Resistance to chemotherapeutics and targeted drugs is one of the main problems in successful cancer therapy. Various mechanisms have been identified to contribute to drug resistance. One of those mechanisms is lysosome-mediated drug resistance. Lysosomes have been shown to trap certain hydrophobic weak base chemotherapeutics, as well as some tyrosine kinase inhibitors, thereby being sequestered away from their intracellular target site. Lysosomal sequestration is in most cases followed by the release of their content from the cell by exocytosis. Lysosomal accumulation of anticancer drugs is caused mainly by ion-trapping, but active transport of certain drugs into lysosomes was also described. Lysosomal low pH, which is necessary for ion-trapping is achieved by the activity of the V-ATPase. This sequestration can be successfully inhibited by lysosomotropic agents and V-ATPase inhibitors in experimental conditions. Clinical trials have been performed only with lysosomotropic drug chloroquine and their results were less successful. The aim of this review is to give an overview of lysosomal sequestration and expression of acidifying enzymes as yet not well known mechanism of cancer cell chemoresistance and about possibilities how to overcome this form of resistance.

• MeSH
• chemorezistence * účinky léků   MeSH
• exocytóza MeSH
• koncentrace vodíkových iontů MeSH
• lidé MeSH
• lyzozomy účinky léků   enzymologie   MeSH
• nádorové buněčné linie MeSH
• nádory farmakoterapie   enzymologie   MeSH
• protinádorové látky farmakologie   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• vakuolární protonové ATPasy antagonisté a inhibitory   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Tyrosine kinase inhibitors (TKIs) are being increasingly used to treat various malignancies. Although they were designed to target aberrant tyrosine kinases, they are also intimately linked with the mechanisms of multidrug resistance (MDR) in cancer cells. MDR-related solute carrier (SLC) and ATB-binding cassette (ABC) transporters are responsible for TKI uptake and efflux, respectively. However, the role of TKIs appears to be dual because they can act as substrates and/or inhibitors of these transporters. In addition, several TKIs have been identified to be sequestered into lysosomes either due to their physiochemical properties or via ABC transporters expressed on the lysosomal membrane. Since the development of MDR represents a great concern in anticancer treatment, it is important to elucidate the interactions of TKIs with MDR-related transporters as well as to improve the properties that would prevent TKIs from diffusing into lysosomes. These findings not only help to avoid MDR, but also help to define the possible impact of combining TKIs with other anticancer drugs, leading to more efficient therapy and fewer adverse effects in patients.

• MeSH
• ABC transportéry genetika   metabolismus   MeSH
• biologický transport MeSH
• chemorezistence účinky léků   MeSH
• inhibitory proteinkinas farmakologie   terapeutické užití   MeSH
• klinické zkoušky jako téma MeSH
• lidé MeSH
• lyzozomy účinky léků   metabolismus   MeSH
• membránové transportní proteiny genetika   metabolismus   MeSH
• mnohočetná léková rezistence účinky léků   MeSH
• nádory farmakoterapie   genetika   metabolismus   MeSH
• přehodnocení terapeutických indikací léčivého přípravku * MeSH
• SLC transportéry genetika   metabolismus   MeSH
• výsledek terapie MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

Lysosomal sequestration of anticancer therapeutics lowers their cytotoxic potential, reduces drug availability at target sites, and contributes to cancer resistance. Only recently has it been shown that lysosomal sequestration of weak base drugs induces lysosomal biogenesis mediated by activation of transcription factor EB (TFEB) which, in turn, enhances their accumulation capacity, thereby increasing resistance to these drugs. Here, we addressed the question of whether lysosomal biogenesis is the only mechanism that increases lysosomal sequestration capacity. We found that lysosomal sequestration of some tyrosine kinase inhibitors (TKIs), gefitinib (GF) and imatinib (IM), induced expansion of the lysosomal compartment. However, an expression analysis of lysosomal genes, including lysosome-associated membrane proteins 1, 2 (LAMP1, LAMP2), vacuolar ATPase subunit B2 (ATP6V1B2), acid phosphatase (ACP), and galactosidase beta (GLB) controlled by TFEB, did not reveal increased expression. Instead, we found that both studied TKIs, GF and IM, induced lysosomal fusion which was dependent on nicotinic acid adenine dinucleotide phosphate (NAADP) mediated Ca2+signaling. A theoretical analysis revealed that lysosomal fusion is sufficient to explain the enlargement of lysosomal sequestration capacity. In conclusion, we demonstrated that extracellular TKIs, GF and IM, induced NAADP/Ca2+ mediated lysosomal fusion, leading to enlargement of the lysosomal compartment with significantly increased sequestration capacity for these drugs without apparent lysosomal biogenesis.

• MeSH
• biogeneze organel MeSH
• buňky K562 MeSH
• chemorezistence účinky léků   MeSH
• gefitinib farmakologie   MeSH
• imatinib mesylát farmakologie   MeSH
• lidé MeSH
• lyzozomy účinky léků   metabolismus   MeSH
• nádorové buněčné linie MeSH
• protinádorové látky farmakologie   MeSH
• signální transdukce účinky léků   MeSH
• transkripční faktory BHLH-Zip účinky léků   metabolismus   MeSH
• tyrosinkinasy antagonisté a inhibitory   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The specific effects of sodium selenite (selenite) on a chemoresistant human bladder cancer cell line RT-112/D21 were investigated during 72 h. Selenite at low concentration of 2.5 μmol (otherwise tolerated in normal urothelial cells UROtsa) suppressed growth and proliferation of the tested cancer cells via induced oxidative stress. Selenite further altered mitochondrial functions (i.e. decreased mitochondrial membrane potential, increased production of superoxide and reduced ATP synthesis), disrupted lysosomal membranes and activated autophagy. These changes in selenite-exposed cells ultimately resulted in their demise via necrosis and other cell death modality displaying heterotypic apoptotic and autophagic features.

• MeSH
• apoptóza účinky léků   MeSH
• autofagie účinky léků   MeSH
• buněčná smrt účinky léků   MeSH
• chemorezistence účinky léků   MeSH
• lidé MeSH
• lyzozomy účinky léků   metabolismus   MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• mitochondrie účinky léků   metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádory močového měchýře farmakoterapie   metabolismus   patologie   MeSH
• proliferace buněk účinky léků   MeSH
• seleničitan sodný farmakologie   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The Lysosomal sequestration of weak-base anticancer drugs is one putative mechanism for resistance to chemotherapy but it has never been directly proven. We addressed the question of whether the lysosomal sequestration of tyrosine kinase inhibitors (TKIs) itself contributes to the drug resistance in vitro. Our analysis indicates that lysosomal sequestration of an anticancer drug can significantly reduce the concentration at target sites, only when it simultaneously decreases its extracellular concentration due to equilibrium, since uncharged forms of weak-base drugs freely diffuse across cellular membranes. Even though the studied TKIs, including imatinib, nilotinib, and dasatinib, were extensively accumulated in the lysosomes of cancer cells, their sequestration was insufficient to substantially reduce the extracellular drug concentration. Lysosomal accumulation of TKIs also failed to affect the Bcr-Abl signaling. Cell pre-treatment with sunitinib significantly enhanced the lysosomal accumulation of the TKIs used; however, without apparent lysosomal biogenesis. Importantly, even increased lysosomal sequestration of TKIs neither decreased their extracellular concentrations nor affected the sensitivity of Bcr-Abl to TKIs. In conclusion, our results clearly show that the lysosomal sequestration of TKIs failed to change their concentrations at target sites, and thus, can hardly contribute to drug resistance in vitro.

• MeSH
• buňky K562 MeSH
• chemorezistence * MeSH
• extracelulární prostor účinky léků   metabolismus   MeSH
• inhibitory proteinkinas farmakologie   MeSH
• lidé MeSH
• lyzozomy účinky léků   metabolismus   MeSH
• sunitinib farmakologie   MeSH
• tyrosinkinasy metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Nanodiamonds (ND), especially fluorescent NDs, represent potentially applicable drug and probe carriers for in vitro/in vivo applications. The main purpose of this study was to relate physical-chemical properties of carboxylated NDs to their intracellular distribution and impact on membranes and cell immunity-activation of inflammasome in the in vitro THP-1 cell line model. Dynamic light scattering, nanoparticle tracking analysis, and microscopic methods were used to characterize ND particles and their intracellular distribution. Fluorescent NDs penetrated the cell membranes by both macropinocytosis and mechanical cutting through cell membranes. We proved accumulation of fluorescent NDs in lysosomes. In this case, lysosomes were destabilized and cathepsin B was released into the cytoplasm and triggered pathways leading to activation of inflammasome NLRP3, as detected in THP-1 cells. Activation of inflammasome by NDs represents an important event that could underlie the described toxicological effects in vivo induced by NDs. According to our knowledge, this is the first in vitro study demonstrating direct activation of inflammasome by NDs. These findings are important for understanding the mechanism(s) of action of ND complexes and explain the ambiguity of the existing toxicological data.

• MeSH
• buněčná membrána účinky léků   metabolismus   ultrastruktura   MeSH
• dynamický rozptyl světla MeSH
• elektronová mikroskopie MeSH
• fluorescence MeSH
• inflamasomy účinky léků   imunologie   metabolismus   MeSH
• intravitální mikroskopie metody   MeSH
• kathepsin B imunologie   metabolismus   MeSH
• konfokální mikroskopie MeSH
• lidé MeSH
• lyzozomy účinky léků   imunologie   metabolismus   ultrastruktura   MeSH
• mikroskopie atomárních sil MeSH
• nanodiamanty aplikace a dávkování   chemie   MeSH
• pinocytóza MeSH
• protein NLRP3 imunologie   metabolismus   MeSH
• THP-1 buňky MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The exceptionally high cellular uptake of gold nanorods (GNRs) bearing cationic surfactants makes them a promising tool for biomedical applications. Given the known specific toxic and stress effects of some preparations of cationic nanoparticles, the purpose of this study was to evaluate, in an in vitro and in vivo in mouse, the potential harmful effects of GNRs coated with (16-mercaptohexadecyl)trimethylammonium bromide (MTABGNRs). Interestingly, even after cellular accumulation of high amounts of MTABGNRs sufficient for induction of photothermal effect, no genotoxicity (even after longer-term accumulation), induction of autophagy, destabilization of lysosomes (dominant organelles of their cellular destination), alterations of actin cytoskeleton, or in cell migration could be detected in vitro. In vivo, after intravenous administration, the majority of GNRs accumulated in mouse spleen followed by lungs and liver. Microscopic examination of the blood and spleen showed that GNRs interacted with white blood cells (mononuclear and polymorphonuclear leukocytes) and thrombocytes, and were delivered to the spleen red pulp mainly as GNR-thrombocyte complexes. Importantly, no acute toxic effects of MTABGNRs administered as 10 or 50 μg of gold per mice, as well as no pathological changes after their high accumulation in the spleen were observed, indicating good tolerance of MTABGNRs by living systems.

• MeSH
• autofagie účinky léků   MeSH
• kvartérní amoniové sloučeniny metabolismus   MeSH
• lidé MeSH
• lyzozomy účinky léků   metabolismus   MeSH
• mezenchymální kmenové buňky cytologie   účinky léků   MeSH
• mikrofilamenta účinky léků   metabolismus   MeSH
• mutageny toxicita   MeSH
• myši inbrední C57BL MeSH
• nádorové buněčné linie MeSH
• nanotrubičky chemie   toxicita   ultrastruktura   MeSH
• podocyty účinky léků   metabolismus   MeSH
• pohyb buněk účinky léků   MeSH
• poškození DNA MeSH
• slezina účinky léků   patologie   MeSH
• sulfhydrylové sloučeniny metabolismus   MeSH
• tkáňová distribuce MeSH
• trombocyty účinky léků   patologie   ultrastruktura   MeSH
• zlato metabolismus   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Cationic colloidal gold nanorods (GNRs) have a great potential as a theranostic tool for diverse medical applications. GNRs' properties such as cellular internalization and stability are determined by physicochemical characteristics of their surface coating. GNRs modified by (16-mercaptohexadecyl)trimethylammonium bromide (MTAB), MTABGNRs, show excellent cellular uptake. Despite their promise for biomedicine, however, relatively little is known about the cellular pathways that facilitate the uptake of GNRs, their subcellular fate and intracellular persistence. Here we studied the mechanism of cellular internalization and long-term fate of GNRs coated with MTAB, for which the synthesis was optimized to give higher yield, in various human cell types including normal diploid versus cancerous, and dividing versus nondividing (senescent) cells. The process of MTABGNRs internalization into their final destination in lysosomes proceeds in two steps: (1) fast passive adhesion to cell membrane mediated by sulfated proteoglycans occurring within minutes and (2) slower active transmembrane and intracellular transport of individual nanorods via clathrin-mediated endocytosis and of aggregated nanorods via macropinocytosis. The expression of sulfated proteoglycans was the major factor determining the extent of uptake by the respective cell types. Upon uptake into proliferating cells, MTABGNRs were diluted equally and relatively rapidly into daughter cells; however, in nondividing/senescent cells the loss of MTABGNRs was gradual and very modest, attributable mainly to exocytosis. Exocytosed MTABGNRs can again be internalized. These findings broaden our knowledge about cellular uptake of gold nanorods, a crucial prerequisite for future successful engineering of nanoparticles for biomedical applications such as photothermal cancer therapy or elimination of senescent cells as part of the emerging rejuvenation approach.

• MeSH
• buněčná membrána účinky léků   metabolismus   MeSH
• endocytóza účinky léků   fyziologie   MeSH
• exocytóza * účinky léků   fyziologie   MeSH
• konfokální mikroskopie MeSH
• kultivační média MeSH
• kvartérní amoniové sloučeniny chemická syntéza   chemie   MeSH
• lidé MeSH
• lyzozomy účinky léků   MeSH
• mikroskopie elektronová rastrovací MeSH
• nádorové buněčné linie MeSH
• nanotrubičky analýza   chemie   MeSH
• polylysin chemie   farmakokinetika   MeSH
• proliferace buněk účinky léků   MeSH
• proteoglykany chemie   metabolismus   MeSH
• průtoková cytometrie MeSH
• stabilita léku MeSH
• sulfhydrylové sloučeniny chemie   MeSH
• techniky syntetické chemie MeSH
• zlato chemie   farmakokinetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Chloroquine (CQ), an anti-malarial drug, has immune-modulating activity and lysosomotropic activity. In this study, we investigated CQ sensitizes TRAIL-mediated apoptosis in human renal cancer Caki cells. Combination of CQ and TRAIL significantly induces apoptosis in human renal cancer Caki cells and various human cancer cells, but not in normal mouse kidney cells (TMCK-1) and human mesangial cells (MC). CQ up-regulates DR5 mRNA and protein expression in a dose- and time- dependent manner. Interestingly, CQ regulates DR5 expression through the increased stability in the mRNA and protein of DR5, rather than through the increased transcriptional activity of DR5. Moreover, we found that CQ decreased the expression of Cbl, an E3 ligase of DR5, and knock-down of Cbl markedly enhanced DR5 up-regulation. Other lysosomal inhibitors, including monensin and nigericin, also up-regulated DR5 and sensitized TRAIL-mediated apoptosis. Therefore, this study demonstrates that lysosomal inhibition by CQ may sensitize TRAIL-mediated apoptosis in human renal cancer Caki cells via DR5 up-regulation.

• MeSH
• apoptóza účinky léků   MeSH
• chlorochin aplikace a dávkování   MeSH
• genový knockdown MeSH
• lidé MeSH
• lyzozomy účinky léků   genetika   MeSH
• messenger RNA biosyntéza   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• nádory ledvin farmakoterapie   genetika   patologie   MeSH
• protein TRAIL biosyntéza   genetika   MeSH
• protoonkogenní proteiny c-cbl genetika   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• TRAIL receptory biosyntéza   genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Non-thermal plasma has been recognized as a promising tool across a vast variety of biomedical applications, with the potential to create novel therapeutic methods. However, the understanding of the molecular mechanisms behind non-thermal plasma cellular effects remains a significant challenge. In this study, we show how two types of different non-thermal plasmas induce cell death in mammalian cell cultures via the formation of multiple intracellular reactive oxygen/nitrogen species. Our results showed a discrepancy in the superoxide accumulation and lysosomal activity in response to air and helium plasma, suggesting that triggered signalling cascades might be grossly different between different plasmas. In addition, the effects of ozone, a considerable component of non-thermal plasma, have been simultaneously evaluated and have revealed much faster and higher cytotoxic effects. Our findings offer novel insight into plasma-induced cellular responses, and provide a basis for better controlled biomedical applications.

• MeSH
• acetylcystein farmakologie   MeSH
• annexin A5 MeSH
• antioxidancia farmakologie   MeSH
• buněčná smrt účinky léků   MeSH
• buňky 3T3 MeSH
• helium chemie   MeSH
• krysa rodu rattus MeSH
• lyzozomy účinky léků   MeSH
• membránový potenciál mitochondrií účinky léků   MeSH
• myši MeSH
• nádorové buněčné linie MeSH
• neuroglie cytologie   účinky léků   metabolismus   MeSH
• ozon chemie   MeSH
• plazmové plyny farmakologie   MeSH
• reaktivní formy dusíku agonisté   antagonisté a inhibitory   metabolismus   MeSH
• reaktivní formy kyslíku agonisté   antagonisté a inhibitory   metabolismus   MeSH
• signální transdukce MeSH
• viabilita buněk účinky léků   MeSH
• vzduch MeSH
• zvířata MeSH
• Check Tag
• krysa rodu rattus MeSH
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH