A tumour suppressor miRNA, miR-128-3p, is widely involved in various biological processes and has been found to get downregulated in breast cancer patients. We previously published that ectopically expressed miR-128-3p suppressed migration, invasion, cell cycle arrest, and breast cancer stem cells. In the present study, we explored the role of Empagliflozin (EMPA) as a miR-128-3p functionality-mimicking drug in inducing ferroptosis by inhibiting CD98hc. Given that CD98hc is one of the proteins critical in triggering ferroptosis, we confirmed that miR-128-3p and EMPA inhibited SP1, leading to inhibition of CD98hc expression. Further, transfection with siCD98hc, miR-128-3p mimics, and inhibitors was performed to assess their involvement in the ferroptosis of anoikis-resistant cells. We proved that anoikis-resistant cells possess high ROS and iron levels. Further, miR-128-3p and EMPA treatments induced ferroptosis by inhibiting GSH and enzymatic activity of GPX4 and also induced lipid peroxidation. Moreover, EMPA suppressed bioluminescence of 4T1-Red-FLuc induced thoracic cavity, peritoneal tumour burden and lung nodules in an in-vivo metastatic model of breast cancer. Collectively, we revealed that EMPA sensitized the ECM detached cells to ferroptosis by synergically activating miR-128-3p and lowering the levels of SP1 and CD98hc, making it a potential adjunct drug for breast cancer chemotherapy.

• Klíčová slova
• 4T1 cells, Anoikis resistance, Breast cancer, Ferroptosis, Metastasis, Reactive oxygen species,
• MeSH
• anoikis * účinky léků   genetika   MeSH
• benzhydrylové sloučeniny * farmakologie   MeSH
• ferroptóza * účinky léků   genetika   MeSH
• glifloziny farmakologie   MeSH
• glukosidy * farmakologie   MeSH
• kotransportní proteiny pro sodík a fosfát - typ IIb MeSH
• lidé MeSH
• mikro RNA * genetika   metabolismus   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory prsu * patologie   metabolismus   farmakoterapie   genetika   MeSH
• peroxidace lipidů účinky léků   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• regulace genové exprese u nádorů * účinky léků   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
• Názvy látek
• benzhydrylové sloučeniny * MeSH
• empagliflozin MeSH Prohlížeč
• glifloziny MeSH
• glukosidy * MeSH
• kotransportní proteiny pro sodík a fosfát - typ IIb MeSH
• mikro RNA * MeSH
• MIRN128 microRNA, human MeSH Prohlížeč
• reaktivní formy kyslíku MeSH
• SLC34A2 protein, human MeSH Prohlížeč

Hyaluronan, a linear glycosaminoglycan comprising D-N-acetylglucosamine and D-glucuronic acid, is the main component of the extracellular matrix. Its influence on cell proliferation, migration, inflammation, signalling, and other functions, depends heavily on its molecular weight and chemical modification. Unsaturated HA oligosaccharides are available in defined length and purity. Their potential therapeutic utility can be further improved by chemical modification, e. g., reduction. No synthesis of such modified oligosaccharides, either stepwise or by hyaluronan cleavage, has been reported yet. Here we show a three-step synthesis (esterification, depolymerization and reduction) of unsaturated even numbered hyaluronan oligosaccharides with carboxylates and the reducing terminus reduced to an alcohol. Particular oligosaccharides were synthesised. The modified oligosaccharides are not cleaved by mammalian or bacterial hyaluronidase and do not affect the growth of mouse and human fibroblasts. Further, MTT and NRU viability tests showed that they inhibit the growth of human colon carcinoma cells HT-29 by 20-50 % in concentrations 500-1000 μg/mL. Interestingly, this effect takes place regardless of CD44 receptor expression and was not observed with unmodified HA oligosaccharides. These compounds could serve as enzymatically stable building blocks for biologically active substances.

• Klíčová slova
• CD44, Fragmentation, Hyaluronan, Oligosaccharide, Reduction, Stability,
• MeSH
• antigeny CD44 metabolismus   MeSH
• buňky HT-29 MeSH
• cytostatické látky * farmakologie   chemie   chemická syntéza   MeSH
• fibroblasty účinky léků   MeSH
• hyaluronoglukosaminidasa * metabolismus   antagonisté a inhibitory   MeSH
• kyselina hyaluronová * chemie   farmakologie   MeSH
• lidé MeSH
• myši MeSH
• oligosacharidy * chemie   farmakologie   MeSH
• proliferace buněk * účinky léků   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny CD44 MeSH
• cytostatické látky * MeSH
• hyaluronoglukosaminidasa * MeSH
• kyselina hyaluronová * MeSH
• oligosacharidy * MeSH

Cylindrospermopsin, a potent hepatotoxin produced by harmful cyanobacterial blooms, poses environmental and human health concerns. We used a 3D human liver in vitro model based on spheroids of HepG2 cells, in combination with molecular and biochemical assays, automated imaging, targeted LC-MS-based proteomics, and lipidomics, to explore cylindrospermopsin effects on lipid metabolism and the processes implicated in hepatic steatosis. Cylindrospermopsin (1 μM, 48 h) did not significantly affect cell viability but partially reduced albumin secretion. However, it increased neutral lipid accumulation in HepG2 spheroids while decreasing phospholipid levels. Simultaneously, cylindrospermopsin upregulated genes for lipogenesis regulation (SREBF1) and triacylglycerol synthesis (DGAT1/2) and downregulated genes for fatty acid synthesis (ACLY, ACCA, FASN, SCD1). Fatty acid uptake, oxidation, and lipid efflux genes were not significantly affected. Targeted proteomics revealed increased levels of perilipin 2 (adipophilin), a major hepatocyte lipid droplet-associated protein. Lipid profiling quantified 246 lipid species in the spheroids, with 28 significantly enriched and 15 downregulated by cylindrospermopsin. Upregulated species included neutral lipids, sphingolipids (e.g., ceramides and dihexosylceramides), and some glycerophospholipids (phosphatidylethanolamines, phosphatidylserines), while phosphatidylcholines and phosphatidylinositols were mostly reduced. It suggests that cylindrospermopsin exposures might contribute to developing and progressing towards hepatic steatosis or metabolic dysfunction-associated steatotic liver disease (MASLD).

• Klíčová slova
• Harmful cyanobacterial blooms, Hepatospheroids, LC-MS-Based lipid profiling, MAFLD, Metabolic dysfunction-associated fatty liver disease, NAFLD, Non-alcoholic fatty liver disease,
• MeSH
• alkaloidy * farmakologie   MeSH
• bakteriální toxiny * metabolismus   MeSH
• buněčné sféroidy účinky léků   metabolismus   MeSH
• buňky Hep G2 MeSH
• homeostáza účinky léků   MeSH
• játra * metabolismus   účinky léků   MeSH
• lidé MeSH
• lipidomika MeSH
• lipogeneze účinky léků   MeSH
• metabolismus lipidů * účinky léků   MeSH
• proteomika MeSH
• toxiny kmene Cyanobacteria * MeSH
• uracil * analogy a deriváty   metabolismus   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• alkaloidy * MeSH
• bakteriální toxiny * MeSH
• cylindrospermopsin MeSH Prohlížeč
• toxiny kmene Cyanobacteria * MeSH
• uracil * MeSH

Straightforward access to enantiomerically pure 3,4-diamino-3,4-dideoxyphytosphingosines, as novel analogues of natural d-ribo-phytosphingosine was accomplished, starting from two available chirons: dimethyl l-tartrate and d-isoascorbic acid. A sequential Overman rearrangement followed by late-stage introduction of the alkyl side chain moiety via olefin cross-metathesis is the cornerstone of this approach. The preliminary evaluation study of the synthesised sphingomimetics, based on their ability to inhibit a proliferation of human cancer cells, showed promising cytotoxicity against Jurkat and HeLa cells for (2R,3R,4S)-2,3,4-triaminooctadecan-1-ol trihydrochloride.

• Klíčová slova
• Cytotoxic activity, OCM, Sequential rearrangement, Sphingoid bases, d-ribo-phytosphingosine,
• MeSH
• antitumorózní látky farmakologie   chemie   chemická syntéza   MeSH
• HeLa buňky MeSH
• Jurkat buňky MeSH
• lidé MeSH
• proliferace buněk * účinky léků   MeSH
• sfingosin * analogy a deriváty   chemie   farmakologie   chemická syntéza   MeSH
• stereoizomerie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antitumorózní látky MeSH
• phytosphingosine MeSH Prohlížeč
• sfingosin * MeSH

Checkpoint kinase 1 (Chk1) plays an important role in regulation of the cell cycle, DNA damage response and cell death, and represents an attractive target in anticancer therapy. Small-molecule inhibitors of Chk1 have been intensively investigated either as single agents or in combination with various chemotherapeutic drugs and they can enhance the chemosensitivity of numerous tumor types. Here we newly demonstrate that pharmacological inhibition of Chk1 using potent and selective inhibitor SCH900776, currently profiled in phase II clinical trials, significantly enhances cytotoxic effects of the combination of platinum-based drugs (cisplatin or LA-12) and TRAIL (tumor necrosis factor-related apoptosis inducing ligand) in human prostate cancer cells. The specific role of Chk1 in the drug combination-induced cytotoxicity was confirmed by siRNA-mediated silencing of this kinase. Using RNAi-based methods we also showed the importance of Bak-dependent mitochondrial apoptotic pathway in the combined anticancer action of SCH900776, cisplatin and TRAIL. The triple drug combination-induced cytotoxicity was partially enhanced by siRNA-mediated Mcl-1 silencing. Our findings suggest that targeting Chk1 may be used as an efficient strategy for sensitization of prostate cancer cells to killing action of platinum-based chemotherapeutic drugs and TRAIL.

• Klíčová slova
• SCH900776, TRAIL, cell death, checkpoint kinase 1, cisplatin, prostate cancer,
• MeSH
• antitumorózní látky * farmakologie   MeSH
• apoptóza účinky léků   MeSH
• checkpoint kinasa 1 * metabolismus   antagonisté a inhibitory   MeSH
• cisplatina * farmakologie   MeSH
• inhibitory proteinkinas farmakologie   MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• nádorové buněčné linie MeSH
• nádory prostaty * farmakoterapie   patologie   metabolismus   MeSH
• organoplatinové sloučeniny farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• protein TRAIL * farmakologie   metabolismus   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antitumorózní látky * MeSH
• checkpoint kinasa 1 * MeSH
• CHEK1 protein, human MeSH Prohlížeč
• cisplatina * MeSH
• inhibitory proteinkinas MeSH
• organoplatinové sloučeniny MeSH
• protein TRAIL * MeSH

Herein, we describe the general design, synthesis, characterization, and biological activity of new multitargeting Pt(IV) prodrugs that combine antitumor cisplatin and dasatinib, a potent inhibitor of Src kinase. These prodrugs exhibit impressive antiproliferative and anti-invasive activities in tumor cell lines in both two-dimensional (2D) monolayers of cell cultures and three-dimensional (3D) spheroids. We show that the cisplatin moiety and dasatinib in the investigated Pt(IV) complexes are both involved in the mechanism of action in MCF7 breast cancer cells and act synergistically. Thus, combining dasatinib and cisplatin into one molecule, compared to using individual components in a mix, may bring several advantages, such as significantly higher activity in cancer cell lines and higher selectivity for tumor cells. Most importantly, Pt(IV)-dasatinib complexes hold significant promise for potential anticancer therapies by targeting epithelial-mesenchymal transition, thus preventing the spread and metastasis of tumors, a value unachievable by a simple combination of both individual components.

• MeSH
• antitumorózní látky * farmakologie   chemie   chemická syntéza   MeSH
• cisplatina * farmakologie   MeSH
• dasatinib * farmakologie   chemie   chemická syntéza   MeSH
• léky antitumorózní - screeningové testy MeSH
• lidé MeSH
• MFC-7 buňky MeSH
• nádorové buněčné linie MeSH
• organoplatinové sloučeniny farmakologie   chemie   chemická syntéza   MeSH
• prekurzory léčiv * farmakologie   chemie   chemická syntéza   MeSH
• proliferace buněk účinky léků   MeSH
• synergismus léků * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antitumorózní látky * MeSH
• cisplatina * MeSH
• dasatinib * MeSH
• organoplatinové sloučeniny MeSH
• prekurzory léčiv * MeSH

Using supramolecular self-assembled nanocomposite materials made from protein and polysaccharide components is becoming more popular because of their unique properties, such as biodegradability, hierarchical structures, and tunable multifunctionality. However, the fabrication of these materials in a reproducible way remains a challenge. This study presents a new evaporation-induced self-assembly method producing layered hydrogel membranes (LHMs) using tropocollagen grafted by partially deacetylated chitin nanocrystals (CO-g-ChNCs). ChNCs help stabilize tropocollagen's helical conformation and fibrillar structure by forming a hierarchical microstructure through chemical and physical interactions. The LHMs show improved mechanical properties, cytocompatibility, and the ability to control drug release using octenidine dihydrochloride (OCT) as a drug model. Because of the high synergetic performance between CO and ChNCs, the modulus, strength, and toughness increased significantly compared to native CO. The biocompatibility of LHM was tested using the normal human dermal fibroblast (NHDF) and the human osteosarcoma cell line (Saos-2). Cytocompatibility and cell adhesion improved with the introduction of ChNCs. The extracted ChNCs are used as a reinforcing nanofiller to enhance the performance properties of tropocollagen hydrogel membranes and provide new insights into the design of novel LHMs that could be used for various medical applications, such as control of drug release in the skin and bone tissue regeneration.

• MeSH
• biokompatibilní materiály chemie   farmakologie   MeSH
• buněčná adheze účinky léků   MeSH
• chitin chemie   MeSH
• fibroblasty účinky léků   cytologie   MeSH
• hydrogely * chemie   farmakologie   MeSH
• lidé MeSH
• membrány umělé MeSH
• nádorové buněčné linie MeSH
• nanočástice chemie   MeSH
• nanokompozity chemie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• biokompatibilní materiály MeSH
• chitin MeSH
• hydrogely * MeSH
• membrány umělé MeSH

Tandem donor splice sites (5'ss) are unique regions with at least two GU dinucleotides serving as splicing cleavage sites. The Δ3 tandem 5'ss are a specific subclass of 5'ss separated by 3 nucleotides which can affect protein function by inserting/deleting a single amino acid. One 5'ss is typically preferred, yet factors governing particular 5'ss choice are not fully understood. A highly conserved exon 21 of the STAT3 gene was chosen as a model to study Δ3 tandem 5'ss splicing mechanisms. Based on multiple lines of experimental evidence, endogenous U1 snRNA most likely binds only to the upstream 5'ss. However, the downstream 5'ss is used preferentially, and the splice site choice is not dependent on the exact U1 snRNA binding position. Downstream 5'ss usage was sensitive to exact nucleotide composition and dependent on the presence of downstream regulatory region. The downstream 5'ss usage could be best explained by two novel interactions with endogenous U6 snRNA. U6 snRNA enables the downstream 5'ss usage in STAT3 exon 21 by two mechanisms: (i) binding in a novel non-canonical register and (ii) establishing extended Watson-Crick base pairing with the downstream regulatory region. This study suggests that U6:5'ss interaction is more flexible than previously thought.

• MeSH
• exony * MeSH
• HeLa buňky MeSH
• lidé MeSH
• místa sestřihu RNA * MeSH
• RNA malá jaderná * metabolismus   genetika   MeSH
• sekvence nukleotidů MeSH
• sestřih RNA MeSH
• transkripční faktor STAT3 * metabolismus   genetika   MeSH
• vazba proteinů MeSH
• vazebná místa genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• místa sestřihu RNA * MeSH
• RNA malá jaderná * MeSH
• STAT3 protein, human MeSH Prohlížeč
• transkripční faktor STAT3 * MeSH
• U1 small nuclear RNA MeSH Prohlížeč
• U6 small nuclear RNA MeSH Prohlížeč

Rituximab (RTX) plus chemotherapy (R-CHOP) applied as a first-line therapy for lymphoma leads to a relapse in approximately 40% of the patients. Therefore, novel approaches to treat aggressive lymphomas are being intensively investigated. Several RTX-resistant (RR) cell lines have been established as surrogate models to study resistance to R-CHOP. Our study reveals that RR cells are characterized by a major downregulation of CD37, a molecule currently explored as a target for immunotherapy. Using CD20 knockout (KO) cell lines, we demonstrate that CD20 and CD37 form a complex, and hypothesize that the presence of CD20 stabilizes CD37 in the cell membrane. Consequently, we observe a diminished cytotoxicity of anti-CD37 monoclonal antibody (mAb) in complement-dependent cytotoxicity in both RR and CD20 KO cells that can be partially restored upon lysosome inhibition. On the other hand, the internalization rate of anti-CD37 mAb in CD20 KO cells is increased when compared to controls, suggesting unhampered efficacy of antibody drug conjugates (ADCs). Importantly, even a major downregulation in CD37 levels does not hamper the efficacy of CD37-directed chimeric antigen receptor (CAR) T cells. In summary, we present here a novel mechanism of CD37 regulation with further implications for the use of anti-CD37 immunotherapies.

• Klíčová slova
• B-cell lymphoma, CAR T-cells, CD20, CD37, immunotherapy, rituximab,
• MeSH
• antigeny CD20 * imunologie   metabolismus   genetika   MeSH
• antigeny nádorové imunologie   genetika   MeSH
• B-buněčný lymfom * imunologie   terapie   genetika   farmakoterapie   MeSH
• chemorezistence účinky léků   MeSH
• chimerické antigenní receptory imunologie   genetika   metabolismus   MeSH
• cyklofosfamid farmakologie   terapeutické užití   MeSH
• doxorubicin farmakologie   aplikace a dávkování   MeSH
• imunoterapie * metody   MeSH
• lidé MeSH
• monoklonální protilátky farmakologie   terapeutické užití   MeSH
• nádorové buněčné linie MeSH
• protokoly antitumorózní kombinované chemoterapie farmakologie   terapeutické užití   MeSH
• regulace genové exprese u nádorů MeSH
• rituximab * farmakologie   terapeutické užití   MeSH
• tetraspaniny * genetika   metabolismus   MeSH
• vinkristin farmakologie   terapeutické užití   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny CD20 * MeSH
• antigeny nádorové MeSH
• CD37 protein, human MeSH Prohlížeč
• chimerické antigenní receptory MeSH
• cyklofosfamid MeSH
• doxorubicin MeSH
• monoklonální protilátky MeSH
• rituximab * MeSH
• tetraspaniny * MeSH
• vinkristin MeSH

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.

• Klíčová slova
• HER2, cancer, electron transport chain, mitochondria, reactive oxygen species,
• 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