Browsing by Author "Peralta, Octavio"
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Item Association of genetic variants at TOX3, 2q35 and 8q24 with the risk of familial and early-onset breast cancer in a South-American population(Springer, 2014) Elematore, Isabel; Gonzalez-Hormazabal, Patricio; Reyes, José; Blanco, Rafael; Bravo, Teresa; Peralta, Octavio; Gomez, Fernando; Waugh, Enrique; Margarit, Sonia; Ibañez, Gladys; Romero, Carmen; Pakomio, Janara; Roizen, Gigia; Gabriella, Di Capua; Jara, LilianRecent Genome-Wide Association Studies have identified several single nucleotide polymorphisms (SNPs) associated with breast cancer (BC) among women of Asian, European, and African-American ancestry. Nevertheless, the contribution of these variants in the South American population is unknown. Furthermore, there is little information about the effect of these risk alleles in women with early BC diagnosis. In the present study, we evaluated the association between rs3803662 (TOX3, also known as TNRC9), rs13387042 (2q35), and rs13281615 (8q24) with BC risk in 344 Chilean BRCA1/2-negative BC cases and in 801 controls. Two SNPs, rs3803662 and rs13387042, were significantly associated with increased BC risk in familial BC and in non-familial early-onset BC. The risk of BC increased in a dose-dependent manner with the number of risk alleles (P-trend < 0.0001 and 0.0091, respectively). The odds ratios for BC in familial BC and in early-onset non-familial BC were 3.76 (95%CI 1.02-13.84, P = 0.046) and 8.0 (95%CI 2.20-29.04, P = 0.002), respectively, for the maximum versus minimum number of risk alleles. These results indicate an additive effect of the TOX3 rs3803662 and 2q35 rs13387042 alleles for BC risk. We also evaluated the interaction between rs3803662 and rs13387042 SNPs. We observed an additive interaction only in non-familial early-onset BC cases (AP = 0.72 (0.28-1.16), P = 0.001). No significant association was observed for rs13281615 (8q24) with BC risk in women from the Chilean population. The strongly increased risk associated with the combination of low-penetrance risk alleles supports the polygenic inheritance model of BC.Item Association of genetic variants at TOX3, 2q35 and 8q24 with the risk of familial and early-onset breast cancer in a South-American population(2014) Elematore, Isabel; Gonzalez-Hormazabal, Patricio; Reyes, Jose M.; Blanco, Rafael; Bravo, Teresa; Peralta, Octavio; Gomez, Fernando; Waugh, Enrique; Margarit, Sonia; Ibañez, Gladys; Romero, Carmen; Pakomio, Janara; Roizen, Gigia; Di Capua, Gabriella A.; Jara, LilianAbstract Recent Genome-Wide Association Studies have identified several single nucleotide polymorphisms (SNPs) associated with breast cancer (BC) among women of Asian, European, and African-American ancestry.Nevertheless, the contribution of these variants in the South American population is unknown. Furthermore, there is little information about the effect of these risk alleles in women with early BC diagnosis. In the present study, we evaluated the association between rs3803662 (TOX3, also known as TNRC9), rs13387042 (2q35), and rs13281615 (8q24) with BC risk in 344 Chilean BRCA1/2-negative BC cases and in 801 controls. Two SNPs, rs3803662 and rs13387042, were significantly associated with increased BC risk in familial BC and in non-familial early-onset BC. The risk of BC increased in a dose-dependent manner with the number of risk alleles (P-trend \0.0001 and 0.0091, respectively). The odds ratios for BC in familial BC and in early-onset non-familial BC were 3.76 (95 %CI 1.02–13.84, P = 0.046) and 8.0 (95 %CI 2.20–29.04, P = 0.002), respectively, for the maximum versus minimum number of risk alleles. These results indicate an additive effect of the TOX3 rs3803662 and 2q35 rs13387042 alleles for BC risk. We also evaluated the interaction between rs3803662 and rs13387042 SNPs. We observed an additive interaction only in non-familial early-onset BC cases (AP = 0.72 (0.28–1.16), P = 0.001). No significant association was observed for rs13281615 (8q24) with BC risk in women from the Chilean population. The strongly increased risk associated with the combination of low-penetrance risk alleles supports the polygenic inheritance model of BC.Item Genetic variants in FGFR2 and MAP3K1 are associated with the risk of familial and early-onset breast cancer in a south-american population(Springer, 2013) Jara, Lilian; Gonzalez-Hormazabal, Patricio; Cerceño, Kerube; Di Capua, Gabriella; Jose, Reyes; Blanco, Rafael; Bravo, Teresa; Peralta, Octavio; Gomez, Fernando; Waugh, Enrique; Margarit, Sonia; Ibañez, Gladys; Romero, Carmen; Pakomio, Janara; Roizen, GigiaGenome-Wide Association Studies have identified several loci associated with breast cancer (BC) in populations of different ethnic origins. One of the strongest associations was found in the FGFR2 gene, and MAP3K1 has been proposed as a low-penetrance BC risk factor. In this study, we evaluated the associations among FGFR2 SNPs rs2981582, rs2420946, and rs1219648; and MAP3K1 rs889312, with BC risk in 351 BRCA1/2-negative Chilean BC cases and 802 controls. All the SNPs studied were significantly associated with increased BC risk in familial BC and in non-familial early-onset BC, in a dose-dependent manner. Subjects with 3 risk alleles were at a significantly increased risk of BC compared with subjects with 0-2 risk alleles, in both familial BC and early-onset non-familial BC (OR = 1.47, 95 % CI 1.04-2.07, P = 0.026 and OR = 2.04 95 % CI 1.32-3.24, P < 0.001, respectively). In the haplotype analysis, the FGFR2 rs2981582 T / rs2420946 T / rs1219648 G haplotype (ht2) was associated with a significantly increased BC risk compared with the rs2981582 C / rs2420946 C / rs1219648 A haplotype in familial BC and in non-familial early-onset BC (OR = 1.32, 95 % CI 1.06-1.65, P = 0.012; OR = 1.46, 95 % CI 1.11-1.91, P = 0.004, respectively). When the FGFR2 ht2 and MAP3K1 rs889312 were evaluated as risk alleles, the risk of BC increased in a dose-dependent manner as the number of risk alleles increased (P trend <0.0001), indicating an additive effect. Nevertheless, there is no evidence of an interaction between FGFR2 ht2 and the MAP3K1 rs889312 C allele. These findings suggest that genetic variants in the FGFR2 and MAP3K1 genes may contribute to genetic susceptibility to BC.Item Spectrum of BRCA1/2 point mutations and genomic rearrangements in high-risk breast/ovarian cancer Chilean families(2011) González Hormazabal, Patricio; Gutiérrez Enríquez, Sara; Gaete, Daniel; Reyes, José M.; Peralta, OctavioThe distribution of BRCA1/2 germline mutations in breast/ovarian cancer (BC/OC) families varies among different populations. In the Chilean population, there are only two reports of mutation analysis of BRCA1/2, and these included a low number of BC and/or OC patients. Moreover, the prevalence of BRCA1/2 genomic rearrangements in Chilean and in other South American populations is unknown. In this article, we present the mutation-detection data corresponding to a set of 326 high-risk families analyzed by conformation-sensitive gel electrophoresis and heteroduplex analysis. To determine the contribution of BRCA1/2 LGRs in Chilean BC patients, we analyzed 56 high-risk subjects with no pathogenic BRCA1/2 point mutations. Germline BRCA1/2 point mutations were found in 23 (7.1%) of the 326 Chilean families. Families which had at least three BC and/or OC cases showed the highest frequency of mutations (15.9%). We identified 14 point pathogenic mutations. Three recurrent mutations in BRCA1 (c.187_188delAG, c.2605_2606delTT, and c.3450_3453delCAAG) and three in BRCA2 (c.4969_4970insTG, c.5374_5377delTATG, and c.6503_6504delTT) contributed to 63.6 and 66.7% of all the deleterious mutations of each gene, which may reflect the presence of region-specific founder effects. Taken together BRCA1/2 recurrent point mutations account for 65.2% (15/23) of the BRCA1/2 (+) families. No large deletions or duplications involving BRCA1/2 were identified in a subgroup of 56 index cases negative for BRCA1/2 point mutations. Our study, which is the largest conducted to date in a South American population, provides a comprehensive analysis on the type and distribution of BRCA1/2 mutations and allelic variants.Item The BARD1 Cys557Ser variant and risk of familial breast cancer in a South-American population(Springer, 2012) Gonzalez-Hormazabal, Patricio; Reyes, Jose; Blanco, Rafael; Bravo, Teresa; Carrera, Ignacio; Peralta, Octavio; Gomez, Fernando; Waugh, Enrique; Margarit, Sonia; Ibañez, Gladys; Santos, Jose; Jara, LilianSince the discovery of the BRCA1 and BRCA2 genes, much work has been carried out to identify further breast cancer (BC) susceptibility genes. BARD1 (BRCA1-associated ring domain) was originally identified as a BRCA1-interacting protein but has also been described in tumor-suppressive functions independent of BRCA1. Some association studies have suggested that the BARD1 Cys557Ser variant might be associated with increased risk of BC, but others have failed to confirm this finding. To date, this variant has not been analyzed in Spanish or South-American populations. In this study, using a case–control design, we analyzed the C-terminal Cys557Ser change in 322 Chilean BC cases with no mutations in BRCA1 or BRCA2 and in 570 controls in order to evaluate its possible association with BC susceptibility. BARD1 Cys557Ser was associated with an increased BC risk (P = 0.04, OR = 3.4 [95 % CI 1.2–10.2]) among cases belonging to families with a strong family history of BC. No difference between single cases affected with age <50 years at diagnosis (n = 117) and controls was observed for carriers of Cys/Ser genotype. It is likely that this variant is not involved in BC risk in this group of women. We also analyzed a possible interaction between BARD1 557Ser/XRCC3 241Met variants considering the role of both genes in the maintenance of genome integrity. The combined genotype Cys/Ser-carrier with the XRCC3 241Met allele was associated with an increased BC risk (P = 0.02, OR = 5.01 [95 % CI 1.36–18.5]) among women belonging to families with at least three BC and/or ovarian cancer cases. Our results suggest that BARD1 557Ser and XRCC3 241Met may play roles in BC risk in women with a strong family history of BC. Nevertheless there is no evidence of an interaction between the two SNPs. These findings should be confirmed by other studies and in other populations.Item Variants in DNA double-strand break repair genes and risk of familial breast cancer in a South American population(2010) Jara, Lilian; Dubois, Karen; Gaete, Daniel; de Mayo, Tomas; Ratkevicius, Nikalai; Bravo, Teresa; Margarit, Sonia; Blanco, Rafael; Gomez, Fernando; Waugh, Enrique; Peralta, Octavio; Reyes, Jose M.; Ibanez, Gladys; Gonzalez-Hormazabal, PatricioThe double-strand break (DSB) DNA repair pathway has been implicated in breast cancer (BC). RAD51 and its paralogs XRCC3 and RAD51D play an important role in the repair of DSB through homologous recombination (HR). Some polymorphisms including XRCC3-Thr241Met, RAD51-135G[C, and RAD51D-E233G have been found to confer increased BC susceptibility. In order to detect novel mutations that may contribute to BC susceptibility, 150 patients belonging to 150 Chilean BRCA1/2-negative families were screened for mutations in XRCC3. No mutations were detected in the XRCC3 gene. In addition, using a case–control design we studied the XRCC3-Thr241Met, and RAD51D-E233G polymorphisms in 267 BC cases and 500 controls to evaluate their possible association with BC susceptibility. The XRCC3 Met/Met genotype was associated with an increased BC risk (P = 0.003, OR = 2.44 [95%CI 1.34–4.43]). We did not find an association between E233G polymorphism and BC risk. We also analyzed the effect of combined genotypes among RAD51-135G[C, Thr241Met, and E233G polymorphisms on BC risk. No interaction was observed between Thr241Met and 135G[C. The combined genotype Thr/Met–E/G was associated with an increased BC risk among women who (a) have a family history of BC, (b) are BRCA1/2-negative, and (c) were \50 years at onset (n = 195) (P = 0.037, OR = 10.5 [95%CI 1.16–94.5]). Our results suggested that the variability of the DNA HR repair genes XRCC3 and RAD51D may play a role in BC risk, but this role may be underlined by a mutual interaction between these genes. These findings should be confirmed in other populations.