemotherapeutic compounds can cross the placenta, the possibility that prenatal chemotherapy exposure mutates the offspring's genome and/or epigenome, with potential deleterious effects later in life, urges to be investigated. METHODS AND ANALYSES: This multicentric observational study aims to collect cord blood, meconium and neonatal buccal cells at birth, as well as peripheral blood, buccal cells and urine from infants when 6, 18 and/or 36 months of age. Using bulk and single-cell approaches, we will compare samples from chemotherapy-treated pregnant patients with cancer, pregnant patients with cancer not treated with chemotherapy and healthy pregnant women. Potential chemotherapy-related newborn genomic and/or epigenomic alterations, such as single nucleotide variants, copy number variants and DNA-methylation alterations, will be identified in mononuclear and epithelial cells, isolated from blood, buccal swabs and urine. DNA from maternal peripheral blood and paternal buccal cells will be used to determine de novo somatic mutations in the neonatal blood and epithelial cells. Additionally, the accumulated exposure of the fetus, and biological effective dose of alkylating agents, will be assessed in meconium and cord blood via mass spectrometry approaches. ETHICS AND DISSEMINATION: The Ethics Committee Research of UZ/KU Leuven (EC Research) and the Medical Ethical Review Committee of University Medical Center Amsterdam have approved the study. Results of this study will be disseminated via presentations at (inter)national conferences, through peer-reviewed, open-access publications, via social media platforms aimed to inform patients and healthcare workers, and through the website of the International Network on Cancer, Infertility and Pregnancy (www.cancerinpregnancy.org).


Asunto(s)
Neoplasias , Efectos Tardíos de la Exposición Prenatal , Recién Nacido , Lactante , Niño , Embarazo , Humanos , Femenino , Epigenómica , Mucosa Bucal , Genómica , ADN , Neoplasias/tratamiento farmacológico , Neoplasias/genética
9.
Nat Commun ; 15(1): 2725, 2024 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-38548751

RESUMEN

Reactive Oxygen Species (ROS) derived from mitochondrial respiration are frequently cited as a major source of chromosomal DNA mutations that contribute to cancer development and aging. However, experimental evidence showing that ROS released by mitochondria can directly damage nuclear DNA is largely lacking. In this study, we investigated the effects of H2O2 released by mitochondria or produced at the nucleosomes using a titratable chemogenetic approach. This enabled us to precisely investigate to what extent DNA damage occurs downstream of near- and supraphysiological amounts of localized H2O2. Nuclear H2O2 gives rise to DNA damage and mutations and a subsequent p53 dependent cell cycle arrest. Mitochondrial H2O2 release shows none of these effects, even at levels that are orders of magnitude higher than what mitochondria normally produce. We conclude that H2O2 released from mitochondria is unlikely to directly damage nuclear genomic DNA, limiting its contribution to oncogenic transformation and aging.


Asunto(s)
Peróxido de Hidrógeno , Mitocondrias , Especies Reactivas de Oxígeno/metabolismo , Peróxido de Hidrógeno/metabolismo , Mitocondrias/metabolismo , ADN/metabolismo , Daño del ADN , ADN Mitocondrial/genética , ADN Mitocondrial/metabolismo
10.
Cancer Cell ; 42(3): 487-496.e6, 2024 Mar 11.
Artículo en Inglés | MEDLINE | ID: mdl-38471458

RESUMEN

Co-culture of intestinal organoids with a colibactin-producing pks+E. coli strain (EcC) revealed mutational signatures also found in colorectal cancer (CRC). E. coli Nissle 1917 (EcN) remains a commonly used probiotic, despite harboring the pks operon and inducing double strand DNA breaks. We determine the mutagenicity of EcN and three CRC-derived pks+E. coli strains with an analytical framework based on sequence characteristic of colibactin-induced mutations. All strains, including EcN, display varying levels of mutagenic activity. Furthermore, a machine learning approach attributing individual mutations to colibactin reveals that patients with colibactin-induced mutations are diagnosed at a younger age and that colibactin can induce a specific APC mutation. These approaches allow the sensitive detection of colibactin-induced mutations in ∼12% of CRC genomes and even in whole exome sequencing data, representing a crucial step toward pinpointing the mutagenic activity of distinct pks+E. coli strains.


Asunto(s)
Neoplasias Colorrectales , Escherichia coli , Péptidos , Policétidos , Humanos , Escherichia coli/genética , Mutación , Daño del ADN , Mutágenos , Organoides
11.
Cell Stem Cell ; 30(11): 1421-1433, 2023 11 02.
Artículo en Inglés | MEDLINE | ID: mdl-37832550

RESUMEN

Mutation accumulation in stem cells has been associated with cancer risk. However, the presence of numerous mutant clones in healthy tissues has raised the question of what limits cancer initiation. Here, we review recent developments in characterizing mutation accumulation in healthy tissues and compare mutation rates in stem cells during development and adult life with corresponding cancer risk. A certain level of mutagenesis within the stem cell pool might be beneficial to limit the size of malignant clones through competition. This knowledge impacts our understanding of carcinogenesis with potential consequences for the use of stem cells in regenerative medicine.


Asunto(s)
Medicina Regenerativa , Células Madre , Adulto , Humanos , Mutación/genética , Células Madre/patología , Carcinogénesis/genética , Carcinogénesis/patología
12.
Cell Genom ; 3(9): 100389, 2023 Sep 13.
Artículo en Inglés | MEDLINE | ID: mdl-37719152

RESUMEN

Detection of somatic mutations in single cells has been severely hampered by technical limitations of whole-genome amplification. Novel technologies including primary template-directed amplification (PTA) significantly improved the accuracy of single-cell whole-genome sequencing (WGS) but still generate hundreds of artifacts per amplification reaction. We developed a comprehensive bioinformatic workflow, called the PTA Analysis Toolbox (PTATO), to accurately detect single base substitutions, insertions-deletions (indels), and structural variants in PTA-based WGS data. PTATO includes a machine learning approach and filtering based on recurrence to distinguish PTA artifacts from true mutations with high sensitivity (up to 90%), outperforming existing bioinformatic approaches. Using PTATO, we demonstrate that hematopoietic stem cells of patients with Fanconi anemia, which cannot be analyzed using regular WGS, have normal somatic single base substitution burdens but increased numbers of deletions. Our results show that PTATO enables studying somatic mutagenesis in the genomes of single cells with unprecedented sensitivity and accuracy.

13.
Nat Commun ; 14(1): 4998, 2023 08 17.
Artículo en Inglés | MEDLINE | ID: mdl-37591832

RESUMEN

Optimization of CRISPR/Cas9-mediated genome engineering has resulted in base editors that hold promise for mutation repair and disease modeling. Here, we demonstrate the application of base editors for the generation of complex tumor models in human ASC-derived organoids. First we show efficacy of cytosine and adenine base editors in modeling CTNNB1 hot-spot mutations in hepatocyte organoids. Next, we use C > T base editors to insert nonsense mutations in PTEN in endometrial organoids and demonstrate tumorigenicity even in the heterozygous state. Moreover, drug sensitivity assays on organoids harboring either PTEN or PTEN and PIK3CA mutations reveal the mechanism underlying the initial stages of endometrial tumorigenesis. To further increase the scope of base editing we combine SpCas9 and SaCas9 for simultaneous C > T and A > G editing at individual target sites. Finally, we show that base editor multiplexing allow modeling of colorectal tumorigenesis in a single step by simultaneously transfecting sgRNAs targeting five cancer genes.


Asunto(s)
Células Madre Adultas , ARN Guía de Sistemas CRISPR-Cas , Adulto , Humanos , Oncogenes , Carcinogénesis/genética , Transformación Celular Neoplásica , Organoides
14.
iScience ; 25(12): 105610, 2022 Dec 22.
Artículo en Inglés | MEDLINE | ID: mdl-36458259

RESUMEN

Mitochondria are small organelles that play an essential role in the energy production of eukaryotic cells. Defects in their genomes are associated with diseases, such as aging and cancer. Here, we analyzed the mitochondrial genomes of 532 whole-genome sequencing samples from cancers and normal clonally expanded single cells. We show that the mitochondria of normal cells accumulate mutations with age and that most of the mitochondrial mutations found in cancer are the result of healthy mutation accumulation. We also show that the normal HSPCs of patients with leukemia have an increased mitochondrial mutation load. Finally, we show that secondary pediatric cancers and chemotherapy treatments do not impact the mitochondrial mutation load and mtDNA copy numbers of most cells, suggesting that damage to the mitochondrial genome is not a major driver for carcinogenesis. Overall, these findings may contribute to our understanding of mitochondrial genomes and their role in cancer.

15.
Cell Stem Cell ; 29(12): 1621-1623, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36459965

RESUMEN

As the stem cell community mourns the loss of New York Stem Cell Foundation founder Susan Solomon, we also look to celebrate her legacy. In this Voices, members of the 2022 class of NYSCF Roberston Investigators share how NYSCF community support will impact them and the bold ideas they will pursue as a result.


Asunto(s)
Investigadores , Células Madre , Femenino , Humanos , New York , Apoyo Comunitario
16.
Nat Commun ; 13(1): 6722, 2022 11 07.
Artículo en Inglés | MEDLINE | ID: mdl-36344511

RESUMEN

Sister chromatid exchanges (SCEs) are products of joint DNA molecule resolution, and are considered to form through homologous recombination (HR). Indeed, SCE induction upon irradiation requires the canonical HR factors BRCA1, BRCA2 and RAD51. In contrast, replication-blocking agents, including PARP inhibitors, induce SCEs independently of BRCA1, BRCA2 and RAD51. PARP inhibitor-induced SCEs are enriched at difficult-to-replicate genomic regions, including common fragile sites (CFSs). PARP inhibitor-induced replication lesions are transmitted into mitosis, suggesting that SCEs can originate from mitotic processing of under-replicated DNA. Proteomics analysis reveals mitotic recruitment of DNA polymerase theta (POLQ) to synthetic DNA ends. POLQ inactivation results in reduced SCE numbers and severe chromosome fragmentation upon PARP inhibition in HR-deficient cells. Accordingly, analysis of CFSs in cancer genomes reveals frequent allelic deletions, flanked by signatures of POLQ-mediated repair. Combined, we show PARP inhibition generates under-replicated DNA, which is processed into SCEs during mitosis, independently of canonical HR factors.


Asunto(s)
Inhibidores de Poli(ADP-Ribosa) Polimerasas , Intercambio de Cromátides Hermanas , Inhibidores de Poli(ADP-Ribosa) Polimerasas/farmacología , Sitios Frágiles del Cromosoma , Recombinación Homóloga/genética , ADN
17.
EMBO Mol Med ; 14(10): e16001, 2022 10 10.
Artículo en Inglés | MEDLINE | ID: mdl-35916583

RESUMEN

Rhabdomyosarcomas (RMS) are mesenchyme-derived tumors and the most common childhood soft tissue sarcomas. Treatment is intense, with a nevertheless poor prognosis for high-risk patients. Discovery of new therapies would benefit from additional preclinical models. Here, we describe the generation of a collection of 19 pediatric RMS tumor organoid (tumoroid) models (success rate of 41%) comprising all major subtypes. For aggressive tumors, tumoroid models can often be established within 4-8 weeks, indicating the feasibility of personalized drug screening. Molecular, genetic, and histological characterization show that the models closely resemble the original tumors, with genetic stability over extended culture periods of up to 6 months. Importantly, drug screening reflects established sensitivities and the models can be modified by CRISPR/Cas9 with TP53 knockout in an embryonal RMS model resulting in replicative stress drug sensitivity. Tumors of mesenchymal origin can therefore be used to generate organoid models, relevant for a variety of preclinical and clinical research questions.


Asunto(s)
Organoides , Rabdomiosarcoma , Niño , Humanos , Organoides/patología , Rabdomiosarcoma/diagnóstico , Rabdomiosarcoma/patología
18.
Cancer Discov ; 12(8): 1860-1872, 2022 08 05.
Artículo en Inglés | MEDLINE | ID: mdl-35678530

RESUMEN

Childhood cancer survivors are confronted with various chronic health conditions like therapy-related malignancies. However, it is unclear how exposure to chemotherapy contributes to the mutation burden and clonal composition of healthy tissues early in life. Here, we studied mutation accumulation in hematopoietic stem and progenitor cells (HSPC) before and after cancer treatment of 24 children. Of these children, 19 developed therapy-related myeloid neoplasms (t-MN). Posttreatment HSPCs had an average mutation burden increase comparable to what treatment-naïve cells accumulate during 16 years of life, with excesses up to 80 years. In most children, these additional mutations were induced by clock-like processes, which are also active during healthy aging. Other patients harbored mutations that could be directly attributed to treatments like platinum-based drugs and thiopurines. Using phylogenetic inference, we demonstrate that most t-MN in children originate after the start of treatment and that leukemic clones become dominant during or directly after chemotherapy exposure. SIGNIFICANCE: Our study shows that chemotherapy increases the mutation burden of normal blood cells in cancer survivors. Only few drugs damage the DNA directly, whereas in most patients, chemotherapy-induced mutations are caused by processes similar to those present during normal aging. This article is highlighted in the In This Issue feature, p. 1825.


Asunto(s)
Antineoplásicos , Neoplasias Primarias Secundarias , Antineoplásicos/efectos adversos , Antineoplásicos/uso terapéutico , Niño , Células Madre Hematopoyéticas/patología , Humanos , Mieloma Múltiple/inducido químicamente , Mieloma Múltiple/genética , Mutación , Neoplasias/complicaciones , Neoplasias/tratamiento farmacológico , Neoplasias/genética , Neoplasias Primarias Secundarias/inducido químicamente , Neoplasias Primarias Secundarias/genética , Neoplasias Primarias Secundarias/patología , Filogenia
19.
Bone Marrow Transplant ; 57(9): 1357-1364, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35690693

RESUMEN

Allogeneic hematopoietic cell transplantation (HCT) is a potentially curative therapy for patients with a variety of malignant and non-malignant diseases. Despite its life-saving potential, HCT is associated with significant morbidity and mortality. Reciprocal interactions between hematopoietic stem cells (HSCs) and their surrounding bone marrow (BM) niche regulate HSC function during homeostatic hematopoiesis as well as regeneration. However, current pre-HCT conditioning regimens, which consist of high-dose chemotherapy and/or irradiation, cause substantial short- and long-term toxicity to the BM niche. This damage may negatively affect HSC function, impair hematopoietic regeneration after HCT and predispose to HCT-related morbidity and mortality. In this review, we summarize current knowledge on the cellular composition of the human BM niche after HCT. We describe how pre-HCT conditioning affects the cell types in the niche, including endothelial cells, mesenchymal stromal cells, osteoblasts, adipocytes, and neurons. Finally, we discuss therapeutic strategies to prevent or repair conditioning-induced niche damage, which may promote hematopoietic recovery and improve HCT outcome.


Asunto(s)
Médula Ósea , Trasplante de Células Madre Hematopoyéticas , Células Endoteliales , Hematopoyesis , Células Madre Hematopoyéticas/metabolismo , Humanos , Nicho de Células Madre/fisiología
20.
STAR Protoc ; 3(2): 101361, 2022 06 17.
Artículo en Inglés | MEDLINE | ID: mdl-35573477

RESUMEN

Mutational signatures have been identified in cancer genomes, providing information about the causes of cancer and treatment vulnerabilities. This protocol describes an assay to determine the genotoxic mechanisms underlying these signatures using cord-blood derived hematopoietic stem and progenitor cells (CB-HSPCs). CB-HSPCs have a low mutation background, enabling sensitive detection of mutations. First, CB-HSPCs are exposed in vitro, sorted, and clonally expanded. This expansion enables whole-genome sequencing to detect the mutation load and respective patterns induced during genotoxic exposure. For complete details on the use and execution of this protocol, please refer to de Kanter et al. (2021).


Asunto(s)
Sangre Fetal , Células Madre Hematopoyéticas , Daño del ADN , Genoma , Humanos , Secuenciación Completa del Genoma
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