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.

• Klíčová slova
• CLL, p53, phosphorylation,
• 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
• Názvy látek
• ATM protein MeSH
• doxorubicin MeSH
• nádorový supresorový protein p53 * MeSH

Patients with chronic lymphocytic leukemia (CLL) bearing TP53 mutations experience chemorefractory disease and are therefore candidates for targeted therapy. However, the significance of low-burden TP53 mutations with <10% variant allele frequency (VAF) remains a matter for debate. Herein, we describe clonal evolution scenarios of low-burden TP53 mutations, the clinical impact of which we analyzed in a "real-world" CLL cohort. TP53 status was assessed by targeted next-generation sequencing (NGS) in 511 patients entering first-line treatment with chemo- and/or immunotherapy and 159 patients in relapse before treatment with targeted agents. Within the pretherapy cohort, 16% of patients carried low-burden TP53 mutations (0.1% to 10% VAF). Although their presence did not significantly shorten event-free survival after first-line therapy, it affected overall survival (OS). In a subgroup with TP53 mutations of 1% to 10% VAF, the impact on OS was observed only in patients with unmutated IGHV who had not received targeted therapy, as patients benefited from switching to targeted agents, regardless of initial TP53 mutational status. Analysis of the clonal evolution of low-burden TP53 mutations showed that the highest expansion rates were associated with fludarabine, cyclophosphamide, and rituximab regimen in both first- and second-line treatments (median VAF increase, 14.8× and 11.8×, respectively) in contrast to treatment with less intense treatment regimens (1.6×) and no treatment (0.8×). In the relapse cohort, 33% of patients carried low-burden TP53 mutations, which did not expand significantly upon targeted treatment (median VAF change, 1×). Sporadic cases of TP53 mutations' clonal shifts were connected with the development of resistance-associated mutations. Altogether, our data support the incorporation of low-burden TP53 variants in clinical decision making.

• MeSH
• chronická lymfatická leukemie genetika   terapie   MeSH
• dospělí MeSH
• imunoterapie MeSH
• Kaplanův-Meierův odhad MeSH
• klonální evoluce * účinky léků   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mutace účinky léků   MeSH
• nádorové buňky kultivované MeSH
• nádorový supresorový protein p53 genetika   MeSH
• protokoly protinádorové kombinované chemoterapie terapeutické užití   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• nádorový supresorový protein p53 MeSH
• TP53 protein, human MeSH Prohlížeč

Chronic lymphocytic leukemia is associated with a highly heterogeneous disease course in terms of clinical outcomes and responses to chemoimmunotherapy. This heterogeneity is partly due to genetic aberrations identified in chronic lymphocytic leukemia cells such as mutations of TP53 and/or deletions in chromosome 17p [del(17p)], resulting in loss of one TP53 allele. These aberrations are associated with markedly decreased survival and predict impaired response to chemoimmunotherapy thus being among the strongest predictive markers guiding treatment decisions in chronic lymphocytic leukemia. Clinical trials demonstrate the importance of accurately testing for TP53 aberrations [both del(17p) and TP53 mutations] before each line of treatment to allow for appropriate treatment decisions that can optimize patients' outcomes. The current report reviews the diagnostic methods to detect TP53 disruption better, the role of TP53 aberrations in treatment decisions and current therapies available for patients with chronic lymphocytic leukemia carrying these abnormalities. The standardization in sequencing technologies for accurate identification of TP53 mutations and the importance of continued evaluation of TP53 aberrations throughout initial and subsequent lines of therapy remain unmet clinical needs as new therapeutic alternatives become available.

• MeSH
• chromozomální delece * MeSH
• chronická lymfatická leukemie diagnóza   genetika   terapie   MeSH
• lidé MeSH
• lidské chromozomy, pár 17 genetika   MeSH
• mutace * MeSH
• nádorový supresorový protein p53 genetika   MeSH
• přežití bez známek nemoci MeSH
• prognóza MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• nádorový supresorový protein p53 MeSH

In chronic lymphocytic leukemia (CLL), TP53 gene defects, due to deletion of the 17p13 locus and/or mutation(s) within the TP53 gene, are associated with resistance to chemoimmunotherapy and a particularly dismal clinical outcome. On these grounds, analysis of TP53 aberrations has been incorporated into routine clinical diagnostics to improve patient stratification and optimize therapeutic decisions. The predictive implications of TP53 aberrations have increasing significance in the era of novel targeted therapies, i.e., inhibitors of B-cell receptor (BcR) signaling and anti-apoptotic BCL2 family members, owing to their efficacy in patients with TP53 defects. In this report, the TP53 Network of the European Research Initiative on Chronic Lymphocytic Leukemia (ERIC) presents updated recommendations on the methodological approaches for TP53 mutation analysis. Moreover, it provides guidance to ensure that the analysis is performed in a timely manner for all patients requiring treatment and that the data is interpreted and reported in a consistent, standardized, and accurate way. Since next-generation sequencing technologies are gaining prominence within diagnostic laboratories, this report also offers advice and recommendations for the interpretation of TP53 mutation data generated by this methodology.

• MeSH
• chronická lymfatická leukemie genetika   MeSH
• geny p53 genetika   MeSH
• lidé MeSH
• mutační analýza DNA metody   MeSH
• vysoce účinné nukleotidové sekvenování metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• směrnice pro lékařskou praxi MeSH
• Geografické názvy
• Evropa MeSH

Chronic lymphocytic leukemia is a disease with up-regulated expression of the transmembrane tyrosine-protein kinase ROR1, a member of the Wnt/planar cell polarity pathway. In this study, we identified COBLL1 as a novel interaction partner of ROR1. COBLL1 shows clear bimodal expression with high levels in chronic lymphocytic leukemia patients with mutated IGHV and approximately 30% of chronic lymphocytic leukemia patients with unmutated IGHV. In the remaining 70% of chronic lymphocytic leukemia patients with unmutated IGHV, COBLL1 expression is low. Importantly, chronic lymphocytic leukemia patients with unmutated IGHV and high COBLL1 have an unfavorable disease course with short overall survival and time to second treatment. COBLL1 serves as an independent molecular marker for overall survival in chronic lymphocytic leukemia patients with unmutated IGHV. In addition, chronic lymphocytic leukemia patients with unmutated IGHV and high COBLL1 show impaired motility and chemotaxis towards CCL19 and CXCL12 as well as enhanced B-cell receptor signaling pathway activation demonstrated by increased PLCγ2 and SYK phosphorylation after IgM stimulation. COBLL1 expression also changes during B-cell maturation in non-malignant secondary lymphoid tissue with a higher expression in germinal center B cells than naïve and memory B cells. Our data thus suggest COBLL1 involvement not only in chronic lymphocytic leukemia but also in B-cell development. In summary, we show that expression of COBLL1, encoding novel ROR1-binding partner, defines chronic lymphocytic leukemia subgroups with a distinct response to microenvironmental stimuli, and independently predicts survival of chronic lymphocytic leukemia with unmutated IGHV.

• MeSH
• analýza přežití MeSH
• chronická lymfatická leukemie klasifikace   diagnóza   genetika   mortalita   MeSH
• lidé MeSH
• mutace MeSH
• pohyb buněk MeSH
• polarita buněk MeSH
• prognóza MeSH
• signální dráha Wnt MeSH
• sirotčí receptory podobné receptoru tyrosinkinasy metabolismus   MeSH
• těžké řetězce imunoglobulinů genetika   MeSH
• transkripční faktory metabolismus   MeSH
• variabilní oblast imunoglobulinu genetika   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• COBLL1 protein, human MeSH Prohlížeč
• ROR1 protein, human MeSH Prohlížeč
• sirotčí receptory podobné receptoru tyrosinkinasy MeSH
• těžké řetězce imunoglobulinů MeSH
• transkripční faktory MeSH
• variabilní oblast imunoglobulinu MeSH

The rapid progress in next-generation sequencing technologies has significantly contributed to our knowledge of the genetic events associated with the development, progression and treatment resistance of chronic lymphocytic leukemia patients. Together with the discovery of new driver mutations, next-generation sequencing has revealed an immense degree of both intra- and inter-tumor heterogeneity and enabled us to describe marked clonal evolution. Advances in immunogenetics may be implemented to detect minimal residual disease more sensitively and to track clonal B cell populations, their dynamics and molecular characteristics. The interpretation of these aspects is indispensable to thoroughly examine the genetic background of chronic lymphocytic leukemia. We review and discuss the recent results provided by the different next-generation sequencing techniques used in studying the chronic lymphocytic leukemia genome, as well as future perspectives in the methodologies and applications.

• Klíčová slova
• CLL prognosis, chronic lymphocytic leukemia, clonal evolution, immunogenetics, next-generation sequencing,
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Accurate assessment of TP53 gene status in sporadic tumors and in the germline of individuals at high risk of cancer due to Li-Fraumeni Syndrome (LFS) has important clinical implications for diagnosis, surveillance, and therapy. Genomic data from more than 20,000 cancer genomes provide a wealth of information on cancer gene alterations and have confirmed TP53 as the most commonly mutated gene in human cancer. Analysis of a database of 70,000 TP53 variants reveals that the two newly discovered exons of the gene, exons 9β and 9γ, generated by alternative splicing, are the targets of inactivating mutation events in breast, liver, and head and neck tumors. Furthermore, germline rearrange-ments in intron 1 of TP53 are associated with LFS and are frequently observed in sporadic osteosarcoma. In this context of constantly growing genomic data, we discuss how screening strategies must be improved when assessing TP53 status in clinical samples. Finally, we discuss how TP53 alterations should be described by using accurate nomenclature to avoid confusion in scientific and clinical reports. Cancer Res; 77(6); 1250-60. ©2017 AACR.

• MeSH
• genetická variace genetika   MeSH
• lidé MeSH
• nádorový supresorový protein p53 genetika   MeSH
• nádory diagnóza   genetika   terapie   MeSH
• řízení kvality * MeSH
• směrnice pro lékařskou praxi jako téma normy   MeSH
• validační studie jako téma MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• nádorový supresorový protein p53 MeSH
• TP53 protein, human MeSH Prohlížeč

Revolutionary progress has recently changed the landscape of chronic lymphocytic leukemia (CLL). Powerful prognostic factors, especially p53 mutation and/or deletion and IGHV mutation status, have refined individual patient prognosis. Purine analogs and monoclonal antibodies paved the way from palliative treatment to chemoimmunotherapy capable of eradication of minimal residual disease and prolongation of survival. Obinutuzumab (GA-101) and ofatumumab have been recently approved for the treatment of comorbid patients. Bendamustine is available for first-line treatment of patients ineligible for fludarabine, cyclophosphamide, and rituximab (FCR). High-dose glucocorticoids combined with rituximab represent a promising option for refractory CLL; ofatumumab is approved for fludarabine- and alemtuzumab-refractory patients. Allogeneic stem cell transplantation is the only curative option but is feasible in a highly selected group of patients only. The novel small molecule inhibitors ibrutinib and idelalisib have been recently approved for relapsed/refractory CLL. This review provides practical advice for diagnosis, prognostication and treatment of CLL.

• Klíčová slova
• chronic, drug therapy, ibrutinib, idelalisib, leukemia, lymphocytic, obinutuzumab, ofatumumab, prognosis,
• Publikační typ
• časopisecké články MeSH

• MeSH
• adenin analogy a deriváty   MeSH
• alely MeSH
• bicyklické sloučeniny heterocyklické terapeutické užití   MeSH
• chinazolinony terapeutické užití   MeSH
• chronická lymfatická leukemie diagnóza   farmakoterapie   genetika   patologie   MeSH
• cílená molekulární terapie MeSH
• exprese genu MeSH
• fosfatidylinositol-3-kinasy třídy I antagonisté a inhibitory   genetika   metabolismus   MeSH
• frekvence genu MeSH
• lidé MeSH
• nádorové biomarkery genetika   metabolismus   MeSH
• nádorový supresorový protein p53 nedostatek   genetika   MeSH
• piperidiny MeSH
• prognóza MeSH
• proteinkinasa BTK MeSH
• protinádorové látky terapeutické užití   MeSH
• puriny terapeutické užití   MeSH
• pyrazoly terapeutické užití   MeSH
• pyrimidiny terapeutické užití   MeSH
• sulfonamidy terapeutické užití   MeSH
• tyrosinkinasy antagonisté a inhibitory   genetika   metabolismus   MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• úvodníky MeSH
• Názvy látek
• adenin MeSH
• bicyklické sloučeniny heterocyklické MeSH
• chinazolinony MeSH
• fosfatidylinositol-3-kinasy třídy I MeSH
• ibrutinib MeSH Prohlížeč
• idelalisib MeSH Prohlížeč
• nádorové biomarkery MeSH
• nádorový supresorový protein p53 MeSH
• PIK3CD protein, human MeSH Prohlížeč
• piperidiny MeSH
• proteinkinasa BTK MeSH
• protinádorové látky MeSH
• puriny MeSH
• pyrazoly MeSH
• pyrimidiny MeSH
• sulfonamidy MeSH
• TP53 protein, human MeSH Prohlížeč
• tyrosinkinasy MeSH
• venetoclax MeSH Prohlížeč

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. We therefore developed a new ATM-p53 functional assay with the aim to (i) identify and (ii) distinguish abnormalities of TP53 versus ATM and (iii) enable the identification of additional defects in the ATM-p53 pathway. Reversed transcriptase multiplex ligation-dependent probe amplification (RT-MLPA) was used to measure ATM and/or p53-dependent genes at the RNA level following DNA damage using irradiation. Here, we showed that this assay is able to identify and distinguish three subgroups of CLL tumors (i.e., TP53-defective, ATM-defective and WT) and is also able to detect additional samples with a defective DDR, without molecular aberrations in TP53 and/or ATM. These findings make the ATM-p53 RT-MLPA functional assay a promising prognostic tool for predicting treatment responses in CLL.

• MeSH
• ATM protein genetika   metabolismus   MeSH
• biotest MeSH
• chemorezistence genetika   MeSH
• chronická lymfatická leukemie farmakoterapie   genetika   metabolismus   patologie   MeSH
• doxorubicin farmakologie   MeSH
• epigeneze genetická MeSH
• lidé MeSH
• multiplexová polymerázová řetězová reakce metody   MeSH
• mutace * MeSH
• nádorový supresorový protein p53 genetika   metabolismus   MeSH
• polymerázová řetězová reakce s reverzní transkripcí metody   MeSH
• poškození DNA MeSH
• protinádorové látky farmakologie   MeSH
• regulace genové exprese u leukemie * MeSH
• RNA nádorová genetika   MeSH
• senzitivita a specificita MeSH
• vidarabin analogy a deriváty   farmakologie   MeSH
• záření gama MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ATM protein, human MeSH Prohlížeč
• ATM protein MeSH
• doxorubicin MeSH
• fludarabine MeSH Prohlížeč
• nádorový supresorový protein p53 MeSH
• protinádorové látky MeSH
• RNA nádorová MeSH
• vidarabin MeSH