The variable clinical course in chronic lymphocytic leukaemia (CLL) largely depends on p53 functionality and B-cell receptor (BCR) signalling propensity; however, it is unclear if there is any crosstalk between these pathways. We show that DNA damage response (DDR) activation leads to down-modulating the transcriptional factor FOXP1, which functions as a positive BCR signalling regulator and its high levels are associated with worse CLL prognosis. We identified microRNA (miRNA) miR-34a as the most prominently upregulated miRNA during DDR in CLL cells in vitro and in vivo during FCR therapy (fludarabine, cyclophosphamide, rituximab). MiR-34a induced by DDR activation and p53 stabilization potently represses FOXP1 expression by binding in its 3'-UTR. The low FOXP1 levels limit BCR signalling partially via derepressing BCR-inhibitory molecule CD22. We also show that low miR-34a levels can be used as a biomarker for worse response or shorter progression free survival in CLL patients treated with FCR chemoimmunotherapy, and shorter overall survival, irrespective of TP53 status. Additionally, we have developed a method for the absolute quantification of miR-34a copies and defined precise prognostic/predictive cutoffs. Overall, herein, we reveal for the first time that B cells limit their BCR signalling during DDR by down-modulating FOXP1 via DDR-p53/miR-34a axis.
- MeSH
- chronická lymfatická leukemie farmakoterapie genetika metabolismus patologie MeSH
- cyklofosfamid aplikace a dávkování MeSH
- dospělí MeSH
- forkhead transkripční faktory genetika metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- mikro RNA genetika MeSH
- míra přežití MeSH
- nádorové biomarkery genetika metabolismus MeSH
- následné studie MeSH
- poškození DNA účinky léků genetika MeSH
- prognóza MeSH
- protokoly antitumorózní kombinované chemoterapie terapeutické užití MeSH
- receptory antigenů B-buněk genetika metabolismus MeSH
- regulace genové exprese u nádorů MeSH
- represorové proteiny genetika metabolismus MeSH
- rituximab aplikace a dávkování MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- signální transdukce MeSH
- vidarabin aplikace a dávkování analogy a deriváty 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
- Publikační typ
- abstrakt z konference MeSH
Follicular lymphoma (FL) is a common indolent B-cell malignancy with a variable clinical course. An unfavorable event in its course is histological transformation to a high-grade lymphoma, typically diffuse large B-cell lymphoma. Recent studies show that genetic aberrations of MYC or its overexpression are associated with FL transformation (tFL). However, the precise molecular mechanisms underlying tFL are unclear. Here we performed the first profiling of expression of microRNAs (miRNAs) in paired samples of FL and tFL and identified 5 miRNAs as being differentially expressed. We focused on one of these miRNAs, namely miR-150, which was uniformly downmodulated in all examined tFLs (∼3.5-fold), and observed that high levels of MYC are responsible for repressing miR-150 in tFL by binding in its upstream region. This MYC-mediated repression of miR-150 in B cells is not dependent on LIN28A/B proteins, which influence the maturation of miR-150 precursor (pri-miR-150) in myeloid cells. We also demonstrated that low miR-150 levels in tFL lead to upregulation of its target, namely FOXP1 protein, which is a known positive regulator of cell survival, as well as B-cell receptor and NF-κB signaling in malignant B cells. We revealed that low levels of miR-150 and high levels of its target, FOXP1, are associated with shorter overall survival in FL and suggest that miR-150 could serve as a good biomarker measurable in formalin-fixed paraffin-embedded tissue. Overall, our study demonstrates the role of the MYC/miR-150/FOXP1 axis in malignant B cells as a determinant of FL aggressiveness and its high-grade transformation.
- MeSH
- aktivace transkripce MeSH
- difúzní velkobuněčný B-lymfom genetika patologie MeSH
- down regulace MeSH
- folikulární lymfom diagnóza genetika patologie MeSH
- forkhead transkripční faktory genetika MeSH
- lidé MeSH
- mikro RNA genetika MeSH
- nádorová transformace buněk genetika patologie MeSH
- prognóza MeSH
- protoonkogenní proteiny c-myc genetika MeSH
- regulace genové exprese u nádorů * MeSH
- represorové proteiny genetika MeSH
- upregulace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
Molekulární podstata folikulárního lymfomu (FL) byla částečně poodhalena již poměrně dávno zjištěním, že téměř ve všech případech je v maligních B lymfocytech přítomna translokace genu BCL2 do oblasti kódující těžký řetězec imunoglobulinů. Tato aberace vede k ektopické a konstitutivní expresi antiapoptotického BCL2 v B lymfocytech. Samotná však zřejmě není pro vznik onemocnění postačující, což naznačují jak výsledky získané na myším modelu, tak i častý výskyt translokace BCL2 v B lymfocytech zdravých jedinců. Předpokládalo se, že musí existovat další aberace, jejichž výskyt je spojen se vznikem FL. K jejich odhalení přispěl nedávno rozvoj metod masivního paralelního sekvenování (sekvenování nové generace), díky kterému bylo popsáno množství genetických aberací, které provázejí vznik a progresi této malignity. Skutečnost, že některé z nich se vyskytují již v raných stadiích FL a jsou sdílené většinou pacientů, zásadně koriguje předešlou představu o vzniku tohoto onemocnění. FL navíc u nezanedbatelné části pacientů podléhá histologické transformaci do agresivnějšího onemocnění, což s sebou nese další specifické aberace. V tomto přehledovém článku shrnujeme nejnovější poznatky o molekulárních drahách zapojených v biologii FL a jejich význam v kontextu přirozeného vývoje B lymfocytů. Pochopení molekulární patogeneze FL je základem pro vývoj nových cílených léčiv, stratifikaci pacientů a možná i volbu léčby pro skupiny pacientů dle specifických aberací.
The molecular pathogenesis of follicular lymphoma (FL) was partially revealed by the discovery of BCL2 translocations to the region encoding the immunoglobulin heavy chain, which accompany the vast majority of cases. This aberration leads to the ectopic and constitutive expression of anti-apoptotic BCL2 protein in B-cells. Nevertheless, the aberration alone is not sufficient for FL development, which suggests necessity of further genetic aberrations acquisition for neoplastic transformation to FL. Their discovery has been enabled by recent progress in the field of massive parallel sequencing (next generation sequencing), which revealed high number of genetic aberrations connected with onset and progression of FL. The occurrence of many of these aberrations in the early stages of the disease, and the fact that they are shared by the majority of patients with FL, fundamentally changed our former understanding of the disease onset. Furthermore, in a large fraction of patients, FL undergoes histological transformation to a more aggressive lymphoma, which is also associated with specific genetic alterations. In this review, we summarize the current knowledge of molecular pathways connected with FL biology and discuss their role in the context of normal B-cell development. Understanding of FL biology is essential for the development of new targeted therapies and the stratification of patients, and potentially also for the selection of treatment for specific patients who share the same genetic aberrations.
- MeSH
- apoptóza MeSH
- B-lymfocyty fyziologie MeSH
- chromozomální aberace MeSH
- epigeneze genetická MeSH
- folikulární lymfom * etiologie MeSH
- geny myc MeSH
- lidé MeSH
- mikro RNA fyziologie MeSH
- mutace genetika MeSH
- protoonkogenní proteiny c-bcl-2 fyziologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- přehledy MeSH
OBJECTIVE: Mesial temporal lobe epilepsy (mTLE) is a severe neurological disorder characterized by recurrent seizures. mTLE is frequently accompanied by neurodegeneration in the hippocampus resulting in hippocampal sclerosis (HS), the most common morphological correlate of drug resistance in mTLE patients. Incomplete knowledge of pathological changes in mTLE+HS complicates its therapy. The pathological mechanism underlying mTLE+HS may involve abnormal gene expression regulation, including posttranscriptional networks involving microRNAs (miRNAs). miRNA expression deregulation has been reported in various disorders, including epilepsy. However, the miRNA profile of mTLE+HS is not completely known and needs to be addressed. METHODS: Here, we have focused on hippocampal miRNA profiling in 33 mTLE+HS patients and nine postmortem controls to reveal abnormally expressed miRNAs. In this study, we significantly reduced technology-related bias (the most common source of false positivity in miRNA profiling data) by combining two different miRNA profiling methods, namely next generation sequencing and miRNA-specific quantitative real-time polymerase chain reaction. RESULTS: These methods combined have identified and validated 20 miRNAs with altered expression in the human epileptic hippocampus; 19 miRNAs were up-regulated and one down-regulated in mTLE+HS patients. Nine of these miRNAs have not been previously associated with epilepsy, and 19 aberrantly expressed miRNAs potentially regulate the targets and pathways linked with epilepsy (such as potassium channels, γ-aminobutyric acid, neurotrophin signaling, and axon guidance). SIGNIFICANCE: This study extends current knowledge of miRNA-mediated gene expression regulation in mTLE+HS by identifying miRNAs with altered expression in mTLE+HS, including nine novel abnormally expressed miRNAs and their putative targets. These observations further encourage the potential of microRNA-based biomarkers or therapies.
- MeSH
- dospělí MeSH
- down regulace MeSH
- epilepsie temporálního laloku genetika metabolismus patologie chirurgie MeSH
- hipokampus metabolismus patologie chirurgie MeSH
- kvantitativní polymerázová řetězová reakce MeSH
- lidé středního věku MeSH
- lidé MeSH
- mikro RNA genetika MeSH
- mladiství MeSH
- mladý dospělý MeSH
- počítačová simulace MeSH
- regulace genové exprese * MeSH
- sekvenční analýza RNA MeSH
- skleróza MeSH
- stanovení celkové genové exprese MeSH
- upregulace MeSH
- vysoce účinné nukleotidové sekvenování MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mladiství MeSH
- mladý dospělý MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Publikační typ
- abstrakt z konference MeSH
- Klíčová slova
- histologická transformace, protein FOXP1,
- MeSH
- difúzní velkobuněčný B-lymfom * genetika metabolismus MeSH
- folikulární lymfom * genetika metabolismus MeSH
- forkhead transkripční faktory genetika MeSH
- lidé MeSH
- mikro RNA * genetika metabolismus MeSH
- nádorová transformace buněk MeSH
- nádorové biomarkery genetika metabolismus MeSH
- progrese nemoci MeSH
- represorové proteiny genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Tiaprofenic acid is a widely used anti-inflammatory drug; however, the reductive metabolism of tiaprofenic acid is not yet well understood. Here, we compared the reduction of tiaprofenic acid in microsomes and cytosol from the human liver. The microsomes exhibited lower Km value toward tiaprofenic acid than the cytosol (Km = 164 ± 18 μM vs. 569 ± 74 μM, respectively), whereas the cytosol showed higher specific activity during reduction than the microsomes (Vmax = 728 ± 52 pmol mg of protein-1 min-1 vs. 285 ± 11 pmol mg of protein-1 min-1, respectively). Next, a panel of recombinant carbonyl reducing enzymes from AKR and SDR superfamilies has been studied to find the enzymes responsible for the cytosolic reduction of tiaprofenic acid. CBR1 was identified as the reductase of tiaprofenic acid with high specific activity (56,965 ± 6741 pmol mg of protein-1 min-1). Three other enzymes, AKR1A1, AKR1B10, and AKR1C4, were also able to reduce tiaprofenic acid, but with very low activity. Thus, CBR1 was shown to be a tiaprofenic acid reductase in vitro and was also suggested to be the principal tiaprofenic acid reductase in vivo.
- MeSH
- alkoholoxidoreduktasy chemie genetika metabolismus MeSH
- biokatalýza MeSH
- cytosol enzymologie MeSH
- dehydrogenasy/reduktasy s krátkým řetězcem chemie genetika metabolismus MeSH
- játra enzymologie metabolismus MeSH
- kinetika MeSH
- lidé MeSH
- mikrozomy enzymologie MeSH
- propionáty chemie metabolismus MeSH
- rekombinantní proteiny biosyntéza chemie izolace a purifikace MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
