- Publikační typ
- abstrakt z konference MeSH
Práce předkládá popis případu s vyslovenou závažnou suspekcí na izolovanou difuzní infiltraci ledviny leukemickými myeloidními buňkami, avšak bez primárního postižení kostní dřeně a bez patologického nálezu na zobrazovacím vyšetření. To vše u pacientky došetřované pro současné febrilie nejasné etiologie, akutní neoligurickou renální insuficienci, mikrocytární anémii, váhový úbytek, nechutenství, suchý kašel a mírnou splenomegalii. Pro hematologa neobvyklý a nevysvětlitelný případ tak vyžadoval komplexní diagnostický postup zahrnující opakovaná bioptická vyšetření kostní dřeně a ledviny, která následně leukemickou infiltraci nepotvrdila. Symptomatologie a patologické laboratorní nálezy promptně zareagovaly na zavedenou léčbu kortikoidy a stav byl uzavřen jako akutní tubulointersticiální nefritida.
This article describes a case of highly suspected isolated diffuse kidney infiltration by myeloid leukemic cells, without primary bone marrow involvement or any pathological imaging findings in a patient presenting with fever of unknown origin, acute kidney injury, microcytic anaemia, weight loss, anorexia, dry cough and mild splenomegaly. This complex diagnostic process thus required repeated biopsy of both bone marrow and kidney, which subsequently ruled out leukemic infiltration. The presenting symptoms and pathological laboratory findings responded promptly to corticosteroid treatment, and our patient was finally diagnosed with tubulointerstitial nephritis.
- MeSH
- akutní myeloidní leukemie MeSH
- biopsie MeSH
- diferenciální diagnóza MeSH
- horečka neznámého původu MeSH
- hormony kůry nadledvin aplikace a dávkování terapeutické užití MeSH
- intersticiální nefritida * diagnóza terapie MeSH
- ledviny anatomie a histologie diagnostické zobrazování MeSH
- lidé MeSH
- mladiství MeSH
- renální insuficience diagnóza MeSH
- vyšetřování kostní dřeně MeSH
- Check Tag
- lidé MeSH
- mladiství MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
- práce podpořená grantem MeSH
Genome methylation profiles define naïve-like (n-CLL), memory-like (m-CLL), and intermediate (i-CLL) subsets of chronic lymphocytic leukaemia (CLL). The profiles can be easily determined by the analysis of the five-CpG signature. m-CLL, i-CLL, and n-CLL with the good, intermediate, and poor prognoses, respectively, differ by the somatic hypermutation status of the immunoglobulin heavy chain variable gene (IGHV), a widely used prognostic predictor in CLL. We have previously shown that the expression of WNT5A, encoding a ROR1 ligand, distinguishes patients with the worse outcome within the prognostically favourable IGHV-mutated subgroup. To analyse the mechanisms controlling WNT5A expression, we investigated the methylation status of 54 CpG sites within the WNT5A promoter and its relation to the WNT5A gene expression. In a cohort of 59 CLL patients balanced for combinations of IGHV and WNT5A statuses, we identified three promoter CpG sites whose methylation level correlated with the WNT5A expression within the IGHV-mutated subgroup. Further, we complemented our data with the methylation status of the five-CpG signature. IGHV-mutated/WNT5A-negative and IGHV-mutated/WNT5A-positive cases overlapped with m‐CLL and i‐CLL methylation subgroups, respectively, while most IGHV‐unmutated samples were assigned to n-CLL. Median methylation levels of all the three CpG sites in the WNT5A promoter were lowest in i-CLL. Finally, a detailed analysis of m-CLL and i-CLL showed that undetectable WNT5A expression predicts longer treatment-free survival with higher statistical significance than the classification according to the five-CpG signature. To conclude, a favourable m-CLL subgroup is associated with mutated IGHV and undetectable WNT5A expression due to its promoter methylation.
- MeSH
- chronická lymfatická leukemie * genetika MeSH
- lidé MeSH
- ligandy MeSH
- metylace DNA MeSH
- mutace MeSH
- prognóza MeSH
- promotorové oblasti (genetika) MeSH
- protein Wnt 5a genetika metabolismus MeSH
- těžké řetězce imunoglobulinů genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Recirculation of chronic lymphocytic leukemia (CLL) cells between the peripheral blood and lymphoid niches plays a critical role in disease pathophysiology, and inhibiting this process is one of the major mechanisms of action for B-cell receptor (BCR) inhibitors such as ibrutinib and idelalisib. Migration is a complex process guided by chemokine receptors and integrins. However, it remains largely unknown how CLL cells integrate multiple migratory signals while balancing survival in the peripheral blood and the decision to return to immune niches. Our study provided evidence that CXCR4/CD5 intraclonal subpopulations can be used to study the regulation of migration of CLL cells. We performed RNA profiling of CXCR4dimCD5bright vs CXCR4brightCD5dim CLL cells and identified differential expression of dozens of molecules with a putative function in cell migration. GRB2-associated binding protein 1 (GAB1) positively regulated CLL cell homing capacity of CXCR4brightCD5dim cells. Gradual GAB1 accumulation in CLL cells outside immune niches was mediated by FoxO1-induced transcriptional GAB1 activation. Upregulation of GAB1 also played an important role in maintaining basal phosphatidylinositol 3-kinase (PI3K) activity and the "tonic" AKT phosphorylation required to sustain the survival of resting CLL B cells. This finding is important during ibrutinib therapy, because CLL cells induce the FoxO1-GAB1-pAKT axis, which represents an adaptation mechanism to the inability to home to immune niches. We have demonstrated that GAB1 can be targeted therapeutically by novel GAB1 inhibitors, alone or in combination with BTK inhibition. GAB1 inhibitors induce CLL cell apoptosis, impair cell migration, inhibit tonic or BCR-induced AKT phosphorylation, and block compensatory AKT activity during ibrutinib therapy.
- MeSH
- adaptorové proteiny signální transdukční biosyntéza MeSH
- adenin analogy a deriváty farmakologie MeSH
- chronická lymfatická leukemie farmakoterapie metabolismus patologie MeSH
- forkhead box protein O1 metabolismus MeSH
- lidé MeSH
- nádorové buněčné linie MeSH
- piperidiny farmakologie MeSH
- pohyb buněk * MeSH
- protoonkogenní proteiny c-akt metabolismus MeSH
- regulace genové exprese u leukemie * MeSH
- signální transdukce * MeSH
- upregulace * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The in vivo rituximab effects in B cell malignancies are only partially understood. Here we analyzed in a large chronic lymphocytic leukemia (CLL) cohort (n = 80) the inter-patient variability in CLL cell count reduction within the first 24 h of rituximab administration in vivo, and a phenomenon of blood repopulation by malignant cells after anti-CD20 antibody therapy. Larger CLL cell elimination after rituximab infusion was associated with lower pre-therapy CLL cell counts, higher CD20 levels, and the non-exhausted capacity of complement-dependent cytotoxicity (CDC). The absolute amount of cell-surface CD20 molecules (CD20 density x CLL lymphocytosis) was a predictor for complement exhaustion during therapy. We also describe that a highly variable decrease in CLL cell counts at 5 h (88 %-2%) following rituximab infusion is accompanied in most patients by peripheral blood repopulation with CLL cells at 24 h, and in ∼20 % of patients, this resulted in CLL counts higher than before therapy. We provide evidence that CLL cells recrudescence is linked with i) CDC exhaustion, which leads to the formation of an insufficient amount of membrane attack complexes, likely resulting in temporary retention of surviving rituximab-opsonized cells by the mononuclear-phagocyte system (followed by their release back to blood), and ii) CLL cells regression from immune niches (CXCR4dimCD5bright intraclonal subpopulation). Patients with major peripheral blood CLL cell repopulation exhibited a longer time-to-progression after chemoimmunotherapy compared to patients with lower or no repopulation, suggesting chemotherapy vulnerability of CLL cells that repopulate the blood.
- MeSH
- chronická lymfatická leukemie krev farmakoterapie imunologie patologie MeSH
- cytotoxicita imunologická imunologie MeSH
- komplement imunologie MeSH
- lidé MeSH
- následné studie MeSH
- protinádorové látky imunologicky aktivní terapeutické užití MeSH
- rituximab terapeutické užití MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
B-cell receptor (BCR) signaling and T-cell interactions play a pivotal role in chronic lymphocytic leukemia (CLL) pathogenesis and disease aggressiveness. CLL cells can use microRNAs (miRNAs) and their targets to modulate microenvironmental interactions in the lymph node niches. To identify miRNA expression changes in the CLL microenvironment, we performed complex profiling of short noncoding RNAs in this context by comparing CXCR4/CD5 intraclonal cell subpopulations (CXCR4dimCD5bright vs CXCR4brightCD5dim cells). This identified dozens of differentially expressed miRNAs, including several that have previously been shown to modulate BCR signaling (miR-155, miR-150, and miR-22) but also other candidates for a role in microenvironmental interactions. Notably, all 3 miR-29 family members (miR-29a, miR-29b, miR-29c) were consistently down-modulated in the immune niches, and lower miR-29(a/b/c) levels associated with an increased relative responsiveness of CLL cells to BCR ligation and significantly shorter overall survival of CLL patients. We identified tumor necrosis factor receptor-associated factor 4 (TRAF4) as a novel direct target of miR-29s and revealed that higher TRAF4 levels increase CLL responsiveness to CD40 activation and downstream nuclear factor-κB (NF-κB) signaling. In CLL, BCR represses miR-29 expression via MYC, allowing for concurrent TRAF4 upregulation and stronger CD40-NF-κB signaling. This regulatory loop is disrupted by BCR inhibitors (bruton tyrosine kinase [BTK] inhibitor ibrutinib or phosphatidylinositol 3-kinase [PI3K] inhibitor idelalisib). In summary, we showed for the first time that a miRNA-dependent mechanism acts to activate CD40 signaling/T-cell interactions in a CLL microenvironment and described a novel miR-29-TRAF4-CD40 signaling axis modulated by BCR activity.
- MeSH
- adenin analogy a deriváty farmakologie MeSH
- antigeny CD40 genetika metabolismus MeSH
- chronická lymfatická leukemie farmakoterapie genetika metabolismus patologie MeSH
- dospělí MeSH
- faktor 4 asociovaný s receptory TNF genetika metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- mikro RNA genetika MeSH
- míra přežití MeSH
- nádorové biomarkery genetika metabolismus MeSH
- nádorové buňky kultivované MeSH
- následné studie MeSH
- piperidiny farmakologie MeSH
- prognóza MeSH
- protoonkogenní proteiny c-bcr antagonisté a inhibitory MeSH
- protoonkogenní proteiny c-myc genetika metabolismus MeSH
- regulace genové exprese u nádorů * MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
Introduction of small-molecule inhibitors of B-cell receptor signaling and BCL2 protein significantly improves therapeutic options in chronic lymphocytic leukemia. However, some patients suffer from adverse effects mandating treatment discontinuation, and cases with TP53 defects more frequently experience early progression of the disease. Development of alternative therapeutic approaches is, therefore, of critical importance. Here we report details of the anti-chronic lymphocytic leukemia single-agent activity of MU380, our recently identified potent, selective, and metabolically robust inhibitor of checkpoint kinase 1. We also describe a newly developed enantioselective synthesis of MU380, which allows preparation of gram quantities of the substance. Checkpoint kinase 1 is a master regulator of replication operating primarily in intra-S and G2/M cell cycle checkpoints. Initially tested in leukemia and lymphoma cell lines, MU380 significantly potentiated efficacy of gemcitabine, a clinically used inducer of replication stress. Moreover, MU380 manifested substantial single-agent activity in both TP53-wild type and TP53-mutated leukemia and lymphoma cell lines. In chronic lymphocytic leukemia-derived cell lines MEC-1, MEC-2 (both TP53-mut), and OSU-CLL (TP53-wt) the inhibitor impaired cell cycle progression and induced apoptosis. In primary clinical samples, MU380 used as a single-agent noticeably reduced the viability of unstimulated chronic lymphocytic leukemia cells as well as those induced to proliferate by anti-CD40/IL-4 stimuli. In both cases, effects were comparable in samples harboring p53 pathway dysfunction (TP53 mutations or ATM mutations) and TP53-wt/ATM-wt cells. Lastly, MU380 also exhibited significant in vivo activity in a xenotransplant mouse model (immunodeficient strain NOD-scid IL2Rγnull ) where it efficiently suppressed growth of subcutaneous tumors generated from MEC-1 cells.
- MeSH
- antimetabolity antitumorózní farmakologie MeSH
- apoptóza MeSH
- buněčný cyklus MeSH
- checkpoint kinasa 1 antagonisté a inhibitory MeSH
- chemorezistence účinky léků MeSH
- chronická lymfatická leukemie farmakoterapie genetika patologie MeSH
- deoxycytidin analogy a deriváty farmakologie MeSH
- inhibitory proteinkinas farmakologie MeSH
- lidé MeSH
- mutace * MeSH
- myši inbrední NOD MeSH
- myši SCID MeSH
- myši MeSH
- nádorové biomarkery genetika MeSH
- nádorové buňky kultivované MeSH
- nádorový supresorový protein p53 genetika MeSH
- piperidiny farmakologie MeSH
- proliferace buněk MeSH
- pyrazoly farmakologie MeSH
- pyrimidiny farmakologie MeSH
- regulace genové exprese u nádorů účinky léků MeSH
- synergismus léků * MeSH
- xenogenní modely - testy antitumorózní aktivity MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- myši MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
- Publikační typ
- abstrakt z konference MeSH
