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

We tested the role of substituents at the C3' and C3'N positions of the taxane molecule to identify taxane derivatives capable of overcoming acquired resistance to paclitaxel. Paclitaxel-resistant sublines SK-BR-3/PacR and MCF-7/PacR as well as the original paclitaxel-sensitive breast cancer cell lines SK-BR-3 and MCF-7 were used for testing. Increased expression of the ABCB1 transporter was found to be involved in the acquired resistance. We tested three groups of taxane derivatives: (1) phenyl group at both C3' and C3'N positions, (2) one phenyl at one of the C3' and C3'N positions and a non-aromatic group at the second position, (3) a non-aromatic group at both C3' and C3'N positions. We found that the presence of phenyl groups at both C3' and C3'N positions is associated with low capability of overcoming acquired paclitaxel resistance compared to taxanes containing at least one non-aromatic substituent at the C3' and C3'N positions. The increase in the ATPase activity of ABCB1 transporter after the application of taxanes from the first group was found to be somewhat higher than after the application of taxanes from the third group. Molecular docking studies demonstrated that the docking score was the lowest, i.e. the highest binding affinity, for taxanes from the first group. It was intermediate for taxanes from the second group, and the highest for taxanes from the third group. We conclude that at least one non-aromatic group at the C3' and C3'N positions of the taxane structure, resulting in reduced affinity to the ABCB1 transporter, brings about high capability of taxane to overcome acquired resistance of breast cancer cells to paclitaxel, due to less efficient transport of the taxane compound out of the cancer cells.

• Klíčová slova
• ABCB1 transporter, Acquired resistance to paclitaxel, Breast cancer cells, Molecular docking, Taxane derivates,
• MeSH
• biologický transport MeSH
• chemorezistence * genetika   MeSH
• fytogenní protinádorové látky chemie   metabolismus   farmakologie   MeSH
• lidé MeSH
• MFC-7 buňky MeSH
• molekulární struktura MeSH
• nádory prsu farmakoterapie   genetika   metabolismus   patologie   MeSH
• P-glykoproteiny genetika   metabolismus   MeSH
• paclitaxel chemie   metabolismus   farmakologie   MeSH
• proliferace buněk účinky léků   MeSH
• simulace molekulového dockingu MeSH
• vazba proteinů MeSH
• viabilita buněk účinky léků   MeSH
• vztah mezi dávkou a účinkem léčiva MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• srovnávací studie MeSH
• Názvy látek
• ABCB1 protein, human MeSH Prohlížeč
• fytogenní protinádorové látky MeSH
• P-glykoproteiny MeSH
• paclitaxel MeSH

The Hedgehog pathway is one of the major driver pathways in pancreatic ductal adenocarcinoma. This study investigated prognostic importance of Hedgehog signaling pathway in pancreatic cancer patients who underwent a radical resection. Tumors and adjacent non-neoplastic pancreatic tissues were obtained from 45 patients with histologically verified pancreatic cancer. The effect of experimental taxane chemotherapy on the expression of Hedgehog pathway was evaluated in vivo using a mouse xenograft model prepared using pancreatic cancer cell line Paca-44. Mice were treated by experimental Stony Brook Taxane SB-T-1216. The transcript profile of 34 Hedgehog pathway genes in patients and xenografts was assessed using quantitative PCR. The Hedgehog pathway was strongly overexpressed in pancreatic tumors and upregulation of SHH, IHH, HHAT and PTCH1 was associated with a trend toward decreased patient survival. No association of Hedgehog pathway expression with KRAS mutation status was found in tumors. Sonic hedgehog ligand was overexpressed, but all other downstream genes were downregulated by SB-T-1216 treatment in vivo. Suppression of HH pathway expression in vivo by taxane-based chemotherapy suggests a new mechanism of action for treatment of this aggressive tumor.

• MeSH
• duktální karcinom slinivky břišní farmakoterapie   genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mutace MeSH
• myši nahé MeSH
• nádory slinivky břišní farmakoterapie   genetika   MeSH
• přežití bez známek nemoci MeSH
• proteiny hedgehog genetika   MeSH
• protoonkogenní proteiny p21(ras) genetika   MeSH
• senioři MeSH
• taxoidy aplikace a dávkování   terapeutické užití   MeSH
• transkriptom účinky léků   MeSH
• výsledek terapie MeSH
• xenogenní modely - testy protinádorové aktivity MeSH
• zvířata MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• KRAS protein, human MeSH Prohlížeč
• proteiny hedgehog MeSH
• protoonkogenní proteiny p21(ras) MeSH
• taxoidy 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

Resistance of tumours to taxanes causes chemotherapy failure in numerous patients. Resistance is partly due to the low tumour uptake of taxanes and their rapid metabolism. Structural modifications of taxanes can reduce their P-glycoprotein-related efflux or decrease metabolism and consequently increase taxane efficiency. This study compared cytotoxicity and effects of the cell cycle, transport and metabolism of novel taxanes SB-T-1102, SB-T-1103, SB-T-1214 and SB-T-1216, fluorinated SB-T-12851, SB-T-12852, SB-T-12853, SB-T-12854 and IDN5109 with paclitaxel in paclitaxel-sensitive (MDA-MB-435) and paclitaxel-resistant (NCI/ADR-RES) human cancer cells. We have shown before that NCI/ADR-RES cells were 1,000-fold less sensitive to paclitaxel than MDA-MB-435 cells in correspondence to P-glycoprotein overexpression and up to 20-fold lower uptake of the drug in the resistant cells. The uptake of novel taxanes was 1.2 to 3.8 times lower than that of paclitaxel in the MDA-MB-435 cells, but 1.5 to 6.5 times higher in NCI/ADR-RES cells. NCI/ADR-RES cells were correspondingly only 2- to 6.6-fold less sensitive than the MDA-MB-435 cells to novel taxanes. Both cell lines showed minimal metabolism of the novel taxanes which was therefore not responsible for their different sensitivity, the observed differences in their individual efficiency and higher effects than paclitaxel. All novel taxanes caused G(2)/M block of the cell cycle similar to paclitaxel, but lower at concentrations by order of magnitude. Thus, structural modifications of taxanes resulting in their decreased P-glycoprotein-related transport probably caused their higher efficiency than paclitaxel in multidrug-resistant NCI/ADR-RES tumour cells.

• MeSH
• buněčné kultury MeSH
• buněčný cyklus účinky léků   MeSH
• chemorezistence účinky léků   MeSH
• lidé MeSH
• mnohočetná léková rezistence účinky léků   MeSH
• molekulární struktura MeSH
• nádorové buněčné linie MeSH
• protinádorové látky * metabolismus   farmakokinetika   farmakologie   MeSH
• taxoidy * metabolismus   farmakokinetika   farmakologie   MeSH
• viabilita buněk účinky léků   MeSH
• vysokoúčinná kapalinová chromatografie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• protinádorové látky * MeSH
• taxoidy * 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