Bálint Tóbiás

Marked Increase in CYP24A1 Gene Expression in Human Papillary Thyroid Cancer

The active metabolite of vitamin D3, 1,25-dihydroxyvitamin D3 (1,25-D3) inhibits cell growth and induces cell differentiation and apoptosis in numerous tumors, such as colon, breast, and prostate cancers (1–3). However, the anticancer effect of 1,25-D3 cannot always be seen in a clinical setting. In case of colon cancers, a marked increase in the expression of the 1,25D3 inactivating enzyme, the 24-hydroxylase (CYP24A1), has been observed (4). The role of 1,25-D3 in the development of thyroid carcinomas has not yet been established. However, Sharma et al. (5) observed the correlation of high baseline CYP24A1 and relatively low stimulation after calcitriol treatment (compared with sensitive cells) with lack of growth inhibition in numerous thyroid cancer cell lines. We have also examined the gene expression of the inactivating CYP24A1 and the activating 1-alpha-hydroxylase (CYP27B1) enzyme in human thyroid cancers. To date, gene expression analysis of thyroid samples (both normal and papillary tumor tissue of the same patient) was carried out in six unrelated, consecutive, Hungarian, Caucasian patients at our Thyroid Clinic. All surgically removed thyroid tissue samples underwent histological examination, and papillary tumor was identified in all cases. The study was approved by the Regional Committee of Science and Research Ethics, Semmelweis University (SOTE-TUKEB 1160-0/20101018EKU), and all patients gave written informed consent. Total RNA was isolated from each sample with Roche High Pure Total RNA Isolation kit. Five hundred nanograms of total RNA was reverse-transcribed to cDNA. The expression differences of selected genes were analyzed by Taqman probe-based quantitative real-time reverse transcriptase– polymerase chain reaction. Relative quantification was carried out from collected data (threshold cycle numbers) by Applied Biosystems 7500 System SDS software 1.3. CYP24A1 mRNA expression was markedly increased in all but one papillary cancer compared with that of normal thyroid tissue, sometimes reaching 300-fold elevation (Supplementary Fig. S1; Supplementary Data are available online at www.liebertonline.com/thy). No significant alteration was seen in CYP27B1 gene activity between neoplastic and normal tissues. There was no significant difference in serum 25-OHvitamin D3 concentrations among patients (mean: 28.03 ng/ mL, range: 22.7–31.9 ng/mL). In this letter, we report marked increases in the 1,25-D3neutralizing CYP24A1 gene expression in human papillary thyroid cancer. The tumor cell growth-inhibiting role of vitamin D3 has been extensively studied in different malignancies (1–3). The interest in the association of vitamin-D3 serum levels with various cancer incidences has dramatically increased. However, only very limited data are available on the relationship between serum vitamin D3 concentrations and malignant thyroid conditions (6,7). The pilot study of Laney et al. showed levels of vitamin D and rates of vitamin D deficiency to be similar between patients with thyroid nodules, thyroid cancer in remission, and active thyroid cancer (8). However, the results of Stepien et al. revealed significantly lower calcitriol concentrations in patients with papillary, follicular, and anaplastic thyroid cancers (7). This finding could be attributable to higher CYP24A1 levels cleaving calcitriol, as there were no differences in serum 25-OH-vitamin D3. Earlier, calcitriol had also been shown to attenuate thyrotropinstimulated growth and iodide uptake by rat thyroid cells (FRTL-5) (9,10). Papillary cancer is the most common thyroid malignancy. The role of vitamin D3 in the prevention or development of this disorder has to be yet determined. The increase in CYP24A1 expression in this cancer type could be a ‘‘protective’’ mechanism against the well-known anticancer effect of calcitriol. The observation of Sharma et al. (5) regarding increased expression of CYP24A1 in thyroid cancer cell lines corroborates this notion. One of the cell lines they used was human papillary thyroid carcinoma cell line, whereas the other ones showed the features of human anaplastic thyroid carcinoma. Also, the most resistant cell lines to calcitriol had the highest baseline levels of CYP24A1. In our study at this stage, the number of examined tumor tissues does not allow drawing of statistically significant conclusion about the correlation of tumor histopathological stage or aggressiveness with CYP24A1 levels. Khadzkou et al. demonstrated enhanced 1-alphahydroxylase expression but concluded that this elevation did not show large differences in CYP27B1 expression in papillary thyroid cancer and its metastasis compared with normal

Fast and robust next-generation sequencing technique using ion torrent personal genome machine for the screening of neurofibromatosis type 1 (NF1) gene

Neurofibromatosis type 1 (NF1) gene exhibits one of the highest spontaneous mutation rates in the human genome. Identification of the NF1 mutation is challenging because the NF1 gene is very large and complex, lacking mutational “hot spots.” There is no clustering of mutations, there are several pseudogenes, and a wide spectrum of different types of mutation has been recognized. To date, NF1 mutations or deleted regions have been detected with a number of techniques. With the appearance of next-generation sequencing (NGS) machines, molecular biology is in a new revolutionary phase. Our aim was to work out a method to use the high-throughput NGS machine, Ion Torrent PGM, in diagnostic settings for neurofibromatosis type 1. In our examination, we could reveal 21 distinct variations in NF1 gene in seven patients. This is an absolutely new method for exploring the genetic background of neurofibromatosis type 1 exhibiting the extremely high throughput of NGS in a diagnostic setting.

New approach to analyze genetic and clinical data in bisphosphonate‐induced osteonecrosis of the jaw

OBJECTIVES Osteonecrosis of the jaw (ONJ) is a major complication associated with long-term use of bisphosphonates (BP). We aimed to investigate the effect of CYP2C8 rs1934951 SNP and its relationship to a number of clinical and biochemical factors in 46 Hungarian subjects with bisphosphonate-induced ONJ. METHODS Blood samples were collected from each subject and genomic DNA was extracted. SNP analysis of CYP2C8 gene was carried out by predesigned TaqMan primer/probe sets. The genetic data together with clinical and biochemical variables were evaluated by chi-square test, logistic regression, and principal component analysis (PCA). RESULTS The risk of mandibular localization of ONJ was 19.2-fold higher in subjects with AG genotype than in normal GG genotype. PCA revealed strong positive correlations between maxillar localization of ONJ and a group of variables including intravenous BP application and serum lipid markers. Mandibular localization of ONJ was correlated positively with serum calcium, 25-hydroxy-vitamin D and PTH levels, oral BP application, and the length of BP therapy. The degree of the disease and the number of recurrences were correlated with the application of hormone-deprivation therapy for breast cancer patients. CONCLUSION The statistical approach applying PCA to our data may contribute to the better understanding of factors playing role in the development of bisphosphonate-induced ONJ.

Clinical Use of Next-Generation Sequencing in the Diagnosis of Wilson’s Disease

Objective. Wilsons disease is a disorder of copper metabolism which is fatal without treatment. The great number of disease-causing ATP7B gene mutations and the variable clinical presentation of WD may cause a real diagnostic challenge. The emergence of next-generation sequencing provides a time-saving, cost-effective method for full sequencing of the whole ATP7B gene compared to the traditional Sanger sequencing. This is the first report on the clinical use of NGS to examine ATP7B gene. Materials and Methods. We used Ion Torrent Personal Genome Machine in four heterozygous patients for the identification of the other mutations and also in two patients with no known mutation. One patient with acute on chronic liver failure was a candidate for acute liver transplantation. The results were validated by Sanger sequencing. Results. In each case, the diagnosis of Wilsons disease was confirmed by identifying the mutations in both alleles within 48 hours. One novel mutation (p.Ala1270Ile) was found beyond the eight other known ones. The rapid detection of the mutations made possible the prompt diagnosis of WD in a patient with acute liver failure. Conclusions. According to our results we found next-generation sequencing a very useful, reliable, time-saving, and cost-effective method for diagnosing Wilsons disease in selected cases.

Next-generation sequencing of common osteogenesis imperfecta-related genes in clinical practice.

Next generation sequencing (NGS) is a rapidly developing area in genetics. Utilizing this technology in the management of disorders with complex genetic background and not recurrent mutation hot spots can be extremely useful. In this study, we applied NGS, namely semiconductor sequencing to determine the most significant osteogenesis imperfecta-related genetic variants in the clinical practice. We selected genes coding collagen type I alpha-1 and-2 (COL1A1, COL1A2) which are responsible for more than 90% of all cases. CRTAP and LEPRE1/P3H1 genes involved in the background of the recessive forms with relatively high frequency (type VII and VIII) represent less than 10% of the disease. In our six patients (1–41 years), we identified 23 different variants. We found a total of 14 single nucleotide variants (SNV) in COL1A1 and COL1A2, 5 in CRTAP and 4 in LEPRE1. Two novel and two already well-established pathogenic SNVs have been identified. Among the newly recognized mutations, one results in an amino acid change and one of them is a stop codon. We have shown that a new full-scale cost-effective NGS method can be developed and utilized to supplement diagnostic process of osteogenesis imperfecta with molecular genetic data in clinical practice.

Effects of imatinib and nilotinib on the whole transcriptome of cultured murine osteoblasts

Numerous clinical observations have confirmed that breakpoint cluster region-abelson fusion oncoprotein tyrosine kinase inhibitors used in leukemia treatment alter bone physiology in a complex manner. The aim of the present study was to analyze the whole transcriptome of cultured murine osteoblasts and determine the changes following treatment with imatinib and nilotinib using Sequencing by Oligonucleotide Ligation and Detection next generation RNA sequencing. This study also aimed to identify candidate signaling pathways and network regulators by multivariate Ingenuity Pathway Analysis. Based on the right-tailed Fishers exact test, significantly altered pathways including upstream regulators were defined for each drug. The correlation between these pathways and bone metabolism was also examined. The preliminary results suggest the two drugs have different mechanisms of action on osteoblasts, and imatinib was shown to have a greater effect on gene expression. Data also indicated the potential role of a number of genes and signaling cascades that may contribute to identifying novel targets for the treatment of metabolic bone diseases.

Comparative study of somatic oncogene mutations in normal thyroid tissues and thyroid neoplasms

Az elmult evekben tobb munkacsoportnak sikerult olyan szomatikus mutaciokat (BRAF, NRAS, HRAS, KRAS genekben) es genatrendeződeseket (RET/PTC, PAX8/PPAR-gamma) azonositani, amelyek osszefuggest mutatnak a pajzsmirigydaganatok kialakulasaval. Jelen vizsgalatban 11 szemely 22 (11 koros es 11 betegsegmentes) intraoperativ pajzsmirigy-szovetmintait elemeztek. A RAS gencsalad es a BRAF genek szomatikus egypontos nukleotid polimorfizmusait LigthCycler olvadaspontanalizis-modszerrel, mig a genatrendeződeseket valos idejű polimeraz lancreakcio modszerevel vizsgaltak. A daganatos mintakban 3 BRAF-, 2 NRAS-, 1 HRAS-mutaciot, valamint 1 RET/PTC1 atrendeződest talaltak. Az eredmenyek megerősitik a nemzetkozi adatokat, miszerint ezek az egypontos nukleotidpolimorfizmusok es genatrendeződesek megtalalhatok a daganatos pajzsmirigyszovetekben. Valoszinűsithető, hogy ezen genetikai vizsgalatokkal kiegeszult citologiai vizsgalat segitheti a malignus gobok azonositasat, illetve elkepzelhető, hogy prognosztikai faktorkent el...It is established that numerous somatic oncogene mutation (BRAF, NRAS, HRAS, KRAS) and gene translocations (RET/PTC, PAX8/PPAR-gamma) are associated with the development of thyroid cancer. In this study 22 intraoperative thyroid tissue samples (11 pathologic and 11 normal) were examined. Somatic single nucleotide polymorphisms were analyzed by LigthCycler melting method, while translocations were identified by real-time polymerase chain reaction technique. In tumorous sample 3 BRAF, 2 NRAS and one HRAS mutations were found, as well as one RET/PTC1 translocation. Results confirm international data showing that these oncogene mutations and translocations are linked to thyroid cancer. Cytological examination completed with genetic data may support the diagnosis of thyroid malignancies. In addition, genetic alterations may indicate malignant transformation and may become prognostic factors in future.

Comprehensive examination of somatic oncogene mutation in normal and pathologic thyroid tissues

Az elmult evekben tobb munkacsoportnak sikerult olyan szomatikus mutaciokat (BRAF, NRAS, HRAS, KRAS genekben) es genatrendeződeseket (RET/PTC, PAX8/PPAR-gamma) azonositani, amelyek osszefuggest mutatnak a pajzsmirigydaganatok kialakulasaval. Jelen vizsgalatban 11 szemely 22 (11 koros es 11 betegsegmentes) intraoperativ pajzsmirigy-szovetmintait elemeztek. A RAS gencsalad es a BRAF genek szomatikus egypontos nukleotid polimorfizmusait LigthCycler olvadaspontanalizis-modszerrel, mig a genatrendeződeseket valos idejű polimeraz lancreakcio modszerevel vizsgaltak. A daganatos mintakban 3 BRAF-, 2 NRAS-, 1 HRAS-mutaciot, valamint 1 RET/PTC1 atrendeződest talaltak. Az eredmenyek megerősitik a nemzetkozi adatokat, miszerint ezek az egypontos nukleotidpolimorfizmusok es genatrendeződesek megtalalhatok a daganatos pajzsmirigyszovetekben. Valoszinűsithető, hogy ezen genetikai vizsgalatokkal kiegeszult citologiai vizsgalat segitheti a malignus gobok azonositasat, illetve elkepzelhető, hogy prognosztikai faktorkent el...It is established that numerous somatic oncogene mutation (BRAF, NRAS, HRAS, KRAS) and gene translocations (RET/PTC, PAX8/PPAR-gamma) are associated with the development of thyroid cancer. In this study 22 intraoperative thyroid tissue samples (11 pathologic and 11 normal) were examined. Somatic single nucleotide polymorphisms were analyzed by LigthCycler melting method, while translocations were identified by real-time polymerase chain reaction technique. In tumorous sample 3 BRAF, 2 NRAS and one HRAS mutations were found, as well as one RET/PTC1 translocation. Results confirm international data showing that these oncogene mutations and translocations are linked to thyroid cancer. Cytological examination completed with genetic data may support the diagnosis of thyroid malignancies. In addition, genetic alterations may indicate malignant transformation and may become prognostic factors in future.

Next-generation Sequencing in the Clinical Decision Making in Hypertrophic Cardiomyopathy

Next generation sequencing (NGS) is becoming a valuable tool in clinical decisions. Here, we discuss the case of a family (2 parents with 3 children) with hypertrophic cardiomyopathy where we applied a NGS method developed by us to determine the genetic background of the disease. When the youngest sister underwent sudden cardiac arrest and successful reanimation, her genome was tested with this approach and two disease-causing heterozygous mutations in the MYBPC3 gene (p.R495Q and p.S593fs*11) were identified. After this, all of the family members were screened targeting these two mutations. The mother carried the frameshift mutation (p.S593fs*11) while the father’s genome contained the point mutation (p.R495Q). All the children were compound heterozygous. Information collected from our genetic testing panel helped to make the decision of implanting ICD that is associated potentially severe complications in children. This case further reinforces that a full-scale, cost-effective NGS method can be utilized to supplement diagnostic and therapeutic processes of hypertrophic cardiomyopathy in clinical practice.

Az onkohematológiai betegségek kezelésében használt tirozinkináz-gátló imatinib és nilotinib csonthatásainak irodalmi áttekintése és a saját kutatási eredmények bemutatása

Absztrakt A tirozinkinaz-gatlok bizonyos onkohematologiai betegsegek kezeleseben elterjedten hasznalt gyogyszerek. Tobb klinikai tanulmany igazolta, hogy a BCR-ABL specifikus tirozinkinaz-gatlok alkalmazasa komplex es meg nem egyertelműen azonositott modon valtoztatja meg a csontszovet elettani folyamatait. Mivel a kezelesek egyre tobb beteget erintenek, illetve hosszu evtizedekig vagy akar elethosszig is tarthatnak, indokolt ezen mechanizmusok molekularis hatterenek reszletesebb megismerese. A szerzők osszefoglaljak az imatinibbel es a nilotinibbel vegzett, csontanyagcserehez kapcsolodo alapkutatasi eredmenyeket, human klinikai megfigyeleseket, kiegeszitve in vitro osteoblast-sejtkulturakon vegzett sajat kiserleteik eredmenyeivel. Az osszefoglalt kutatasi eredmenyek alapjan az imatinib es a nilotinib csontsejtekre gyakorolt hatasa fugg az alkalmazott hatoanyag-koncentraciotol, a sejtek erettsegi allapotatol, illetve az altaluk kotott receptor-tirozinkinaz utvonalak megoszlasi aranyatol. Jelen kozlemenyben elsőkent keszitettek a hazai szakirodalomban hianypotlo, atfogo irodalmi attekintest a tirozinkinaz-gatlok csontanyagcseret befolyasolo hatasaival kapcsolatban es vegeztek teljes transzkriptom-analizist osteoblastokon a sejtszintű hatasmechanizmus jobb megerteset szolgalva. Orv. Hetil., 2016, 157(36), 1429–1437. | Abstract Tyrosine kinase inhibitors are widely used for treatment of certain oncohematological diseases. Several clinical studies have confirmed that specific BCR-ABL tyrosine kinase inhibitors alter the physiological process of bone tissue in a complex and unclearly identified manner. Since these treatments are being given to more and more patients, and the therapy takes decades or lasts even lifelong, it is justifiable to obtain more detailed knowledge of the molecular background of these mechanisms. In this article the authors summarize preliminary research results and human clinical observations on imatinib and nilotinib which are related to bone metabolism, and present the results of their own experiments in in vitro osteoblast cultures. Based on the presented results, the effects of imatinib and nilotinib on bone cells depend on the concentration of imatinib and nilotinib, the maturation stage of the cells and the distribution ratio of receptor tyrosine kinase signaling pathways. In this study the authors firstly prepared a stop-gap, comprehensive review in the Hungarian literature, regarding the effects of tyrosine kinase inhibitors on bone metabolism. In addition they firstly performed whole transcriptome analysis on osteoblasts in order to obtain a better understanding of the cellular molecular mechanisms. Orv. Hetil., 2016, 157(36), 1429–1437.Tyrosine kinase inhibitors are widely used for treatment of certain oncohematological diseases. Several clinical studies have confirmed that specific BCR-ABL tyrosine kinase inhibitors alter the physiological process of bone tissue in a complex and unclearly identified manner. Since these treatments are being given to more and more patients, and the therapy takes decades or lasts even lifelong, it is justifiable to obtain more detailed knowledge of the molecular background of these mechanisms. In this article the authors summarize preliminary research results and human clinical observations on imatinib and nilotinib which are related to bone metabolism, and present the results of their own experiments in in vitro osteoblast cultures. Based on the presented results, the effects of imatinib and nilotinib on bone cells depend on the concentration of imatinib and nilotinib, the maturation stage of the cells and the distribution ratio of receptor tyrosine kinase signaling pathways. In this study the authors firstly prepared a stop-gap, comprehensive review in the Hungarian literature, regarding the effects of tyrosine kinase inhibitors on bone metabolism. In addition they firstly performed whole transcriptome analysis on osteoblasts in order to obtain a better understanding of the cellular molecular mechanisms. Orv. Hetil., 2016, 157(36), 1429-1437.