Hlavním cílem tohoto projektu je studium genetických a fenotypických markerů oxysterolové signalizace z hlediska jejich významu pro hormonální terapii karcinomu prsu. V případě, že se podaří spojit tyto markery s prognózou pacientů, případně je navrhnout jako nástroje k individualizované terapii lze, delším časovém horizontu, očekávat významný socio-ekonomický přínos pro pacienty i systém zdravotní péče v ČR. Tento projekt má rovněž za cíl odhalit mechanismus působení markerů a navrhnout cenově dostupnou metodiku k jejich sledování. Projekt svým zaměřením přispěje k řešení několika priorit Programu na podporu zdravotnického aplikovaného výzkumu a vývoje, zejména podoblasti 1.3 Nádorová onemocnění a dílčích cílů 1.3.1 Nádorová biologie a 1.3.2 Individualizace diagnostiky a terapie. Výsledky řešení projektu budou publikovány v impaktovaných odborných časopisech, prezentovány na specializovaných vědeckých setkáních a implementovány do programů celoživotního vzdělávání lékařských pracovníků. Hlavními příjemci výsledků budou vědečtí pracovníci, pedagogové, lékaři v onkologii a pacienti.; In the frame of this project, we plan to evaluate importance of genetic and phenotypic markers of oxysterol signaling for endocrine therapy of breast carcinoma. In the long-term perspective, we expect significant socio-economic benefit for both patients and health care system with the use of these markers for prognosis and individualized therapy. This project also aims to elucidate mechanisms of action of validated markers and to determine cost-effective method for their screening. Project will contribute to the solution of several priorities of the Czech Program for Medical Research and Innovation, particularly of the domain 1.3 Cancer (subdomains 1.3.1 tumor biology and 1.3.2 individualization of diagnostics and therapy). Results of the project will be published in impacted scientific journals, presented at specialized scientific meetings, and implemented into whole-life education programs for medical personnel. Scientists, lecturers and physicians in the area of experimental and clinical oncology and patients will be major users of the project results.

• MeSH
• hormonální substituční terapie MeSH
• lidé MeSH
• nádorové biomarkery analýza   MeSH
• nádory prsu diagnóza   farmakoterapie   MeSH
• oxysteroly analýza   MeSH
• prognóza MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH

• Konspekt
• Patologie. Klinická medicína
• NLK Obory
• onkologie
• genetika, lékařská genetika
• NLK Publikační typ
• závěrečné zprávy o řešení grantu AZV MZ ČR

Breast cancer patients with high cholesterol biosynthesis signature had poorer therapeutic outcome. Cytochrome P450 (CYP) 2D6 is crucial in the oxidation of tamoxifen to generate active metabolites, 4-hydroxytamoxifen and endoxifen. CYP2D6 variants with C100T substitution encode null or poor functional proteins. This study aims to examine the association of C100T genotypes and serum lipid levels with plasma drug levels in patients. Plasma tamoxifen concentration was positively associated with serum triglyceride concentration, adjusting for age and C100T genotype. Overweight (body mass index >24.0) patients with high serum cholesterol (≥200 mg/dL) had increased risks of ineffective endoxifen levels (<5.97 ng/mL). Compared to the low-cholesterol group, the high-cholesterol group had a lower 4-hydroxytamoxifen or endoxifen level in T/T carriers. In T/T carriers, the high-cholesterol group had an increased risk of an ineffective endoxifen level. Metastasis, hot flash/flushing, and high alanine transaminase did not relate to plasma 4-hydroxytamoxifen or endoxifen levels. Results indicate that C100T and high serum cholesterol are risk factors of ineffective endoxifen levels in Taiwanese breast cancer patients. These findings warrant further studies of a large hypercholesterolemic population to examine the outcome of increased doses of tamoxifen.

• MeSH
• cholesterol krev   MeSH
• cytochrom P-450 CYP2D6 metabolismus   MeSH
• dospělí MeSH
• fenotyp MeSH
• genotyp MeSH
• hormonální protinádorové látky krev   MeSH
• lidé středního věku MeSH
• lidé MeSH
• nádory prsu krev   metabolismus   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• tamoxifen analogy a deriváty   krev   MeSH
• Check Tag
• dospělí MeSH
• 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

Multidrug resistance to anticancer drugs, which is often associated with enhanced expression of the ATP‑binding cassette (ABC) transporter P‑glycoprotein (encoded by the ABCB1 gene) may limit the effects of cancer therapy. Epigenetic regulation of ABCB1 expression may thus have a clinical impact. A detailed assessment of ABCB1 promoter methylation is of importance for predicting therapy outcome and prognosis. Thus, validated methods for the analysis of ABCB1 promoter methylation are urgently required. In the present study, high‑resolution melting (HRM) analysis of the CpG island regions covering the distal promoter of the ABCB1 gene was developed and compared with pyrosequencing. In addition, the clinical effects of the methylation status of the ABCB1 promoter were analyzed in patients with breast and ovarian carcinoma prior and subsequent to chemotherapy treatment. HRM analysis of ABCB1 methylation correlated with the results of pyrosequencing (P=0.001) demonstrating its analytical validity and utility. Hypermethylation of the analyzed ABCB1 promoter region was significantly correlated with low levels of the ABCB1 transcript in tumors from a subset of patients with breast and ovarian carcinoma prior to chemotherapy but not following treatment. Finally, high ABCB1 transcript levels were observed in tumors of patients with short progression‑free survival prior to chemotherapy. Our data suggest the existence of functional epigenetic changes in the ABCB1 gene with prognostic value in tumor tissues of patients with breast and ovarian carcinoma. The clinical importance of such changes should be further evaluated.

• MeSH
• denaturace nukleových kyselin MeSH
• duktální karcinom prsu farmakoterapie   genetika   patologie   MeSH
• epigeneze genetická MeSH
• invazivní růst nádoru MeSH
• lidé MeSH
• metylace DNA * MeSH
• míra přežití MeSH
• nádorové biomarkery genetika   MeSH
• nádory prsu farmakoterapie   genetika   patologie   MeSH
• nádory vaječníků farmakoterapie   genetika   patologie   MeSH
• následné studie MeSH
• P-glykoproteiny genetika   MeSH
• polymerázová řetězová reakce metody   MeSH
• prognóza MeSH
• promotorové oblasti (genetika) * MeSH
• regulace genové exprese u nádorů MeSH
• retrospektivní studie MeSH
• serózní cystadenokarcinom farmakoterapie   genetika   patologie   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

BACKGROUND/AIMS: MiRNA-301a-3p is an oncogenic miRNA whose expression is associated with tumor development, metastases and overall poor prognosis. Estrogen receptor α (ERα) is one of the estrogen hormone-activated transcription factors, which regulates a large number of genes and is involved in the mammary gland development. Expression of ERα is considered to be a good indicator for endocrine therapy and breast cancer survival. Loss of ERα in breast cancer patients indicates invasiveness and poor prognosis. In this study, we focus on the regulation of ERα by miR-301a and its role in transition from estrogen-dependent to estrogen-independent breast cancer. METHODS: Expression of miR-301a-3p was measured by qRT-PCR in tumor tissue samples from 111 patients with primary breast carcinoma and in mammospheres representing in vitro model of cancer stem-like cells. Dual reporter luciferase assay and complementary experiments were performed to validate ESR1 as a direct target of miR-301a-3p. The effect of miR-301a-3p on estrogen signaling was evaluated on the level of gene and protein expression and growth response to estrogens. Finally, the effect of miR-301a-3p expression on tumor growth was studied in nude mice. RESULTS: We identified ESR1 as a direct target of miR-301a-3p. Ectopic miR-301a-3p causes a decrease in ESR1 mRNA and protein level and modulates the expression of ERα target genes in ERα positive breast cancer cells. Consistently, miR-301a-3p causes a decrease in sensitivity of MCF7 cells to 17β-estradiol and inhibits the growth of estrogen dependent tumor in nude mice. Yet, the mice tumors have significantly increased expression of genes related to cancer stem-like cells and epithelial to mesenchymal transition suggesting enrichment of the population of cells with more invasive properties, in line with our observation that miR-301a-3p expression is highly increased in mammospheres which show a decrease in estrogenic signaling. Importantly, miR-301a-3P level is also increased in primary breast cancer samples exhibiting an ER/PR negative phenotype. CONCLUSION: Our results confirm ESR1 as a direct target of miR-301a-3p and suggest that miR-301a-3p likely contributes to development of estrogen independence, which leads to a more invasive phenotype of breast cancer.

• MeSH
• 3' nepřekládaná oblast MeSH
• alfa receptor estrogenů analýza   genetika   metabolismus   MeSH
• estrogeny metabolismus   MeSH
• lidé MeSH
• mikro RNA genetika   MeSH
• myši inbrední BALB C MeSH
• myši nahé MeSH
• nádorové buněčné linie MeSH
• nádory prsu genetika   metabolismus   patologie   MeSH
• regulace genové exprese u nádorů * MeSH
• signální transdukce MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Oxysterols are oxidized derivatives of cholesterol, both endogenous and exogenous. They have been implicated in numerous pathologies, including cancer. In addition to their roles in carcinogenesis, proliferation, migration, apoptosis, and multiple signalling pathways, they have been shown to modulate cancer therapy. They are known to affect therapy of hormonally positive breast cancer through modulating oestrogen receptor activity. Oxysterols have also been shown in various in vitro models to influence efficacy of chemotherapeutics, such as doxorubicin, vincristine, cisplatin, 5-fluorouracil, and others. Their effects on the immune system should also be considered in immunotherapy. Selective anti-cancer cytotoxic properties of some oxysterols make them candidates for new therapeutic molecules. Finally, differences in oxysterol levels in blood of cancer patients in different stages or versus healthy controls, and in tumour versus non-tumour tissues, show potential of oxysterols as biomarkers for cancer management and patient stratification for optimization of therapy. LINKED ARTICLES: This article is part of a themed issue on Oxysterols, Lifelong Health and Therapeutics. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v178.16/issuetoc.

• MeSH
• biologické markery MeSH
• imunitní systém MeSH
• imunoterapie MeSH
• lidé MeSH
• nádory * farmakoterapie   MeSH
• oxysteroly * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

Breast cancer is the most common cancer in women in the world. The role of germline genetic variability in ATP-binding cassette (ABC) transporters in cancer chemoresistance and prognosis still needs to be elucidated. We used next-generation sequencing to assess associations of germline variants in coding and regulatory sequences of all human ABC genes with response of the patients to the neoadjuvant cytotoxic chemotherapy and disease-free survival (n = 105). A total of 43 prioritized variants associating with response or survival in the above testing phase were then analyzed by allelic discrimination in the large validation set (n = 802). Variants in ABCA4, ABCA9, ABCA12, ABCB5, ABCC5, ABCC8, ABCC11, and ABCD4 associated with response and variants in ABCA7, ABCA13, ABCC4, and ABCG8 with survival of the patients. No association passed a false discovery rate test, however, the rs17822931 (Gly180Arg) in ABCC11, associating with response, and the synonymous rs17548783 in ABCA13 (survival) have a strong support in the literature and are, thus, interesting for further research. Although replicated associations have not reached robust statistical significance, the role of ABC transporters in breast cancer should not be ruled out. Future research and careful validation of findings will be essential for assessment of genetic variation which was not in the focus of this study, e.g., non-coding sequences, copy numbers, and structural variations together with somatic mutations.

• MeSH
• ABC transportéry genetika   MeSH
• alely MeSH
• frekvence genu MeSH
• genetická variace * MeSH
• genotyp MeSH
• jednonukleotidový polymorfismus MeSH
• Kaplanův-Meierův odhad MeSH
• lidé MeSH
• lokus kvantitativního znaku MeSH
• nádorové biomarkery * MeSH
• nádory prsu diagnóza   genetika   mortalita   terapie   MeSH
• neoadjuvantní terapie MeSH
• prognóza MeSH
• protokoly protinádorové kombinované chemoterapie terapeutické užití   MeSH
• výsledek terapie MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• cholesterol krev   metabolismus   MeSH
• lidé MeSH
• nádory prsu krev   chirurgie   MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• dopisy MeSH

BACKGROUND AND OBJECTIVE: Membrane solute carrier transporters play an important role in the transport of a wide spectrum of substrates including anticancer drugs and cancer-related physiological substrates. This study aimed to assess the prognostic relevance of gene expression and genetic variability of selected solute carrier transporters in breast cancer. METHODS: Gene expression was determined by quantitative real-time polymerase chain reaction. All SLC46A1 and SLCO1A2 exons and surrounding non-coding sequences in DNA extracted from the blood of patients with breast cancer (exploratory phase) were analyzed by next-generation sequencing technology. Common variants (minor allele frequency ≥ 5%) with in silico-predicted functional relevance were further analyzed in a large cohort of patients with breast cancer (n = 815) and their prognostic and predictive potential was estimated (validation phase). RESULTS: A gene expression and bioinformatics analysis suggested SLC46A1 and SLCO1A2 to play a putative role in the prognosis of patients with breast cancer. In total, 135 genetic variants (20 novel) were identified in both genes in the exploratory phase. Of these variants, 130 were non-coding, three missense, and two synonymous. One common variant in SLCO1A2 and four variants in SLC46A1 were predicted to be pathogenic by in silico programs and subsequently validated. A SLC46A1 haplotype block composed of rs2239911-rs2239910-rs8079943 was significantly associated with ERBB2/HER2 status and disease-free survival of hormonally treated patients. CONCLUSIONS: This study revealed the prognostic value of a SLC46A1 haplotype block for breast cancer that should be further studied.

• MeSH
• analýza přežití MeSH
• folátový přenašeč spřažený s transportem protonů genetika   MeSH
• genetická variace * MeSH
• haplotypy MeSH
• kvantitativní polymerázová řetězová reakce MeSH
• lidé MeSH
• nádorové biomarkery genetika   MeSH
• nádory prsu genetika   MeSH
• přenašeče organických aniontů genetika   MeSH
• prognóza MeSH
• regulace genové exprese u nádorů MeSH
• sekvenční analýza DNA MeSH
• vysoce účinné nukleotidové sekvenování MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cardiotoxicity is a serious adverse reaction to cancer chemotherapy and may lead to critical heart damage. Imatinib mesylate (IMB), a selective tyrosine kinase inhibitor, is sometimes accompanied by severe cardiovascular complications. To minimize risk, early biomarkers of such complications are of utmost importance. At the present time, microRNAs (miRNAs) are intensively studied as potential biomarkers of many pathological processes. Many miRNAs appear to be specific in some tissues, including the heart. In the present study we have explored the potential of specific miRNAs to be early markers of IMB-induced cardiotoxicity. Doxorubicin (DOX), an anthracycline with well-known cardiotoxicity, was used for comparison. NMRI mice were treated with IMB or DOX for nine days in doses corresponding to the highest recommended doses in oncological patients, following which plasmatic levels of miRNAs were analyzed in miRNA microarrays and selected cardio-specific miRNAs were quantified using qPCR. The plasmatic level of miR-1a, miR-133a, miR-133b, miR-339, miR-7058, miR-6236 and miR-6240 were the most different between the IMB-treated and control mice. Interestingly, most of the miRNAs affected by DOX were also affected by IMB showing the same trends. Concerning selected microRNAs in the hearts of individual mice, only miR-34a was significantly increased after DOX treatment, and only miR-205 was significantly decreased after IMB and DOX treatment. However, no changes in any miRNA expression correlated with the level of troponin T, a classical marker of heart injury.

• MeSH
• doxorubicin toxicita   MeSH
• imatinib mesylát farmakologie   MeSH
• mikro RNA krev   genetika   metabolismus   MeSH
• myši MeSH
• regulace genové exprese účinky léků   MeSH
• srdce účinky léků   MeSH
• transkriptom účinky léků   MeSH
• troponin T krev   genetika   metabolismus   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

Oxysterols, oxygenated derivatives of cholesterol, are formed in the human body or ingested. Experimental evidence suggests that due to their diverse functions, e.g. modulating the activity of receptors such as liver X receptors, oxysterol-binding and metabolizing proteins, and several ATP binding cassette transporters, oxysterols may contribute to a number of human disorders including cancer. Genetic variability of oxysterol pathways represents another side of this process, affecting carcinogenesis and cancer progression. This review summarizes information about both the physiological role of oxysterol pathway genes and observed associations between their genetic variability and cancer incidence, progression, and therapy outcome. Besides candidate gene studies, results of genome-wide association studies are presented as well. The survey of available data shows some potential genetic biomarkers that, if clinically validated, may allow the stratification of individuals into genetically defined groups for prediction of individual cancer risk and subsequent screening strategies for early diagnosis.

• MeSH
• časná detekce nádoru MeSH
• lidé MeSH
• nádorové biomarkery metabolismus   MeSH
• nádory diagnóza   genetika   metabolismus   MeSH
• oxysteroly metabolismus   MeSH
• signální transdukce * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH