OBJECTIVES: ATP-Binding Cassette (ABC) transporters may cause treatment failure by transporting of anticancer drugs outside of the tumor cells. Multidrug resistance-associated protein 1 coded by the ABCC1 gene has recently been suggested as a potential prognostic marker in breast cancer patients. This study aimed to explore tagged haplotype covering nucleotide binding domain 1 of ABCC1 in relation with corresponding transcript levels in tissues and clinical phenotype of breast cancer patients. METHODS: The distribution of twelve ABCC1 polymorphisms was assessed by direct sequencing in peripheral blood DNA (n = 540). RESULTS: Tumors from carriers of the wild type genotype in rs35623 or rs35628 exhibited significantly lower levels of ABCC1 transcript than those from carriers of the minor allele (p = 0.003 and p = 0.004, respectively). The ABCC1 transcript levels significantly increased in the order CT-GT>CC-GT>CC-GG for the predicted rs35626-rs4148351 diplotype. Chemotherapy-treated patients carrying the T allele in rs4148353 had longer disease-free survival than those with the GG genotype (p = 0.043). On the other hand, hormonal therapy-treated patients with the AA genotype in rs35628 had significantly longer disease-free survival than carriers of the G allele (p = 0.012). CONCLUSIONS: Taken together, our study shows that genetic variability in the nucleotide binding domain 1 has a significant impact on the ABCC1 transcript level in the target tissue and may modify survival of breast cancer patients.

• MeSH
• analýza přežití * MeSH
• jednonukleotidový polymorfismus * MeSH
• lidé středního věku MeSH
• lidé MeSH
• messenger RNA genetika   MeSH
• nádory prsu genetika   patofyziologie   MeSH
• proteiny spojené s mnohočetnou rezistencí k lékům genetika   metabolismus   MeSH
• senioři MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• messenger RNA MeSH
• multidrug resistance-associated protein 1 MeSH Prohlížeč
• proteiny spojené s mnohočetnou rezistencí k lékům 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