Validation of differences in gene expression (biomarkers already identified by our pilot studies) between patients with breast carcinoma treated by standard, mainly hormonal therapy, will be the main goal of this project. Markers representing metabolism (e.g. cytochromes P450) and transport (ABC and SLC transporters) of anticancer drugs will be studied in relation to clinico-pathological characteristics, therapy outcome and survival of patients. Mechanism of action of successfully validated candidate markers will be studied by correlation of gene expression with protein level and analysis of relation of genotype to phenotype. Methylation of regulatory elements of DNA of candidate biomarkers will also be studied as independent prognostic or predictive marker. Breast tumor cell line models differing in expression of hormonal receptors (estrogen and progesterone) will be employed in order to help us in elucidation of mechanisms of action of biomarkers by alternative approach.

Hlavním záměrem projektu je validace rozdílů, v genové expresi mezi nádorovými tkáněmi pacientů léčených standardní, především hormonální terapií karcinomu prsu, identifikovaných v předchozí pilotní studii. Budou studovány markery metabolismu (např.: cytochromy P450) a transportu (ABC a SLC transportéry) cytostatik ve vztahu ke klinicko-patologickým charakteristikám, přežívání a účinnosti léčby pacientek. U úspěšně validovaných kandidátních markerů budeme studovat mechanismus jakým markery působí (korelace genové exprese s hladinou proteinu, vztah genotypu k fenotypu). Budeme studovat i methylaci regulačních oblastí DNA genů kandidátních biomarkerů jako možný nezávislý marker prognózy a predikce účinku terapie. Pozornost budeme věnovat rovněž studiu modelových buněčných linií karcinomu prsu, které se mezi sebou liší v expresi hormonálních receptorů pro estrogen a progesteron. U těchto linií se pokusíme vysledovat mechanismus nezávislou cestou.

• MeSH
• cytostatické látky MeSH
• exprese genu MeSH
• genetická predispozice k nemoci MeSH
• karcinom genetika   MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• metylace DNA MeSH
• nádorové biomarkery MeSH
• nádorové buněčné linie MeSH
• nádory prsu genetika   MeSH
• prediktivní hodnota testů MeSH
• receptory pro estrogeny MeSH
• receptory progesteronu MeSH
• ženy MeSH

• Konspekt
• Biochemie. Molekulární biologie. Biofyzika
• NLK Obory
• molekulární biologie, molekulární medicína
• gynekologie a porodnictví
• onkologie
• NLK Publikační typ
• závěrečné zprávy o řešení grantu IGA MZ ČR

BACKGROUND: Apoptosis plays a critical role in cancer cell survival and tumor development. We provide a hypothesis-generating screen for further research by exploring the expression profile and genetic variability of caspases (2, 3, 7, 8, 9, and 10) in breast carcinoma patients. This study addressed isoform-specific caspase transcript expression and genetic variability in regulatory sequences of caspases 2 and 9. METHODS: Gene expression profiling was performed by quantitative real-time PCR in tumor and paired non-malignant tissues of two independent groups of patients. Genetic variability was determined by high resolution melting, allelic discrimination, and sequencing analysis in tumor and peripheral blood lymphocyte DNA of the patients. RESULTS: CASP3 A+B and S isoforms were over-expressed in tumors of both patient groups. The CASP9 transcript was down-regulated in tumors of both groups of patients and significantly associated with expression of hormonal receptors and with the presence of rs4645978-rs2020903-rs4646034 haplotype in the CASP9 gene. Patients with a low intratumoral CASP9A/B isoform expression ratio (predicted to shift equilibrium towards anti-apoptotic isoform) subsequently treated with adjuvant chemotherapy had a significantly shorter disease-free survival than those with the high ratio (p=0.04). Inheritance of CC genotype of rs2020903 in CASP9 was associated with progesterone receptor expression in tumors (p=0.003). CONCLUSIONS: Genetic variability in CASP9 and expression of its splicing variants present targets for further study.

• MeSH
• cílená molekulární terapie * MeSH
• genetická transkripce * MeSH
• genetická variace * genetika   MeSH
• kaspasa 9 genetika   metabolismus   MeSH
• kaspasy * genetika   metabolismus   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádory prsu * enzymologie   genetika   MeSH
• regulace genové exprese u nádorů * MeSH
• stanovení celkové genové exprese MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• ženské pohlaví MeSH

Microtubules are vitally important for eukaryotic cell division. Therefore, we evaluated the relevance of mitotic kinesin KIF14, protein-regulating cytokinesis 1 (PRC1), and citron kinase (CIT) for the prognosis of breast carcinoma patients. Transcript levels were assessed by quantitative real-time PCR in tissues from two independent groups of breast carcinoma patients and compared with clinical data. Tissue PRC1 protein levels were estimated using immunoblotting, and the PRC1 tagged haplotype was analyzed in genomic DNA. A functional study was performed in MDA-MB-231 cells in vitro. KIF14, PRC1, and CIT transcripts were overexpressed in tumors compared with control tissues. Tumors without expression of hormonal receptors or high-grade tumors expressed significantly higher KIF14 and PRC1 levels than hormonally-positive or low-grade tumors. Patients with high intra-tumoral PRC1 levels had significantly worse disease-free survival than patients with low levels. PRC1 rs10520699 and rs11852999 polymorphisms were associated with PRC1 transcript levels, but not with patientś survival. Paclitaxel-induced PRC1 expression, but PRC1 knockdown did not modify the paclitaxel cytotoxicity in vitro. PRC1 overexpression predicts poor disease-free survival of patients with breast carcinomas. Genetic variability of PRC1 and the protein interaction with paclitaxel cytotoxicity do not explain this association.

• MeSH
• buněčná smrt účinky léků   MeSH
• genový knockdown MeSH
• Kaplanův-Meierův odhad MeSH
• lidé MeSH
• messenger RNA genetika   metabolismus   MeSH
• nádorové buněčné linie MeSH
• nádory prsu genetika   patologie   MeSH
• paclitaxel farmakologie   MeSH
• polymorfismus genetický MeSH
• přežití bez známek nemoci * MeSH
• proteiny buněčného cyklu genetika   metabolismus   MeSH
• regulace genové exprese u nádorů * účinky léků   MeSH
• studie případů a kontrol MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

The aim of the present study was to introduce methods for exome sequencing of two ATP-binding cassette (ABC) transporters ABCC8 and ABCD2 recently suggested to play a putative role in breast cancer progression and prognosis of patients. We performed next generation sequencing targeted at analysis of all exons in ABCC8 and ABCD2 genes and surrounding noncoding sequences in blood DNA samples from 24 patients with breast cancer. The revealed alterations were characterized by in silico tools. We then compared the most frequent functionally relevant polymorphism rs757110 in ABCC8 with clinical data of patients. In total, the study identified 113 genetic alterations (>70 % novel ones) in both genes. Of these alterations, 83 were noncoding, 13 synonymous, 10 frameshifts and 7 were missense alterations. Four in silico programs predicted pathogenicity of two polymorphisms and four newly identified alterations. Rs757110 polymorphism in ABCC8 did not significantly associate with clinical data of the patients. In conclusion, exome sequencing identified several functionally relevant alterations in ABCC8 and ABCD2 genes that may further be used for a larger follow-up study aiming to assess their clinical significance.

• MeSH
• ABC transportéry genetika   MeSH
• dospělí MeSH
• exom genetika   MeSH
• genetické asociační studie * metody   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádory prsu diagnóza   genetika   MeSH
• receptory sulfonylurey genetika   MeSH
• sekvenční analýza DNA * metody   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Variations in the TP53 gene have been suggested to play a role in many cancers, including breast. We previously observed an association between TP53 haplotypes based on four polymorphisms (rs17878362, rs1042522, rs12947788, and rs17884306) and the risk of colorectal and pancreatic cancer. Based on these results, in the present study, we have investigated the same polymorphisms and their haplotypes in 705 breast cancer cases and 611 healthy controls in relation to the disease risk, histopathological features of the tumor and clinical outcomes. In comparison to the most common haplotype A1-G-C-G, all the other identified haplotypes were globally associated with a significantly decreased breast cancer risk (P = 0.006). In particular, the A2-G-C-G haplotype was associated with a marked decreased risk of breast cancer when compared with the common haplotype (P = 0.0001). Moreover, rs1042522 in patients carrying the GC genotype and receiving only the anthracycline-based chemotherapy was associated with both overall and disease-free survival (recessive model for overall survival HR = 0.30 95% CI 0.11-0.80, P = 0.02 and for disease-free survival HR = 0.42 95% CI 0.21-0.84, P = 0.01). Present results suggest common genetic features in the susceptibility to breast and gastrointestinal cancers in respect to TP53 variations. In fact, similar haplotype distributions were observed for breast, colorectal, and pancreatic patients in associations with cancer risk. Rs1042522 polymorphism (even after applying the Dunn-Bonferroni correction for multiple testing) appears to be an independent prognostic marker in breast cancer patients.

• MeSH
• genetická predispozice k nemoci genetika   MeSH
• genotyp MeSH
• geny p53 genetika   MeSH
• haplotypy genetika   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádory prsu genetika   MeSH
• rizikové faktory MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Publikační typ
• abstrakt z konference MeSH

Metabolism of anticancer drugs affects their antitumor effects. This study has investigated the associations of gene expression of enzymes metabolizing anticancer drugs with therapy response and survival of breast carcinoma patients. Gene expression of 13 aldo-keto reductases (AKRs), carbonyl reductase 1, and 10 cytochromes P450 (CYPs) was assessed using quantitative real-time polymerase chain reaction in tumors and paired adjacent nonneoplastic tissues from 68 posttreatment breast carcinoma patients. Eleven candidate genes were then evaluated in an independent series of 50 pretreatment patients. Protein expression of the most significant genes was confirmed by immunoblotting. AKR1A1 was significantly overexpressed and AKR1C1-4, KCNAB1, CYP2C19, CYP3A4, and CYP3A5 downregulated in tumors compared with control nonneoplastic tissues after correction for multiple testing. Significant association of CYP2B6 transcript levels in tumors with expression of hormonal receptors was found in the posttreatment set and replicated in the pretreatment set of patients. Significantly higher intratumoral levels of AKR1C1, AKR1C2, or CYP2W1 were found in responders to neoadjuvant chemotherapy compared with nonresponders. Patients with high AKR7A3 or CYP2B6 levels in the pretreatment set had significantly longer disease-free survival than patients with low levels. Protein products of AKR1C1, AKR1C2, AKR7A3, CYP3A4, and carbonyl reductase (CBR1) were found in tumors and those of AKR1C1, AKR7A3, and CBR1 correlated with their transcript levels. Small interfering RNA-directed knockdown of AKR1C2 or vector-mediated upregulation of CYP3A4 in MDA-MB-231 model cell line had no effect on cell proliferation after paclitaxel treatment in vitro. Prognostic and predictive roles of drug-metabolizing enzymes strikingly differ between posttreatment and pretreatment breast carcinoma patients. Mechanisms of action of AKR1C2, AKR7A3, CYP2B6, CYP3A4, and CBR1 should continue to be further followed in breast carcinoma patients and models.

• MeSH
• aldehydreduktasa biosyntéza   genetika   MeSH
• imunoblotting MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• lidé MeSH
• nádorové buňky kultivované MeSH
• nádory prsu genetika   metabolismus   patologie   MeSH
• prognóza MeSH
• proliferace buněk MeSH
• prospektivní studie MeSH
• průtoková cytometrie MeSH
• regulace genové exprese u nádorů * MeSH
• RNA nádorová genetika   MeSH
• systém (enzymů) cytochromů P-450 biosyntéza   genetika   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• Publikační typ
• abstrakt z konference MeSH