BACKGROUND: Radiation-induced intestinal injury (RIII) interrupts the scheduled processes of abdominal and pelvic radiotherapy (RT) and compromises the quality of life of cancer survivors. However, the specific regulators and mechanisms underlying the effects of RIII remain unknown. The biological effects of RT are caused primarily by DNA damage, and ataxia telangiectasia mutated (ATM) is a core protein of the DNA damage response (DDR). However, whether ATM is regulated by deubiquitination signaling remains unclear. METHODS: We established animal and cellular models of RIII. The effects of ubiquitin-specific protease 15 (USP15) on DNA damage and radion-induced intestinal injury were evaluated. Mass spectrometry analysis, truncation tests, and immunoprecipitation were used to identify USP15 as a binding partner of ATM and to investigate the ubiquitination of ATM. Finally, the relationship between the USP15/ATM axes was further determined via subsequent experiments. RESULTS: In this study, we identified the deubiquitylating enzyme USP15 as a regulator of DNA damage and the pathological progression of RIII. Irradiation upregulates the expression of USP15, whereas pharmacological inhibition of USP15 exacerbates radiation-induced DNA damage and RIII both in vivo and in vitro. Mechanistically, USP15 interacts with, deubiquitinates, and stabilises ATM via K48-linked deubiquitination. Notably, ATM overexpression blocks the effect of USP15 genetic inhibition on DNA damage and RIII progression. CONCLUSIONS: These findings describe ATM as a novel deubiquitination target of USP15 upon radiation-induced DNA damage and intestinal injury, and provides experimental support for USP15/ATM axis as a potential target for developing strategies that mitigate RIII.
- MeSH
- ATM protein * metabolismus genetika MeSH
- lidé MeSH
- modely nemocí na zvířatech MeSH
- myši MeSH
- poškození DNA * MeSH
- radiační poranění metabolismus genetika MeSH
- specifické proteázy ubikvitinu * metabolismus genetika MeSH
- střeva účinky záření patologie MeSH
- ubikvitinace * MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
Ataxia-telangiectasia (A-T) is an autosomal-recessive disorder caused by pathogenic variants (PVs) of the ATM gene, predisposing children to hematological malignancies. We investigated their characteristics and outcomes to generate data-based treatment recommendations. In this multinational, observational study we report 202 patients aged ≤25 years with A-T and hematological malignancies from 25 countries. Ninety-one patients (45%) presented with mature B-cell lymphomas, 82 (41%) with acute lymphoblastic leukemia/lymphoma, 21 (10%) with Hodgkin lymphoma and 8 (4%) with other hematological malignancies. Four-year overall survival and event-free survival (EFS) were 50.8% (95% confidence interval [CI], 43.6-59.1) and 47.9% (95% CI 40.8-56.2), respectively. Cure rates have not significantly improved over the last four decades (P = .76). The major cause of treatment failure was treatment-related mortality (TRM) with a four-year cumulative incidence of 25.9% (95% CI, 19.5-32.4). Germ line ATM PVs were categorized as null or hypomorphic and patients with available genetic data (n = 110) were classified as having absent (n = 81) or residual (n = 29) ATM kinase activity. Four-year EFS was 39.4% (95% CI, 29-53.3) vs 78.7% (95% CI, 63.7-97.2), (P < .001), and TRM rates were 37.6% (95% CI, 26.4-48.7) vs 4.0% (95% CI, 0-11.8), (P = .017), for those with absent and residual ATM kinase activity, respectively. Absence of ATM kinase activity was independently associated with decreased EFS (HR = 0.362, 95% CI, 0.16-0.82; P = .009) and increased TRM (hazard ratio [HR] = 14.11, 95% CI, 1.36-146.31; P = .029). Patients with A-T and leukemia/lymphoma may benefit from deescalated therapy for patients with absent ATM kinase activity and near-standard therapy regimens for those with residual kinase activity.
- MeSH
- ATM protein * genetika MeSH
- dítě MeSH
- dospělí MeSH
- hematologické nádory * genetika mortalita MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- předškolní dítě MeSH
- teleangiektatická ataxie * genetika komplikace mortalita MeSH
- zárodečné mutace * MeSH
- Check Tag
- dítě MeSH
- dospělí MeSH
- kojenec MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- předškolní dítě MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- multicentrická studie MeSH
- pozorovací studie MeSH
Doporučené postupy klinické péče o nosiče patogenních variant v klinicky relevantních nádorových predispozičních genech definují kroky primární a sekundární prevence, která by měla být těmto osobám ve vysokém riziku vzniku dědičných nádorů v ČR poskytnuta. Tvorba doporučení byla organizována pracovní skupinou onkogenetiky Společnosti lékařské genetiky a genomiky (SLG ČLS JEP) ve spolupráci se zástupci onkologie a onkogynekologie. Doporučené postupy vycházejí z aktuálních doporučení National Comprehensive Cancer Network (NCCN), European Society of Medical Oncology (ESMO) a zohledňují kapacitní možnosti našeho zdravotnictví.
The Guidelines for Clinical Practice for carriers of pathogenic variants in clinically relevant cancer predisposition genes define the steps of primary and secondary prevention that should be provided to these individuals at high risk of developing hereditary cancer in the Czech Republic. The drafting of the guidelines was organized by the Oncogenetics Working Group of the Society for Medical Genetics and Genomics of J. E. Purkyně Czech Medical Society (SLG ČLS JEP) in cooperation with the representatives of oncology and oncogynecology. The guidelines are based on the current recommendations of the National Comprehensive Cancer Network (NCCN), European Society of Medical Oncology (ESMO) and take into account the capacity of the Czech healthcare system.
- MeSH
- ATM protein genetika MeSH
- checkpoint kinasa 2 genetika MeSH
- genetická predispozice k nemoci * MeSH
- geny BRCA1 MeSH
- geny BRCA2 MeSH
- nádory prostaty diagnóza genetika prevence a kontrola MeSH
- nádory prsu diagnóza genetika prevence a kontrola MeSH
- nádory slinivky břišní diagnóza genetika prevence a kontrola MeSH
- nádory vaječníků diagnóza genetika prevence a kontrola MeSH
- primární prevence metody MeSH
- protein FANCN genetika MeSH
- sekundární prevence metody MeSH
- směrnice pro lékařskou praxi jako téma MeSH
- zárodečné mutace MeSH
BACKGROUND: The ATM kinase constitutes a master regulatory hub of DNA damage and activates the p53 response pathway by phosphorylating the MDM2 protein, which develops an affinity for the p53 mRNA secondary structure. Disruption of this interaction prevents the activation of the nascent p53. The link of the MDM2 protein-p53 mRNA interaction with the upstream DNA damage sensor ATM kinase and the role of the p53 mRNA in the DNA damage sensing mechanism, are still highly anticipated. METHODS: The proximity ligation assay (PLA) has been extensively used to reveal the sub-cellular localisation of the protein-mRNA and protein-protein interactions. ELISA and co-immunoprecipitation confirmed the interactions in vitro and in cells. RESULTS: This study provides a novel mechanism whereby the p53 mRNA interacts with the ATM kinase enzyme and shows that the L22L synonymous mutant, known to alter the secondary structure of the p53 mRNA, prevents the interaction. The relevant mechanistic roles in the DNA Damage Sensing pathway, which is linked to downstream DNA damage response, are explored. Following DNA damage (double-stranded DNA breaks activating ATM), activated MDMX protein competes the ATM-p53 mRNA interaction and prevents the association of the p53 mRNA with NBS1 (MRN complex). These data also reveal the binding domains and the phosphorylation events on ATM that regulate the interaction and the trafficking of the complex to the cytoplasm. CONCLUSION: The presented model shows a novel interaction of ATM with the p53 mRNA and describes the link between DNA Damage Sensing with the downstream p53 activation pathways; supporting the rising functional implications of synonymous mutations altering secondary mRNA structures.
TP53 gene abnormalities represent the most important biomarker in chronic lymphocytic leukemia (CLL). Altered protein modifications could also influence p53 function, even in the wild-type protein. We assessed the impact of p53 protein phosphorylations on p53 functions as an alternative inactivation mechanism. We studied p53 phospho-profiles induced by DNA-damaging agents (fludarabine, doxorubicin) in 71 TP53-intact primary CLL samples. Doxorubicin induced two distinct phospho-profiles: profile I (heavily phosphorylated) and profile II (hypophosphorylated). Profile II samples were less capable of activating p53 target genes upon doxorubicin exposure, resembling TP53-mutant samples at the transcriptomic level, whereas standard p53 signaling was triggered in profile I. ATM locus defects were more common in profile II. The samples also differed in the basal activity of the hypoxia pathway: the highest level was detected in TP53-mutant samples, followed by profile II and profile I. Our study suggests that wild-type TP53 CLL cells with less phosphorylated p53 show TP53-mutant-like behavior after DNA damage. p53 hypophosphorylation and the related lower ability to respond to DNA damage are linked to ATM locus defects and the higher basal activity of the hypoxia pathway.
- MeSH
- ATM protein genetika metabolismus MeSH
- chronická lymfatická leukemie * genetika MeSH
- doxorubicin farmakologie MeSH
- fosforylace MeSH
- geny p53 MeSH
- hypoxie genetika MeSH
- lidé MeSH
- nádorový supresorový protein p53 * metabolismus MeSH
- poškození DNA MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
PURPOSE: Germline missense variants of unknown significance in cancer-related genes are increasingly being identified with the expanding use of next-generation sequencing. The ataxia telangiectasia-mutated (ATM) gene on chromosome 11 has more than 1,000 germline missense variants of unknown significance and is a tumor suppressor. We aimed to determine if rare germline ATM variants are more frequent in chronic lymphocytic leukemia (CLL) compared with other hematologic malignancies and if they influence the clinical characteristics of CLL. METHODS: We identified 3,128 patients (including 825 patients with CLL) in our hematologic malignancy clinic who had received clinical-grade sequencing of the entire coding region of ATM. We ascertained the comparative frequencies of germline ATM variants in categories of hematologic neoplasms, and, in patients with CLL, we determined whether these variants affected CLL-associated characteristics such as somatic 11q deletion. RESULTS: Rare germline ATM variants are present in 24% of patients with CLL, significantly greater than that in patients with other lymphoid malignancies (16% prevalence), myeloid disease (15%), or no hematologic neoplasm (14%). Patients with CLL with germline ATM variants are younger at diagnosis and twice as likely to have 11q deletion. The ATM variant p.L2307F is present in 3% of patients with CLL, is associated with a three-fold increase in rates of somatic 11q deletion, and is a hypomorph in cell-based assays. CONCLUSION: Germline ATM variants cluster within CLL and affect the phenotype of CLL that develops, implying that some of these variants (such as ATM p.L2307F) have functional significance and should not be ignored. Further studies are needed to determine whether these variants affect the response to therapy or account for some of the inherited risk of CLL.
- MeSH
- ATM protein * genetika MeSH
- chronická lymfatická leukemie * farmakoterapie MeSH
- lidé MeSH
- mutace MeSH
- nádorové supresorové proteiny genetika MeSH
- protein-serin-threoninkinasy genetika terapeutické užití MeSH
- proteiny buněčného cyklu genetika MeSH
- teleangiektatická ataxie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Research Support, N.I.H., Extramural MeSH
Prevalence mutací genu ATM je v naší populaci nízká. Zatímco jeho vliv na zvýšení incidence nádorů je znám, výběr jednotlivých léčebných modalit u pozitivně testovaných pacientek není většinou jednoznačný. Uvádíme přehled studií a kazuistik u pacientek s časným karcinomem prsu s mutacemi v proteinu ATM a jejich vliv na rozhodování v klinické praxi. Mutace v genu ATM riziko vzniku kontralaterálního tumoru prsu zvyšuje v případě jakékoli vzácné missense varianty ATM; nositelky této mutace, které obdržely radiační terapii pro svůj první karcinom prsu, měly významně zvýšené riziko rozvoje kontralaterálního karcinomu prsu ve srovnání s neexponovanými ženami (2,8-3,3*), pro jiné varianty to však není potvrzeno. Údaje o toxicitě radioterapie jsou rozporuplné, jasnou kontraindikací zůstávají jen mutace v genu TP53, jinak není jednoznačná kontraindikace ani pro mutaci skupiny genů BRCA. U missence variant ATM lze riziko toxicity předpokládat a prokázáno je i zvýšené riziko pozdní poradiační fibrózy. Další data jsou o riziku podávání antracyklinů jednak pro nižší účinek u některých variant a jednak pro vyšší toxicitu. V systémové protinádorové léčbě jsou preferovanou variantou taxany. Naplánování protinádorové léčby u pacientek s časným karcinomem prsu s mutací v genu ATM je záležitostí multidisciplinárního týmu, kde je klíčové vyjádření genetika. Adjuvantní radioterapii a adjuvantní léčbu antracykliny je vždy nutno indikovat uvážlivě s ohledem na poměr rizik.
The prevalence of ATM mutations in our population is low, while the importance of increasing the incirdence of tumors is known, the individual treatment modalities and their choice in a positively tested patient is mostly not clear. We present reviews of studies and case reports in patients with mutations in the ATM protein and their influence on decision-making in clinical practice in patients with early breast cancer. A mutation in the ATM gene increases the risk of developing a contralateral breast tumor in carriers of any rare ATM missense variant who received radiation therapy for a first breast cancer had an optimal risk of developing a contralateral breast cancer compared to unexposed women by 2.8-33*, for other variants it however, it is not confirmed. The data on the toxicity of radiotherapy are full, the only clear contraindications to the contradiction remain are mutations in the TP53 gene, otherwise there is no clear contraindication even for the BRCA group mutation, although the risk of toxicity can be assumed for the ATM missense variant mutation and the risk of late consultation fibrosis can also be proven. Other data are about the risk of administering anthracyclines, both because of a lower effect in some variants and because of higher toxicity. In systemic antitumor treatment, taxanes are the preferred variant. Planning antitumor treatment in patients with early breast cancer and with a mutation in the ATM gene is a matter of a multidisciplinary team, where the expression of genetics is key. Adjuvant radiotherapy and adjuvant anthracycline treatment must always be indicated judiciously with regard to the risk ratio.
- MeSH
- adjuvantní radioterapie škodlivé účinky MeSH
- antracykliny škodlivé účinky terapeutické užití MeSH
- ATM protein * analýza účinky záření MeSH
- časná detekce nádoru MeSH
- lidé MeSH
- nádory prsu * diagnóza farmakoterapie genetika radioterapie MeSH
- protokoly protinádorové léčby MeSH
- tolerance záření MeSH
- týmová péče o pacienty MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
The MRE11, RAD50, and NBN genes encode for the nuclear MRN protein complex, which senses the DNA double strand breaks and initiates the DNA repair. The MRN complex also participates in the activation of ATM kinase, which coordinates DNA repair with the p53-dependent cell cycle checkpoint arrest. Carriers of homozygous germline pathogenic variants in the MRN complex genes or compound heterozygotes develop phenotypically distinct rare autosomal recessive syndromes characterized by chromosomal instability and neurological symptoms. Heterozygous germline alterations in the MRN complex genes have been associated with a poorly-specified predisposition to various cancer types. Somatic alterations in the MRN complex genes may represent valuable predictive and prognostic biomarkers in cancer patients. MRN complex genes have been targeted in several next-generation sequencing panels for cancer and neurological disorders, but interpretation of the identified alterations is challenging due to the complexity of MRN complex function in the DNA damage response. In this review, we outline the structural characteristics of the MRE11, RAD50 and NBN proteins, the assembly and functions of the MRN complex from the perspective of clinical interpretation of germline and somatic alterations in the MRE11, RAD50 and NBN genes.
- MeSH
- ATM protein genetika metabolismus MeSH
- DNA vazebné proteiny genetika metabolismus MeSH
- enzymy opravy DNA genetika metabolismus MeSH
- homologní protein MRE11 genetika metabolismus MeSH
- hydrolasy působící na anhydridy kyselin genetika metabolismus MeSH
- jaderné proteiny genetika metabolismus MeSH
- lidé MeSH
- nádorové supresorové proteiny * genetika MeSH
- oprava DNA genetika MeSH
- proteiny buněčného cyklu * metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Germline pathogenic ATM (ataxia-telangiectasia mutated) variants are associated with the risk of multiple cancers; however, genetic testing reveals a large number of ATM variants of uncertain significance (VUS). Here, we studied germline ATM variants occurring in a real-world cohort of 336 patients with chronic lymphocytic leukaemia (CLL) and public cancer whole-exome/genome-sequencing datasets (445 CLL, 75 mantle cell lymphoma, 216 metastatic breast cancer, 140 lung cancer patients). We found that two-thirds of rare germline ATM variants are pathogenic (18%-50%) or VUS-predicted pathogenic (50%-82%), depending on cancer type and reaching a prevalence of up to 8%, and one-third are VUS-predicted benign. Patients with both pathogenic and VUS-predicted pathogenic variants, all heterozygous, mostly missense, are more predisposed to biallelic ATM inactivation by acquiring deletion (del)11q than patients without these variants, similar to patients with somatic ATM variants. A functional assay of ATM activity in primary CLL cells proved that VUS-predicted pathogenic ATM variants partially reduce ATM activity and concurrent del(11q) leads to complete loss of ATM activity. The rare germline variants were associated with reduced progression-free survival in CLL on novel agents, comparable to somatic ATM or TP53 disruptions. Our results highlight the need to determine the pathogenicity of VUS in clinically relevant genes such as ATM.
- MeSH
- ATM protein * genetika MeSH
- chronická lymfatická leukemie * genetika MeSH
- kohortové studie MeSH
- lidé MeSH
- lymfom z plášťových buněk genetika MeSH
- nádory prsu * genetika MeSH
- zárodečné mutace MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Chemoresistance of cancer cells is a hallmark of treatment failure and the poor patient prognosis. The mechanism of resistance is often connected to the overexpression of specific kinases involved in DNA damage response cascade. Contrary, selected kinase inhibition can augment cancer cell sensitization to conventional therapy, enabling more efficient treatment. Among those kinases, ataxia-telangiectasia and Rad3-related kinase (ATR), the major responder to replication stress, stands out as one of the most attractive targets. Inspired by clinical candidates targeting ATR, we designed and prepared a small, focused library of 40 novel compounds building on 7-azaindoles, 2,7-diazaindoles, and 1H-pyrazoles as core structures. All the compounds alone or combined with cisplatin (CDDP) were screened against a panel of nine cancer cell lines and one healthy cell line. Three highlighted compounds (3, 22, and 29) were selected for broad oncology panel screening containing 104 kinases. Only compound 29, the 2,7-diazaindole representative, showed ATR inhibitory efficacy with the IC50 around 10 μM. In contrast, the compound 22, 7-azaindole congener with the most pronounced cytotoxicity profile exceeding CDDP alone or in combination with CDDP, expressed the multi-kinase activity. Highlighted representatives, including compound 29, were also effective alone against primary glioblastoma. Overall, we showed that 7-azaindole, and 2,7-diazaindole scaffolds could be considered novel pharmacophores delivering anticancer activity.
- MeSH
- antitumorózní látky * farmakologie MeSH
- ATM protein MeSH
- cisplatina farmakologie MeSH
- indoly MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- pyrazoly farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
