The small-molecule alkaloid halofuginone (HF) is obtained from febrifugine. Recent studies on HF have aroused widespread attention owing to its universal range of noteworthy biological activities and therapeutic functions, which range from parasite infections and fibrosis to autoimmune diseases. In particular, HF is believed to play an excellent anticancer role by suppressing the proliferation, adhesion, metastasis, and invasion of cancers. This review supports the goal of demonstrating various anticancer effects and molecular mechanisms of HF. In the studies covered in this review, the anticancer molecular mechanisms of HF mainly included transforming growth factor-β (TGF-β)/Smad-3/nuclear factor erythroid 2-related factor 2 (Nrf2), serine/threonine kinase proteins (Akt)/mechanistic target of rapamycin complex 1(mTORC1)/wingless/integrated (Wnt)/β-catenin, the exosomal microRNA-31 (miR-31)/histone deacetylase 2 (HDAC2) signaling pathway, and the interaction of the extracellular matrix (ECM) and immune cells. Notably, HF, as a novel type of adenosine triphosphate (ATP)-dependent inhibitor that is often combined with prolyl transfer RNA synthetase (ProRS) and amino acid starvation therapy (AAS) to suppress the formation of ribosome, further exerts a significant effect on the tumor microenvironment (TME). Additionally, the combination of HF with other drugs or therapies obtained universal attention. Our results showed that HF has significant potential for clinical cancer treatment.

• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

We designed and synthesized a set of four 2'-deoxyribonucleoside 5'-O-triphosphates (dNTPs) bearing cationic substituents (protonated amino, methylamino, dimethylamino and trimethylammonium groups) attached to position 5 of pyrimidines or position 7 of 7-deazapurines through hex-1-ynyl or propargyl linker. These cationic dNTPs were studied as substrates in enzymatic synthesis of modified and hypermodified DNA using KOD XL DNA polymerase. In primer extension (PEX), we successfully obtained DNA containing one, two, three, or (all) four modified nucleotides, each bearing a different cationic modification. The cationic dNTPs were somewhat worse substrates compared to previously studied dNTPs bearing hydrophobic or anionic modifications, but the polymerase was still able to synthesize sequences up to 73 modified nucleotides. We also successfully combined one cationic modification with one anionic and two hydrophobic modifications in PEX. In polymerase chain reaction (PCR), we observed exponential amplification only in the case of one cationic modification, while the combination of more cationic nucleotides gave either very low amplification or no PCR product. The hypermodified oligonucleotides prepared by PEX were successfully re-PCRed and sequenced by Sanger sequencing. Biophysical studies of hybridization, denaturation, and circular dichroism spectroscopy showed that the presence of cationic modifications increases the stability of duplexes.

• MeSH
• deoxyribonukleotidy metabolismus   chemie   MeSH
• DNA-dependentní DNA-polymerasy * metabolismus   chemie   MeSH
• DNA * chemie   biosyntéza   metabolismus   MeSH
• kationty * chemie   MeSH
• polymerázová řetězová reakce MeSH
• puriny chemie   biosyntéza   MeSH
• pyrimidiny chemie   MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND: Up to 65% of patients with chronic myeloid leukemia (CML) who are treated with imatinib do not achieve sustained deep molecular response, which is required to attempt treatment-free remission. Asciminib is the only approved BCR::ABL1 inhibitor that Specifically Targets the ABL Myristoyl Pocket. This unique mechanism of action allows asciminib to be combined with adenosine triphosphate-competitive tyrosine kinase inhibitors to prevent resistance and enhance efficacy. The phase II ASC4MORE trial investigated the strategy of adding asciminib to imatinib in patients who have not achieved deep molecular response with imatinib. METHODS: In ASC4MORE, 84 patients with CML in chronic phase not achieving deep molecular response after ≥ 1 year of imatinib therapy were randomized to asciminib 40 or 60 mg once daily (QD) add-on to imatinib 400 mg QD, continued imatinib 400 mg QD, or switch to nilotinib 300 mg twice daily. RESULTS: More patients in the asciminib 40- and 60-mg QD add-on arms (19.0% and 28.6%, respectively) achieved MR4.5 (BCR::ABL1 ≤ 0.0032% on the International Scale) at week 48 (primary endpoint) than patients in the continued imatinib (0.0%) and switch to nilotinib (4.8%) arms. Fewer patients discontinued asciminib 40- and 60-mg QD add-on treatment (14.3% and 23.8%, respectively) than imatinib (76.2%, including crossover patients) and nilotinib (47.6%). Asciminib add-on was tolerable, with rates of AEs and AEs leading to discontinuation less than those with nilotinib, although higher than those with continued imatinib (as expected in these patients who had already been tolerating imatinib for ≥ 1 year). No new or worsening safety signals were observed with asciminib add-on vs the known asciminib monotherapy safety profile. CONCLUSIONS: Overall, these results support asciminib add-on as a treatment strategy to help patients with CML in chronic phase stay on therapy to safely achieve rapid and deep response, although further investigation is needed before this strategy is incorporated into clinical practice. TRIAL REGISTRATION: NCT03578367.

• MeSH
• bcr-abl fúzní proteiny antagonisté a inhibitory   MeSH
• chronická myeloidní leukemie * farmakoterapie   MeSH
• dospělí MeSH
• imatinib mesylát * terapeutické užití   MeSH
• inhibitory proteinkinas terapeutické užití   aplikace a dávkování   MeSH
• lidé středního věku MeSH
• lidé MeSH
• následné studie MeSH
• niacinamid analogy a deriváty   MeSH
• protokoly protinádorové kombinované chemoterapie * terapeutické užití   MeSH
• pyrazoly MeSH
• pyrimidiny terapeutické užití   aplikace a dávkování   MeSH
• senioři MeSH
• výsledek terapie MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• klinické zkoušky, fáze II MeSH
• multicentrická studie MeSH
• randomizované kontrolované studie MeSH

The Sec translocon is a highly conserved membrane assembly for polypeptide transport across, or into, lipid bilayers. In bacteria, secretion through the core channel complex-SecYEG in the inner membrane-is powered by the cytosolic ATPase SecA. Here, we use single-molecule fluorescence to interrogate the conformational state of SecYEG throughout the ATP hydrolysis cycle of SecA. We show that the SecYEG channel fluctuations between open and closed states are much faster (~20-fold during translocation) than ATP turnover, and that the nucleotide status of SecA modulates the rates of opening and closure. The SecY variant PrlA4, which exhibits faster transport but unaffected ATPase rates, increases the dwell time in the open state, facilitating pre-protein diffusion through the pore and thereby enhancing translocation efficiency. Thus, rapid SecYEG channel dynamics are allosterically coupled to SecA via modulation of the energy landscape, and play an integral part in protein transport. Loose coupling of ATP-turnover by SecA to the dynamic properties of SecYEG is compatible with a Brownian-rachet mechanism of translocation, rather than strict nucleotide-dependent interconversion between different static states of a power stroke.

• MeSH
• adenosintrifosfát metabolismus   MeSH
• adenosintrifosfatasy genetika   metabolismus   MeSH
• bakteriální proteiny * metabolismus   MeSH
• nukleotidy metabolismus   MeSH
• proteiny SecA metabolismus   MeSH
• proteiny z Escherichia coli * metabolismus   MeSH
• translokační kanály SEC chemie   MeSH
• transport proteinů MeSH
• Publikační typ
• časopisecké články MeSH

Mutations in DNA polymerase gamma (POLG) are known as the predominant cause of inherited mitochondrial disorders. But how these POLG mutations disturb mitochondrial function remains to be determined. Furthermore, no effective therapy, to date, has been reported for POLG diseases. Using differentiated SH-SY5Y cells, a human neuronal model cell line, the current study investigated whether the novel POLG variant p.A962T impairs mitochondrial function. This involved quantifying mitochondrial DNA (mtDNA) content using PCR and assessing the expression levels of the subunits of complex IV (COXI-IV), a complex I subunit NDUFV1 and Cytochrome C (Cyto C) release using Western blotting. Activities of mitochondrial complex I, II, and IV were measured using colorimetric assays. Mitochondrial membrane potential (delta Psim) and ATP were evaluated using fluorescence assays and luminescent assays, respectively. In addition, we investigated whether mitochondrial transplantation (MT) using Pep-1-conjugated mitochondria could compensate for mitochondrial defects caused by the variant in cells carrying mutant POLG. The results of this study showed that POLG p.A962T mutation resulted in mitochondrial defects, including mitochondrial DNA (mtDNA) depletion, membrane potential (delta Psim) depolarization and adenosine triphosphate (ATP) reduction. Mechanistically, POLG mutation-caused mtDNA depletion led to the loss of mtDNA-encoded subunits of complex I and IV and thus compromised their activities. POLG p.A962T mutation is a pathogenic mutation leading to mitochondrial malfunction and mtDNA depletion in neurons. Cell-penetrating peptide Pep-1-mediated MT treatment compensated for mitochondrial defects induced by these POLG variants, suggesting the therapeutic application of this method in POLG diseases.

• MeSH
• DNA polymeráza gama * genetika   metabolismus   MeSH
• DNA-dependentní DNA-polymerasy genetika   metabolismus   MeSH
• lidé MeSH
• membránový potenciál mitochondrií MeSH
• mitochondriální DNA genetika   MeSH
• mitochondriální nemoci genetika   metabolismus   MeSH
• mitochondrie * metabolismus   MeSH
• mutace * MeSH
• nádorové buněčné linie MeSH
• neurony * metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Induction of autophagy represents an effective survival strategy for nutrient-deprived or stressed cancer cells. Autophagy contributes to the modulation of communication within the tumor microenvironment. Here, we conducted a study of the metabolic and signaling implications associated with autophagy induced by glutamine (Gln) and serum starvation and PI3K/mTOR inhibitor and autophagy inducer NVP-BEZ235 (BEZ) in the head and neck squamous cell carcinoma (HNSCC) cell line FaDu. We compared the effect of these different types of autophagy induction on ATP production, lipid peroxidation, mitophagy, RNA cargo of extracellular vesicles (EVs), and EVs-associated cytokine secretome of cancer cells. Both BEZ and starvation resulted in a decline in ATP production. Simultaneously, Gln starvation enhanced oxidative damage of cancer cells by lipid peroxidation. In starved cells, there was a discernible fragmentation of the mitochondrial network coupled with an increase in the presence of tumor susceptibility gene 101 (TSG101) on the mitochondrial membrane, indicative of the sorting of mitochondrial cargo into EVs. Consequently, the abundance of mitochondrial RNAs (mtRNAs) in EVs released by FaDu cells was enhanced. Notably, mtRNAs were also detectable in EVs isolated from the serum of both HNSCC patients and healthy controls. Starvation and BEZ reduced the production of EVs by cancer cells, yet the characteristic molecular profile of these EVs remained unchanged. We also found that alterations in the release of inflammatory cytokines constitute a principal response to autophagy induction. Importantly, the specific mechanism driving autophagy induction significantly influenced the composition of the EVs-associated cytokine secretome.

• MeSH
• adenosintrifosfát * metabolismus   MeSH
• autofagie * účinky léků   MeSH
• dlaždicobuněčné karcinomy hlavy a krku metabolismus   genetika   patologie   MeSH
• extracelulární vezikuly * metabolismus   účinky léků   MeSH
• glutamin * metabolismus   MeSH
• lidé MeSH
• mitochondrie metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádory hlavy a krku metabolismus   patologie   genetika   MeSH
• oxidační stres * MeSH
• RNA mitochondriální * metabolismus   genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The eIF4F translation initiation complex plays a critical role in melanoma resistance to clinical BRAF and MEK inhibitors. In this study, we uncover a function of eIF4F in the negative regulation of the rat sarcoma (RAS)/rapidly accelerated fibrosarcoma (RAF)/mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling pathway. We demonstrate that eIF4F is essential for controlling ERK signaling intensity in treatment-naïve melanoma cells harboring BRAF or NRAS mutations. Specifically, the dual-specificity phosphatase DUSP6/MKP3, which acts as a negative feedback regulator of ERK activity, requires continuous production in an eIF4F-dependent manner to limit excessive ERK signaling driven by oncogenic RAF/RAS mutations. Treatment with small-molecule eIF4F inhibitors disrupts the negative feedback control of MAPK signaling, leading to ERK hyperactivation and EGR1 overexpression in melanoma cells in vitro and in vivo. Furthermore, our quantitative analyses reveal a high spare signaling capacity in the ERK pathway, suggesting that eIF4F-dependent feedback keeps the majority of ERK molecules inactive under normal conditions. Overall, our findings highlight the crucial role of eIF4F in regulating ERK signaling flux and suggest that pharmacological eIF4F inhibitors can disrupt the negative feedback control of MAPK activity in melanomas with BRAF and NRAS activating mutations.

• MeSH
• eukaryotický iniciační faktor 4F * metabolismus   genetika   MeSH
• extracelulárním signálem regulované MAP kinasy metabolismus   MeSH
• fosfatasa 6 s dvojí specificitou metabolismus   genetika   MeSH
• GTP-fosfohydrolasy * metabolismus   genetika   MeSH
• lidé MeSH
• MAP kinasový signální systém * genetika   MeSH
• melanom * genetika   metabolismus   patologie   MeSH
• membránové proteiny * metabolismus   genetika   MeSH
• mutace * MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• protoonkogenní proteiny B-Raf * genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Phosphofructokinase-1 (PFK1) catalyzes the rate-limiting step of glycolysis, committing glucose to conversion into cellular energy. PFK1 is highly regulated to respond to the changing energy needs of the cell. In bacteria, the structural basis of PFK1 regulation is a textbook example of allostery; molecular signals of low and high cellular energy promote transition between an active R-state and inactive T-state conformation, respectively. Little is known, however, about the structural basis for regulation of eukaryotic PFK1. Here, we determine structures of the human liver isoform of PFK1 (PFKL) in the R- and T-state by cryoEM, providing insight into eukaryotic PFK1 allosteric regulatory mechanisms. The T-state structure reveals conformational differences between the bacterial and eukaryotic enzyme, the mechanisms of allosteric inhibition by ATP binding at multiple sites, and an autoinhibitory role of the C-terminus in stabilizing the T-state. We also determine structures of PFKL filaments that define the mechanism of higher-order assembly and demonstrate that these structures are necessary for higher-order assembly of PFKL in cells.

• MeSH
• adenosintrifosfát * metabolismus   MeSH
• alosterická regulace MeSH
• elektronová kryomikroskopie MeSH
• fosfofruktokinasa-1 * metabolismus   chemie   genetika   MeSH
• glykolýza MeSH
• játra enzymologie   metabolismus   MeSH
• konformace proteinů MeSH
• lidé MeSH
• molekulární modely MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The RAS pathway is among the most frequently activated signaling nodes in cancer. However, the mechanisms that alter RAS activity in human pathologies are not entirely understood. The most prevalent post-translational modification within the GTPase core domain of NRAS and KRAS is ubiquitination at lysine 128 (K128), which is significantly decreased in cancer samples compared to normal tissue. Here, we found that K128 ubiquitination creates an additional binding interface for RAS GTPase-activating proteins (GAPs), NF1 and RASA1, thus increasing RAS binding to GAP proteins and promoting GAP-mediated GTP hydrolysis. Stimulation of cultured cancer cells with growth factors or cytokines transiently induces K128 ubiquitination and restricts the extent of wild-type RAS activation in a GAP-dependent manner. In KRAS mutant cells, K128 ubiquitination limits tumor growth by restricting RAL/ TBK1 signaling and negatively regulating the autocrine circuit induced by mutant KRAS. Reduction of K128 ubiquitination activates both wild-type and mutant RAS signaling and elicits a senescence-associated secretory phenotype, promoting RAS-driven pancreatic tumorigenesis.

• MeSH
• GTP-fosfohydrolasy metabolismus   genetika   MeSH
• lidé MeSH
• lysin metabolismus   MeSH
• membránové proteiny metabolismus   genetika   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• neurofibromin 1 MeSH
• protein aktivující GTPasu p120 metabolismus   genetika   MeSH
• protein-serin-threoninkinasy metabolismus   genetika   MeSH
• protoonkogenní proteiny p21(ras) * metabolismus   genetika   MeSH
• Ras proteiny metabolismus   genetika   MeSH
• signální transdukce MeSH
• ubikvitinace * MeSH
• vazba proteinů * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Life manifests as growth, movement or heat production that occurs thanks to the energy accepted from the outside environment. The basis of energy transduction attracted the Czech researchers since the beginning of the 20th century. It further accelerated after World War II, when the new Institute of Physiology was established in 1954. When it was found that energy is stored in the form of adenosine triphosphate (ATP) that can be used by numerous reactions as energy source and is produced in the process called oxidative phosphorylation localized in mitochondria, the investigation focused on this cellular organelle. Although the Czech scientists had to overcome various obstacles including Communist party leadership, driven by curiosity, boldness, and enthusiasm, they characterized broad spectrum of mitochondrial properties in different tissues in (patho)physiological conditions in collaboration with many world-known laboratories. The current review summarizes the contribution of the Czech scientists to the bioenergetic and mitochondrial research in the global context. Keywords: Mitochondria, Bioenergetics, Chemiosmotic coupling.

• MeSH
• biomedicínský výzkum dějiny   trendy   MeSH
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• energetický metabolismus * MeSH
• lidé MeSH
• mitochondrie * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• dějiny 20. století MeSH
• dějiny 21. století MeSH
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• historické články MeSH
• přehledy MeSH
• Geografické názvy
• Česká republika MeSH