BACKGROUND: Resistance to chemotherapy is a major problem in the treatment of patients with triple-negative breast cancer (TNBC). Preclinical data suggest that TNBC is dependent on proteasomes; however, clinical observations indicate that the efficacy of proteasome inhibitors in TNBC may be limited, suggesting the need for combination therapies. METHODS: We compared bortezomib and carfilzomib and their combinations with nelfinavir and lopinavir in TNBC cell lines and primary cells with regard to their cytotoxic activity, functional proteasome inhibition, and induction of the unfolded protein response (UPR). Furthermore, we evaluated the involvement of sXBP1, ABCB1, and ABCG2 in the cytotoxic activity of drug combinations. RESULTS: Carfilzomib, via proteasome β5 + β2 inhibition, is more cytotoxic in TNBC than bortezomib, which inhibits β5 + β1 proteasome subunits. The cytotoxicity of carfilzomib was significantly potentiated by nelfinavir or lopinavir. Carfilzomib with lopinavir induced endoplasmic reticulum stress and pro-apoptotic UPR through the accumulation of excess proteasomal substrate protein in TNBC in vitro. Moreover, lopinavir increased the intracellular availability of carfilzomib by inhibiting carfilzomib export from cells that express high levels and activity of ABCB1, but not ABCG2. CONCLUSION: Proteasome inhibition by carfilzomib combined with nelfinavir/lopinavir represents a potential treatment option for TNBC, warranting further investigation.

• MeSH
• ABC transportér z rodiny G, člen 2 * metabolismus   antagonisté a inhibitory   MeSH
• apoptóza účinky léků   MeSH
• bortezomib * farmakologie   MeSH
• inhibitory HIV-proteasy * farmakologie   MeSH
• inhibitory proteasomu farmakologie   MeSH
• lidé MeSH
• Lopinavir * farmakologie   MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny antagonisté a inhibitory   metabolismus   MeSH
• nelfinavir * farmakologie   MeSH
• oligopeptidy * farmakologie   MeSH
• P-glykoproteiny metabolismus   MeSH
• protokoly antitumorózní kombinované chemoterapie farmakologie   MeSH
• signální dráha UPR * účinky léků   MeSH
• stres endoplazmatického retikula účinky léků   MeSH
• synergismus léků * MeSH
• triple-negativní karcinom prsu * farmakoterapie   patologie   MeSH
• XBP1 metabolismus   genetika   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• antivirové látky MeSH
• fyziologie virů MeSH
• virové struktury MeSH
• virové vakcíny MeSH
• viry * MeSH

BACKGROUND: Multiple myeloma (MM) is an incurable plasma cell malignancy, accounting for approximately 1% of all cancers. Despite recent advances in the treatment of MM, due to the introduction of proteasome inhibitors (PIs) such as bortezomib (BTZ) and carfilzomib (CFZ), relapses and disease progression remain common. Therefore, a major challenge is the development of novel therapeutic approaches to overcome drug resistance, improve patient outcomes, and broaden PIs applicability to other pathologies. METHODS: We performed genetic and drug screens to identify new synthetic lethal partners to PIs, and validated candidates in PI-sensitive and -resistant MM cells. We also tested best synthetic lethal interactions in other B-cell malignancies, such as mantle cell, Burkitt's and diffuse large B-cell lymphomas. We evaluated the toxicity of combination treatments in normal peripheral blood mononuclear cells (PBMCs) and bone marrow stromal cells (BMSCs). We confirmed the combo treatment' synergistic effects ex vivo in primary CD138+ cells from MM patients, and in different MM xenograft models. We exploited RNA-sequencing and Reverse-Phase Protein Arrays (RPPA) to investigate the molecular mechanisms of the synergy. RESULTS: We identified lysine (K)-specific demethylase 1 (LSD1) as a top candidate whose inhibition can synergize with CFZ treatment. LSD1 silencing enhanced CFZ sensitivity in both PI-resistant and -sensitive MM cells, resulting in increased tumor cell death. Several LSD1 inhibitors (SP2509, SP2577, and CC-90011) triggered synergistic cytotoxicity in combination with different PIs in MM and other B-cell neoplasms. CFZ/SP2509 treatment exhibited a favorable cytotoxicity profile toward PBMCs and BMSCs. We confirmed the clinical potential of LSD1-proteasome inhibition in primary CD138+ cells of MM patients, and in MM xenograft models, leading to the inhibition of tumor progression. DNA damage response (DDR) and proliferation machinery were the most affected pathways by CFZ/SP2509 combo treatment, responsible for the anti-tumoral effects. CONCLUSIONS: The present study preclinically demonstrated that LSD1 inhibition could provide a valuable strategy to enhance PI sensitivity and overcome drug resistance in MM patients and that this combination might be exploited for the treatment of other B-cell malignancies, thus extending the therapeutic impact of the project.

• Publikační typ
• časopisecké články MeSH

OBJECTIVES: Progress in multiple myeloma treatment allows patients to achieve deeper responses, for which the assessment of minimal residual disease (MRD) is critical. Typically, bone marrow samples are used for this purpose; however, this approach is site-limited. Liquid biopsy represents a minimally invasive and more comprehensive technique that is not site-limited, but equally challenging. METHODS: While majority of current data comes from short-term studies, we present a long-term study on blood-based MRD monitoring using tumor-specific cell-free DNA detection by ASO-qPCR. One hundred and twelve patients were enrolled into the study, but long-term sampling and analysis were feasible only in 45 patients. RESULTS: We found a significant correlation of quantity of tumor-specific cell-free DNA levels with clinically meaningful events [induction therapy (P = .004); ASCT (P = .012)]. Moreover, length of cfDNA fragments is associated with better treatment response of patients. CONCLUSIONS: These results support the concept of tumor-specific cell-free DNA as a prognostic marker.

• MeSH
• cirkulující nádorová DNA * MeSH
• hodnocení výsledků zdravotní péče MeSH
• kombinovaná terapie MeSH
• lidé MeSH
• management nemoci MeSH
• mnohočetný myelom diagnóza   genetika   terapie   MeSH
• nádorové biomarkery * MeSH
• polymerázová řetězová reakce MeSH
• průtoková cytometrie MeSH
• reziduální nádor diagnóza   genetika   MeSH
• těžké řetězce imunoglobulinů genetika   MeSH
• výsledek terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• antitumorózní látky farmakologie   MeSH
• bortezomib farmakologie   MeSH
• chemorezistence * MeSH
• homeostáza MeSH
• inhibitory proteasomu farmakologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• lipidy chemie   MeSH
• metabolomika MeSH
• mitochondrie metabolismus   MeSH
• mnohočetný myelom farmakoterapie   MeSH
• nádorové buněčné linie MeSH
• oligopeptidy farmakologie   MeSH
• peroxid vodíku chemie   MeSH
• proteasomový endopeptidasový komplex metabolismus   MeSH
• protokoly antitumorózní kombinované chemoterapie farmakologie   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• sbalování proteinů MeSH
• senioři MeSH
• sfingomyeliny biosyntéza   MeSH
• stanovení celkové genové exprese MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• dopisy MeSH
• práce podpořená grantem MeSH

OBJECTIVES: To assess the potential of second-generation proteasome inhibition by carfilzomib and its combination with the human immunodeficiency virus (HIV) protease inhibitors (HIV-PIs) lopinavir and nelfinavir in vitro for improved treatment of clear cell renal cell cancer (ccRCC). MATERIALS AND METHODS: Cytotoxicity, reactive oxygen species (ROS) production, and unfolded protein response (UPR) activation of proteasome inhibitors, HIV-PIs, and their combination were assessed in three cell lines and primary cells derived from three ccRCC tumours by MTS assay, flow cytometry, quantitative reverse transcriptase-polymerase chain reaction and western blot, respectively. Proteasome activity was determined by activity based probes. Flow cytometry was used to assess apoptosis by annexin V/propidium iodide assay and ATP-binding cassette sub-family B member 1 (ABCB1) activity by MitoTrackerTM Green FM efflux assay (Thermo Fisher Scientific, MA, USA). RESULTS: Lopinavir and nelfinavir significantly increased the cytotoxic effect of carfilzomib in all cell lines and primary cells. ABCB1 efflux pump inhibition, induction of ROS production, and UPR pre-activation by lopinavir were identified as underlying mechanisms of this strong synergistic effect. Combined treatment led to unresolved protein stress, increased activation of pro-apoptotic UPR pathway, and a significant increase in apoptosis. CONCLUSION: The combination of the proteasome inhibitor carfilzomib and the HIV-PIs lopinavir and nelfinavir has a strong synergistic cytotoxic activity against ccRCCin vitro at therapeutically relevant drug concentrations. This effect is most likely explained by synergistic UPR triggering and ABCB1-modulation caused by HIV-PIs. Our findings suggest that combined treatment of second-generation proteasome inhibitors and HIV-PIs should be investigated in patients with metastatic RCC within a clinical trial.

• MeSH
• antitumorózní látky terapeutické užití   MeSH
• chemorezistence MeSH
• inhibitory HIV-proteasy terapeutické užití   MeSH
• inhibitory proteasomu terapeutické užití   MeSH
• karcinom z renálních buněk farmakoterapie   MeSH
• lidé MeSH
• Lopinavir terapeutické užití   MeSH
• nádorové buněčné linie MeSH
• nádory ledvin farmakoterapie   MeSH
• nelfinavir terapeutické užití   MeSH
• stres endoplazmatického retikula účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Východiska: Přirozená reakce organizmu na hypoxii je regulována různými mechanizmy a transkripčními faktory, zahrnujícími hypoxií indukovatelné faktory (HIFs). Aktivace HIF-1α je u nádorových buněk spojována se zvýšenou expresí P-glykoproteinu a multilékovou rezistencí. V této retrospektivní analýze jsme sledovali kandidátní jednonukleotidové polymorfizmy (single-nucleotide polymorphisms - SNP) genů HIF-1α a HIF-1β a jejich spojení s rizikem vzniku onemocnění monoklonální gamapatie nejasného významu (monoclonal gammopathy of undetermined significance - MGUS) nebo mnohočetného myelomu (MM). Soubor pacientů a metody: Genotypy jednonukleotidových polymorfizmů spojovaných s hypoxií byly určovány pomocí real time polymerázové řetězové reakce alelické diskriminace u nezávislé skupiny pacientů s monoklonální gamapatií (MG) (275 pacientů s MM a 228 s MGUS) a u 219 kontrol bez nádorového onemocnění. Výsledky: Při porovnání pacientů s MM a kontrol jsme pozorovali příznivější vliv genotypu CG genu HIF-1β (rs2228099) oproti genotypu CC (OR 0,65; CI 0,45-0,95; p = 0,026). Obdobně i při zohlednění věku pacientů a jejich indexu tělesné hmotnosti byla signifikantně nižší šance (OR 0,55; p = 0,045) rozvoje onemocnění MM u genotypu CG oproti CC. Log-rank test potvrdil souvislost GT haplotypu (rs11549467, rs2057482) genu HIF-1α s lepším celkovým přežitím (medián 41,8 měsíce; (CI 35,1-48,5) u haplotypu „žádné GT“ a medián 93,8 měsíce (CI 31,3-156,4) u haplotypu „nejméně jeden GT“ (p = 0,0500). Dále byla zjištěna významná souvislost mezi jednonukleotidovými polymorfizmy v genu MDR1 a léčebným účinkem u 110 pacientů s MM léčených bortezomibem. Závěr: Naše studie ukázala možnou genetickou predispozici k riziku rozvoje MG a/nebo k léčebné odpovědi pacientů s MM, nicméně je třeba provést další studie k potvrzení naší počáteční analýzy.

Background: Adaptive response to hypoxia is regulated by several mechanisms and transcription factors, including hypoxia-inducible factors (HIFs). Activation of HIF-1α is associated with increased expression of P-glycoprotein and multidrug resistance in cancer cells. In this retrospective study, we analyzed candidate single-nucleotide polymorphisms (SNPs) in HIF-1α and HIF-1β associated with risk of monoclonal gammopathy of undetermined significance (MGUS) or multiple myeloma (MM). Patients and Methods: Genotypes of SNPs associated with hypoxia were determined in an independent cohort of monoclonal gammopathies (MG) (275 MM and 228 MGUS patients) and in 219 cancer-free controls by real time polymerase chain reaction allelic discrimination. Results: When MM patients were compared to controls, protective role of CG genotype compared to CC in HIF-1β (rs2228099) for MM development was observed (OR = 0.65; CI 0.45-0.95; p = 0.026). Even after adjustment for patients´ age and body mass index (BMI), there were significantly lower odds (OR = 0.55; p = 0.045) of developing MM patients of CG genotype in comparison to CC genotype. Log-rank test confirmed association of GT haplotype (rs11549467, rs2057482) in HIF-1α with better overall survival (median 41.8 months; (CI 35.1-48.5)) for „none GT“ and median 93.8 months (CI 31.3-156.4) for „at least one GT“ haplotype (p = 0.0500). Further, significant associations between SNPs in MDR1 and outcome of MM were found in 110 MM patients that underwent bortezomib-based treatment. Conclusion: Our study showed a genetic predisposition for risk of MG development and/or outcome of MM patients; nevertheless, further studies are needed to confirm our initial analysis.

• MeSH
• analýza přežití MeSH
• genotyp MeSH
• hypoxie MeSH
• klinická studie jako téma MeSH
• lidé MeSH
• mnohočetný myelom * genetika   MeSH
• paraproteinemie genetika   MeSH
• polymerázová řetězová reakce metody   MeSH
• polymorfismus genetický MeSH
• Check Tag
• lidé MeSH

Although tumor cells are the most reliable source of tumor DNA, biopsy of the tumor is an invasive procedure that should be avoided in some cases. The main limitation of any biopsy is sampling of one tumor site, which may not represent all malignant clones due to the heterogeneity of the tumor. These clones respond to treatment differently and thus directly influence survival of the patient. Circulating cell-free DNA (cfDNA) is released from multiple tumor sites, reflects overall heterogeneity of the tumor, and correlates with its progression. Detection of tumor-specific genetic and epigenetic aberrations in cfDNA could have a direct impact on molecular diagnosis, prognosis, follow-up of disease, monitoring of minimal residual disease, and response to treatment. While most cfDNA data are still experimental, they are very promising. This review focuses on cfDNA in hematological malignancies.

• MeSH
• cirkulující nádorová DNA * MeSH
• diagnostické techniky molekulární MeSH
• genetická variace MeSH
• hematologické nádory krev   diagnóza   genetika   MeSH
• lidé MeSH
• nádorové biomarkery * MeSH
• prognóza MeSH
• tekutá biopsie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

• Publikační typ
• abstrakt z konference MeSH

BACKGROUND: Extramedullary disease in multiple myeloma patients is an uncommon event occurring either at the time of diagnosis, or during disease progression/relapse. This manifestation is frequently associated with poor outcome and resistance to treatment. We evaluated chromosomal alterations of plasma cells of multiple myeloma patients with extramedullary relapse, either in the bone marrow (BM) or at extramedullary sites, and in previous BM collection by interphase fluorescence in situ hybridization. MATERIAL AND METHODS: Thirty-one patients [25 BM plasma cells (BMPCs), 18 extramedullary tumor plasma cells], of which 12 had paired samples of BM and extramedullary plasma cells and 14 had previous collection of BM, were investigated for the presence of chromosomal aberrations (CHAs): del(17)(p13), del(13)(q14), 14q32 disruption, t(4;14)(p16;q32), t(14;16)(q32;q23), gain(1)(q21), and hyperdiploidy status. RESULTS: Overall, in unrelated samples, t(4;14) was more prevalent in extramedullary plasma cells, and hyperdiploidy was more frequent in BMPCs. In paired samples, there was a higher frequency of del(13)(q14) and 14q32 disruption in BMPCs. Frequency of all studied CHAs was higher in BMPCs of extramedullary patients than in their previous sample collection. CONCLUSION: These data show that plasma cells harbor more aberrations during their transformation into extramedullary form.

• MeSH
• chromozomální aberace * MeSH
• dospělí MeSH
• hybridizace in situ fluorescenční MeSH
• kostní dřeň patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• metastázy nádorů MeSH
• mnohočetný myelom diagnóza   genetika   patologie   MeSH
• nádorové biomarkery MeSH
• progrese nemoci MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• staging nádorů MeSH
• translokace genetická 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