BACKGROUND: Amplification of HER2, a receptor tyrosine kinase and a breast cancer-linked oncogene, is associated with aggressive disease. HER2 protein is localised mostly at the cell membrane, but a fraction translocates to mitochondria. Whether and how mitochondrial HER2 contributes to tumorigenicity is currently unknown. METHODS: We enriched the mitochondrial (mt-)HER2 fraction in breast cancer cells using an N-terminal mitochondrial targeting sequence and analysed how this manipulation impacts bioenergetics and tumorigenic properties. The role of the tyrosine kinase activity of mt-HER2 was assessed in wild type, kinase-dead (K753M) and kinase-enhanced (V659E) mtHER2 constructs. RESULTS: We document that mt-HER2 associates with the oxidative phosphorylation system, stimulates bioenergetics and promotes larger respiratory supercomplexes. mt-HER2 enhances proliferation and invasiveness in vitro and tumour growth and metastatic potential in vivo, in a kinase activity-dependent manner. On the other hand, constitutively active mt-HER2 provokes excessive mitochondria ROS generation, sensitises to cell death, and restricts growth of primary tumours, suggesting that regulation of HER2 activity in mitochondria is required for the maximal pro-tumorigenic effect. CONCLUSIONS: mt-HER2 promotes tumorigenicity by supporting bioenergetics and optimal redox balance.

• MeSH
• buněčné dýchání fyziologie   MeSH
• energetický metabolismus MeSH
• karcinogeneze metabolismus   MeSH
• lidé MeSH
• mitochondrie * metabolismus   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory prsu * metabolismus   genetika   MeSH
• oxidativní fosforylace MeSH
• proliferace buněk MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• receptor erbB-2 * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Gene inactivation of the cyclin-dependent kinase inhibitors p16INK4a, p15INK4b and p21WAF is frequently mediated by promoter gene methylation, whereas histone deacetylases (HDACs) control gene expression through their ability to deacetylate proteins. The effect of suberohydroxamic acid (SBHA) and 5-Aza-2'-deoxycytidine (Decitabine) (DAC) treatments on the transcription of CDKN2A, CDKN2B and CDKN1A genes, and their effects on molecular biological behavior were examined in two myeloma cell lines, RPMI8226 and U266, which differ in p53-functionality and IL-6 expression. In both tested myeloma cell lines, a non-methylated state of the CDKN2B gene promoter region was detected with normal gene expression, and the same level of p15INK4b protein was detected by immunocytochemical staining. Furthermore, in myeloma cells treated with SBHA and DAC alone, the expression of both p15INK4b and p21WAF was significantly upregulated in RPMI8226 cells (p53-functional, without IL-6 expression), whereas in the U266 cell line (p53 deleted, expressing IL-6) only p21WAF expression was significantly increased. Moreover, the analysis revealed that treatment with DAC induced DNMT3B enhancement in U266 cells. In conclusion, in myeloma cells with IL-6 expression, significantly increased DNMT3B expression indicated the tumorigenic consequences of 5-Aza-2'deoxycytidine treatment, which requires careful use in diseases involving epigenetic dysregulation, such as multiple myeloma (MM).

• MeSH
• decitabin * farmakologie   MeSH
• DNA-(cytosin-5-)methyltransferasa * genetika   metabolismus   MeSH
• epigeneze genetická * MeSH
• inhibitor p15 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• inhibitor p16 cyklin-dependentní kinasy genetika   metabolismus   MeSH
• interleukin-6 genetika   metabolismus   MeSH
• lidé MeSH
• metylace DNA MeSH
• mnohočetný myelom * genetika   metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádorový supresorový protein p53 genetika   metabolismus   MeSH
• proteiny buněčného cyklu genetika   metabolismus   MeSH
• umlčování genů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

PURPOSE: Mantle cell lymphoma (MCL) is an aggressive subtype of B-cell non-Hodgkin lymphomas characterized by (over)expression of BCL2. A BCL2-targeting drug, venetoclax, has promising anticancer activity in MCL. We analyzed molecular mechanisms of venetoclax resistance in MCL cells and tested strategies to overcome it. EXPERIMENTAL DESIGN: We confirmed key roles of proapoptotic proteins BIM and NOXA in mediating venetoclax-induced cell death in MCL. Both BIM and NOXA are, however, differentially expressed in cell lines compared with primary cells. First, NOXA protein is significantly overexpressed in most MCL cell lines. Second, deletions of BIM gene harbored by three commonly used MCL cell lines (JEKO-1, MINO, and Z138) were not found by array comparative genomic hybridization using a validation set of 24 primary MCL samples. RESULTS: We demonstrated that MCL1 and NOXA play important roles in mediating resistance to venetoclax. Consequently, we tested an experimental treatment strategy based on cotargeting BCL2 with venetoclax and MCL1 with a highly specific small-molecule MCL1 inhibitor S63845. The combination of venetoclax and S63845 demonstrated synthetic lethality in vivo on a panel of five patient-derived xenografts established from patients with relapsed MCL with adverse cytogenetics. CONCLUSIONS: Our data strongly support investigation of venetoclax in combination with S63845 as an innovative treatment strategy for chemoresistant MCL patients with adverse cytogenetics in the clinical grounds.

• MeSH
• antitumorózní látky farmakologie   MeSH
• bicyklické sloučeniny heterocyklické farmakologie   MeSH
• chemorezistence MeSH
• lidé MeSH
• lokální recidiva nádoru farmakoterapie   metabolismus   patologie   MeSH
• lymfom z plášťových buněk farmakoterapie   metabolismus   patologie   MeSH
• myši inbrední NOD MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• protein MCL-1 antagonisté a inhibitory   metabolismus   MeSH
• protoonkogenní proteiny c-bcl-2 antagonisté a inhibitory   metabolismus   MeSH
• pyrimidiny farmakologie   MeSH
• sulfonamidy farmakologie   MeSH
• synergismus léků * MeSH
• thiofeny farmakologie   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

• MeSH
• B-lymfocyty imunologie   patologie   MeSH
• buňky kostní dřeně imunologie   patologie   MeSH
• chronická lymfatická leukemie genetika   imunologie   patologie   MeSH
• difúzní velkobuněčný B-lymfom genetika   imunologie   patologie   MeSH
• folikulární lymfom genetika   imunologie   patologie   MeSH
• hematopoetické kmenové buňky imunologie   patologie   MeSH
• hematopoéza genetika   imunologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lymfom z plášťových buněk genetika   imunologie   patologie   MeSH
• mnohočetný myelom genetika   imunologie   patologie   MeSH
• nádorové proteiny genetika   imunologie   MeSH
• regulace genové exprese u nádorů MeSH
• senioři MeSH
• stanovení celkové genové exprese MeSH
• studie případů a kontrol MeSH
• věkové faktory MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• dopisy MeSH
• práce podpořená grantem MeSH

• MeSH
• Asijci MeSH
• běloši MeSH
• buněčná diferenciace MeSH
• buňky kostní dřeně imunologie   patologie   MeSH
• chronická lymfatická leukemie etnologie   imunologie   patologie   MeSH
• imunofenotypizace MeSH
• lidé MeSH
• počet lymfocytů MeSH
• prekurzorové B-lymfoidní buňky imunologie   patologie   MeSH
• studie případů a kontrol MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH
• práce podpořená grantem MeSH

PURPOSE: To investigate the roles of BCL2, MCL1, and BCL-XL in the survival of diffuse large B-cell lymphoma (DLBCL). EXPERIMENTAL DESIGNS: Immunohistochemical analysis of 105 primary DLBCL samples, and Western blot analysis of 18 DLBCL cell lines for the expression of BCL2, MCL1, and BCL-XL. Pharmacologic targeting of BCL2, MCL1, and BCL-XL with ABT-199, homoharringtonine (HHT), and ABT-737. Analysis of DLBCL clones with manipulated expressions of BCL2, MCL1, and BCL-XL. Immunoprecipitation of MCL1 complexes in selected DLBCL cell lines. Experimental therapy aimed at inhibition of BCL2 and MCL1 using ABT-199 and HHT, single agent, or in combination, in vitro and in vivo on primary cell-based murine xenograft models of DLBCL. RESULTS: By the pharmacologic targeting of BCL2, MCL1, and BCL-XL, we demonstrated that DLBCL can be divided into BCL2-dependent and MCL1-dependent subgroups with a less pronounced role left for BCL-XL. Derived DLBCL clones with manipulated expressions of BCL2, MCL1, and BCL-XL, as well as the immunoprecipitation experiments, which analyzed MCL1 protein complexes, confirmed these findings at the molecular level. We demonstrated that concurrent inhibition of BCL2 and MCL1 with ABT-199 and HHT induced significant synthetic lethality in most BCL2-expressing DLBCL cell lines. The marked cytotoxic synergy between ABT-199 and HHT was also confirmed in vivo using primary cell-based murine xenograft models of DLBCL. CONCLUSIONS: As homoharringtonine is a clinically approved antileukemia drug, and ABT-199 is in advanced phases of diverse clinical trials, our data might have direct implications for novel concepts of early clinical trials in patients with aggressive DLBCL.

• MeSH
• apoptóza účinky léků   MeSH
• bicyklické sloučeniny heterocyklické aplikace a dávkování   MeSH
• bifenylové sloučeniny aplikace a dávkování   MeSH
• difúzní velkobuněčný B-lymfom klasifikace   farmakoterapie   genetika   patologie   MeSH
• harringtoniny aplikace a dávkování   MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nitrofenoly aplikace a dávkování   MeSH
• piperaziny aplikace a dávkování   MeSH
• proliferace buněk účinky léků   MeSH
• protein bcl-X biosyntéza   MeSH
• protein MCL-1 biosyntéza   genetika   MeSH
• protoonkogenní proteiny c-bcl-2 biosyntéza   genetika   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• sulfonamidy aplikace a dávkování   MeSH
• xenogenní modely - testy antitumorózní aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Richter syndrome represents the transformation of the chronic lymphocytic leukemia (CLL) into an aggressive lymphoma, most frequently the diffuse large B-cell lymphoma (DLBCL). In this report we describe a patient with CLL, who developed a clonally-related pleomorphic highly-aggressive mantle cell lymphoma (MCL) after five cycles of a fludarabine-based second-line therapy for the first relapse of CLL. Molecular cytogenetic methods together with whole-exome sequencing revealed numerous gene alterations restricted to the MCL clone (apart from the canonical t(11;14)(q13;q32) translocation) including gain of one copy of ATM gene or emergence of TP53, CREBBP, NUP214, FUBP1 and SF3B1 gene mutations. Similarly, gene expression analysis revealed vast differences between the MCL and CLL transcriptome, including overexpression of cyclin D1, downregulation of cyclins D2 and D3, or downregulation of IL4R in the MCL clone. Backtracking analysis using quantitative PCR specifically detecting an MCL-restricted focal deletion of TP53 revealed that the pre-MCL clone appeared in the bone marrow and peripheral blood of the patient approximately 4 years before the clinical manifestation of MCL. Both molecular cytogenetic and sequencing data support the hypothesis of a slow development of the pre-MCL clone in parallel to CLL over several years, and thereby exclude the possibility that the transformation event occurred at the stage of the CLL relapse clone by mere t(11;14)(q13;q32) acquisition.

• MeSH
• chronická lymfatická leukemie genetika   metabolismus   patologie   MeSH
• difúzní velkobuněčný B-lymfom genetika   metabolismus   patologie   MeSH
• hybridizace in situ fluorescenční MeSH
• imunohistochemie MeSH
• lidé středního věku MeSH
• lidé MeSH
• lidské chromozomy, pár 11 MeSH
• lidské chromozomy, pár 14 MeSH
• lymfom z plášťových buněk genetika   metabolismus   patologie   MeSH
• nádorové biomarkery genetika   metabolismus   MeSH
• nádorový supresorový protein p53 genetika   metabolismus   MeSH
• translokace genetická MeSH
• ztráta heterozygozity MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH

Tumor immunotherapy based on the use of chimeric antigen receptor modified T cells (CAR T cells) is a promising approach for the treatment of refractory hematological malignancies. However, a robust response mediated by CAR T cells is observed only in a minority of patients and the expansion and persistence of CAR T cells in vivo is mostly unpredictable.Lenalidomide (LEN) is an immunomodulatory drug currently approved for the treatment of multiple myeloma (MM) and mantle cell lymphoma, while it is clinically tested in the therapy of diffuse large B-cell lymphoma of activated B cell immunophenotype. LEN was shown to increase antitumor immune responses at least partially by modulating the activity of E3 ubiquitin ligase Cereblon, which leads to increased ubiquitinylation of Ikaros and Aiolos transcription factors, which in turn results in changed expression of various receptors on the surface of tumor cells. In order to enhance the effectiveness of CAR-based immunotherapy, we assessed the anti-lymphoma efficacy of LEN in combination with CAR19 T cells or CAR20 T cells in vitro and in vivo using various murine models of aggressive B-cell non-Hodgkin lymphomas (B-NHL).Immunodeficient NSG mice were transplanted with various human B-NHL cells followed by treatment with CAR19 or CAR20 T cells with or without LEN. Next, CAR19 T cells were subjected to series of tests in vitro to evaluate their response and signaling capacity following recognition of B cell in the presence or absence of LEN.Our data shows that LEN significantly enhances antitumor functions of CAR19 and CAR20 T cells in vivo. Additionally, it enhances production of interferon gamma by CAR19 T cells and augments cell signaling via CAR19 protein in T cells in vitro. Our data further suggests that LEN works through direct effects on T cells but not on B-NHL cells. The biochemical events underlying this costimulatory effect of LEN are currently being investigated. In summary, our data supports the use of LEN for augmentation of CAR-based immunotherapy in the clinical grounds.

• MeSH
• chimerické antigenní receptory terapeutické užití   MeSH
• imunomodulace MeSH
• imunomodulační látky terapeutické užití   MeSH
• lenalidomid * terapeutické užití   MeSH
• lidé MeSH
• lymfom terapie   MeSH
• modely nemocí na zvířatech MeSH
• myši MeSH
• protinádorové látky imunologicky aktivní * terapeutické užití   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• práce podpořená grantem MeSH

Lecithin:retinol acyltransferase (LRAT) is the major enzyme responsible for retinol esterification in the mammalian body. LRAT exhibits specific activity in the cells with active retinol metabolism where it converts retinols into retinyl esters, which represents the major storage form of retinol. Besides hepatic stellate cells in the liver, LRAT appears to have a key physiologic role in several other tissues. In this study, we generated a transgenic reporter mouse expressing green fluorescence protein (EGFP) under the control of region containing -1166 bps from promoter upstream from the putative transcriptional start site and 262 bps downstream of this start. Transgenic reporter mice exhibited specific expression in eyes and testes. In eyes, expression of EGFP-reporter is found in lens and lens epithelium and fibers from embryo to adulthood. In testes, LRAT-EGFP reporter is expressed both in Sertoli and in spermatocytes marking initiation of spermatogenesis in prepubertal mice. Our data show that the examined LRAT regulatory region is sufficient to achieve strong and selective expression in the eye and testes but not in liver and other organs.

• MeSH
• acyltransferasy genetika   MeSH
• epitel metabolismus   MeSH
• genetická transkripce genetika   MeSH
• genotyp MeSH
• meióza genetika   MeSH
• myši transgenní MeSH
• myši MeSH
• oční čočka metabolismus   MeSH
• promotorové oblasti (genetika) genetika   MeSH
• regulace genové exprese enzymů genetika   MeSH
• Sertoliho buňky metabolismus   MeSH
• spermatocyty ultrastruktura   MeSH
• spermatogeneze MeSH
• testis metabolismus   MeSH
• vitamin A metabolismus   MeSH
• vývojová regulace genové exprese genetika   MeSH
• zelené fluorescenční proteiny MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Mantle cell lymphoma (MCL) is an aggressive type of B-cell non-Hodgkin lymphoma (NHL) associated with poor prognosis. Animal models of MCL are scarce. We established and characterized various in vivo models of metastatic human MCL by tail vein injection of either primary cells isolated from patients with MCL or established MCL cell lines (Jeko-1, Mino, Rec-1, Hbl-2, and Granta-519) into immunodeficient NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl)/SzJ mice. MCL infiltration was assessed with immunohistochemistry (tissues) and flow cytometry (peripheral blood). Engraftment of primary MCL cells was observed in 7 out of 12 patient samples. The pattern of engraftment of primary MCL cells varied from isolated involvement of the spleen to multiorgan infiltration. On the other hand, tumor engraftment was achieved in all five MCL cell lines used and lymphoma involvement of murine bone marrow, spleen, liver, and brain was observed. Overall survival of xenografted mice ranged from 22 ± 1 to 54 ± 3 days depending on the cell line used. Subsequently, we compared the gene expression profile (GEP) and phenotype of the engrafted MCL cells compared with the original in vitro growing cell lines (controls). We demonstrated that engrafted MCL cells displayed complex changes of GEP, protein expression, and sensitivity to cytotoxic agents when compared with controls. We further demonstrated that our MCL mouse models could be used to test the therapeutic activity of systemic chemotherapy, monoclonal antibodies, or angiogenesis inhibitors. The characterization of MCL murine models is likely to aid in improving our knowledge in the disease biology and to assist scientists in the preclinical and clinical development of novel agents in relapsed/refractory MCL patients.

• MeSH
• imunofenotypizace MeSH
• imunohistochemie MeSH
• játra metabolismus   MeSH
• Kaplanův-Meierův odhad MeSH
• kostní dřeň metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lymfom z plášťových buněk farmakoterapie   genetika   metabolismus   MeSH
• modely nemocí na zvířatech * MeSH
• mozek metabolismus   MeSH
• myši inbrední NOD MeSH
• myši knockoutované MeSH
• myši SCID MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádorové buňky kultivované MeSH
• receptory interleukinů - společná gama-podjednotka nedostatek   genetika   MeSH
• regulace genové exprese u nádorů * MeSH
• senioři MeSH
• slezina metabolismus   MeSH
• transkriptom genetika   MeSH
• transplantace heterologní MeSH
• zvířata MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• myši MeSH
• senioři MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH