IDH1 and IDH2 mutations are frequent events in central chondrosarcoma and central and periosteal chondromas but not in other mesenchymal tumours.

Somatic mutations in isocitrate dehydrogenase 1 (IDH1) and IDH2 occur in gliomas and acute myeloid leukaemia (AML). Since patients with multiple enchondromas have occasionally been reported to have these conditions, we hypothesized that the same mutations would occur in cartilaginous neoplasms. Approximately 1200 mesenchymal tumours, including 220 cartilaginous tumours, 222 osteosarcomas and another ∼750 bone and soft tissue tumours, were screened for IDH1 R132 mutations, using Sequenom(®) mass spectrometry. Cartilaginous tumours and chondroblastic osteosarcomas, wild-type for IDH1 R132, were analysed for IDH2 (R172, R140) mutations. Validation was performed by capillary sequencing and restriction enzyme digestion. Heterozygous somatic IDH1/IDH2 mutations, which result in the production of a potential oncometabolite, 2-hydroxyglutarate, were only detected in central and periosteal cartilaginous tumours, and were found in at least 56% of these, ∼40% of which were represented by R132C. IDH1 R132H mutations were confirmed by immunoreactivity for this mutant allele. The ratio of IDH1:IDH2 mutation was 10.6 : 1. No IDH2 R140 mutations were detected. Mutations were detected in enchondromas through to conventional central and dedifferentiated chondrosarcomas, in patients with both solitary and multiple neoplasms. No germline mutations were detected. No mutations were detected in peripheral chondrosarcomas and osteochondromas. In conclusion, IDH1 and IDH2 mutations represent the first common genetic abnormalities to be identified in conventional central and periosteal cartilaginous tumours. As in gliomas and AML, the mutations appear to occur early in tumourigenesis. We speculate that a mosaic pattern of IDH-mutation-bearing cells explains the reports of diverse tumours (gliomas, AML, multiple cartilaginous neoplasms, haemangiomas) occurring in the same patient.

The protective role of bone morphogenetic protein-8 in the glucocorticoid-induced apoptosis on bone cells.

One of the side effects associated with glucocorticoid therapy is glucocorticoid-induced bone loss. Glucocorticoids partly detain bone formation via the inhibition of osteoblastic function, however, the exact mechanism of this inhibition remains elusive. In this study, we examined the effect of dexamethasone, an active glucocorticoid analogue, on cell viability and expression of bone remodelling-related genes in primary mouse calvarial and cloned MC3T3-E1 osteoblasts. Using sensitive biochemical assays, we demonstrated the apoptotic effect of dexamethasone on osteoblastic cells. Then, utilizing Taqman probe-based quantitative RT-PCR technology, gene expression profiles of 111 bone metabolism-related genes were determined. As a result of dexamethasone treatment we have detected significant apoptotic cell death, and six genes, including Smad3, type-2 collagen α-1, type-9 collagen α-1, matrix metalloproteinase-2, bone morphogenetic protein-4 and bone morphogenetic protein-8 showed (BMP-8) significant changes in their expression on a time- and concentration-dependent manner. BMP-8, (a novel player in bone-metabolism) exhibited a two orders of magnitude elevation in its mRNA level and highly elevated protein concentration by Western blot in response to dexamethasone treatment. The knockdown of BMP-8 by RNA interference significantly increased dexamethasone-induced cell death, confirming a protective role for BMP-8 in the glucocorticoid-induced apoptosis of osteoblasts. Our results suggest that BMP-8 might be an essential player in bone metabolism, especially in response to glucocorticoids.

The role of epidermal growth factor receptor in chordoma pathogenesis: a potential therapeutic target.

Chordoma, the molecular hallmark of which is T (brachyury), is a rare malignant bone tumour with a high risk of local recurrence and a tumour from which metastatic disease is a common late event. Currently, there is no effective drug therapy for treating chordomas, although there is evidence that some patients respond to the empirical use of epidermal growth factor receptor (EGFR) antagonists. The aim of this study was to determine the role of EGFR in the pathogenesis of chordoma. Paraffin-embedded material from 173 chordomas from 160 patients [sacro-coccygeal (n = 94), skull-based (n = 50), and mobile spine (n = 16)] was analysed by immunohistochemistry and revealed total EGFR expression in 69% of cases analysed. Of 147 informative chordomas analysed by FISH, 38% revealed high-level EGFR polysomy, 4% high-level polysomy with focal amplification, 18% low-level polysomy, and 39% disomy. Phospho-receptor tyrosine kinase array membranes showed EGFR activation in the chordoma cell line U-CH1 and all of the three chordomas analysed. Direct sequencing of EGFR (exons 18-21), KRAS, NRAS, HRAS (exons 2, 3), and BRAF (exons 11, 15) using DNA from 62 chordomas failed to reveal mutations. PTEN expression was absent by immunohistochemistry in 19 of 147 (13%) analysed chordomas, only one of which revealed high-level polysomy of EGFR. The EGFR inhibitor tyrphostin (AG 1478) markedly inhibited proliferation of the chordoma cell line U-CH1 in vitro and diminished EGFR phosphorylation in a dose-dependant manner, a finding supported by inhibition of phosphorylated Erk1/2. p-Akt was suppressed to a much lesser degree in these experiments. There was no reduction of T as assessed by western blotting. These data implicate aberrant EGFR signalling in the pathogenesis of chordoma. This study provides a strategy for patient stratification for treatment with EGFR antagonists.

[Changes of gene expression and its role in pathogenesis in fibrous and non-fibrous dysplastic bone tissues in women]. / A génexpresszió változásai és patogenetikai jelentôségük fibrosus dysplasiás és nem fibrosus dysplasiás nôk csontszövetében.

UNLABELLED: Fibrous dysplasia is an isolated skeletal disorder caused by a somatic activating mutation of GNAS1 gene with abnormal unmineralized matrix overproduction and extensive undifferentiated bone cell accumulation in fibro-osseous lesions. The aim of the investigation was to identify genes that are differently expressed in fibrous vs. non-fibrous human bone and to describe the relationships between these genes using multivariate data analysis. MATERIALS AND METHODS: Six bone tissue samples from fibrous dysplastic female patients and 7 bone tissue samples from non-fibrous dysplastic women were examined. The 6 female fibrous samples were taken from the fibrous dysplastic lesion itself while the control samples of 7 non-fibrous dysplastic females were taken from the femoral neck during the hip replacement procedure. The expression differences of selected 118 genes were analyzed in TaqMan probe based quantitative real-time RT-PCR system. RESULTS: The Mann-Whitney U test indicated significant differences in the expression of 27 genes of fibrous dysplasial and non fibrous dysplasial individuals (p≤0.05). Nine genes were significantly up-regulated in fibrous dysplasial women compared to non fibrous dysplasial ones and eighteen genes showed a down-regulated pattern. These significantly altered genes coding for minor collagen molecules, extracellular matrix digesting enzymes, transcription factors, adhesion molecules, growth factors, pro-inflammatory cytokines and lipid metabolism-affected substrates. Canonical variety analysis demonstrated that fibrous dysplastic and non fibrous dysplastic bone tissues can be distinguished by the multiple expression profile analysis of numerous genes controlled via a G-protein coupled pathway and BMP cascade as well as genes coding for extracellular matrix composing molecules. CONCLUSIONS: The significantly altered gene expression profile observed in the fibrous dysplastic human bone tissue may provide further insight into the pathogenetic process of fibrous degeneration of bone.

Gene expression patterns in the bone tissue of women with fibrous dysplasia.

Fibrous dysplasia is an isolated skeletal disorder caused by a somatic activating mutation of GNAS gene with abnormal unmineralized matrix overproduction and extensive undifferentiated bone cell accumulation in the fibro-osseous lesions. The aim of our investigation was to identify genes that are differently expressed in fibrous versus non-fibrous human bone and to describe the relationships between these genes using multivariate data analysis. Six bone tissue samples from female patients with fibrous dysplastia (FD) and seven bone tissue samples from women without FD (non-FD) were examined. The expression differences of selected 118 genes were analyzed by the TaqMan probe-based quantitative real-time RT-PCR system. The Mann-Whitney U-test indicated marked differences in the expression of 22 genes between FD and non-FD individuals. Nine genes were upregulated in FD women compared to non-FD ones and 18 genes showed a downregulated pattern. These altered genes code for minor collagen molecules, extracellular matrix digesting enzymes, transcription factors, adhesion molecules, growth factors, pro-inflammatory cytokines, and lipid metabolism-affected substrates. Canonical variates analysis demonstrated that FD and non-FD bone tissues can be distinguished by the multiple expression profile analysis of numerous genes controlled via a G-protein coupled pathway and BMP cascade as well as genes coding for extracellular matrix composing molecules. The remarkable changed gene expression profile observed in the fibrous dysplastic human bone tissue may provide further insight into the pathogenetic process of fibrous degeneration of bone.

The candidate oncogene CYP24A1: A potential biomarker for colorectal tumorigenesis.

The main autocrine/paracrine role of the active metabolite of vitamin D(3), 1alpha,25-dihydroxyvitamin D(3) (1,25-D(3)), is inhibition of cell growth and induction of cell differentiation and/or apoptosis. Synthesis and degradation of the secosteroid occurs not only in the kidney but also in normal tissue or malignant extrarenal tissues such as the colon. Because 25-hydroxyvitamin D(3) 24-hydroxylase (CYP24A1) is considered to be the main enzyme determining the biological half-life of 1,25-D(3), we have examined expression of the CYP24A1 mRNA (by real-time RT-PCR) and protein (by immunohistochemistry) in normal human colon mucosa, colorectal adenomas, and adenocarcinomas in 111 patients. Although 76% of the normal and benign colonic tissue was either completely devoid of or expressed very low levels of CYP24A1, in the majority of the adenocarcinomas (69%), the enzyme was present at high concentrations. A parallel increased expression of the proliferation marker Ki-67 in the same samples suggests that overexpression of CYP24A1 reduced local 1,25-D(3) availability, decreasing its antiproliferative effect.

Allelic variations of RANKL/OPG signaling system are related to bone mineral density and in vivo gene expression.

OBJECTIVE: Receptor activator of nuclear factor-kappaB ligand/osteoprotegerin (RANKL/OPG) signaling system plays a crucial role in the regulation of bone resorption. Polymorphic variations in the genes may have an influence on gene expression and bone metabolism. In the present study, we aimed to investigate the influence of RANKL/OPG allelic variations on the in vivo human gene expression of five genes, bone mineral density (BMD), and fracture incidence in Hungarian postmenopausal women. METHODS: Three hundred and sixty postmenopausal women (61.6+/-7.9 years) were genotyped. All together, five single nucleotide polymorphisms (SNPs) in the two genes have been investigated. In addition, bone samples from 17 examined subjects were acquired for gene expression studies. Bone densities and fracture data have also been collected. RESULTS: All two SNPs in OPG gene and three SNPs in RANKL gene showed correlation with BMD. Haplotype analysis of these genes gave similar results. The 'CCT' haplotype of RANKL promoter region, which was associated with decreased BMD, exhibited a significantly upregulated expression of RANKL mRNA, while the other haplotypes of RANKL or OPG 15 genes did not. No correlation between genetic variations and fracture data was found. CONCLUSION: We have demonstrated associations between RANKL and OPG haplotypes and BMD as well as between RANKL haplotypes and in vivo RANKL expression in a Hungarian postmenopausal population. Moreover, we have found a new RANKL haplotype associating with reduced BMD and increased in vivo RANKL expression in human bone tissue.

Postmenopausal expression changes of immune system-related genes in human bone tissue.

INTRODUCTION: The molecular and cellular interactions between the immune system and bone tissue have been established. Sex hormone deficiency after menopause has multifunctional role by influencing growth, differentiation, and metabolism of the skeletal and the immune system. DISCUSSION: We have used nonparametric and multidimensional expression pattern analyses to determine significantly changed mRNA profile of immune system-associated genes in postmenopausal (POST) and premenopausal (PRE) nonosteoporotic bone. Ten bone tissue samples from POST patients and six bone tissue samples from PRE women were examined in our study. The transcription differences of the selected 50 genes were analyzed in TaqMan probe-based quantitative real-time reverse transcriptase polymerase chain reaction system. Mann-Whitney test indicated significantly downregulated transcription activity of three genes (CD14, HLA-A/MHCI, ITGAM/CD11b) and upregulated expression of six genes (C3, CD86/B7-2, IL-10, IL-6, TGFB3, TNFSF11/RANKL) in postmenopausal bone. According to the canonical variate analysis results, the groups of POST and PRE women are separable by genes coding for cytokines, costimulator molecules, and cell surface receptors involved in antigen presentation and T cell stimulation processes which have high discriminatory power. Based on a complex gene expression pattern analysis of human bone tissue, we could distinguish POST and PRE states from an immunological aspect. Our data might provide further insight into the changes of the intersystem crosstalk between immune and skeletal homeostasis, as well as local immune response in the altered microenvironment of postmenopausal bone.

Effect of menopause on gene expression pattern in bone tissue of nonosteoporotic women.

OBJECTIVE: Menopausal changes influence the growth, differentiation, and metabolism of bone tissue. Hormonal deficiency at the time of menopause results in marked increases in bone resorption and formation, leading to rapid bone loss. The aim of our investigation was to determine genes characterized by significantly changed mRNA expression rates in postmenopausal versus premenopausal nonosteoporotic bone tissue and to describe the interrelationships among these genes using multivariate data analysis. METHODS: Ten bone tissue samples from postmenopausal nonosteoporotic women and seven bone tissue samples from premenopausal nonosteoporotic women were examined. The expression differences of 118 selected genes were analyzed in a TaqMan probe-based quantitative reverse transcriptase-polymerase chain reaction system. RESULTS: The Mann-Whitney U test indicated significant differences in the expression of 29 genes of postmenopausal and premenopausal nonosteoporotic women. Twenty-eight genes, including extracellular matrix molecules and digesting enzymes, genes belonging to the transforming growth factor-beta/bone morphogenic protein pathway, transcription factors, growth factors, and other candidate genes, were significantly up-regulated in postmenopausal women compared with premenopausal women. Only one gene (ENO1) showed down-regulation after menopause. Based on the multiple mRNA expression profiles of 118 genes, postmenopausal and premenopausal states could be differentiated by enhanced postmenopausal gene expression levels using principal components analysis. Canonical variates analysis demonstrated that postmenopausal and premenopausal nonosteoporotic bone tissues can be distinguished by expression analysis of genes controlled via estrogen receptor-alpha and genes coding for extracellular matrix molecules. CONCLUSIONS: The menopausal state of bone tissue has been unambiguously defined by its complex gene transcription pattern. Significant differences observed in the gene expression profiles of estrogen-deficient human bone tissue provide further insight into the process of postmenopausal changes of bone metabolism.

Transcriptional profiling of immune system-related genes in postmenopausal osteoporotic versus non-osteoporotic human bone tissue.

The functional interaction between the immune system and bone metabolism has been established at both molecular and cellular levels. We have used non-parametric and multidimensional expression pattern analyses to determine significantly changed mRNA profile of immune system-associated genes in postmenopausal osteoporotic (OP) vs. non-osteoporotic (NOP) bone tissue. Seven bone tissue samples from OP patients and ten bone tissue samples from NOP women were examined in our study. The transcription differences of selected 44 genes were analyzed in Taqman probe-based quantitative real-time RT-PCR system. Mann-Whitney test indicated significantly down-regulated transcription activity of 3 genes (FCGR2A, NFKB1 and SCARA3) in OP bone tissue which have prominent role in (antibody) clearance, phagocytosis, pathogen recognition and inflammatory response. According to the canonical variates analysis results, the groups of postmenopausal OP and NOP women are separable by genes coding for cytokines, co-stimulators and cell surface receptors affected in innate immunity which have high discriminatory power. Based on the complex gene expression patterns in human bone cells, we could distinguish OP and NOP states from an immunological aspect. Our data may provide further insights into the changes of the intersystem crosstalk between the immune and skeletal systems, as well as into the local immune response in the altered microenvironment of OP bone.

Effects of the lactase 13910 C/T and calcium-sensor receptor A986S G/T gene polymorphisms on the incidence and recurrence of colorectal cancer in Hungarian population.

BACKGROUND: Epidemiological studies suggested the chemopreventive role of higher calcium intake in colorectal carcinogenesis. We examined genetic polymorphisms that might influence calcium metabolism: lactase (LCT) gene 13910 C/T polymorphism causing lactose intolerance and calcium-sensing receptor (CaSR) gene A986S polymorphism as a responsible factor for the altered cellular calcium sensation. METHODS: 538 Hungarian subjects were studied: 278 patients with colorectal cancer and 260 healthy controls. Median follow-up was 17 months. After genotyping, the relationship between LCT 13910 C/T and CaSR A986S polymorphisms as well as tumor incidence/progression was investigated. RESULTS: in patient with colorectal cancer, a significantly higher LCT CC frequency was associated with increased distant disease recurrence (OR = 4.04; 95% CI = 1.71-9.58; p = 0.006). The disease free survival calculated from distant recurrence was reduced for those with LCT CC genotype (log rank test p = 0.008). In case of CaSR A986S polymorphism, the homozygous SS genotype was more frequent in patients than in controls (OR = 4.01; 95% CI = 1.33-12.07; p = 0.014). The number of LCT C and CaSR S risk alleles were correlated with tumor incidence (p = 0.035). The CCSS genotype combination was found only in patients with CRC (p = 0.033). CONCLUSION: LCT 13910 C/T and CaSR A986S polymorphisms may have an impact on the progression and/or incidence of CRC.

Single nucleotide polymorphisms in new candidate genes are associated with bone mineral density and fracture risk.

OBJECTIVE: Osteoporosis (OP) is a multifactorial disease with high heritability but its exact genetic background is still poorly understood. We examined the effect of 24 single nucleotide polymorphisms (SNPs) located in five genes--alkaline phosphatase, matrix metalloproteinase-2, tissue inhibitor of metalloproteases-2 (TIMP2), fibroblast growth factor receptor-1 (FGFR1), and fatty acid-binding protein-3 (FABP3)--previously not associated with OP. DESIGN: We performed a genotype-phenotype association study at a university hospital. METHODS: A total of 360 Hungarian postmenopausal women were involved in the study. Bone mineral density (BMD) was determined at spine, hip, and distal radius. Genomic DNA was extracted from venous blood samples and a high-throughput genotyping method based on single-based primer extension was applied for allelic discrimination. Robust statistical tools were utilized for multiplex data analysis. RESULTS: SNP rs6996321 in FGFR1 was significantly related to spine BMD (P=0.002) and rs10914367 in FABP3 was associated with hip BMD (P=0.028). Non-vertebral fracture risk was significantly increased in carriers of 'A' allele of rs9900972 in TIMP2 (odds ratio=2.06, P=0.0187). We could also identify validated gene-gene interactions significantly affecting BMD and fracture risk. CONCLUSIONS: We identified two previously unreported SNPs in FGFR1 and FABP3 associated with BMD and a third SNP in TIMP2 related to risk for non-vertebral osteoporotic fractures. This is the first report about the association between these allelic variants and the phenotypes of postmenopausal OP. Further studies need to clarify the role of these genes and their polymorphisms in the process of bone loss.

Effect of vertebroplasty filler materials on viability and gene expression of human nucleus pulposus cells.

Consequences of intradiscal cement leakage--often occurring after vertebral cement augmentation for the treatment of vertebral compression fractures--are still unknown. In this study, we have investigated the influences of vertebroplasty filler materials (polymethylmethacrylate-, calcium phosphate- and calcium sulfate-based bone cement) on isolated nucleus pulposus cells. Cell viability of cultured human nucleus pulposus cells were measured after treatment with vertebroplasty filler materials. Gene expression profile of selected genes was determined with quantitative real-time PCR. The widely used polymethylmethacrylate and calcium phosphate cement significantly decreased cell number in a dose- and time-dependent manner while calcium sulfate cement affected cell viability less. Expression of genes involved in matrix metabolism of nucleus pulposus--aggrecan, collagens, small proteoglycans--as well as important transcription factors have also significantly changed due to treatment (e.g., 2.5-fold decrease in aggrecan expression was determined in cultures due to polymethylmethacrylate treatment). Our results suggest that vertebroplasty filler materials--depending on the type of applied material--can accelerate the degeneration of nucleus pulposus cells resulting in a less flexible disc in case of intradiscal cement leakage. This process may increase the risk of a subsequent new vertebral fracture, the main complication of vertebral augmentation.

Different gene expression patterns in the bone tissue of aging postmenopausal osteoporotic and non-osteoporotic women.

PURPOSE: To identify genes that are differently expressed in osteoporotic and non-osteoporotic human bone and to describe the relationships between these genes using multivariate data analysis. METHODS: Seven bone tissue samples from postmenopausal osteoporotic patients and 10 bone tissue samples from postmenopausal non-osteoporotic women were examined in our study. Messenger RNA was prepared from each sample and reverse transcribed to cDNA. The expression differences of 87 selected genes were analyzed in a Taqman probe-based quantitative real-time RT-PCR system. RESULTS: A Mann-Whitney U-test indicated significant differences in the expression of nine genes (p < or = 0.05). Seven of these nine genes-ALPL, COL1A1, MMP2, MMP13, MMP9, PDGFA, NFKB1-were significantly downregulated in the bone tissue of osteoporotic women, while CD36 and TWIST2 were significantly upregulated in osteoporotic patients. Principal components analysis was used to evaluate data structure and the relationship between osteoporotic and non-osteoporotic phenotypes based on the multiple mRNA expression profiles of 78 genes. Canonical variates analysis demonstrated further that osteoporotic and non-osteoporotic tissues can be distinguished by expression analysis of genes coding growth factors/non-collagen matrix molecules, and genes belonging to the canonical TGFB pathway. CONCLUSION: Significant differences observed in gene expression profiles of osteoporotic and non-osteoporotic human bone tissues provide further insight into the pathogenesis of this disease. Characterization of the differences between osteoporotic and non-osteoporotic bones by expression profiling will contribute to the development of diagnostic tools in the future.

[Review of the application of synthetic bone grafts. The role of the gypsum in bone substitution: molecular biological approach, based on own research results]. / A szintetikus csontpótló graftok alkalmazásának összefoglalása. A gipsz szerepe a csontpótlásban: molekuláris biológiai megközelítéssel, saját eredményeink alapján.

Properties of bone graft can determine the effectiveness, short and long term success of bone substitution procedure. In this paper, a brief report about advantages and disadvantages of modern bone substitution processes is presented and authors have explicated the opportunity of the usage of gypsum as bone graft. Recently, calcium sulfate dihydrate has been demonstrated as safe biodegradable osteoconductive bone void filler. However, its exact mechanism of action on bone cells and the molecular process of bone substitution is yet unknown. Authors have investigated the effect of gypsum on bone cells using molecular biology methods. Gypsum proved to be an ideal culture surface for proliferation of mice preosteoblastic cells, while polymethilmetacrylate bone cement - generally used in clinical practice as bone substitution material - inhibited cell growth. Gene expression profile of cells has significantly changed on gypsum surface - genes involved in new bone formation have expressed with an increased ratio - and an increased alkaline phosphatase activity has been measured from these cultures. Our results support the use of gypsum as synthetic bone graft and new properties of calcium sulfate dihydrate have been demonstrated due to molecular biological approach.

[Impact of CYP3A7*1C polymorphism on bone mineral content in postmenopausal women]. / A CYP3A7*1C-polimorfizmus hatása a csont ásványanyag-tartalmára posztmenopauzás nokben.

INTRODUCTION: CYP3A7*1C polymorphism has been shown to be associated with lower levels of serum dehydroepiandrosterone sulphate in men. The age-related decline of dehydroepiandrosterone sulphate levels is believed to contribute to the development of osteoporosis. We hypothesized that CYP3A7*1C may lead to bone loss through decreased levels of dehydroepiandrosterone sulphate in postmenopausal women. PATIENTS AND METHODS: 319 postmenopausal women were studied and divided into two subgroups: 217 women with osteoporosis and 102 aged-matched women without osteoporosis. The CYP3A7*1C polymorphism was genotyped. Serum dehydroepiandrosterone sulphate levels and bone mineral density were measured. RESULTS: Homozygous CYP3A7*1C carriers had significantly lower bone mineral density at lumbar spine than that of wild type (T-score with CYP3A7*1C mutant type: -3.27 +/- 1.02, T-score with wild type: -1.35 +/- 1.53, p = 0.041) after adjusting for age and DHEAS levels. No association was found between genotypes and dehydroepiandrosterone sulphate levels. CONCLUSION: Our data suggest that CYP3A7 polymorphism might have an influence on bone mass at the lumbar spine independently of serum dehydroepiandrosterone sulphate concentrations.

[Significance of dehydroepiandrosterone and dehydroepiandrosterone sulfate in different diseases]. / A dehidroepiandroszteron és dehidroepiandroszteron-szulfát jelentôsége különbözo kórállapotokban.

Dehydroepiandrosterone and dehydroepiandrosterone-sulfate are precursors of androgens and estrogens, support the gonadal sexual steroid production. The levels of dehydroepiandrosterone and dehydroepiandrosterone-sulfate are maximal between the ages of 20 and 30 years, then start a decline of 2% per year, leaving a residual of 10-20% of the peak production by the eight decade of life. The age-associated decrease may lead to osteoporosis, deterioration of lipid-metabolism, cardiovascular diseases and second type of diabetes mellitus. Decreased levels were found in autoimmune diseases and in sexual dysfunction, too. Intracrinology describes the formation of active hormones which exert their action in the same cells where synthesis took place without release into the pericellular compartment. The high local androgen and estrogen concentration may be important in the pathomechanism of hirsutism, acne, seborrhea, breast and prostate cancer. Administration of dehydroepiandrosterone resulted in a reduction of postmenopausal osteoporosis, also the decreased symptoms in systemic lupus erythematosis, psychiatric diseases and sexual disfunction. The authors summarize the metabolism of dehydroepiandrosterone and dehydroepiandrosterone-sulfate and their role in different diseases.

Effect of gypsum on proliferation and differentiation of MC3T3-E1 mouse osteoblastic cells.

Recently, calcium sulfate dihydrate has been demonstrated as safe biodegradable osteoconductive bone void filler. However, its exact mechanism of action on bone cells is yet unknown. In this study, the influence of gypsum on gene expression and proliferation of MC3T3-E1 mouse pre-osteoblastic cells was investigated. Cells were cultured on gypsum disc, slice, polymethylmethacrylate (PMMA), or plastic culture plate for 15 days. Cell viability, alkaline phosphatase (ALP) activity and expression profile of 15 genes involved in bone metabolism were measured in cultures. Cell proliferation on gypsum was increased by almost 2-fold, while an inhibitory effect of PMMA on proliferation rate of osteoblasts was noted. Cells cultured on gypsum disc surface exhibited an increased ALP activity and markedly different gene expression profile. Quantitative real-time PCR data indicated the expression of genes that might provide a basis for an osteoinductive potential. MC3T3-E1 cells expressed genes typical of bone fracture healing like type II collagen and fibronectin 1. These effects might be related to the calcium content of gypsum and mediated likely via SMAD3. Our results suggest that gypsum can support new bone formation by its calcium content and modulatory effect on gene expression profile of bone cells.