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
• Názvy látek
• adenin MeSH
• antigeny CD40 MeSH
• BCR protein, human MeSH Prohlížeč
• faktor 4 asociovaný s receptory TNF MeSH
• ibrutinib MeSH Prohlížeč
• mikro RNA MeSH
• MIRN29a microRNA, human MeSH Prohlížeč
• MYC protein, human MeSH Prohlížeč
• nádorové biomarkery MeSH
• piperidiny MeSH
• protoonkogenní proteiny c-bcr MeSH
• protoonkogenní proteiny c-myc MeSH
• TRAF4 protein, human MeSH Prohlížeč

The adaptive immune system is responsible for generating immunological response and immunological memory. Regulation of adaptive immunity including B cell and T cell biology was mainly understood from the protein and microRNA perspective. However, long non-coding RNAs (lncRNAs) are an emerging class of non-coding RNAs (ncRNAs) that influence key factors in lymphocyte biology such as NOTCH, PAX5, MYC and EZH2. LncRNAs were described to modulate lymphocyte activation by regulating pathways such as NFAT, NFκB, MYC, interferon and TCR/BCR signalling (NRON, NKILA, BCALM, GAS5, PVT1), and cell effector functions (IFNG-AS1, TH2-LCR). Here we review lncRNA involvement in adaptive immunity and the implications for autoimmune diseases (multiple sclerosis, inflammatory bowel disease, rheumatoid arthritis) and T/B cell leukaemias and lymphomas (CLL, MCL, DLBCL, T-ALL). It is becoming clear that lncRNAs are important in adaptive immune response and provide new insights into its orchestration.

• Klíčová slova
• Adaptive immunity, Autoimmune diseases, B cell, B/T cell activation, Leukaemia, LncRNAs, Lymphocyte development, Lymphoma, T cell, T cell polarization,
• MeSH
• adaptivní imunita genetika   MeSH
• aktivace lymfocytů genetika   MeSH
• lidé MeSH
• nemoc genetika   MeSH
• RNA dlouhá nekódující genetika   fyziologie   MeSH
• signální transdukce genetika   imunologie   MeSH
• T-lymfocyty fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH
• Názvy látek
• RNA dlouhá nekódující MeSH

The approval of BTK and PI3K inhibitors (ibrutinib, idelalisib) represents a revolution in the therapy of B cell malignancies such as chronic lymphocytic leukemia (CLL), mantle-cell lymphoma (MCL), diffuse large B cell lymphoma (DLBCL), follicular lymphoma (FL), or Waldenström's macroglobulinemia (WM). However, these "BCR inhibitors" function by interfering with B cell pathophysiology in a more complex way than anticipated, and resistance develops through multiple mechanisms. In ibrutinib treated patients, the most commonly described resistance-mechanism is a mutation in BTK itself, which prevents the covalent binding of ibrutinib, or a mutation in PLCG2, which acts to bypass the dependency on BTK at the BCR signalosome. However, additional genetic aberrations leading to resistance are being described (such as mutations in the CARD11, CCND1, BIRC3, TRAF2, TRAF3, TNFAIP3, loss of chromosomal region 6q or 8p, a gain of Toll-like receptor (TLR)/MYD88 signaling or gain of 2p chromosomal region). Furthermore, relative resistance to BTK inhibitors can be caused by non-genetic adaptive mechanisms leading to compensatory pro-survival pathway activation. For instance, PI3K/mTOR/Akt, NFkB and MAPK activation, BCL2, MYC, and XPO1 upregulation or PTEN downregulation lead to B cell survival despite BTK inhibition. Resistance could also arise from activating microenvironmental pathways such as chemokine or integrin signaling via CXCR4 or VLA4 upregulation, respectively. Defining these compensatory pro-survival mechanisms can help to develop novel therapeutic combinations of BTK inhibitors with other inhibitors (such as BH3-mimetic venetoclax, XPO1 inhibitor selinexor, mTOR, or MEK inhibitors). The mechanisms of resistance to PI3K inhibitors remain relatively unclear, but some studies point to MAPK signaling upregulation via both genetic and non-genetic changes, which could be co-targeted therapeutically. Alternatively, drugs mimicking the BTK/PI3K inhibition effect can be used to prevent adhesion and/or malignant B cell migration (chemokine and integrin inhibitors) or to block the pro-proliferative T cell signals in the microenvironment (such as IL4/STAT signaling inhibitors). Here we review the genetic and non-genetic mechanisms of resistance and adaptation to the first generation of BTK and PI3K inhibitors (ibrutinib and idelalisib, respectively), and discuss possible combinatorial therapeutic strategies to overcome resistance or to increase clinical efficacy.

• Klíčová slova
• B cell malignancies, B cell receptor, BCR inhibitor, adaptation, ibrutinib, resistance, targeted therapy,
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• BCR signalling, CD22, DNA damage, miR-34a, phosphatase,
• Publikační typ
• úvodníky MeSH

MicroRNA (miRNA) sponges are RNA transcripts containing multiple high-affinity binding sites that associate with and sequester specific miRNAs to prevent them from interacting with their target messenger (m)RNAs. Due to the high specificity of miRNA sponges and strong inhibition of target miRNAs, these molecules have become increasingly applied in miRNA loss-of-function studies. However, improperly designed sponge constructs may sequester off-target miRNAs; thus, it has become increasingly important to develop a tool for miRNA sponge construct design and testing. In this study, we introduce microRNA sponge generator and tester (miRNAsong), a freely available web-based tool for generation and in silico testing of miRNA sponges. This tool generates miRNA sponge constructs for specific miRNAs and miRNA families/clusters and tests them for potential binding to miRNAs in selected organisms. Currently, miRNAsong allows for testing of sponge constructs in 219 species covering 35,828 miRNA sequences. Furthermore, we also provide an example, supplemented with experimental data, of how to use this tool. Using miRNAsong, we designed and tested a sponge for miR-145 inhibition, and cloned the sequence into an inducible lentiviral vector. We found that established cell lines expressing miR-145 sponge strongly inhibited miR-145, thus demonstrating the usability of miRNAsong tool for sponge generation. URL: http://www.med.muni.cz/histology/miRNAsong/.

• MeSH
• HEK293 buňky MeSH
• internet * MeSH
• lidé MeSH
• messenger RNA metabolismus   MeSH
• mikro RNA genetika   metabolismus   MeSH
• počítačová simulace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• messenger RNA MeSH
• mikro RNA MeSH
• MIRN145 microRNA, human MeSH Prohlížeč

Agents targeting B-cell receptor (BCR) signaling-associated kinases such as Bruton tyrosine kinase (BTK) or phosphatidylinositol 3-kinase can induce mobilization of neoplastic B cells from the lymphoid tissues into the blood, which makes them potentially ideal to combine with anti-CD20 monoclonal antibodies (such as rituximab, obinutuzumab, or ofatumumab) for treatment of B-cell lymphomas and chronic lymphocytic leukemia (CLL). Here we show that interactions between leukemia cells and stromal cells (HS-5) upregulate CD20 on CLL cells and that administering ibrutinib downmodulates CD20 (MS4A1) expression in vivo. We observed that CLL cells that have recently exited the lymph node microenvironment and moved into the peripheral blood (CXCR4(dim)CD5(bright) subpopulation) have higher cell surface levels of CD20 than the cells circulating in the bloodstream for a longer time (CXCR4(bright)CD5(dim) cells). We found that CD20 is directly upregulated by CXCR4 ligand stromal cell-derived factor 1 (SDF-1α, CXCL12) produced by stromal cells, and BTK-inhibitor ibrutinib and CXCR4-inhibitor plerixafor block SDF-1α-mediated CD20 upregulation. Ibrutinib also downmodulated Mcl1 levels in CLL cells in vivo and in coculture with stromal cells. Overall, our study provides a first detailed mechanistic explanation of CD20 expression regulation in the context of chemokine signaling and microenvironmental interactions, which may have important implications for microenvironment-targeting therapies.

• MeSH
• adenin analogy a deriváty   MeSH
• antigeny CD20 chemie   genetika   metabolismus   MeSH
• chemokin CXCL12 genetika   metabolismus   MeSH
• chronická lymfatická leukemie farmakoterapie   metabolismus   patologie   MeSH
• lidé MeSH
• nádorové buňky kultivované MeSH
• piperidiny MeSH
• pyrazoly farmakologie   MeSH
• pyrimidiny farmakologie   MeSH
• receptory CXCR4 genetika   metabolismus   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• signální transdukce MeSH
• upregulace MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenin MeSH
• antigeny CD20 MeSH
• chemokin CXCL12 MeSH
• CXCL12 protein, human MeSH Prohlížeč
• CXCR4 protein, human MeSH Prohlížeč
• ibrutinib MeSH Prohlížeč
• piperidiny MeSH
• pyrazoly MeSH
• pyrimidiny MeSH
• receptory CXCR4 MeSH