The main problem precluding successful therapy with conventional taxanes is de novo or acquired resistance to taxanes. Therefore, novel experimental taxane derivatives (Stony Brook taxanes; SB-Ts) are synthesized and tested as potential drugs against resistant solid tumors. Recently, we reported alterations in ABCC3, CPS1, and TRIP6 gene expression in a breast cancer cell line resistant to paclitaxel. The present study aimed to investigate gene expression changes of these three candidate molecules in the highly resistant ovarian carcinoma cells in vitro and corresponding in vivo models treated with paclitaxel and new experimental Stony Brook taxanes of the third generation (SB-T-121605 and SB-T-121606). We also addressed their prognostic meaning in ovarian carcinoma patients treated with taxanes. We estimated and observed changes in mRNA and protein profiles of ABCC3, CPS1, and TRIP6 in resistant and sensitive ovarian cancer cells and after the treatment of resistant ovarian cancer models with paclitaxel and Stony Brook taxanes in vitro and in vivo. Combining Stony Brook taxanes with paclitaxel caused downregulation of CPS1 in the paclitaxel-resistant mouse xenograft tumor model in vivo. Moreover, CPS1 overexpression seems to play a role of a prognostic biomarker of epithelial ovarian carcinoma patients' poor survival. ABCC3 was overexpressed in EOC tumors, but after the treatment with taxanes, its up-regulation disappeared. Based on our results, we can suggest ABCC3 and CPS1 for further investigations as potential therapeutic targets in human cancers.

• Klíčová slova
• ABCC3, CPS1, Stony Brook taxanes, TRIP6, multidrug resistance, ovarian carcinoma, taxanes,
• MeSH
• adaptorové proteiny signální transdukční genetika   MeSH
• chemorezistence genetika   MeSH
• down regulace účinky léků   genetika   MeSH
• epiteliální ovariální karcinom farmakoterapie   genetika   MeSH
• karbamoylfosfátsynthasa (amoniak) genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• myši nahé MeSH
• myši MeSH
• nádorové biomarkery genetika   MeSH
• nádorové buněčné linie MeSH
• nádory vaječníků farmakoterapie   genetika   MeSH
• paclitaxel terapeutické užití   MeSH
• proteiny s doménou LIM genetika   MeSH
• proteiny spojené s mnohočetnou rezistencí k lékům genetika   MeSH
• taxoidy terapeutické užití   MeSH
• transkripční faktory genetika   MeSH
• viabilita buněk účinky léků   genetika   MeSH
• zvířata MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• CPS1 protein, human MeSH Prohlížeč
• karbamoylfosfátsynthasa (amoniak) MeSH
• multidrug resistance-associated protein 3 MeSH Prohlížeč
• nádorové biomarkery MeSH
• paclitaxel MeSH
• proteiny s doménou LIM MeSH
• proteiny spojené s mnohočetnou rezistencí k lékům MeSH
• taxoidy MeSH
• transkripční faktory MeSH
• TRIP6 protein, human MeSH Prohlížeč

It was evidenced that saturated fatty acids (FAs) have a detrimental effect on pancreatic β-cells function and survival, leading to endoplasmic reticulum (ER) calcium release, ER stress, and apoptosis. In the present study, we have tested the effect of three calcium influx inhibitors, i.e., diazoxide, nifedipine, and verapamil, on the apoptosis-inducing effect of saturated stearic acid (SA) in the human pancreatic β-cell lines NES2Y and 1.1B4. We have demonstrated that the application of all three calcium influx inhibitors tested has no inhibitory effect on SA-induced ER stress and apoptosis in both tested cell lines. Moreover, these inhibitors have pro-apoptotic potential per se at higher concentrations. Interestingly, these findings are in contradiction with those obtained with rodent cell lines and islets. Thus our data obtained with human β-cell lines suggest that the prospective usage of calcium channel blockers for prevention and therapy of type 2 diabetes mellitus, developed with the contribution of the saturated FA-induced apoptosis of β-cells, seems rather unlikely.

• Klíčová slova
• 1.1B4, Apoptosis, Calcium influx, Diazoxide, Fatty acids, NES2Y, Nifedipine, Pancreatic β-cells, Type 2 diabetes mellitus, Verapamil,
• Publikační typ
• časopisecké články MeSH

Persistent organochlorine pollutants (POPs) gradually accumulate in the human organism due to their presence in the environment. Some studies have described a correlation between the level of POPs in the human body and the incidence of diabetes, but we know little about the direct effect of POPs on pancreatic beta-cells. We exposed pancreatic beta-cells INS1E to non-lethal concentrations of p,p'-DDT (1,1'-(2,2,2-Trichloroethane-1,1-diyl)bis(4-chlorobenzene)) and p,p'-DDE (1,1'-(2,2-dichloroethene-1,1-diyl)bis(4-chlorobenzene)) for 1 month, and assessed changes in protein expression and the intracellular insulin level. 2-D electrophoresis revealed 6 proteins with changed expression in cells exposed to p,p'-DDT or p,p'-DDE. One of the detected proteins - vitamin D-binding protein (VDBP) - was upregulated in both cells exposed to p,p'-DDT, and cells exposed to p,p'-DDE. Both exposures to pollutants reduced the intracellular level of insulin mRNA, proinsulin, and insulin monomer; p,p'-DDT also slightly reduced the level of hexameric insulin. Overexpression of VDBP caused by the stable transfection of beta-cells with the gene for VDBP decreased both the proinsulin and hexameric insulin level in beta-cells similarly to the reduction detected in cells exposed to p,p'-DDT. Our data suggest that in the cells exposed to p,p'-DDT and p,p'-DDE, the increased VDBP protein level decreased the proinsulin expression in an unknown mechanism.

• MeSH
• beta-buňky účinky léků   metabolismus   MeSH
• buněčné linie MeSH
• DDT toxicita   MeSH
• dichlordifenyldichlorethylen toxicita   MeSH
• inzulin metabolismus   MeSH
• krysa rodu Rattus MeSH
• látky znečišťující životní prostředí toxicita   MeSH
• protein vázající vitamin D metabolismus   MeSH
• testy subchronické toxicity MeSH
• upregulace účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• DDT MeSH
• dichlordifenyldichlorethylen MeSH
• inzulin MeSH
• látky znečišťující životní prostředí MeSH
• protein vázající vitamin D MeSH

BACKGROUND: In previous study we showed that caspase-2 plays the role of an apical caspase in cell death induction by taxanes in breast cancer cells. This study deals with the role of other caspases. We tested breast cancer cell lines SK-BR-3 (functional caspase-3) and MCF-7 (nonfunctional caspase-3). METHODS AND RESULTS: Using western blot analysis we demonstrated the activation of initiator caspase-8 and -9 as well as executioner caspase-6 and -7 in both tested cell lines after application of taxanes (paclitaxel, SB-T-1216) at death-inducing concentrations. Caspase-3 activation was also found in SK-BR-3 cells. Employing specific siRNAs after taxane application, suppression of caspase-3 expression significantly increased the number of surviving SK-BR-3 cells. Inhibition of caspase-7 expression also increased the number of surviving SK-BR-3 and MCF-7 cells. On the other hand, suppression of caspase-8 and caspase-9 expression had no significant effect on cell survival. However, caspase-9 seemed to be involved in the activation of caspase-3 and caspase-7. Caspase-3 and caspase-7 appeared to activate mutually. Furthermore, we observed a significant decrease in mitochondrial membrane potential (flow cytometric analysis) and cytochrome c release (confocal microscopy, western blot after cell fractionation) from mitochondria in SK-BR-3 cells. No such changes were observed in MCF-7 cells after taxane treatment. CONCLUSION: We conclude that the activation of apical caspase-2 results in the activation of caspase-3 and -7 without the involvement of mitochondria. Caspase-9 can be activated directly via caspase-2 or alternatively after cytochrome c release from mitochondria. Subsequently, caspase-9 activation can also lead to caspase-3 and -7 activations. Caspase-3 and caspase-7 activate mutually. It seems that there is also a parallel pathway involving mitochondria that can cooperate in taxane-induced cell death in breast cancer cells.

• Klíčová slova
• Breast cancer, Caspases, Cell death, Taxanes,
• Publikační typ
• časopisecké články MeSH

The study investigated possible mechanisms by which second-generation taxanes, established as significantly more effective than paclitaxel in vitro, suppress a rat lymphoma model in vivo. The studied mechanisms included taxane pharmacokinetics, expression of genes dominating their metabolism (Cyp3a1/2) and transport (Abcb1) and genes controlling tumour angiogenesis (growth factors and receptors). SB-T-1214, SB-T-12854 and IDN5109 suppressed rat lymphoma more effectively than paclitaxel, SB-T-12851, SB-T-12852, SB-T-12853 or IDN5390 as well as P388D1 leukaemia cells in vitro. The greater anti-lymphoma effects of SB-T-1214 in rats corresponded to a higher bioavailability than with SB-T-12854, and lower systemic toxicity of SB-T-1214 for rats reflected its lower cytotoxicity for P388D1 cells in vitro. Suppression of Abcb1 and CYP3a1 expression by SB-T-1214 and IDN5109 could partly explain their anti-lymphoma effects, but not that of SB-T-12854. Growth factors genes Egf, Fgf, Pdgf, and Vegf associated with tumour angiogenesis had significantly lower expression following treatment with anti-lymphoma effective IDN5109 and their receptors were unaffected, whereas inefficient IDN5390 increased expression of the most important Vegf. The effective SB-T-12854 inhibited Egf, Egfr, Fgfr and Pdgfr expression, while the ineffective SB-T-12851, SB-T-12852 and SB-T-12853 inhibited only Egf or Egfr expression. Vegfr expression was inhibited significantly by SB-T-12851 and SB-T-12854, but effect of SB-T-12851 was compromised by induced Vegf expression. The very effective SB-T-1214 decreased the expression of Vegf, Egf and all receptors most prominently indicating the possible supporting role of these genes in anti-lymphoma effects. In conclusion, SB-T-1214, SB-T-12854 and IDN5109 are good candidates for further study.

• MeSH
• cytochrom P-450 CYP3A genetika   MeSH
• krysa rodu Rattus MeSH
• lymfom farmakoterapie   metabolismus   patologie   MeSH
• membránové proteiny genetika   MeSH
• P-glykoproteiny genetika   MeSH
• patologická angiogeneze genetika   MeSH
• plocha pod křivkou MeSH
• potkani Sprague-Dawley MeSH
• protinádorové látky krev   farmakologie   terapeutické užití   MeSH
• regulace genové exprese u nádorů účinky léků   MeSH
• taxoidy krev   farmakologie   terapeutické užití   MeSH
• tumor burden účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• Cyp3a2 protein, rat MeSH Prohlížeč
• Cyp3a23-3a1 protein, rat MeSH Prohlížeč
• cytochrom P-450 CYP3A MeSH
• membránové proteiny MeSH
• multidrug resistance protein 3 MeSH Prohlížeč
• P-glykoproteiny MeSH
• protinádorové látky MeSH
• taxoidy MeSH

The aim of this study is to compare the effects of new fluorinated taxanes SB-T-12851, SB-T-12852, SB-T-12853, and SB-T-12854 with those of the classical taxane paclitaxel and novel non-fluorinated taxane SB-T-1216 on cancer cells. Paclitaxel-sensitive MDA-MB-435 and paclitaxel-resistant NCI/ADR-RES human cancer cell lines were used. Cell growth and survival evaluation, colorimetric assessment of caspases activities, flow cytometric analyses of the cell cycle and the assessment of mitochondrial membrane potential, reactive oxygen species (ROS) and the release of cytochrome c from mitochondria were employed. Fluorinated taxanes have similar effects on cell growth and survival. For MDA-MB-435 cells, the C(50) of SB-T-12851, SB-T-12852, SB-T-12853 and SB-T-12854 was 3 nM, 4 nM, 3 nM and 5 nM, respectively. For NCI/ADR-RES cells, the C(50) of SB-T-12851, SB-T-12852, SB-T-12853, and SB-T-12854 was 20 nM, 20 nM, 10 nM and 10 nM, respectively. Selected fluorinated taxanes, SB-T-12853 and SB-T-12854, at the death-inducing concentrations (30 nM for MDA-MB-435 and 300 nM for NCI/ADR-RES) were shown to activate significantly caspase-3, caspase-9, caspase-2 and also slightly caspase-8. Cell death was associated with significant accumulation of cells in the G(2)/M phase. Cytochrome c was not released from mitochondria and other mitochondrial functions were not significantly impaired. The new fluorinated taxanes appear to use the same or similar mechanisms of cell death induction as compared with SB-T-1216 and paclitaxel. New fluorinated and non-fluorinated taxanes are more effective against drug-resistant cancer cells than paclitaxel. Therefore, new generation of taxanes, either non-fluorinated or fluorinated, are excellent candidates for further and detailed studies.

• MeSH
• buněčná smrt účinky léků   MeSH
• buněčný cyklus účinky léků   MeSH
• chemorezistence účinky léků   MeSH
• cytochromy c metabolismus   MeSH
• DNA nádorová metabolismus   MeSH
• kaspasy metabolismus   MeSH
• lidé MeSH
• mitochondrie účinky léků   metabolismus   MeSH
• nádorové buněčné linie MeSH
• paclitaxel chemie   farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• reaktivní formy kyslíku metabolismus   MeSH
• screeningové testy protinádorových léčiv MeSH
• sloučeniny fluoru chemie   farmakologie   MeSH
• taxoidy chemie   farmakologie   MeSH
• viabilita buněk účinky léků   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• cytochromy c MeSH
• DNA nádorová MeSH
• kaspasy MeSH
• paclitaxel MeSH
• reaktivní formy kyslíku MeSH
• sloučeniny fluoru MeSH
• taxoidy MeSH

BACKGROUND: In this study, the effect of novel taxane SB-T-1216 and paclitaxel on sensitive MDA-MB-435 and resistant NCI/ADR-RES human breast cancer cells was compared. MATERIALS AND METHODS: Cell growth and survival were evaluated after 96-hour incubation with tested concentrations of taxanes. The effect on the formation of microtubule bundles was assessed employing fluorescence microscopy and on the cell cycle employing flow cytometric analysis. The activity of caspases was assessed employing commercial colorimetric kits. RESULTS: The IC(50) (concentration resulting in 50% of living cells in comparison with the control) of SB-T-1216 in sensitive cells was 0.6 nM versus 1 nM for paclitaxel. However, the IC(50) of SB-T-1216 in resistant cells was 1.8 nM versus 300 nM for paclitaxel. Both SB-T-1216 and paclitaxel at death-inducing concentrations induced the formation of microtubule bundles in sensitive as well as resistant cells. Cell death induced in sensitive and resistant cells by paclitaxel was associated with the accumulation of cells in the G(2)/M phase. On the contrary, cell death induced by SB-T-1216 took place without the accumulation of cells in the G(2)/M phase but with a decreased number of G(1) cells and the accumulation of hypodiploid cells. Both SB-T-1216 and paclitaxel activated caspase-3, caspase-9, caspase-2 and caspase-8 in sensitive as well as resistant cells. CONCLUSION: Cell death induced by both paclitaxel and novel taxane SB-T-1216 in breast cancer cells is associated with caspase activation and with the formation of interphase microtubule bundles. Novel taxane SB-T-1216, but not paclitaxel, seems to be capable of inducing cell death without the accumulation of cells in the G(2)/M phase.

• MeSH
• apoptóza účinky léků   MeSH
• buněčné dělení účinky léků   MeSH
• chemorezistence MeSH
• doxorubicin farmakologie   MeSH
• fluorescenční mikroskopie MeSH
• fytogenní protinádorové látky farmakologie   MeSH
• G1 fáze účinky léků   MeSH
• G2 fáze účinky léků   MeSH
• kaspasa 2 metabolismus   MeSH
• kaspasa 3 metabolismus   MeSH
• kaspasa 8 metabolismus   MeSH
• kaspasa 9 metabolismus   MeSH
• lidé MeSH
• mikrotubuly účinky léků   MeSH
• nádorové buněčné linie MeSH
• nádory prsu farmakoterapie   metabolismus   patologie   MeSH
• paclitaxel farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• protinádorová antibiotika farmakologie   MeSH
• taxoidy farmakologie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• srovnávací studie MeSH
• Názvy látek
• doxorubicin MeSH
• fytogenní protinádorové látky MeSH
• kaspasa 2 MeSH
• kaspasa 3 MeSH
• kaspasa 8 MeSH
• kaspasa 9 MeSH
• paclitaxel MeSH
• protinádorová antibiotika MeSH
• taxoidy MeSH