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Christian Schneeberger

Publications and source records attributed to Christian Schneeberger.

At least 19 recordsLinked to original sources
PubMed2007

An estrogen metabolism-related polymorphism of the 17-alpha HSD gene is associated with perimenopausal body mass index.

In a cross-sectional study of 2,802 perimenopausal caucasian women, carriage of at least one mutated allele of the 17-alpha-hydroxysteroid dehydrogenase type 1 (17-alpha HSD) vlV A-->C single nucleotide polymorphism (SNP) was associated with a significantly increased body mass index (mean 24.3 +/- 4.4 kg/m(2) vs. 23.5 +/- 4.2 kg/m(2); P<.001), and obesity was more frequent among mutant allele carriers (P=.06; odds ratio 1.38; 95% confidence interval 0.97-1.95), providing evidence of 17-alpha HSD as a candidate gene of perimenopausal obesity.

Body Mass Index↗
PubMed2006

How valid is single nucleotide polymorphism (SNP) diagnosis for the individual risk assessment of breast cancer?

The number of reports investigating disease susceptibility based on the carriage of low-penetrance, high-frequency single nucleotide polymorphisms (SNPs) has increased in recent years. Evidence is accumulating defining specific individual variations in breast cancer susceptibility. Genetic variations of estradiol and xenobiotics metabolisms as well as genes involved in cell-cycle control have been described as significant contributors to breast cancer susceptibility, with variations depending on ethnic background and co-factors such as smoking and family history of breast cancer. In sum, the highest level of evidence to date linking SNPs and breast cancer comes from nested case-control studies within the prospective Nurses' Health Study. These data establish seven SNPs - hPRB +331G/A, AR CAG repeat, CYP19 (TTTA)10, CYP1A1 MspI, VDR FOK1, XRCC1 Arg194Trp and XRCC2 Arg188His - as small but significant risk factors for spontaneous, non-hereditary breast cancer. In addition, meta-analysis of data in the literature establishes the TGFBR1*6A, HRAS1, GSTP Ile105Val and GSTM1 SNPs as low-penetrance genetic risk factors of sporadic breast cancer. The clinical consequences of such a risk elevation may be detailed instruction of the patient as to general measures of breast cancer prevention such as a low-fat diet, optimization of body mass index, physical exercise, avoidance of alcohol and long-term hormone replacement therapy, and participation in a breast cancer screening program between the ages of 50 and 70 years. Specific surgical or drug interventions such as prophylactic mastectomy and oophorectomy or prophylactic intake of tamoxifen are not indicated based on SNP analysis at this time.

Breast Neoplasms↗
PubMed2005

A common polymorphism within the steroid 5-alpha-reductase type 2 gene and timing of menopause in Caucasian women.

OBJECTIVE: Androgens are thought to play an important role in various reproductive functions. We evaluated the association between a common polymorphism of the steroid 5-alpha-reductase type 2 gene (SRD5A2) involved in androgen metabolism and the timing of menopause. STUDY DESIGN: Three hundred and twenty-three consecutive women were included in this cross-sectional study. The common exon 1 Valine/Leucin polymorphism of the SRD5A2 gene was analyzed using a microarray-based system. RESULTS: No significant association between the SRD5A2 polymorphism and age (years) at natural menopause was ascertained. There were no significant differences in the background characteristics of the subjects among SDR5A2 genotypes including the number of full term pregnancies, age at first delivery, BMI, personal or family history of breast cancer, smoking status and personal history of recurrent abortion. A multivariate regression analysis showed that the number of full term pregnancies, but not smoking, an increased body mass index, or a history of breast cancer significantly influenced timing of natural menopause. CONCLUSION: In the present study the number of full term pregnancies, but not the common V89L SRD5A2 polymorphism, is the only significant predictor for the timing of natural menopause in Caucasian women.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2005

Ten polymorphisms of estrogen-metabolizing genes and a family history of colon cancer--an association study of multiple gene-gene interactions.

Estrogen replacement therapy is associated with a reduced risk of colon cancer. Therefore, we evaluated the following ten estrogen metabolism-associated single-nucleotide polymorphisms (SNPs) by sequencing-on-chip technology using solid-phase polymerase chain reaction (PCR) on oligonucleotide microarrays: catechol-O-methyltransferase (COMT) Val158Met G-->A, 17-beta-hydroxysteroid dehydrogenase type 1 (HSD17) vlV A-->C, cytochrome P-450 (CYP) 17 A2 allele T-->C, CYP1A1 MspI RFLP T-->C, CYP1A1 Ile462Val A-->G, CYP19 Arg264Cys C-->T, CYP19 C1558T C-->T, CYP 1B1 Leu432Val, CYP1B1 Asn453Ser, and estrogen receptor (ER) alpha IVS1 -401-->C in 76 patients with a family history of colon cancer and 722 healthy controls. Using stepwise logistic regression models, we found that none of the investigated SNPs is associated with a family history of colon cancer in a univariate and multivariate logistic regression model. In addition, when all two-way interactions of the investigated SNPs were ascertained, no significant interactions between SNPs were observed. In conclusion, we found no association between the carriage of one or multiple SNPs of the estrogen metabolism and a family history of colon cancer.

Adult↗
PubMed2005

Ten estrogen-related polymorphisms and endometriosis: a study of multiple gene-gene interactions.

OBJECTIVE: Genetic as well as hormonal factors are known to influence the development and clinical course of endometriosis. We aimed to investigate the association among 10 single nucleotide polymorphisms (SNPs) involved in the estrogen metabolism and endometriosis and to develop a multiple genetic model. METHODS: In a case-control study, we investigated the genotype frequencies of 10 estrogen metabolizing SNPs in 32 patients with endometriosis and 790 healthy controls using sequencing-on-chip-technology with solid-phase polymerase chain reaction on oligonucleotide microarrays: catechol-O-methyltransferase, Val158Met G->A, 17-beta-hydroxysteroid dehydrogenase type 1 (HSD17), vlV A->C, cytochrome P450 (CYP), 17 A2 allele T->C, CYP1A1 MspI RFLP T->C, CYP1A1 Ile462Val A->G, CYP19 Arg264Cys C->T, CYP19 C1558T C->T, CYP 1B1 Leu432Val, CYP1B1 Asn453Ser, and estrogen receptor alpha IVS1 -401>C. Associations and 2-way interaction models between SNPs were calculated by stepwise logistic regression models. RESULTS: In a univariate model, HSD17 vlV A->C was associated with a significantly increased risk of endometriosis (P = .004; odds ratio 3.9, 95% confidence interval 1.6-9.8). When all 2-way interactions of investigated SNPs were ascertained, no significant interactions among SNPs were observed. In a multivariate model, HSD17 vlV A->C was also significantly associated with endometriosis (P = .002). CONCLUSION: We present data on multiple SNPs in patients with endometriosis indicating an association between HSD17 gene variation and the disease. Although not able to demonstrate interaction models of SNPs, we provide evidence of HSD17 vlV A->C as a low penetrance genetic marker of endometriosis. LEVEL OF EVIDENCE: II-2.

Adult↗
PubMed2004

The influence of Nos3 polymorphisms on age at menarche and natural menopause.

OBJECTIVE: Deficiency of the gene encoding endothelial nitric oxide synthase, i.e. Nos3, has been reported to be associated with late menarche, reduced ovulation rates, fewer deliveries, and earlier onset of menopause in a mouse model. METHODS: We assessed the Glu298Asp and the T-786C polymorphisms of Nos3 in 87 consecutive healthy postmenopausal women by pyro- and capillary-sequencing, respectively. Results were correlated with age at menarche and natural menopause, number of miscarriages and live births, as well as body mass index (BMI) and smoking habits. RESULTS: Allelic frequencies of the Glu298Asp polymorphism of Nos3 were 121 (69.5%) and 53 (30.5%) for the wild-type G allele and the mutant T allele, respectively. Forty-one women (47.1%) were homozygote wild-type (G/G), 39 (44.9%) were heterozygote (G/T), and 7 (8.0%) were homozygote mutant (T/T). Allelic frequencies of the T-786C polymorphism of Nos3 were 105 (60.6%) and 69 (39.4%) for the wild-type T allele and the mutant C allele, respectively. Thirty-three women (38.0%) were homozygote wild-type (T/T), 39 (45.1%) were heterozygote (T/C), and 15 (16.9%) were homozygote mutant (C/C). Presence of at least one mutant allele of the Glu298Asp or the T-786C polymorphisms of Nos3 were not associated with age at menarche, natural menopause, and number of miscarriages and deliveries. BMI above 27 kg/m2 and smoking were associated with earlier onset of natural menopause (47.8 years versus 50.2 years (P = 0.01) and 46.8 years versus 49.8 years (p = 0.02)). CONCLUSIONS: Our data show that smoking and increased BMI, but not Glu298Asp or the T-786C polymorphisms of Nos3, are associated with an early onset of natural menopause.

Age Factors↗
PubMed2004

Estrogen-metabolizing gene polymorphisms in the assessment of breast carcinoma risk and fibroadenoma risk in Caucasian women.

BACKGROUND: Genes encoding enzymes involved in estrogen metabolism are held to be candidate genes for associations with breast disease. In these candidate genes, no critical combination of single-nucleotide polymorphisms (SNPs) for assessing breast carcinoma risk has been reported to date. METHODS: In a large case-control study, the authors investigated 10 estrogen-metabolizing SNPs in 396 patients with breast carcinoma, 154 patients with fibroadenoma, and 1936 healthy control patients without breast carcinoma in their personal history. The following 10 SNPs were analyzed using sequencing-on-chip technology via a solid-phase polymerase chain reaction assay performed on oligonucleotide microarrays: catechol-O-methyltransferase Val158Met G-->A, 17-beta-hydroxysteroid dehydrogenase type 1 vIV A-->C, cytochrome P-450 (CYP) family 17 A2 allele T-->C, CYP1A1-1 MspI restriction fragment length polymorphism (RFLP) T-->C, CYP1A1-2 Ile462Val A-->G, CYP19-1 Trp39Arg T-->C, CYP19-2 Arg264Cys C-->T, CYP19-3 Cys1558Thr C-->T, steroid-5-alpha reductase type 2 Val89Leu G-->C, and vitamin D receptor BsmI RFLP. A total of 21,350 genotypes were evaluated. Associations and two-way interaction models were calculated using stepwise logistic regression. RESULTS: In a multiple model, CYP1A1-1 (P = 0.004) and CYP1A1-2 (P = 0.03) were found to be associated with significantly decreased and increased risks of breast carcinoma, respectively. When two-way interactions involving investigated SNPs were ascertained, no significant interactions among polymorphisms were noted. Comparison of patients with fibroadenoma with control patients revealed significantly increased and decreased risks of fibroadenoma when the mutant alleles of CYP17 (P = 0.02) and CYP1A1-1 (P = 0.04), respectively, were present. CONCLUSIONS: The authors obtained the first SNP data indicating that CYP17 and CYP1A1-1 play a role in the pathogenesis of fibroadenoma. Although the authors were not able to develop interaction models involving SNPs, they did provide evidence that CYP1A1 is a low-penetrance susceptibility gene with respect to breast carcinoma in a large series of Caucasian women.

Breast Neoplasms↗
PubMed2004

Quantitative determination of carbon monoxide in cell culture supernatants by spectrophotometric analysis.

A simple, sensitive, nonradioactive method for measuring carbon monoxide (CO) in cell culture supernatant is described. Dissolved CO reacts with hemoglobin (Hb) to carboxyhemoglobin (HbCO) in a modified Conway cell. HbCO is quantified by spectrophotometric analysis, and total concentration of CO given in microg CO/l cell culture supernatant is mathematically calculated. Furthermore, we compared our newly developed method with a recently published method. Confluent human umbilical vein epithelial cells (HUVEC) were incubated with 10(-6) M hydrocortisone known to induce heme oxygenase-2 protein and transcript expression for 4 h and CO production was measured. Levels following hydrocortisone treatment were significantly enhanced compared to controls when using our newly developed technique (p<0.05), whereas only a nonsignificant trend could be observed using the recently published method. We conclude that this nonradioactive technique to quantify CO is more sensitive than previous ones, thereby allowing to measure even physiologic quantities of CO in aqueous solutions.

Carbon Monoxide↗
PubMed2004

GENOSENSE Diagnostics GmbH.

GENOSENSE Diagnostics GmbH, a company specialized in preventive genetic diagnostics, has committed itself to applying molecular medical knowledge to realizing the vision of individual, preventive and patient-tailored medicine. GENOSENSE offers a unique line of preventive genomic diagnostic profiles. Each profile focuses on a carefully selected set of polymorphisms associated with particular diseases or physiologic imbalances. GENOSENSE does not only provide the genetic test results, but highly capable medical experts 'translate' the results into a clinical language and assist the customer with established support regarding their medical interpretation. In addition, the company provides academic institutions and pharmaceutical companies with turnkey solutions for research-based projects.

Drug Industry↗
PubMed2004

Applications of polymorphisms and pharmacogenomics in obstetrics and gynecology.

The number of reports investigating disease susceptibility based on the carriage of low-penetrance, high-frequency polymorphisms has steadily increased over the last years. Evidence based on meta-analyses of individual case-control studies is accumulating, defining specific individual variations in disease susceptibility. For example, genetic variations of the estradiol metabolism have been described as significant contributors to disease susceptibility with variations depending on ethnic background. In the field of obstetrics and gynecology, the genetic contribution of polymorphic markers to a series of disorders has been characterized. These disorders include recurrent pregnancy loss, pre-eclampsia, endometriosis, breast cancer, and hormone replacement therapy (HRT)-related complications such as thrombosis. Among other genetic markers, thrombophilic genetic variants, such as the Factor V Leiden and prothrombin G20210A polymorphisms, as well as genetic variants of cytochrome P450 (CYP) enzymes, for example, CYP19 and CYP1B1, have been established as genetic risk markers and disease modifiers of recurrent and sporadic pregnancy loss and HRT-independent and -dependent breast cancer, respectively. In addition, meta-analyses of data in the literature established the TGFBR1*6A, GSTP I105V, and TP53 R72P polymorphisms, as well as the GSTM1 gene deletion as low-penetrance genetic risk factors of sporadic breast cancer. With respect to genetic modulation of therapeutic effects, beneficial effects of estrogen replacement therapy and HRT are modulated by the carriage of single nucleotide polymorphisms, for example, osteoprotection and blood lipid changes by the estrogen receptor-alpha (ER-a) PvuII polymorphism. Polymorphisms of the catechol-O-methyltransferase (COMT), ER-alpha, IL-1 receptor antagonist, and Factor V genes have been demonstrated to modulate the timing of natural menopause. Lastly, a strong genetic contribution of polymorphisms to the development and the clinical course of endometriosis has been established with data pointing to polymorphisms of the COMT, GST, NAT-2, and ER-alpha genes as susceptibility markers. In summary, the available evidence points to a number of polymorphisms of a wide variety of genes as strong hereditary determinants of the susceptibility to benign and malignant gynecologic and obstetric conditions.

Female↗
PubMed2003

Polymorphism of the interleukin-1beta gene and endometriosis.

OBJECTIVE: Experimental data indicate that interleukin (IL)-1 plays a role in the pathogenesis of endometriosis. We determined the genotype and the allele frequencies of the IL1B exon 5 polymorphism and the corresponding IL-1beta serum levels in women with endometriosis. METHODS: We genotyped 92 women with surgically and histologically confirmed endometriosis and 69 controls without history of endometriosis. Both groups were of middle European genetic background for the IL1B exon 5 polymorphism (at position +3954). Genotyping was performed by pyrosequencing. IL-1beta serum levels were analyzed by a commercially available enzyme-linked immunosorbent assay. RESULTS: Allele frequencies in women with endometriosis and controls were 76.6% and 76.8%, respectively, for the E1 allele (wild type) and 23.4% and 23.2%, respectively, for the E2 allele (polymorphic) (odds ratio 1.01; P > .99). The investigated polymorphism of the IL-1beta gene was not correlated with IL-1beta serum levels. CONCLUSIONS: We did not find an association between the IL1B exon 5 polymorphism, endometriosis, or increased serum IL-1beta levels.

Alleles↗
PubMed2003

Comparison of p53 mutational status with mRNA and protein expression in a panel of 24 human breast carcinoma cell lines.

We analyzed the p53 mutational status, mRNA and protein expression in 24 human breast carcinoma cell lines. Following measurement of their DNA content with flow cytometry, we ascertained the copy numbers of the centromere of chromosome 17 (cen17) and p53 with fluorescence in situ hybridization (FISH). A functional yeast assay (FASAY) was used to screen for inactivating mutations. Positive results were subsequently verified by DNA sequencing. Finally, we assessed the mRNA expression with a competitive reverse transcription-polymerase chain reaction (RT-PCR) assay and the protein expression with immunocytochemical staining, western blot, and quantitative flow cytometry. The DNA content of the cell lines ranged from 0.85 to 2.58. Nine cell lines had concordant copy numbers (between two and four) of p53 and cen17, whereas 12 had more, and three less cen17 than p53 copies. The FASAY was successful in all but one cell line and revealed the presence of mutated alleles in 16 of them, 13 cell lines expressed only the mutated, and three both the mutated and the wild-type alleles. The mutations were comprised of 11 missense, two nonsense, and three frameshift mutations. Immunocytochemical staining, western blot and quantitative flow cytometry yielded comparable p53 protein expression results. However, both the mRNA and the protein expression levels varied considerably in the different cell lines and no consistent pattern with regard to the respective p53 mutational status became evident. The results obtained in these breast carcinoma cell lines indicate that no clear-cut linear relationship exists between the p53 mutational status and the extent of its respective mRNA and protein expression. Therefore, direct DNA analyses and functional assays remain the only methods for the reliable detection of p53 mutations.

Breast Neoplasms↗
PubMed2003

Analysis of an interleukin-6 gene promoter polymorphism in women with endometriosis by pyrosequencing.

Interleukin (IL)-6 has been implicated in the etiology of endometriosis. A single nucleotide polymorphism (SNP) at position -174 in the IL-6 gene promoter appears to influence IL-6 transcription rates in vitro and basal IL-6 levels in vivo. We determined the genotype and the allele frequencies of the -174 IL-6 promoter polymorphism and the corresponding IL-6 serum levels in women with endometriosis. The pyrosequencing technique was used to assess the IL-6 genotypes in 94 women with histologically confirmed endometriosis (study group). A series of 70 healthy women without history of uterine disease served as clinical controls (control group).Allele frequencies for the G allele among women with and without endometriosis were 59.6% and 55.0%, respectively (P =.430; odds ratio [OR] 0.83, 95% confidence interval [CI] 0.53, 1.29). Homozygotes for the protective allele C were present in 17.0% of women with endometriosis and in 18.6% of controls were homozygous for the protective allele C (P =.797; OR 0.90, 95% CI 0.40, 2.02). When patients with various disease manifestations were compared, we found an association between the -174 G allele and chocolate cysts (P =.037). Serum levels of IL-6 were significantly higher in women with endometriosis than in controls (P <.001), with highest levels in women with chocolate cysts. There was no association between serum IL-6 levels and IL-6 genotype. The IL-6 promoter polymorphism -174 G/C does not contribute significantly to overall disease susceptibility but does predispose the carrier to distinct endometriosis with chocolate cysts. A genetically determined high IL-6 response might play a pathogenic role in this disease condition.

Alleles↗
PubMed2002

Accessing single nucleotide polymorphisms in genomic DNA by direct multiplex polymerase chain reaction amplification on oligonucleotide microarrays.

This study introduces a DNA microarray-based genotyping system for accessing single nucleotide polymorphisms (SNPs) directly from a genomic DNA sample. The described one-step approach combines multiplex amplification and allele-specific solid-phase PCR into an on-chip reaction platform. The multiplex amplification of genomic DNA and the genotyping reaction are both performed directly on the microarray in a single reaction. Oligonucleotides that interrogate single nucleotide positions within multiple genomic regions of interest are covalently tethered to a glass chip, allowing quick analysis of reaction products by fluorescence scanning. Due to a fourfold SNP detection approach employing simultaneous probing of sense and antisense strand information, genotypes can be automatically assigned and validated using a simple computer algorithm. We used the described procedure for parallel genotyping of 10 different polymorphisms in a single reaction and successfully analyzed more than 100 human DNA samples. More than 99% of genotype data were in agreement with data obtained in control experiments with allele-specific oligonucleotide hybridization and capillary sequencing. Our results suggest that this approach might constitute a powerful tool for the analysis of genetic variation.

Algorithms↗
PubMed2002

Serum vascular endothelial growth factor and serum leptin in patients with cervical cancer.

OBJECTIVE: Serum levels of vascular endothelial growth factor (VEGF) can be seen as surrogate markers of angiogenesis. Recently, leptin, which is involved in the control of satiety and energy expenditure, was also shown to modulate angiogenesis. As angiogenesis plays an abundant role in cervical carcinogenesis, we evaluated serum VEGF and leptin in patients with cervical intraepithelial neoplasia (CIN) and cervical cancer. METHODS: Serum VEGF and leptin were measured in 84 patients with cervical cancer, in 28 patients with CIN I-III, and in 35 healthy women, using a commercially available enzyme-linked immunosorbent assay and radioimmunoassay, respectively. RESULTS: Serum VEGF was significantly elevated in patients with cervical cancer and in patients with CIN I-III compared to healthy women. In patients with cervical cancer serum VEGF was significantly correlated with tumor stage, but not with lymph node involvement and histological grade. Univariate and multivariate analyses showed that elevated pretreatment serum VEGF was not associated with the duration of disease-free and overall survival. Serum leptin did not differ among patients with cervical cancer, patients with CIN I-III, and healthy women. Serum leptin was significantly correlated with body mass index (BMI). All further analyses were performed with absolute and serum leptin corrected by BMI. No differences in serum leptin could be ascertained between patients with cervical cancer and patients with CIN I-III. Serum leptin was not associated with any clinicopathological parameter and patients' survival. No correlation between serum VEGF and leptin was found. CONCLUSIONS: It can be speculated that serum VEGF might be used as a surrogate marker of angiogenesis in patients with cervical cancer. Our data support the concept that VEGF plays a role in malignant transformation and tumor growth, but not in the lymphatic spread of cervical cancer. This is the first report on leptin in a gynecological malignancy. Our results show that serum leptin falls short of being a useful marker in patients with cervical cancer.

Adult↗
PubMed2002

PROGINS receptor gene polymorphism is associated with endometriosis.

OBJECTIVE: To investigate the association between the 306-base pair insertion polymorphism in intron G of the progesterone receptor (PROGINS) and endometriosis. DESIGN: Case-control study. SETTING: Tertiary care center. PATIENT(S): Ninety-five white women with surgically diagnosed and histologically confirmed endometriosis and 107 white women without endometriosis (controls). INTERVENTION(S): Determination of PROGINS was performed by polymerase chain reaction and gel electrophoresis. MAIN OUTCOIME MEASURE(S): Frequency and distribution of the PROGINS allele. RESULT(S): Frequencies of the mutant allele T2 was 0.17 among women with endometriosis and 0.08 among controls (odds ratio, 2.41 [CI, 1.31-4.53]). Homozygosity for allele T2 was present in 3.2% of women with endometriosis and 0.9% of controls. CONCLUSION(S): PROGINS appears to be associated with endometriosis in white persons.

Adult↗
PubMed2002

Catechol-O-methyltransferase polymorphism and endometriosis.

PURPOSE: Catechol-O-methyltransferase (COMT) inactivates the estradiol metabolites, 2-hydroxy and 4-hydroxy catechols, which have been implicated in the pathogenesis of endometriosis. A COMT valine to methionine polymorphism (G-to-A) in exon 4 of the COMT gene is polymorphic in the human population, with 25% of Caucasians being homozygous for the low-activity allele (COMT-L) of the enzyme. In a case-control study we investigated whether this COMT polymorphism is associated with endometriosis. METHODS: Polymerase chain reaction was performed to analyze the COMT genotype among women with surgically and histologically confirmed endometriosis (study group; n = 91) and in women without evidence of endometriosis confirmed by laparoscopy or laparotomy (control group; n = 92). RESULTS: Allele frequencies for the low-activity allele (COMT-L) among women with endometriosis and controls were 0.50 and 0.50, respectively (p = 0.999; odds ratio = 1.0, 95% CI: 0.66-1.51). CONCLUSIONS: Our results suggest that the valine to methionine polymorphism in exon 4 of the COMT gene is not associated with the risk of endometriosis compared to a surgical control population.

Adolescent↗