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.

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.

Vascular endothelial growth factor polymorphisms in relation to breast cancer development and prognosis.

PURPOSE: Angiogenesis is a necessary step in tumor growth and metastasis. Vascular endothelial growth factor (VEGF) is a major mediator of breast cancer angiogenesis. Therefore, we investigated the association of polymorphisms in the VEGF gene with breast cancer risk and prognostic characteristics of the tumors in a large case-control study. EXPERIMENTAL DESIGN: We examined three polymorphisms in the VEGF gene (-2578C/A, -1154G/A, and +936C/T) in 571 familial breast cancer cases from Poland and Germany and -2578C/A, -634G/C, and +936C/T polymorphisms in 974 unselected breast cancer cases from Sweden together with ethnically and geographically selected controls. RESULTS: None of the polymorphisms or any haplotype was significantly associated with either familial or unselected breast cancers. Our study suggests that the +936C/T polymorphism is unlikely to be associated with breast cancer. We also analyzed the unselected cases for genotypes or haplotypes that associated with tumor characteristics. The -634CC genotype and the -2578/-634 CC haplotype were significantly associated with high tumor aggressiveness (large tumor size and high histologic grade, P < 0.01) and the -2578AA genotype and the -2578/-634 AG haplotype with low histologic grade tumors (P = 0.04). The genotypes and haplotypes were not related with other tumor characteristics such as regional or distant metastasis, stage at diagnosis, or estrogen or progesterone receptor status. CONCLUSIONS: Although none of the polymorphisms studied in the VEGF gene was found to influence susceptibility to breast cancer significantly, some of the VEGF genotypes and haplotypes may influence tumor growth through an altered expression of VEGF and tumor angiogenesis.

Association of NCOA3 polymorphisms with breast cancer risk.

The nuclear receptor coactivator 3 (NCOA3, also known as AIB1) is a coactivator of nuclear receptors like the estrogen receptor. NCOA3 is overexpressed in approximately 60% of primary human breast tumors, and high levels of NCOA3 expression are associated with tamoxifen resistance and worse survival rate. In contrast, NCOA3 deficiency suppresses v-Ha-ras-induced breast cancer initiation and progression in mice. Here, we analyzed the influence of NCOA3 coding single nucleotide polymorphisms on breast cancer risk by performing a case-control study using a German and a Polish study population and identified an association between NCOA3 polymorphisms and breast cancer. A joint analysis of the German and the Polish study population revealed a significant protective effect for the 1758G>C (Q586H) and 2880A>G (T960T) variants. In addition, haplotype analysis showed a protective effect of the 1758C-2880A and 1758G-2880G haplotypes (odds ratio 0.79; 95% confidence interval, 0.67-0.93; P = 0.004). Because of the impact of NCOA3 in antiestrogen therapy resistance, these polymorphisms might also influence therapy outcome in breast cancer.

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.

Large BRCA1 gene deletions are found in 3% of German high-risk breast cancer families.

We have tested for large BRCA1 gene rearrangements in German high-risk breast and ovarian cancer families previously screened negative for point mutations by dHPLC and sequencing. Using the novel MLPA method, two deletions of exons 1A, 1B and 2 and exon 17, respectively, were detected in four out of 75 families investigated in Southern Germany. An identical exon 17 deletion with the same breakpoints and a deletion of exons 1A, 1B and 2 were found by fluorescent multiplex PCR in two out of 30 families investigated in Northern Germany. Combining both populations, genomic rearrangements were found in 6% of the mutation-negative families and 3% of all high-risk families and account for 8% of all BRCA1 mutations. Our data indicate that the exon 17 deletion may be a founder mutation in the German population. The prevalence of BRCA1 gene deletions or duplications in our patients is similar to previous reports from Germany and France. Genomic quantification by MLPA is a useful method for molecular diagnostics in high-risk breast cancer families.

p16INK4a immunohistochemistry improves interobserver agreement in the diagnosis of cervical intraepithelial neoplasia.

It has been repeatedly shown that there is a substantial lack of interobserver reproducibility in the histologic diagnosis of cervical intraepithelial neoplasia (CIN), which might be improved by a more specific diagnostic biomarker. Cervical cancer and CIN, but not other cervical epithelia, express high levels of the cyclin-dependent kinase inhibitor p16, suggesting that staining for this marker could help to more precisely identify CIN in tissue sections and therefore reduce variation in interpretation of cervical lesions. To test this hypothesis, 194 cervical cone biopsy samples were selected from a routine histopathology laboratory. Two consecutive sections from each biopsy were stained with hematoxylin and eosin and with a p16 -specific monoclonal antibody, respectively. Five experienced cervical pathologists examined the slides. The agreement in the diagnosis between pairs or groups of observers was calculated by kappa statistics. Significant discrepancies were observed in the diagnostic interpretation of hematoxylin and eosin-stained slides, particularly for low-grade lesions (kappa value 0.60 [95% confidence interval 0.58-0.63]). There was significantly better agreement in the interpretation of p16 expression (kappa value 0.91 [95% confidence interval 0.84-0.99]). Expression of p16 was restricted to CIN 2/CIN 3, CIN 1 associated with high-risk human papillomavirus, or cervical cancer. p16 immunostaining allowed precise identification of even small CIN or cervical cancer lesions in biopsy sections and helped to reduce interobserver variation in the histopathologic interpretation of cervical biopsy specimens. Thus, p16 immunohistochemistry can reduce false-negative and false-positive biopsy interpretation and thereby significantly improve cervical (pre)-cancer diagnosis.

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.

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.

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).

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.

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.

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).

The rare ERBB2 variant Ile654Val is associated with an increased familial breast cancer risk.

Overexpression of the proto-oncogene ERBB2 (HER2/NEU) has been observed in 20-30% of breast cancers involving poor prognosis. Genetic alterations within ERBB2 have been shown to induce carcinogenesis and metastasis. We investigated eight annotated single nucleotide polymorphisms for occurrence in familial breast cancer samples. The confirmed variants Ile654Val, Ile655Val and Ala1170Pro were analysed in subsequent epidemiological studies on familial breast cancer risk. While Ala1170Pro resides within a C-terminally located regulatory domain, the two adjacent polymorphisms Ile654Val and Ile655Val are part of the transmembrane domain. A case-control study analysing a cohort of 348 German familial breast cancer cases and 960 corresponding controls showed no significant association of either Ile655Val (OR = 1.05, 95% CI = 0.82-1.34, P = 0.728) or Ala1170Pro (OR = 0.94, 95% CI = 0.74-1.20, P = 0.632) with familial breast cancer risk. Differences in haplotype frequencies between cases and controls could also not be detected. The ERBB2 variant Ile654Val, however, revealed an increased risk for carriers of the heterozygous Val654 allele (OR = 2.56, 95% CI = 1.08-6.08, P = 0.028). The rare Val654 variant is linked with the more frequent Val655, resulting in two consecutive valine instead of two isoleucine residues within the transmembrane domain. Computational analyses suggest that the Val654-Val655 allele provokes receptor dimerization and activation, thus stimulating kinase activity and cell transformation. We hypothesize that ERBB2 Val654 represents an oncogenic variant which might, in addition, influence clinical outcome and predict a worse prognosis.

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.

Breast cancer in young women (< or = 35 years): Genomic aberrations detected by comparative genomic hybridization.

Sporadic breast cancer in young women is different from the one in older patients regarding pathological features and aggressiveness of the tumors, but the spectrum of genetic alterations are largely unknown. We used comparative genomic hybridization (CGH) to analyze DNA copy number changes in 88 tumor samples from women

The insulin-like growth factor-1 pathway mediator genes: SHC1 Met300Val shows a protective effect in breast cancer.

The insulin-like growth factor 1 (IGF-1) pathway plays an important role in regulating cell proliferation, differentiation and apoptosis. IRS1, IRS2 and SHC1 are the key mediators for the downstream pathway processes. Genetic variation within these genes may lead to altered signalling. We screened IRS1, IRS2 and SHC1 for published coding region polymorphisms and choose five of them, IRS1 Ala804Ala and Gly972Arg, IRS2 Cys816Cys and Gly1057Asp and SHC1 Met300Val, for further analysis. We studied the association of the polymorphisms with breast cancer risk using a case-control design with Polish familial breast cancer cases and respective controls. For the polymorphisms in IRS1 and IRS2 no differences in the allele, genotype or haplotype distributions could be detected between the case and control subjects. Carriers of the variant allele of the SHC1 polymorphism were at decreased risk of breast cancer (OR 0.54, 95% CI 0.32-0.90, P = 0.016). A non-significant trend for a protective effect of the SHC1 Val300 allele was also seen in an independent population consisting of German familial breast cancer cases and matched controls. The joint analysis after Mantel-Haenzsel adjustment of the two populations gave an OR of 0.62 (95% CI 0.41-0.93, P = 0.02) for the SHC1 Val300 carriers. A stronger effect was detected in women diagnosed below the age of 50 (OR 0.54, 95% CI 0.32-0.89, P = 0.01). A genotype combination analysis of the non-synonymous polymorphisms in the IRS1, IRS2 and SHC1 genes did not show any effect on breast cancer risk.

Polymorphisms and haplotype structures in genes for transforming growth factor beta1 and its receptors in familial and unselected breast cancers.

Alterations in TGF-beta signaling appear to be associated with an altered risk of developing cancer, including breast cancer. We carried out a case-control study on 8 polymorphisms, including 5 in the TGF-beta1 gene (G-800A, C-509T, Leu10-->Pro, Arg25-->Pro and Thr263-->Ile), a polyalanine polymorphism (9A-->6A) in the TGF-betaRI gene and 2 (G-875A and A-364G) in the TGF-betaRII gene, using samples from 2 different populations, Polish familial and Finnish unselected breast cancer cases, together with ethnically and geographically matched controls. Additionally, familial breast cancer cases with respective controls from Sweden and Germany were studied in the Leu10-->Pro polymorphism, making the total number of familial cases 659. Allele, genotype and haplotype analysis on the TGF-beta1 gene as well as an analysis of the combinations of genotypes of the TGF-beta1 and its receptor genes in each individual were performed. Population differences in the allele and genotype distributions were found from 5 of the polymorphisms and 3 common haplotypes from the TGF-beta1 gene between the Finnish and other populations. However, no statistically significant difference between the breast cancer and healthy control groups was found for any of the 8 polymorphisms nor did the haplotype or genotype combination analysis reach statistical significance. Thus, none of the studied polymorphisms from the TGF-beta1 and its receptor genes was found to influence significantly susceptibility to breast cancer. The possible contribution of 6A/6A homozygosity in the TGF-betaRI gene to breast cancer needs to be confirmed in an independent study.