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Biomedical subjects

Rita K Schmutzler

Publications and source records attributed to Rita K Schmutzler.

At least 19 recordsLinked to original sources

Transcription factor 7-like 2 (TCF7L2) variant is associated with familial breast cancer risk: a case-control study.

BACKGROUND: The transcription factor 7-like 2 (TCF7L2) is a critical component of the Wnt/beta-catenin pathway. Aberrant TCF7L2 expression modifies Wnt signaling and mediates oncogenic effects through the upregulation of c-MYC and cyclin D. Genetic alterations in TCF7L2 may therefore affect cancer risk. Recently, TCF7L2 variants, including the microsatellite marker DG10S478 and the nearly perfectly linked SNP rs12233372, were identified to associate with type 2 diabetes. METHODS: We investigated the effect of the TCF7L2 rs12255372 variant on familial breast cancer (BC) risk by means of TaqMan allelic discrimination, analyzing BRCA1/2 mutation-negative index patients of 592 German BC families and 735 control individuals. RESULTS: The T allele of rs12255372 showed an association with borderline significance (OR = 1.19, 95% C.I. = 1.01-1.42, P = 0.04), and the Cochran-Armitage test for trend revealed an allele dose-dependent association of rs12255372 with BC risk (Ptrend = 0.04). CONCLUSION: Our results suggest a possible influence of TCF7L2 rs12255372 on the risk of familial BC.

Adult↗

The functional genetic variant Ile646Val located in the kinase binding domain of the A-kinase anchoring protein 10 is associated with familial breast cancer.

Overexpression of cAMP-dependent protein kinase A (PKA) is a hallmark of the great majority of human cancers including breast cancer. A-kinase anchoring proteins (AKAPs) coordinate the specificity of PKA signalling by localizing the kinase to its subcellular sites. We tested the hypothesis whether the functional amino acid exchange Ile646Val, located in the kinase-binding domain of AKAP10, is a low-penetrance familial breast cancer risk factor. Ile646Val alters the binding of AKAP10 to PKA and is associated with morbidity. The analysis of 787 BRCA1/2 mutation-negative familial breast cancer patients and 993 controls revealed an association of the AKAP10 Ile646Val polymorphism with increased familial breast cancer risk [odds ratio (OR)=1.25, 95% confidence interval (CI) 1.03-1.51, P=0.024]. Our previous study has shown that AKAP13 Lys526Gln is associated with familial breast cancer (OR=1.58). Here, we discovered that carriers of both variants, AKAP10 Ile646Val and AKAP13 Lys526Gln, are at a further enhanced breast cancer risk (OR=2.41, 95% CI 1.30-4.46, P=0.005). PKA is a major target of therapeutic anticancer strategies. Phosphorylation of the estrogen receptor (ER) alpha by PKA induces resistance against the anti-estrogen tamoxifen. Our results indicate for the first time the importance of AKAP10 Ile646Val for familial breast cancer susceptibility. Due to the impact of Ile646Val on the subcellular localization of PKA, it will be interesting to investigate whether this polymorphism influences the effectiveness of PKA and tamoxifen based therapeutic anticancer concepts.

A Kinase Anchor Proteins↗

Aurora kinases A and B and familial breast cancer risk.

Aurora genes play a crucial role in tumourigenesis and are overexpressed in many kinds of cancers. We investigated whether coding variants within the Aurora genes are associated with familial breast cancer risk. While AURKA Phe31Ile (1712T>A) and AURKB Thr298Met (893G>A) showed no association, the synonymous AURKB Ser295Ser (885A>G) polymorphism resulted in an increased breast cancer risk for carriers of the homozygous 885G genotype (OR=1.45, 95% CI=1.05-2.0, P=0.02). Due to the impact of aurora kinases in the loss of chromosomal integrity during carcinogenesis, this variant may also influence the therapy outcome in breast cancer.

Aurora Kinase A↗

Association of the ARLTS1 Cys148Arg variant with familial breast cancer risk.

Recently, ARLTS1 (ADP-ribosylation factor-like tumor suppressor gene 1) has been identified as a tumor suppressor gene, playing a major role in apoptotic signaling. The ARLTS1 Trp149Stop mutation has been shown to predispose to general familial cancer and high-risk familial breast cancer (BC), provoking the attenuation of apoptotic function. We studied the impact of the ARLTS1 Pro131Leu and Cys148Arg variants on high-risk familial and familial BC risk, investigating 482 familial BC cases (including 305 high-risk cases) and 530 control individuals. Unlike ARLTS1 Pro131Leu, Cys148Arg revealed a significant association with an increased risk of high-risk familial BC (odds ratio (OR)=1.47, 95% confidence interval (95% CI)=1.04-2.06, p=0.03) in a dose-dependent manner (ptrend=0.007). The genotype distribution of Cys148Arg in familial cases was similar, indicating significance as well (OR=1.48, 95% CI=1.10-1.99, p=0.009; ptrend=0.003). On the basis of the small number of 46 cases, we additionally showed an association between the Trp149Stop mutation and an increased risk of bilateral BC (OR=4.11, 95% CI=1.27-13.31, p=0.011).

ADP-Ribosylation Factors↗

Associations of genetic variants in the estrogen receptor coactivators PPARGC1A, PPARGC1B and EP300 with familial breast cancer.

The mitogen effect of the ovarian steroid estrogen is a strong risk factor for breast cancer development. This effect is mainly mediated by the estrogen receptor alpha, a hormone inducible transcription factor, which activates gene expression through recruiting multiple coactivators, such as PPARGC1A, PPARGC1B and EP300. We tested the hypothesis that non-conservative, putative functional amino acid exchanges in PPARGC1A, PPARGC1B and EP300 act as low-penetrance familial breast cancer risk factors. The analysis of 816 BRCA1/2 mutation-negative familial breast cancer patients and 1012 controls revealed an association of the PPARGC1A Thr612Met polymorphism with familial breast cancer (OR = 1.35, 95% CI 1.00-1.81, P = 0.049), high-risk familial breast cancer (OR = 1.51, 95% CI 1.08-2.12, P = 0.017) and bilateral familial breast cancer (OR = 2.30, 95% CI 1.24-4.28, P = 0.009). Logistic regression analyses of the PPARGC1B Ala203Pro variant showed an increased familial breast cancer risk of heterozygous and homozygous variant allele carriers (OR = 1.48, 95% CI 1.15-1.91, P = 0.002). The genotype-combination analysis of the associated PPARGC1A Thr612Met variant and the associated PPARGC1B Ala203Pro variant suggests an allele dose-dependent breast cancer risk (P(trend) = 0.0004). Our results indicate for the first time the importance of inherited variants in the estrogen receptor coactivator genes PPARGC1A and PPARGC1B for familial breast cancer susceptibility. Owing to their impact on estrogen signaling, these polymorphisms might also influence adjuvant anti-estrogen therapy, using agents such as tamoxifen and raloxifen, and outcome of breast cancer patients.

Breast Neoplasms↗

Polymorphisms in genes involved in GH1 release and their association with breast cancer risk.

The regulation of growth hormone 1 (GH1) and insulin-like-growth factor-1 (IGF-1) release is under the influence of three pituitary hormones [growth hormone releasing hormone (GHRH), ghrelin (GHRL) and somatostatin (SST)], which act in an autocrine/paracrine fashion in the breast. By binding to their respective receptors, they control cell proliferation, differentiation and apoptosis in a GH1/IGF-1-dependent manner. We investigated single nucleotide polymorphisms (SNPs) in the GHRH, GHRHR, GHRL, GHSR, SST and SSTR2 gene regions in a Polish and a German cohort of 798 breast cancer cases and 1011 controls. Our study revealed an association of a novel TC repeat polymorphism in the SST promoter with a decreased breast cancer risk in the Polish study population [odds ratio (OR), 0.65; 95% confidence interval (CI), 0.44-0.96]. The closely linked SNP IVS1 A+46G showed the same trend. For both polymorphisms the association was stronger in women above the age of 50 (OR, 0.33; 95% CI, 0.14-0.76 and OR, 0.39; 95% CI, 0.18-0.87, respectively). The protective effect of these polymorphisms was confirmed in a haplotype analysis among women above 50 years of age and carrying the two variant alleles (OR, 0.37; 95% CI, 0.17-0.80). In the independent German population, we observed slightly decreased ORs among women above the age of 50 years. In the SSTR2 gene, carriers of the promoter 21/21 TG repeat genotype were at a decreased breast cancer risk (OR, 0.62; 95% CI, 0.41-0.94) compared to carriers of the other genotypes in the Polish population. Furthermore, we identified a protective effect of the GHRHR C-261T SNP in both populations (joint analysis CT+TT versus CC: OR, 0.80; 95% CI, 0.65-0.99). This effect was carried by a haplotype containing the protective allele. Thus, our study concludes a possible protective influence of distinct polymorphisms in genes involved in GH1 release on breast cancer risk.

Adolescent↗

Interaction of Werner and Bloom syndrome genes with p53 in familial breast cancer.

Mutations of the human RecQ helicase genes WRN and BLM lead to rare autosomal recessive disorders, Werner and Bloom syndromes, which are associated with premature ageing and cancer predisposition. We tested the hypothesis whether three polymorphic, non-conservative amino acid exchanges in WRN and BLM act as low-penetrance familial breast cancer risk factors. Moreover, we examined the putative impact of p53 MspI 1798G>A, which is completely linked to p53PIN3, a 16 bp insertion/duplication that has been associated with reduced p53 expression, on familial breast cancer risk. Genotyping analyses, performed on 816 BRCA1/2 mutation-negative German familial breast cancer patients and 1012 German controls, revealed a significant association of the WRN Cys1367Arg polymorphism with familial breast cancer (OR = 1.28, 95% CI 1.06-1.54) and high-risk familial breast cancer (OR = 1.32, 95% CI 1.06-1.65). The analysis of p53 MspI 1798G>A, which is completely linked to p53PIN3, showed a significantly increased familial breast cancer risk for carriers of the 16 bp insertion/duplication, following a recessive mode (OR = 2.15, 95% CI = 1.12-4.11). WRN Cys1367Arg, located in the C-terminus, the binding site of p53, is predicted to be damaging. The joint effect of WRN Cys1367Arg and p53 MspI resulted in an increased breast cancer risk compared to the single polymorphisms (OR = 3.39, 95% CI 1.19-9.71). In conclusion, our study indicates the importance of inherited variants in the WRN and p53 genes for familial breast cancer susceptibility.

Adenosine Triphosphatases↗

Association of prolactin and its receptor gene regions with familial breast cancer.

CONTEXT: The contribution of prolactin (PRL) through its receptor (PRLR) to the pathogenesis and progression of human mammary tumors has received recent attention. OBJECTIVE: We investigated whether genetic variation in the PRL and PRLR genes is associated with the risk of breast cancer (BC). DESIGN: We conducted a case-control study with a total of seven single nucleotide polymorphisms (SNPs). SETTING: The study was conducted at an academic research laboratory and university clinics. PATIENTS AND OTHER PARTICIPANTS: A total of 441 German familial, unrelated BC cases and 552 controls matched by age, ethnicity, and geographical region participated in the study. INTERVENTION(S): There were no interventions. MAIN OUTCOME MEASURES(S): SNP genotype and haplotype distributions and haplotype interactions were correlated with the risk of BC. RESULTS: Two SNPs (rs1341239 and rs12210179) within the PRL promoter regions were significantly associated with increased risk in homozygotes for the variant alleles [odds ratio (OR), 1.67 and 95% confidence interval (CI), 1.11-2.50; and OR, 2.09 and 95% CI, 1.23-3.52, respectively]. The PRL haplotype containing the variant alleles of the promoter SNPs increased significantly the risk of BC (OR 1.42, 95%CI 1.07-1.90). A PRLR haplotype was associated with a significant decrease in BC risk (OR 0.69, 95% CI 0.54-0.89). An increasing number of PRL and PRLR risk haplotypes led to a significant trend of increasing risk for BC (chi(2) = 12.15; P = 0.007). CONCLUSIONS: Genetic variation in the PRL and PRLR genes was shown to influence BC risk. Additional studies are needed to further clarify the role of the PRL and PRLR genes in the risk of BC.

Adult↗

The single nucleotide polymorphism IVS1+309 in mouse double minute 2 does not affect risk of familial breast cancer.

The mouse double minute 2 (MDM2) oncoprotein promotes cell survival and cell cycle progression by inhibiting the p53 tumor suppressor protein. Further, MDM2 overexpression can inhibit DNA double-strand break repair in a p53-independent manner. Recently, it was shown that a single nucleotide polymorphism (SNP) in the MDM2 promoter was associated with an accelerated tumor formation in individuals with a p53 mutation. The present case-control study investigated the association of this SNP (IVS1+309) with the risk and the age of onset of familial breast cancer in patients with unknown p53 mutation status. Data from 549 women affected by familial breast cancer and 1,065 healthy controls were analyzed. The cases did not carry BRCA1/2 mutations. Cases and controls showed a similar genotype distribution and the SNP did not seem to modify the age of onset of familial breast cancer. The data were also examined taking into account the presence of any additional cancer after breast cancer and the family history of cases; however, no association was found. These results suggest that the SNP IVS1+309 alone affects neither the risk nor the age of onset of heritable breast cancer.

Adult↗

Outcome of a structured surveillance programme in women with a familial predisposition for breast cancer.

We aimed to prospectively evaluate the efficacy of a multi-modal surveillance programme for the early detection of familial breast cancer. Ultrasound, mammography and breast magnetic resonance imaging were evaluated in 413 women who participated in a prospective study with a median follow-up of 2.2 years (range 1-6.75 years). Of these, 49 women carried a BRCA mutation, 203 were at high and 161 at moderate risk. Breast carcinomas diagnosed within the programme were compared with 297 carcinomas previously observed in the risk group and 7894 carcinomas documented in the regional cancer registry within the same time period. Overall, 41 breast carcinomas and no interval carcinoma were detected. The detection rates averaged 107.2/1000 for mutation carriers with highest rates between 20 and 39 years of age, 45.8/1000 for high-risk women with highest rates between 40 and 49 years of age and 23.9/1000 for moderate-risk women with highest rates between 50 and 74 years of age. Overall, 82.8% of the breast carcinomas were node negative and 85.4% pre-invasive or smaller than 2 cm. In comparison, of breast carcinomas detected outside the programme only 47.8% were node negative (P=0.0005) and 43.8% pre-invasive or smaller than 2 cm (P<0.000 01). Of those gathered in the local cancer registry 55.7% were node negative (P=0.004) and 47.6% pre-invasive or smaller than 2 cm (P<0.000 01). Our data indicate that (1) there is a strong correlation between breast cancer detection rates, risk status and age at disease onset and (2) a multi-modal surveillance programme can detect early-stage hereditary breast carcinomas.

Adult↗

c-MYC Asn11Ser is associated with increased risk for familial breast cancer.

c-MYC is a multifaceted protein that regulates cell proliferation, differentiation and apoptosis. Its crucial role in diverse cancers has been demonstrated in several studies. Here, we analysed the influence of the rare c-MYC Asn11Ser polymorphism on familial breast cancer risk by performing a case-control study with a Polish (cases n = 349; controls n = 441) and a German (cases n = 356; controls n = 655) study population. All cases have been tested negative for mutations in the BRCA1 and BRCA2 genes. A joint analysis of the Polish and the German study population revealed a 54% increased risk for breast cancer associated with the heterozygous Asn11Ser variant (OR = 1.54, 95% CI 1.05-2.26, p = 0.028). The breast cancer risk associated with this genotype increases above the age of 50 years (OR = 2.24, 95% CI 1.20-4.21, p = 0.012). The wild-type amino acid Asn of this polymorphism is located in the N-terminal MYC transactivation domain and is highly conserved not only among most diverse species but also in the N-MYC homologue. Due to the pivotal role of c-MYC in diverse tumours, this variant might affect the genetic susceptibility of other cancers as well.

Amino Acid Sequence↗

Association of the CASP10 V410I variant with reduced familial breast cancer risk and interaction with the CASP8 D302H variant.

Dysregulation of apoptosis plays a crucial role in carcinogenesis. As part of death receptor- and mitochondrion-mediated apoptosis, the homologues caspases 10 and 8 may act as low-penetrance breast cancer (BC) susceptibility genes. In death receptor-mediated apoptosis, engagement of death receptors by their ligands involves the assembly of the death-inducing signalling complex (DISC). In mitochondrion-mediated apoptosis, the release of cytochrome c into the cytosol results in apoptosome formation. Recruitment of both caspases 10 and 8 (CASP10 and CASP8, respectively) to DISC and apoptosome leads to their activation by dimerization. We investigated the influence of the coding CASP10 variant V410I (G1228A) by performing a case-control study - using 511 familial BC cases and 547 control subjects - on BC risk and revealed a significant association of V410I with a reduced risk (OR = 0.62, 95% CI = 0.43-0.88, P = 0.0076) related to the number of variant alleles (P(trend) = 0.0039). As CASP10 and CASP8 functionally co-operate during apoptosis, we analysed the mutual effect of both CASP10 V410I and CASP8 D302H, resulting in a significant association between the number of the variant alleles I410 and H302 and a highly decreased familial BC risk (OR = 0.35, P(trend) = 0.007), pointing to the interaction between the CASP10 and CASP8 polymorphisms in breast carcinogenesis.

Adult↗

Association of genetic variants in the Rho guanine nucleotide exchange factor AKAP13 with familial breast cancer.

The A-kinase anchor protein 13 (AKAP13, alias BRX and lbc) tethers cAMP-dependent protein kinase to its subcellular environment and catalyses Rho GTPases activity as a guanine nucleotide exchange factor. The crucial role of members of the Rho family of GTPases in carcinogenesis is well established and targeting Rho proteins with antineoplastic compounds has become a major effort in the fight against cancer. Thus, genetic alterations within the candidate cancer susceptibility gene AKAP13 would be expected to provoke a constitutive Rho signalling, thereby facilitating the development of cancer. Here, we analysed the potential impact of four polymorphic non-conservative amino acid exchanges (Arg494Trp, Lys526Gln, Asn1086Asp and Gly2461Ser) in AKAP13 on familial breast cancer. We performed a case-control study using genomic DNA of BRCA1/2 mutation-negative German female index patients from 601 unrelated families, among a subset of 356 high-risk families, and 1053 German female unrelated controls. The newfound Lys526Gln polymorphism revealed a significant association with familial breast cancer (OR = 1.58, 95% CI = 1.07-2.35) and an even stronger association with high-risk familial breast cancer (OR = 1.85, 95% CI = 1.19-2.88). Haplotype analyses were in line with genotype results displaying a similar significance as analyses of individual polymorphisms. Due to the pivotal role of AKAP13 in the Rho GTPases signalling network, this variant might affect the susceptibility to other cancers as well.

A Kinase Anchor Proteins↗

Association of death receptor 4 haplotype 626C-683C with an increased breast cancer risk.

Dysregulation of apoptosis plays a crucial role in carcinogenesis. Tumour necrosis factor-related apoptosis-inducing ligand stimulates the extrinsic apoptotic pathway by binding to death receptor 4 (DR4). Thus, genetic alterations within the candidate tumour suppressor gene DR4 would be expected to provoke a deficient apoptotic signalling thereby facilitating the development of cancer. The DR4 variants Thr209Arg and Glu228Ala were genotyped in a series of 521 breast cancer cases and 1100 control subjects from Germany, determining their impact on breast cancer risk. Neither Thr209Arg (626C>G) nor Glu228Ala (683A>C) alone were significantly associated with breast cancer risk [odds ratio (OR) = 0.84, 95% confidence interval (CI) = 0.65-1.08, P = 0.18 and OR = 0.89, 95% CI = 0.72-1.12, P = 0.30]. However, haplotype analysis revealed a 3.5-fold risk for carriers of the 626C-683C haplotype (OR = 3.52, 95% CI = 1.45-8.52, P = 0.003).

Adult↗

TP53-binding protein variants and breast cancer risk: a case-control study.

INTRODUCTION: The TP53-binding protein (53BP1) has been shown to influence TP53-mediated transcriptional activation, thus playing a pivotal role in DNA damage signalling. Genetic aberrations in TP53 and in ATM and CHEK2 predispose to cancer. We have therefore examined the effects of 53BP1 single nucleotide polymorphisms (D353E, G412S, and K1136Q) and the novel 53BP1 6bp deletion (1347_1352delTATCCC) on breast cancer risk. METHODS: Allelic discrimination was performed to investigate the frequencies of 53BP1 D353E, G412S, and K1136Q and of 1347_1352delTATCCC in 353 patients with breast cancer and 960 control individuals. RESULTS: No significant association of 53BP1 D353E, G412S, or K1136Q with breast cancer risk was detected. 53BP1 1347_1352delTATCCC, leading to the loss of an isoleucine and a proline residue, showed a nonsignificant inverse association with breast cancer risk (odds ratio = 0.61, 95% confidence interval = 0.22 to 1.68, P = 0.34). CONCLUSION: The lack of association casts doubt on the putative effects of D353E, G412S, and K1136Q on breast cancer risk. Investigating a larger study cohort might elucidate the influence of the 6bp deletion 1347_1352delTATCCC. Studying the functional effect and the impact of this variant on the risk of other cancers may be revealing.

Adult↗