BACKGROUND: Glioblastoma is the commonest malignant brain tumor and has a very poor prognosis. Reduced expression of the MGMT gene (10q26.3), influenced primarily by the methylation of two differentially methylated regions (DMR1 and DMR2), is associated with a good response to temozolomide treatment. However, suitable methods for detecting the methylation of the MGMT gene promoter and setting appropriate cutoff values are debated. RESULTS: A cohort of 108 patients with histologically and genetically defined glioblastoma was retrospectively examined with methylation-specific Sanger sequencing (sSeq) and methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) methods. The DMR2 region was methylated in 29% of samples, whereas DMR1 was methylated in 12% of samples. Methylation detected with the MS-MLPA method using probes MGMT_215, MGMT_190, and MGMT_124 from the ME012-A1 kit (located in DMR1 and DMR2) correlated with the methylation of the corresponding CpG dinucleotides detected with sSeq (p = 0.005 for probe MGMT_215; p < 0.001 for probe MGMT_190; p = 0.016 for probe MGMT_124). The threshold for methylation detection with the MS-MLPA method was calculated with a ROC curve analysis and principal components analysis of the data obtained with the MS-MLPA and sSeq methods, yielding a weighted value of 0.362. Thus, methylation of the MGMT gene promoter was confirmed in 36% of samples. These patients had statistically significantly better overall survival (p = 0.003). CONCLUSIONS: Our results show that the threshold for methylation detection with the MS-MLPA method determined here is useful from a diagnostic perspective because it allows the stratification of patients who will benefit from specific treatment protocols, including temozolomide. Detailed analysis of the MGMT gene promoter enables the more-precise and personalized treatment of patients with glioblastoma.

• MeSH
• CpG ostrůvky genetika   MeSH
• DNA modifikační methylasy * genetika   MeSH
• dospělí MeSH
• enzymy opravy DNA * genetika   MeSH
• glioblastom * genetika   farmakoterapie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• metylace DNA * genetika   MeSH
• nádorové supresorové proteiny * genetika   MeSH
• nádory mozku * genetika   MeSH
• promotorové oblasti (genetika) * genetika   MeSH
• retrospektivní studie MeSH
• sekvenční analýza DNA metody   MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• temozolomid terapeutické užití   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH
• validační studie MeSH

This prospective population-based study on a group of 132 resected IDH-wildtype (IDH-wt) glioblastoma (GBM) patients assesses the prognostic and predictive value of selected genetic biomarkers and clinical factors for GBM as well as the dependence of these values on the applied therapeutic modalities. The patients were treated in our hospital between June 2006 and June 2015. Clinical data and tumor samples were analyzed to determine the frequencies of TP53, MDM2, EGFR, RB1, BCR, and CCND1 gene aberrations and the duplication/deletion statuses of the 9p21.3, 1p36.3, 19q13.32, and 10p11.1 chromosome regions. Cut-off values distinguishing low (LCN) and high (HCN) copy number status for each marker were defined. Additionally, MGMT promoter methylation and IDH1/2 mutation status were investigated retrospectively. Young age, female gender, Karnofsky scores (KS) above 80, chemoradiotherapy, TP53 HCN, and CCND1 HCN were identified as positive prognostic factors, and smoking was identified as a negative prognostic factor. Cox proportional regression models of the chemoradiotherapy patient group revealed TP53 HCN and CCND1 HCN to be positive prognostic factors for both progression-free survival and overall survival. These results confirmed the influence of key clinical factors (age, KS, adjuvant oncotherapy, and smoking) on survival in GBM IDH-wt patients and demonstrated the prognostic and/or predictive importance of CCND1, MDM2, and 22q12.2 aberrations.

• MeSH
• DNA modifikační methylasy genetika   MeSH
• glioblastom * genetika   terapie   MeSH
• isocitrátdehydrogenasa genetika   MeSH
• lidé MeSH
• metylace DNA MeSH
• mutace MeSH
• nádory mozku * genetika   terapie   MeSH
• prospektivní studie MeSH
• retrospektivní studie MeSH
• Check Tag
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Interindividual differences in DNA repair systems may play a role in modulating the individual risk of developing colorectal cancer. To better ascertain the role of DNA repair gene polymorphisms on colon and rectal cancer risk individually, we evaluated 15,419 single nucleotide polymorphisms (SNPs) within 185 DNA repair genes using GWAS data from the Colon Cancer Family Registry (CCFR) and the Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO), which included 8,178 colon cancer, 2,936 rectum cancer cases and 14,659 controls. Rs1800734 (in MLH1 gene) was associated with colon cancer risk (p-value = 3.5 × 10-6 ) and rs2189517 (in RAD51B) with rectal cancer risk (p-value = 5.7 × 10-6 ). The results had statistical significance close to the Bonferroni corrected p-value of 5.8 × 10-6 . Ninety-four SNPs were significantly associated with colorectal cancer risk after Binomial Sequential Goodness of Fit (BSGoF) procedure and confirmed the relevance of DNA mismatch repair (MMR) and homologous recombination pathways for colon and rectum cancer, respectively. Defects in MMR genes are known to be crucial for familial form of colorectal cancer but our findings suggest that specific genetic variations in MLH1 are important also in the individual predisposition to sporadic colon cancer. Other SNPs associated with the risk of colon cancer (e.g., rs16906252 in MGMT) were found to affect mRNA expression levels in colon transverse and therefore working as possible cis-eQTL suggesting possible mechanisms of carcinogenesis.

• MeSH
• biologická variabilita populace genetika   MeSH
• DNA modifikační methylasy genetika   MeSH
• DNA vazebné proteiny genetika   MeSH
• dospělí MeSH
• enzymy opravy DNA genetika   MeSH
• genetická predispozice k nemoci * MeSH
• hodnocení rizik MeSH
• jednonukleotidový polymorfismus MeSH
• karcinogeneze genetika   MeSH
• kolon patologie   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• MutL homolog 1 genetika   MeSH
• nádorové supresorové proteiny genetika   MeSH
• nádory rekta genetika   patologie   MeSH
• nádory tračníku genetika   patologie   MeSH
• oprava DNA genetika   MeSH
• registrace statistika a číselné údaje   MeSH
• rektum patologie   MeSH
• senioři MeSH
• studie případů a kontrol MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH

• MeSH
• azacytidin analogy a deriváty   farmakologie   terapeutické užití   MeSH
• DNA modifikační methylasy genetika   metabolismus   MeSH
• DNA-(cytosin-5)-methyltransferasa 1 antagonisté a inhibitory   MeSH
• epigeneze genetická MeSH
• hematopoetické kmenové buňky MeSH
• lidé MeSH
• metylace DNA * genetika   účinky léků   MeSH
• mutace genetika   MeSH
• myelodysplastické syndromy * farmakoterapie   genetika   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

PURPOSE: The enzyme O6-methylguanine-DNA methyltransferase (MGMT) is an important component of the DNA repair machinery. MGMT removes O6-methylguanine from the DNA by transferring the methyl group to a cysteine residue in its active site. Recently, we detected the single nucleotide polymorphism (SNP) rs12917 (C/T) in the MGMT sequence adjacent to the active site in Hodgkin lymphoma (HL) cell line KM-H2. We now investigated whether this SNP is also present in other HL cell lines and patient samples. Furthermore, we asked whether this SNP might have an impact on metabolic response in 2-deoxy-2-[18F]fluoro-D-glucose positron emission tomography ([18F]FDG-PET), and on overall treatment outcome based on follow-up intervals of at least 34 months. PROCEDURES: We determined the frequency of this MGMT polymorphism in 5 HL cell lines and in 29 pediatric HL (PHL) patients. The patient cohort included 17 female and 12 male patients aged between 4 and 18 years. After characterization of the sequence, we tested a possible association between rs12917 and age, gender, Ann Arbor stage, treatment group, metabolic response following two courses of OEPA (vincristine, etoposide, prednisone, and doxorubicin) chemotherapy, radiotherapy indication, and relapse status. RESULTS: We detected the minor T allele in four of five HL cell lines. 11/29 patients carried the minor T allele whereas 18/29 patients showed homozygosity for the major C allele. Interestingly, we observed significantly better metabolic response in PHL patients carrying the rs12917 C allele resulting in a lower frequency of radiotherapy indication. CONCLUSION: MGMT polymorphism rs12917 seems to affect chemotherapy response in PHL. The prognostic value of this polymorphism should be investigated in a larger patient cohort.

• MeSH
• dítě MeSH
• DNA modifikační methylasy genetika   MeSH
• enzymy opravy DNA genetika   MeSH
• fluorodeoxyglukosa F18 chemie   MeSH
• Hodgkinova nemoc diagnostické zobrazování   genetika   MeSH
• jednonukleotidový polymorfismus genetika   MeSH
• lidé MeSH
• mladiství MeSH
• nádorové buněčné linie MeSH
• nádorové supresorové proteiny genetika   MeSH
• pozitronová emisní tomografie * MeSH
• předškolní dítě MeSH
• sekvence nukleotidů MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• předškolní dítě MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

The inducible repair enzyme O6-methylguanine-DNA methyltransferase (MGMT) eliminates O6-methylguanine adducts in DNA and protects the cells from damaging effects of alkylating agents. We have found that anti-MGMT antibodies recognize both the MGMT protein with a mol. weight ~ 24 kDa and a protein with a mol. weight ~ 48 kDa, which was named MARP (anti-methyltransferase antibody recognizable protein). A number of growth factors and cytokines were shown to regulate the expression of MGMT and MARP proteins. The ranges of concentrations of several growth factors and cytokines that caused increasing or decreasing protein amounts in human cell cultures were determined. The results of special biological experiments have allowed us to assume a possible role of MARP in the repair of alkyl adducts in human cells.

• MeSH
• buněčné kultury MeSH
• buněčné linie MeSH
• buňky Hep G2 MeSH
• cytokiny farmakologie   MeSH
• DNA modifikační methylasy genetika   MeSH
• enzymy opravy DNA genetika   MeSH
• lidé MeSH
• mezibuněčné signální peptidy a proteiny farmakologie   MeSH
• nádorové supresorové proteiny genetika   MeSH
• regulace genové exprese účinky léků   MeSH
• techniky in vitro MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

• Klíčová slova
• metylační stav promotoru MGMT,
• MeSH
• bevacizumab terapeutické užití   MeSH
• cílená molekulární terapie * MeSH
• DNA modifikační methylasy genetika   MeSH
• enzymy opravy DNA genetika   MeSH
• glioblastom * diagnóza   terapie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie MeSH
• nádorové biomarkery genetika   MeSH
• nádorové supresorové proteiny genetika   MeSH
• nádory mozku diagnóza   terapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH

PURPOSE: Imaging biomarker research focuses on discovering relationships between radiological features and histological findings. In glioblastoma patients, methylation of the O(6)-methylguanine methyltransferase (MGMT) gene promoter is positively correlated with an increased effectiveness of current standard of care. In this paper, the authors investigate texture features as potential imaging biomarkers for capturing the MGMT methylation status of glioblastoma multiforme (GBM) tumors when combined with supervised classification schemes. METHODS: A retrospective study of 155 GBM patients with known MGMT methylation status was conducted. Co-occurrence and run length texture features were calculated, and both support vector machines (SVMs) and random forest classifiers were used to predict MGMT methylation status. RESULTS: The best classification system (an SVM-based classifier) had a maximum area under the receiver-operating characteristic (ROC) curve of 0.85 (95% CI: 0.78-0.91) using four texture features (correlation, energy, entropy, and local intensity) originating from the T2-weighted images, yielding at the optimal threshold of the ROC curve, a sensitivity of 0.803 and a specificity of 0.813. CONCLUSIONS: Results show that supervised machine learning of MRI texture features can predict MGMT methylation status in preoperative GBM tumors, thus providing a new noninvasive imaging biomarker.

• MeSH
• DNA modifikační methylasy genetika   MeSH
• enzymy opravy DNA genetika   MeSH
• glioblastom diagnostické zobrazování   genetika   chirurgie   MeSH
• lidé MeSH
• magnetická rezonanční tomografie metody   MeSH
• metylace DNA * MeSH
• mozek diagnostické zobrazování   chirurgie   MeSH
• nádorové biomarkery genetika   MeSH
• nádorové supresorové proteiny genetika   MeSH
• nádory mozku diagnostické zobrazování   genetika   chirurgie   MeSH
• promotorové oblasti (genetika) MeSH
• retrospektivní studie MeSH
• ROC křivka MeSH
• support vector machine MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

Gliomas are a heterogeneous group of tumours varying in prognosis, treatment approach, and overall survival. Recently, novel markers have been identified which are linked to patient prognosis and therapeutic response. Especially the mutation of the enzyme isocitrate dehydrogenase 1 or 2 (IDH1/2) gene and the O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status seem to be the most important predictors of survival. From 2012 to 2015, 94 Czech patients with primary brain tumours were enrolled into the study. The IDH1/2 mutation was detected by denaturing capillary electrophores.The methylation status of the MGMT gene and other 46 genes was revealed by MS-MLPA. In all 94 patients, the clinical data were correlated with molecular markers by Kaplan-Meier analyses and Cox regression model. The MGMT promoter methylation status was established and compared to clinical data. In our study eight different probes were used to elucidate the MGMT methylation status; hypermethylation was proclaimed if four and more probes were positive. This 3 : 5 ratio was tested and confirmed by Kaplan-Meier and Cox analyses. The study confirmed the importance of the IDH1/2 mutation and hypermethylation of the MGMT gene promoter being present in tumour tissue. Both markers are independent positive survival predictors; in the Cox model the IDH hazard ratio was 0.10 and in the case of MGMT methylation it reached 0.32. The methylation analysis of the panel of additional 46 genes did not reveal any other significant epigenetic markers; none of the candidate genes have been confirmed in the Cox regression analyses as an independent prognostic factor.

• MeSH
• DNA modifikační methylasy genetika   MeSH
• enzymy opravy DNA genetika   MeSH
• epigeneze genetická MeSH
• gliom enzymologie   genetika   MeSH
• isocitrátdehydrogenasa genetika   MeSH
• Kaplanův-Meierův odhad MeSH
• lidé středního věku MeSH
• lidé MeSH
• metylace DNA genetika   MeSH
• mutace genetika   MeSH
• nádorové supresorové proteiny genetika   MeSH
• nádory mozku enzymologie   genetika   MeSH
• přežití bez známek nemoci MeSH
• promotorové oblasti (genetika) * MeSH
• regresní analýza MeSH
• ROC křivka MeSH
• senzitivita a specificita MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Oligodendrogliomy patří k vzácným, avšak nejlépe prozkoumaným nádorům v neuroonkologii. Již dlouho je známa jejich větší senzitivita na radioterapii a chemoterapii ve srovnání s ostatními gliomy. Specifickým nálezem je častá přítomnost chromozomální kodelece 1p/19q. Teprve výsledky dlouhodobého sledování nemocných ve dvou zásadních klinických studiích fáze III – RTOG 9402 a EORTC 26951 prokázaly příznivý účinek kombinované onkologické léčby radioterapie a chemoterapie v kombinaci prokarbazin, lomustin‑CCNU a vinkristin (PCV) u nemocných s anaplastickým oligodendrogliomem a anaplastickým oligoastrocytomem s 1p/19q kodelecí. Přítomnost kodelece 1p/19q je důležitým dia­gnostickým, pozitivním prognostickým a silným prediktivním bio­markerem oligodendrogliomů. Diskutuje se o dalších molekulárně genetických charakteristikách oligodendrogliomů – mutaci metabolického enzymu Izocitrát dehydrogenázy 1 a 2 (IDH 1/2), metylaci promotoru genu pro O‑6–metylguanin‑metyltransferázu (MGMT), hypermetylačním stavu ostrůvků cytozin‑guanin nádorového genomu (G‑CIMP) a možnosti léčby těchto nádorů. Uvedeny jsou aktuální poznatky optimálního managementu anaplastických oligodendrogliomů respektující zásady personalizované medicíny.

Oligodendrogliomas are uncommon but extensively investigated tumours in neurooncology. Their superior sensitivity to radiotherapy and chemotherapy compared to other gliomas has long been known. Chromosomal codeletion 1p/19q is frequent in this tumour type. A long-term follow up of two landmark phase III trials – RTOG 9402 and EORTC 26951 has shown a favourable effect of combined radiotherapy and chemotherapy - procarbazine, lomustine (CCNU), vincristine – in patients with anaplastic oligodendrogliomas and anaplastic oligoastrocytomas carrying the codeletion 1p/19q. This codeletion serves as an important diagnostic, positive prognostic and strong predictive biomarker. The role of the other molecular biomarkers (isocitrate dehydrogenase – IDH1, IDH2 mutations, methylation of the MGMT promoter, glioma cytosine - guanine islands methylator phenotype – G-CIMP) in oligodendroglial tumours is also discussed. All these data facilitate the new personalised approach to the management and treatment of anaplastic oligodendroglial tumours.

• Klíčová slova
• RTOG 9402, EORTC 26951,
• MeSH
• alkylační protinádorové látky farmakologie   MeSH
• dakarbazin analogy a deriváty   terapeutické užití   MeSH
• delece genu MeSH
• DNA modifikační methylasy * genetika   MeSH
• enzymy opravy DNA * genetika   MeSH
• glutaráty metabolismus   MeSH
• isocitrátdehydrogenasa * genetika   metabolismus   MeSH
• klinické zkoušky, fáze III jako téma MeSH
• kombinovaná terapie MeSH
• lidé MeSH
• lidské chromozomy, pár 1 genetika   MeSH
• lidské chromozomy, pár 19 genetika   MeSH
• lomustin farmakologie   MeSH
• molekulární biologie MeSH
• mutace genetika   MeSH
• nádorové biomarkery MeSH
• nádory nervového systému * diagnóza   genetika   terapie   MeSH
• oligodendrogliom * diagnóza   genetika   terapie   MeSH
• přežití MeSH
• prognóza MeSH
• prokarbazin farmakologie   MeSH
• protokoly protinádorové kombinované chemoterapie * terapeutické užití   MeSH
• randomizované kontrolované studie jako téma MeSH
• retrospektivní studie MeSH
• staging nádorů MeSH
• vinkristin farmakologie   MeSH
• výsledek terapie MeSH
• vysokoenergetická radioterapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• práce podpořená grantem MeSH
• přehledy MeSH