Chemotherapy resistance, particularly multidrug resistance (MDR), remains a significant barrier to effective cancer treatment, leading to high mortality rates. The development of novel therapeutic strategies targeting key molecular mechanisms to counteract drug resistance is thus an urgent clinical need. In this study, we evaluated the potential of the small molecule SCO-101 to restore chemotherapy sensitivity in drug-resistant cancer cells. Using in silico and in vitro models such as molecular docking, cell viability, colony formation, dye efflux, transporter assays and chemotherapy retention, we assessed the impact of SCO-101 on drug retention and response in several drug-resistant cancer cells. SCO-101 was found to inhibit the activity of breast cancer resistance protein (BCRP/ABCG2) and UDP Glucuronosyltransferase Family 1 Member A1 (UGT1A1), two key proteins involved in drug resistance by cellular drug excretion and drug metabolism. Our results demonstrate that inhibition of these proteins by SCO-101 leads to increased intracellular drug accumulation, enhancing the cytotoxic effects of chemotherapy agents. Additionally, we identified a strong correlation between high ABCG2 expression and MDR in non-drug-resistant models, where cells exhibiting elevated ABCG2 levels displayed chemotherapy resistance, which was effectively reversed by SCO-101 co-treatment. These findings highlight the therapeutic potential of SCO-101 in overcoming MDR by inhibiting drug efflux mechanisms and metabolism, thereby enhancing chemotherapy efficacy. SCO-101 is currently undergoing clinical trials as an orally administered drug and is considered a promising strategy for improving cancer treatment outcomes in patients with drug-resistant tumors.

• Klíčová slova
• ABCG2, BCRP, SCO-101, UGT1A1, cancer multidrug resistance,
• MeSH
• ABC transportér z rodiny G, člen 2 * antagonisté a inhibitory   metabolismus   chemie   MeSH
• chemorezistence * účinky léků   MeSH
• diketopiperaziny MeSH
• heterocyklické sloučeniny tetra- a více cyklické MeSH
• lidé MeSH
• mnohočetná léková rezistence účinky léků   MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny * antagonisté a inhibitory   metabolismus   chemie   genetika   MeSH
• nádory * farmakoterapie   metabolismus   MeSH
• protinádorové látky * farmakologie   MeSH
• simulace molekulového dockingu MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• 3-(6-isobutyl-9-methoxy-1,4-dioxo-1,2,3,4,6,7,12,12a-octahydropyrazino(1',2'-1,6)pyrido(3,4-b)indol-3-yl)propionic acid tert-butyl ester MeSH Prohlížeč
• ABC transportér z rodiny G, člen 2 * MeSH
• ABCG2 protein, human MeSH Prohlížeč
• diketopiperaziny MeSH
• heterocyklické sloučeniny tetra- a více cyklické MeSH
• nádorové proteiny * MeSH
• protinádorové látky * MeSH

Endometrial stromal tumors are rare lesions with a diverse morphology, which may make achieving the correct diagnosis challenging in some cases. We report a case of a uterine mesenchymal tumor diagnosed as endometrial stromal nodule with a peculiar whorled morphology and GREB1::CTNNB1 fusion confirmed by transcriptome RNA sequencing. The tumor was sharply demarcated, lacked invasive growth, and had benign behavior, as the patient remained without disease recurrence 15 years later. Immunohistochemically, the tumor cells showed diffuse nuclear expression of beta-catenin, confirming the activation of the beta-catenin pathway. Our case represents only the 4th reported case of CTNNB1-rearranged endometrial stromal tumor with extensive whorling. The biological nature of uterine tumors characterized by whorled morphology and rearrangement of CTNNB1 is not yet clear, which underscores the importance of genetic profiling for accurate diagnosis and potential targeted therapies in malignant cases.

• Klíčová slova
• ESN, Endometrial stromal tumors, GREB1, GREB1::CTNNB1 fusion, Uterine mesenchymal tumors,
• MeSH
• beta-katenin * genetika   MeSH
• endometriální stromální nádory * genetika   patologie   MeSH
• fúze genů MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádorové biomarkery * genetika   analýza   MeSH
• nádorové proteiny * genetika   MeSH
• nádory endometria * genetika   patologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• kazuistiky MeSH
• Názvy látek
• beta-katenin * MeSH
• CTNNB1 protein, human MeSH Prohlížeč
• GREB1 protein, human MeSH Prohlížeč
• nádorové biomarkery * MeSH
• nádorové proteiny * MeSH

Bruton tyrosine kinase (BTK) inhibitor therapy induces peripheral blood lymphocytosis in chronic lymphocytic leukemia (CLL), which lasts for several months. It remains unclear whether nongenetic adaptation mechanisms exist, allowing CLL cells' survival during BTK inhibitor-induced lymphocytosis and/or playing a role in therapy resistance. We show that in approximately 70% of CLL cases, ibrutinib treatment in vivo increases Akt activity above pretherapy levels within several weeks, leading to compensatory CLL cell survival and a more prominent lymphocytosis on therapy. Ibrutinib-induced Akt phosphorylation (pAktS473) is caused by the upregulation of Forkhead box protein O1 (FoxO1) transcription factor, which induces expression of Rictor, an assembly protein for the mTORC2 protein complex that directly phosphorylates Akt at serine 473 (S473). Knockout or inhibition of FoxO1 or Rictor led to a dramatic decrease in Akt phosphorylation and growth disadvantage for malignant B cells in the presence of ibrutinib (or PI3K inhibitor idelalisib) in vitro and in vivo. The FoxO1/Rictor/pAktS473 axis represents an early nongenetic adaptation to B cell receptor (BCR) inhibitor therapy not requiring PI3Kδ or BTK kinase activity. We further demonstrate that FoxO1 can be targeted therapeutically and its inhibition induces CLL cells' apoptosis alone or in combination with BTK inhibitors (ibrutinib, acalabrutinib, pirtobrutinib) and blocks their proliferation triggered by T cell factors (CD40L, IL-4, and IL-21).

• Klíčová slova
• Drug therapy, Hematology, Leukemias, Oncology, Signal transduction,
• MeSH
• adenin * analogy a deriváty   farmakologie   MeSH
• chronická lymfatická leukemie * farmakoterapie   metabolismus   genetika   patologie   MeSH
• forkhead box protein O1 * metabolismus   genetika   MeSH
• fosforylace MeSH
• lidé MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny metabolismus   genetika   MeSH
• piperidiny * farmakologie   MeSH
• protein RICTOR * genetika   metabolismus   MeSH
• proteinkinasa BTK metabolismus   genetika   antagonisté a inhibitory   MeSH
• protoonkogenní proteiny c-akt * metabolismus   genetika   MeSH
• pyrazoly * farmakologie   MeSH
• pyrimidiny * farmakologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adenin * MeSH
• BTK protein, human MeSH Prohlížeč
• forkhead box protein O1 * MeSH
• FOXO1 protein, human MeSH Prohlížeč
• ibrutinib MeSH Prohlížeč
• nádorové proteiny MeSH
• piperidiny * MeSH
• protein RICTOR * MeSH
• proteinkinasa BTK MeSH
• protoonkogenní proteiny c-akt * MeSH
• pyrazoly * MeSH
• pyrimidiny * MeSH

Correlated regions of systemic interindividual variation (CoRSIV) represent a small proportion of the human genome showing DNA methylation patterns that are the same in all human tissues, are different among individuals, and are partially regulated by genetic variants in cis. In this study we aimed at investigating single-nucleotide polymorphisms (SNPs) within CoRSIVs and their involvement with pancreatic ductal adenocarcinoma (PDAC) risk. We analyzed 29,099 CoRSIV-SNPs and 133,615 CoRSIV-mQTLs in 14,394 cases and 247,022 controls of European and Asian descent. We observed that the A allele of the rs2976395 SNP was associated with increased PDAC risk in Europeans (p = 2.81 × 10-5). This SNP lies in the prostate stem cell antigen gene and is in perfect linkage disequilibrium with a variant (rs2294008) that has been reported to be associated with risk of many other cancer types. The A allele is associated with the DNA methylation level of the gene according to the PanCan-meQTL database and with overexpression according to QTLbase. The expression of the gene has been observed to be deregulated in many tumors of the gastrointestinal tract including pancreatic cancer; however, functional studies are needed to elucidate the function relevance of the association.

• Klíčová slova
• DNA methylation, pancreatic cancer, risk factors, single‐nucleotide polymorphism,
• MeSH
• alely MeSH
• antigeny nádorové * genetika   MeSH
• Asijci genetika   MeSH
• běloši genetika   MeSH
• duktální karcinom slinivky břišní * genetika   MeSH
• genetická predispozice k nemoci MeSH
• GPI-vázané proteiny * genetika   MeSH
• jednonukleotidový polymorfismus MeSH
• lidé středního věku MeSH
• lidé MeSH
• lokus kvantitativního znaku MeSH
• metylace DNA MeSH
• nádorové proteiny * genetika   MeSH
• nádory slinivky břišní * genetika   MeSH
• studie případů a kontrol MeSH
• vazebná nerovnováha * MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny nádorové * MeSH
• GPI-vázané proteiny * MeSH
• nádorové proteiny * MeSH
• PSCA protein, human MeSH Prohlížeč

• MeSH
• ABC transportér z rodiny G, člen 2 genetika   MeSH
• antigeny krevních skupin * MeSH
• buněčná membrána metabolismus   MeSH
• lidé MeSH
• nádorové proteiny genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• dopisy MeSH
• Názvy látek
• ABC transportér z rodiny G, člen 2 MeSH
• ABCG2 protein, human MeSH Prohlížeč
• antigeny krevních skupin * MeSH
• nádorové proteiny MeSH

The presence of key hypoxia regulators, namely, hypoxia-inducible factor (HIF)-1α or HIF-2α, in tumors is associated with poor patient prognosis. Hypoxia massively activates several genes, including the one encoding the BCRP transporter that proffers multidrug resistance to cancer cells through the xenobiotic efflux and is a determinant of the side population (SP) associated with cancer stem-like phenotypes. As natural medicine comes to the fore, it is instinctive to look for natural agents possessing powerful features against cancer resistance. Hypericin, a pleiotropic agent found in Hypericum plants, is a good example as it is a BCRP substrate and potential inhibitor, and an SP and HIF modulator. Here, we showed that hypericin efficiently accumulated in hypoxic cancer cells, degraded HIF-1/2α, and decreased BCRP efflux together with hypoxia, thus diminishing the SP population. On the contrary, this seemingly favorable result was accompanied by the stimulated migration of this minor population that preserved the SP phenotype. Because hypoxia unexpectedly decreased the BCRP level and SP fraction, we compared the SP and non-SP proteomes and their changes under hypoxia in the A549 cell line. We identified differences among protein groups connected to the epithelial-mesenchymal transition, although major changes were related to hypoxia, as the upregulation of many proteins, including serpin E1, PLOD2 and LOXL2, that ultimately contribute to the initiation of the metastatic cascade was detected. Altogether, this study helps in clarifying the innate and hypoxia-triggered resistance of cancer cells and highlights the ambivalent role of natural agents in the biology of these cells.

• Klíčová slova
• Breast cancer resistance protein, ECM reorganization, Hypericin, Hypoxia, Proteomics, Side population,
• MeSH
• ABC transportér z rodiny G, člen 2 genetika   metabolismus   MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa metabolismus   MeSH
• hypoxie buňky MeSH
• hypoxie MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádorové proteiny genetika   metabolismus   MeSH
• nádory * metabolismus   MeSH
• regulace genové exprese u nádorů MeSH
• transkripční faktory bHLH genetika   metabolismus   MeSH
• vedlejší populace buněk * patologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ABC transportér z rodiny G, člen 2 MeSH
• faktor 1 indukovatelný hypoxií - podjednotka alfa MeSH
• hypericin MeSH Prohlížeč
• nádorové proteiny MeSH
• transkripční faktory bHLH MeSH

The last 2 decades have attended a dynamic evolution in the nosology of poorly differentiated sinonasal tract malignancies, with several new molecularly defined entities having been described in addition to delineation of the genetic driver/s of some established older entities. These discoveries, however, mostly concerned epithelial-derived neoplasms (carcinomas). Adamantinoma-like Ewing sarcoma and biphenotypic sinonasal sarcoma are the major representatives of the newly defined mesenchymal categories. The colorectal cancer associated 2 (COLCA2) has been discovered recently as a colorectal cancer risk gene locus, but fusions involving this gene have not been well characterized. We, herein, describe clinicopathologic and molecular features of a novel sinonasal sarcoma characterized by undifferentiated spindle/round cell morphology and defined by recurrent EWSR1::COLCA2 fusions. All patients (n=5) were adults (3 female and 2 male) with a median age of 46 years (range, 23 to 60 y). The tumors originated in different subsites of the sinonasal tract with frequent multisite involvement. Original diagnoses were undifferentiated or unclassified round cell/spindle cell neoplasm/sarcoma (n=4) and neuroendocrine carcinoma (n=1). Surgery with or without adjuvant chemoradiation was the treatment in all cases. At the last follow-up, 1 patient developed multiple local recurrences over 21 years and another developed local recurrence and distant metastasis to bone 27 months after diagnosis. A third patient developed local recurrence 11 months later. Two patients were disease-free at 23, and 24 months. Histology showed nondescript highly cellular neoplasms with an admixture of spindled and round cells disposed into solid sheets and fascicles with brisk mitotic activity. Immunohistochemistry was negative for all lineage-specific markers with only limited focal membranous CD99 (4 of 5 cases) and weak pankeratin (1 of 5 cases) expression. Targeted RNA sequencing revealed an EWSR1::COLCA2 fusion, verified by EWSR1 fluorescence in situ hybridization, in all cases. This series identifies a novel member in the undifferentiated spindle/round cell sarcoma category with strong predilection for the sinonasal tract. None of >10,000 epithelial and mesenchymal neoplasms tested at the authors' centers during the same period showed this fusion, highlighting rarity of tumors carrying this gene fusion. Accordingly, molecular testing of unclassified sinonasal malignancies/sarcomas showing round and spindle cell morphology is recommended to enhance the identification and further characterization of this entity.

• MeSH
• dospělí MeSH
• Ewingův sarkom * genetika   MeSH
• fúzní onkogenní proteiny genetika   MeSH
• hybridizace in situ fluorescenční MeSH
• kolorektální nádory * MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• nádorové biomarkery genetika   MeSH
• nádorové proteiny genetika   MeSH
• nádory měkkých tkání * MeSH
• nádory vedlejších dutin nosních * MeSH
• paranazální dutiny * patologie   MeSH
• protein EWS vázající RNA genetika   MeSH
• sarkom * genetika   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• COLCA2 protein, human MeSH Prohlížeč
• EWSR1 protein, human MeSH Prohlížeč
• fúzní onkogenní proteiny MeSH
• nádorové biomarkery MeSH
• nádorové proteiny MeSH
• protein EWS vázající RNA MeSH

P21-activated kinases (PAKs) regulate processes associated with cytoskeletal rearrangements, such as cell division, adhesion, and migration. The possible regulatory role of PAKs in cell metabolism has not been well explored, but increasing evidence suggests that a cell metabolic phenotype is related to cell interactions with the microenvironment. We analyzed the impact of PAK inhibition by small molecule inhibitors, small interfering RNA, or gene knockout on the rates of mitochondrial respiration and aerobic glycolysis. Pharmacological inhibition of PAK group I by IPA-3 induced a strong decrease in metabolic rates in human adherent cancer cell lines, leukemia/lymphoma cell lines, and primary leukemia cells. The immediate effect of FRAX597, which inhibits PAK kinase activity, was moderate, indicating that PAK nonkinase functions are essential for cell metabolism. Selective downregulation or deletion of PAK2 was associated with a shift toward oxidative phosphorylation. In contrast, PAK1 knockout resulted in increased glycolysis. However, the overall metabolic capacity was not substantially reduced by PAK1 or PAK2 deletion, possibly due to partial redundancy in PAK1/PAK2 regulatory roles or to activation of other compensatory mechanisms.

• Klíčová slova
• cell metabolism, glycolysis, oxidative phosphorylation, p21-activated kinase 1, p21-activated kinase 2,
• MeSH
• HEK293 buňky MeSH
• HeLa buňky MeSH
• lidé MeSH
• mitochondrie enzymologie   genetika   MeSH
• nádorové mikroprostředí * MeSH
• nádorové proteiny genetika   metabolismus   MeSH
• nádory enzymologie   genetika   MeSH
• p21 aktivované kinasy genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• nádorové proteiny MeSH
• p21 aktivované kinasy MeSH
• PAK1 protein, human MeSH Prohlížeč
• PAK2 protein, human MeSH Prohlížeč

Thousands of non-coding variants have been associated with increased risk of human diseases, yet the causal variants and their mechanisms-of-action remain obscure. In an integrative study combining massively parallel reporter assays (MPRA), expression analyses (eQTL, meQTL, PCHiC) and chromatin accessibility analyses in primary cells (caQTL), we investigate 1,039 variants associated with multiple myeloma (MM). We demonstrate that MM susceptibility is mediated by gene-regulatory changes in plasma cells and B-cells, and identify putative causal variants at six risk loci (SMARCD3, WAC, ELL2, CDCA7L, CEP120, and PREX1). Notably, three of these variants co-localize with significant plasma cell caQTLs, signaling the presence of causal activity at these precise genomic positions in an endogenous chromosomal context in vivo. Our results provide a systematic functional dissection of risk loci for a hematologic malignancy.

• MeSH
• adaptorové proteiny signální transdukční genetika   imunologie   MeSH
• B-lymfocyty imunologie   patologie   MeSH
• chromatin chemie   imunologie   MeSH
• chromozomální proteiny, nehistonové genetika   imunologie   MeSH
• genetická predispozice k nemoci * MeSH
• hodnocení rizik MeSH
• intergenová DNA genetika   imunologie   MeSH
• lidé MeSH
• lokus kvantitativního znaku MeSH
• mnohočetný myelom farmakoterapie   genetika   imunologie   patologie   MeSH
• nádorové proteiny genetika   imunologie   MeSH
• plazmatické buňky imunologie   patologie   MeSH
• polymorfismus genetický MeSH
• primární buněčná kultura MeSH
• proteiny buněčného cyklu genetika   imunologie   MeSH
• protokoly protinádorové kombinované chemoterapie MeSH
• regulace genové exprese u nádorů MeSH
• represorové proteiny genetika   imunologie   MeSH
• sekvence nukleotidů MeSH
• transkripční elongační faktory genetika   imunologie   MeSH
• typy dědičnosti MeSH
• výměnné faktory guaninnukleotidů genetika   imunologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• CDCA7L protein, human MeSH Prohlížeč
• CEP120 protein, human MeSH Prohlížeč
• chromatin MeSH
• chromozomální proteiny, nehistonové MeSH
• ELL2 protein, human MeSH Prohlížeč
• intergenová DNA MeSH
• nádorové proteiny MeSH
• PREX1 protein, human MeSH Prohlížeč
• proteiny buněčného cyklu MeSH
• represorové proteiny MeSH
• SMARCD3 protein, human MeSH Prohlížeč
• transkripční elongační faktory MeSH
• výměnné faktory guaninnukleotidů MeSH
• WAC protein, human MeSH Prohlížeč

The initial activation step in the gating of ubiquitously expressed Orai1 calcium (Ca2+) ion channels represents the activation of the Ca2+-sensor protein STIM1 upon Ca2+ store depletion of the endoplasmic reticulum. Previous studies using constitutively active Orai1 mutants gave rise to, but did not directly test, the hypothesis that STIM1-mediated Orai1 pore opening is accompanied by a global conformational change of all Orai transmembrane domain (TM) helices within the channel complex. We prove that a local conformational change spreads omnidirectionally within the Orai1 complex. Our results demonstrate that these locally induced global, opening-permissive TM motions are indispensable for pore opening and require clearance of a series of Orai1 gating checkpoints. We discovered these gating checkpoints in the middle and cytosolic extended TM domain regions. Our findings are based on a library of double point mutants that contain each one loss-of-function with one gain-of-function point mutation in a series of possible combinations. We demonstrated that an array of loss-of-function mutations are dominant over most gain-of-function mutations within the same as well as of an adjacent Orai subunit. We further identified inter- and intramolecular salt-bridge interactions of Orai subunits as a core element of an opening-permissive Orai channel architecture. Collectively, clearance and synergistic action of all these gating checkpoints are required to allow STIM1 coupling and Orai1 pore opening. Our results unravel novel insights in the preconditions of the unique fingerprint of CRAC channel activation, provide a valuable source for future structural resolutions, and help to understand the molecular basis of disease-causing mutations.

• Klíčová slova
• AND-gate, CRAC channel, Electrophysiology, Gating, Gating checkpoints, Opening-permissive conformation, Orai1, STIM1, Signal propagation,
• MeSH
• bakteriální proteiny genetika   metabolismus   MeSH
• fosfatidylcholiny chemie   metabolismus   MeSH
• gating iontového kanálu genetika   MeSH
• genetické vektory chemie   metabolismus   MeSH
• HEK293 buňky MeSH
• interakční proteinové domény a motivy MeSH
• konformace proteinů, alfa-helix MeSH
• konformace proteinů, beta-řetězec MeSH
• lidé MeSH
• liposomy chemie   metabolismus   MeSH
• luminescentní proteiny genetika   metabolismus   MeSH
• metoda terčíkového zámku MeSH
• mutace MeSH
• nádorové proteiny chemie   genetika   metabolismus   MeSH
• protein ORAI1 chemie   genetika   metabolismus   MeSH
• protein STIM1 chemie   genetika   metabolismus   MeSH
• regulace genové exprese MeSH
• rekombinantní proteiny chemie   genetika   metabolismus   MeSH
• reportérové geny MeSH
• simulace molekulární dynamiky MeSH
• substituce aminokyselin MeSH
• vápník metabolismus   MeSH
• vápníková signalizace * MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• zelené fluorescenční proteiny genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• 1-palmitoyl-2-oleoylphosphatidylcholine MeSH Prohlížeč
• bakteriální proteiny MeSH
• enhanced cyan fluorescent protein MeSH Prohlížeč
• fosfatidylcholiny MeSH
• liposomy MeSH
• luminescentní proteiny MeSH
• nádorové proteiny MeSH
• ORAI1 protein, human MeSH Prohlížeč
• protein ORAI1 MeSH
• protein STIM1 MeSH
• rekombinantní proteiny MeSH
• STIM1 protein, human MeSH Prohlížeč
• vápník MeSH
• yellow fluorescent protein, Bacteria MeSH Prohlížeč
• zelené fluorescenční proteiny MeSH