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Úvod: Dutina ústní představuje komplexní systém, kde probíhá vzájemná chemická komunikace mezi tkáněmi, mikrobiotou a složkami sliny a potravy. Tento článek je zaměřen na hormetické efekty a elektrofilní sloučeniny, které mohou hrát roli v obranných mechanismech proti oxidačnímu stresu a zánětlivým procesům. Hormetické efekty, vyvolané subletálními nebo subtoxickými stresory, mohou aktivovat reparační mechanismy a posílit odolnost tkání proti poškození. Metodika: Analýza byla provedena prostřednictvím vyhledávání ve třech elektronických databázích: Web of Science, PubMed a Scopus. V rámci rešerše jsme se soustředili na studie publikované mezi lety 2000 a 2023, které se zabývaly oxidačně-redukčními procesy, zánětlivými stavy a aktivací Nrf2 dráhy v ústní dutině. Vyloučeny byly studie zaměřené na nádorová onemocnění. Závěr: Elektrofilní sloučeniny působí jako jeden z činitelů zasahujících do homeostázy dutiny ústní a mohou tak představovat terapeutický potenciál v zubním lékařství, konkrétně v parodontologii. Zjištění založená na in vitro a preklinických studiích však vyžadují další ověření v klinických podmínkách, přičemž je třeba zvážit i interakce s orální mikrobiotou.
Introduction: The oral cavity is a complex system in which mutual chemical communication occurs between tissues, microbiota, and components of saliva and food. This paper focuses on hormetic effects and electrophilic compounds, which can play a role in defense mechanisms against oxidative stress and inflammatory processes. Hormetic effects, induced by sublethal or subtoxic stressors, can activate repair mechanisms and enhance tissue resistance to damage. Methods: The analysis was conducted through searches in three electronic databases: Web of Science, PubMed, and Scopus. Our research focused on studies published between 2000 and 2023 that dealt with redox processes, inflammatory conditions, and activation of the Nrf2 pathway in the oral cavity. Studies focused on cancerous diseases were excluded. Conclusion: Electrophilic compounds act as one of the agents that interfere with the homeostasis of the oral cavity, and can thus find therapeutic potential in dentistry, specifically in periodontology. However, findings based on in vitro and preclinical studies require further verification under clinical conditions, and also considering interactions with oral microbiota.
MicroRNA hsa-miR-29 was connected to a number of malignancies. Its target genes are many, among them Mcl-1 that is expressed in three possible isoforms, one of which is anti-apoptotic and another one pro-apoptotic. Ratio of these two isoforms appears to affect cell response to external stimuli. We have demonstrated that miR-29b enhanced etoposide toxicity in HeLa cell line by modulating this ratio of Mcl-1 isoforms. However, it is not known whether the described miR-29 effect is common to various cancer types or even have the opposite effect. This represents a significant problem for possible future applications. In this report, we demonstrate that miR-29b affects toxicity of 60 μM etoposide in cell lines derived from selected malignancies. The mechanism, however, differs among the cell lines tested. Hep G2 cells demonstrated similar effect of miR-29b on etoposide toxicity as was described in HeLa cells, i.e. modulation of Mcl-1 expression. Target protein down-regulated by miR-29b resulting in enhanced etoposide toxicity in Caco-2 cells was, however, Bcl-2 protein. Moreover, H9c2, Hek-293 and ARPE-19 cell lines selected as a representatives of non-malignant cells, showed no effect of miR-29b on etoposide toxicity. Our data suggest that miR-29b could be a common enhancer of etoposide toxicity in malignant cells due to its modulation of Bcl family proteins.
- MeSH
- apoptóza účinky léků genetika MeSH
- buňky Hep G2 MeSH
- Caco-2 buňky MeSH
- etoposid * toxicita farmakologie MeSH
- fytogenní protinádorové látky farmakologie toxicita MeSH
- HEK293 buňky MeSH
- HeLa buňky MeSH
- lidé MeSH
- mikro RNA * genetika metabolismus MeSH
- protein MCL-1 * genetika metabolismus MeSH
- protoonkogenní proteiny c-bcl-2 genetika metabolismus MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Polyphenols, secondary metabolites of plants, exhibit different anti-cancer and cytoprotective properties such as anti-radical, anti-angiogenic, anti-inflammation, or cardioprotective. Some of these activities could be linked to modulation of miRNAs expression. MiRNAs play an important role in posttranscriptional regulation of their target genes that could be important within cell signalling or preservation of cell homeostasis, e.g., cell survival/apoptosis. We evaluated the influence of a non-toxic concentration of taxifolin and quercetin on the expression of majority human miRNAs via Affymetrix GeneChip™ miRNA 3.0 Array. For the evaluation we used two cell models corresponding to liver tissue, Hep G2 and primary human hepatocytes. The array analysis identified four miRNAs, miR-153, miR-204, miR-211, and miR-377-3p, with reduced expression after taxifolin treatment. All of these miRNAs are linked to modulation of ZEB2 expression in various models. Indeed, ZEB2 protein displayed upregulation after taxifolin treatment in a dose dependent manner. However, the modulation did not lead to epithelial mesenchymal transition. Our data show that taxifolin inhibits Akt phosphorylation, thereby diminishing ZEB2 signalling that could trigger carcinogenesis. We conclude that biological activity of taxifolin may have ambiguous or even contradictory outcomes because of non-specific effect on the cell.
- MeSH
- apoptóza účinky léků MeSH
- buňky Hep G2 metabolismus MeSH
- epitelo-mezenchymální tranzice genetika MeSH
- exprese genu účinky léků genetika MeSH
- hepatocyty účinky léků metabolismus MeSH
- lidé MeSH
- mikro RNA účinky léků genetika MeSH
- pohyb buněk účinky léků MeSH
- polyfenoly farmakologie MeSH
- primární buněčná kultura MeSH
- proliferace buněk účinky léků MeSH
- quercetin analogy a deriváty metabolismus farmakologie MeSH
- regulace genové exprese u nádorů účinky léků MeSH
- signální transdukce genetika MeSH
- transkripční faktor Zeb2 účinky léků metabolismus MeSH
- transkriptom účinky léků genetika MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Etoposide is a well-known and widely used anticancer drug that displays several side effects. In addition, tumors often acquire resistance to this drug. Our aim is to develop a combination therapy that would augment toxicity of etoposide in malignant cells. Based on literature and our experiments, we selected mifepristone (RU486) as a potential supporting molecule that is able to enhance etoposide toxicity against cancer cells. All experiments were performed with Hep G2 cells, a well-known and described human hepatocellular carcinoma cell line. By using xCELLigence system, we demonstrated that mifepristone enhances toxicity of etoposide in a dose dependent manner with concomitant caspase-3 activity. We evaluated upregulation of Bax because mifepristone was demonstrated to modulate proapoptotic Bax protein expression. Our data show only weak and not statistically significant increase of Bax expression. On the other hand, we show that mifepristone increases etoposide toxicity via inhibition of ABC transporters, coupled with significant increase of intracellular etoposide concentration. In conclusion, we demonstrate that mifepristone has a synergistic effect with etoposide treatment in the Hep G2 cells and that the effect is related to ABC transporters inhibition.
- MeSH
- ABC transportér z rodiny G, člen 2 antagonisté a inhibitory MeSH
- biologický transport účinky léků MeSH
- buňky Hep G2 MeSH
- buňky K562 MeSH
- etoposid farmakologie MeSH
- fytogenní protinádorové látky farmakologie MeSH
- kaspasa 3 metabolismus MeSH
- lidé MeSH
- mifepriston farmakologie MeSH
- nádorové proteiny antagonisté a inhibitory MeSH
- P-glykoproteiny antagonisté a inhibitory MeSH
- protein X asociovaný s bcl-2 metabolismus MeSH
- synergismus léků MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Quercetin, a flavonoid with multiple proven health benefits to both man and animals, displays a plethora of biological activities, collectively referred to as pleiotropic. The most studied of these are antioxidant and anti-inflammatory but modulation of signalling pathways is important as well. One of the lesser-known and recently discovered roles of quercetin, is modulation of microRNA (miRNA) expression. miRNAs are important posttranscriptional modulators that play a critical role in health and disease and many of these non-coding oligonucleotides are recognized as oncogenic or tumor suppressor miRNAs. This review is an evaluation of the recent relevant literature on the subject, with focus on the ability of quercetin to modulate miRNA expression. It includes a summary of recent knowledge on miRNAs deregulated by quercetin, an overview of quercetin pharmacokinetics and miRNA biogenesis, for the interested reader.
- MeSH
- exprese genu účinky léků MeSH
- lidé MeSH
- mikro RNA účinky léků genetika metabolismus MeSH
- quercetin farmakologie MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- přehledy MeSH
Etoposide is commonly used as a monotherapy or in combination with other drugs for cancer treatments. In order to increase the drug efficacy, ceaseless search for novel combinations of drugs and supporting molecules is under way. MiRNAs are natural candidates for facilitating drug effect in various cell types. We used several systems to evaluate the effect of miR-29 family on etoposide toxicity in HeLa cells. We show that miR-29b significantly increases etoposide toxicity in HeLa cells. Because Mcl-1 protein has been recognized as a miR-29 family target, we evaluated downregulation of Mcl-1 protein splicing variant expression induced by miR-29 precursors and confirmed a key role of Mcl-1 protein in enhancing etoposide toxicity. Despite downregulation of Mcl-1 by all three miR-29 family members, only miR-29b significantly enhanced etoposide toxicity. We hypothesized that this difference may be linked to the change in Mcl-1L/Mcl-1S ratio induced by miR-29b. We hypothesized that the change could be due to miR-29b nuclear shuttling. Using specifically modified miR-29b sequences with enhanced cytosolic and nuclear localization we show that there is a difference, albeit statistically non-significant. In conclusion, we show that miR-29b has the synergistic effect with etoposide treatment in the HeLa cells and that this effect is linked to Mcl-1 protein expression and nuclear shuttling of miR-29b.
- MeSH
- buněčný cyklus účinky léků MeSH
- down regulace MeSH
- etoposid toxicita MeSH
- fytogenní protinádorové látky toxicita MeSH
- HeLa buňky MeSH
- lidé MeSH
- mikro RNA metabolismus MeSH
- protein MCL-1 genetika metabolismus MeSH
- viabilita buněk účinky léků MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
