Polymorphisms of CSF1 and TM7SF4 genes in a case of mild juvenile Paget's disease found using next-generation sequencing

Juvenile Paget's disease (JPD) is a rare autosomal-recessive condition. It is diagnosed in young children and characterized by a generalized increase in bone turnover, bone pain, and skeletal deformity. Our patient was diagnosed after a pathological fracture when she was 11 years old. When we first examined her at the age of 30 she had bone pain and deformity in both the femur and tibia. Serum alkaline phosphatase (ALP) level, radiology, bone scintigraphy, and densitometry were monitored. Next generation sequencing (NGS) technology, namely semiconductor sequencing, was used to determine the genetic background of JPD. Seven target genes and regions were selected and analyzed after literature review (TM7SF4, SQSTM1, TNFRSF11A, TNFRSF11B, OPTN, CSF1, VCP). No clear pathogenic mutation was found, but we detected missense polymorphisms in CSF1 and TM7SF4 genes. After treatment with zoledronic acid, infusion bone pain and ALP level decreased. We can conclude that intravenous zoledronic acid therapy is effective and safe for suppressing bone turnover and improving symptoms in JPD, but the long-term effects on clinical outcomes are unclear. Our findings also suggest that NGS may help explore the pathogenesis and aid the diagnosis of JPD

Pattern of SQSTM1 Gene Variants in a Hungarian Cohort of Paget’s Disease of Bone

Paget’s disease of bone (PDB) is characterized by focal or multifocal increase in bone turnover. One of the most well-established candidate genes for susceptibility to PDB is Sequestosome 1 (SQSTM1). Mutations in SQSTM1 have been documented among Western-European, British and American patients with PDB. However, there is no information on SQSTM1 mutation status in PDB patients from the Central- and Eastern-European regions. In this study, we conducted a mutation screening for SQSTM1 gene variants in 82 PDB patients and 100 control participants in Hungary. Mutations of SQSTM1 were detected in 18 PDB patients (21.95%); associations between genotype and clinical characteristics were also analyzed. Altogether, six different exonic alterations, including two types of UTR variants in the SQSTM1 gene, were observed in our PDB patients. Similarly, to previous genetic studies on Paget’s disease, our most commonly detected variant was the c.1175C > T (p.Pro392Leu) in nine cases (four in monostotic and five in polyostotic form). We have surveyed the germline SQSTM1 variant distribution among Hungarian patients with PDB. We also highlighted that the pattern of the analyzed disease-associated pathophysiological parameters could partially discriminate PDB patients with normal or mutant SQSTM1 genotype. However, our findings also underline and strengthen that not solely SQSTM1 stands in the background of the complex PDB etiology

Pattern of SQSTM1 Gene Variants in a Hungarian Cohort of Paget’s Disease of Bone

Paget’s disease of bone (PDB) is characterized by focal or multifocal increase in bone turnover. One of the most well-established candidate genes for susceptibility to PDB is Sequestosome 1 (SQSTM1). Mutations in SQSTM1 have been documented among Western-European, British and American patients with PDB. However, there is no information on SQSTM1 mutation status in PDB patients from the Central- and Eastern-European regions. In this study, we conducted a mutation screening for SQSTM1 gene variants in 82 PDB patients and 100 control participants in Hungary. Mutations of SQSTM1 were detected in 18 PDB patients (21.95%); associations between genotype and clinical characteristics were also analyzed. Altogether, six different exonic alterations, including two types of UTR variants in the SQSTM1 gene, wereobserved in our PDB patients. Similarly, to previous genetic studies on Paget’s disease, our most commonly detected variant was the c.1175C > T (p.Pro392Leu) in nine cases (four in monostotic and five in polyostotic form). We have surveyedthe germline SQSTM1 variant distribution among Hungarian patients with PDB. We also highlighted that the pattern of the analyzed disease-associated pathophysiological parameters could partially discriminate PDB patients with normal or mutantSQSTM1 genotype. However, our findings also underline and strengthen that not solely SQSTM1 stands in the background of the complex PDB etiolog

CYP24A1 inhibition facilitates the anti-tumor effect of vitamin D3 on colorectal cancer cells

AIM: The effects of vitamin D3 have been investigated on various tumors, including colorectal cancer (CRC). 25-hydroxyvitamin-D3-24-hydroxylase (CYP24A1), the enzyme that inactivates the active vitamin D3 metabolite 1,25-dihydroxyvitamin D3 (1,25-D3), is considered to be the main enzyme determining the biological halflife of 1,25-D3. During colorectal carcinogenesis, the expression and concentration of CYP24A1 increases significantly, suggesting that this phenomenon could be responsible for the proposed efficacy of 1,25-D3 in the treatment of CRC. The aim of this study was to investigate the anti-tumor effects of vitamin D3 on the human CRC cell line Caco-2 after inhibition of the cytochrome P450 component of CYP24A1 activity. METHODS: We examined the expression of CYP24A1 mRNA and the effects of 1,25-D3 on the cell line Caco-2 after inhibition of CYP24A1. Cell viability and proliferation were determined by means of sulforhodamine-B staining and bromodeoxyuridine incorporation, respectively, while cytotoxicity was estimated via the lactate dehydrogenase content of the cell culture supernatant. CYP24A1 expression was measured by realtime reverse transcription polymerase chain reaction. A number of tetralone compounds were synthesized to investigate their CP24A1 inhibitory activity. RESULTS: In response to 1,25-D3, CYP24A1 mRNA expression was enhanced significantly, in a time- and dose-dependent manner. Caco-2 cell viability and proliferation were not influenced by the administration of 1,25-D3 alone, but were markedly reduced by coadministration of 1,25-D3 and KD-35, a CYP24A1-inhibiting tetralone. Our data suggest that the mechanism of action of co-administered KD-35 and 1,25-D3 does not involve a direct cytotoxic effect, but rather the inhibition of cell proliferation. CONCLUSION: These findings demonstrate that the selective inhibition of CYP24A1 by compounds such as KD-35 may be a new approach for enhancement of the anti-tumor effect of 1,25-D3 on CRC

A pajzsmirigygöbök genetikai vizsgálata újgenerációs szekvenáláson alapuló platformon kifejlesztett génpanel segítségével = Genetic testing of thyroid nodules using a gene panel developed on a new generation sequencing platform

Absztrakt: Bevezetés: Vékonytű-biopsziás pajzsmirigygöbminták 25%-ánál bizonytalan citológiai eredményt kapunk. A göbök genetikai vizsgálata hozzájárulhat a pontos diagnózishoz. Célkitűzés: Európában az első és a legtöbb, 23 releváns pajzsmirigyonkogént (568 mutációval) tartalmazó génpanel kialakítása. Módszer: A biopsziás mintákból izolált DNS vizsgálata Ion Torrent újgenerációs szekvenálással történt. Eredmények: Módszerünk validációját tumorszövetmintákon végeztük, ennek során 127, a pajzsmirigydaganatokban eddig nem ismert eltéréseket azonosítottunk. Az AXIN1 a legpolimorfabb génnek, míg a BRAF c.1799T>A (V600E) a leggyakrabban azonosított mutációnak bizonyult. A vékonytű-biopsziás mintáinkban 36-féle, klinikailag releváns variánst detektáltunk, melyek 75%-a az irodalomban még nincs leírva. A citológiailag malignus nyolc mintánk közül hatban, a bizonytalan citológiájú tizennégy mintánk közül nyolcban, míg a citológiailag benignus huszonnyolc mintánk közül húszban azonosítottunk patogén variánst valamely driver génben (BRAF c.1799T>A, NRAS c.181C>A). Következtetés: Olyan validált, megbízhatóan működő újgenerációs szekvenáláson alapú módszert fejlesztettünk ki, amely nagy pozitív prediktív értékkel (89%) és szenzitivitással (79%) képes a pajzsmirigy rosszindulatú elváltozásainak korai felismerésére. Orv Hetil. 2019; 160(36): 1417–1425. | Abstract: Introduction: Twenty-five percent of fine-needle aspiration biopsy samples of thyroid nodules produce indeterminate cytological results. Genetic testing of nodules can contribute to accurate diagnosis. Aim: Developing the first gene panel in Europe utilizing the 23 most relevant thyroid oncogenes with 568 mutations. Method: Examination of the isolated DNA from biopsy samples by Ion Torrent new generation sequencing. Results: The validation of our method was performed on tumor tissue samples, in which 127 genetic variations were identified, yet unknown in thyroid tumors. AXIN1 was the most polymorphic gene, while BRAF c.1799T>A (V600E) was the most frequently identified mutation. We detected 36 clinically relevant variants, 75% of which have not been described in the literature. Six of our 8 cytologically malignant and 8 of our 14 indeterminate as well as 20 of our 28 cytologically benign samples were identified as containing pathologic variants in a driver gene (BRAF c.1799T>A, NRAS c.181C>A). Conclusion: We have developed a validated, reliable new generation sequencing-based method with high positive predictive value (89%) and sensitivity (79%), suitable for the early detection of malignant lesions in the thyroid. Orv Hetil. 2019; 160(36): 1417–1425

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

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