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Inbreeding and Gallbladder Cancer Risk: Homozygosity Associations Adjusted for Indigenous American Ancestry, BMI, and Genetic Risk of Gallstone Disease
(MDPI AG, 2024-12-17)
Francisco Ceballos
;
Felix Boekstegers
;
Dominique Scherer
;
Carol Barahona Ponce
;
Katherine Marcelain
<jats:p>Latin Americans have a rich genetic make-up that translates into heterogeneous fractions of the autosomal genome in runs of homozygosity (FROH) and heterogeneous types and proportions of indigenous American ancestry. While autozygosity has been linked to several human diseases, very little is known about the relationship between inbreeding, genetic ancestry, and cancer risk in Latin Americans. Chile has one of the highest incidences of gallbladder cancer (GBC) in the world, and we investigated the association between inbreeding, GBC, gallstone disease (GSD), and body mass index (BMI) in 4029 genetically admixed Chileans. We calculated individual FROH above 1.5 Mb and weighted polygenic risk scores for GSD, and applied multiple logistic regression to assess the association between homozygosity and GBC risk. We found that homozygosity was due to a heterogeneous mixture of genetic drift and consanguinity in the study population. Although we found no association between homozygosity and overall GBC risk, we detected interactions of FROH with sex, age, and genetic risk of GSD that affected GBC risk. Specifically, the increase in GBC risk per 1% FROH was 19% in men (p-value = 0.002), 30% in those under 60 years of age (p-value = 0.001), and 12% in those with a genetic risk of GSD above the median (p-value = 0.01). The present study highlighted the complex interplay between inbreeding, genetic ancestry, and genetic risk of GSD in the development of GBC. The applied methodology and our findings underscored the importance of considering the population-specific genetic architecture, along with sex- and age-specific effects, when investigating the genetic basis of complex traits in Latin Americans.</jats:p>
1
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Gallbladder Cancer Risk and Indigenous South American Mapuche Ancestry: Instrumental Variable Analysis Using Ancestry-Informative Markers
(2023)
Linda Zollner
;
Felix Boekstegers
;
Carol Barahona Ponce
;
Dominique Scherer
;
Katherine Marcelain
<jats:p>A strong association between the proportion of indigenous South American Mapuche ancestry and the risk of gallbladder cancer (GBC) has been reported in observational studies. Chileans show the highest incidence of GBC worldwide, and the Mapuche are the largest indigenous people in Chile. We set out to assess the confounding-free effect of the individual proportion of Mapuche ancestry on GBC risk and to investigate the mediating effects of gallstone disease and body mass index (BMI) on this association. Genetic markers of Mapuche ancestry were selected based on the informativeness for assignment measure, and then used as instrumental variables in two-sample Mendelian randomization analyses and complementary sensitivity analyses. Results suggested a putatively causal effect of Mapuche ancestry on GBC risk (inverse variance-weighted (IVW) risk increase of 0.8% per 1% increase in Mapuche ancestry proportion, 95% CI 0.4% to 1.2%, p = 6.7 × 10−5) and also on gallstone disease (3.6% IVW risk increase, 95% CI 3.1% to 4.0%), pointing to a mediating effect of gallstones on the association between Mapuche ancestry and GBC. In contrast, the proportion of Mapuche ancestry showed a negative effect on BMI (IVW estimate −0.006 kg/m2, 95% CI −0.009 to −0.003). The results presented here may have significant implications for GBC prevention and are important for future admixture mapping studies. Given that the association between the individual proportion of Mapuche ancestry and GBC risk previously noted in observational studies appears to be free of confounding, primary and secondary prevention strategies that consider genetic ancestry could be particularly efficient.</jats:p>
Scopus© Citations 13 1
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Development and internal validation of a multifactorial risk prediction model for gallbladder cancer in a high‐incidence country
(2023)
Felix Boekstegers
;
Dominique Scherer
;
Carol Barahona Ponce
;
Katherine Marcelain
;
Valentina Gárate‐Calderón
<jats:title>Abstract</jats:title><jats:p>Since 2006, Chile has been implementing a gallbladder cancer (GBC) prevention program based on prophylactic cholecystectomy for gallstone patients aged 35 to 49 years. The effectiveness of this prevention program has not yet been comprehensively evaluated. We conducted a retrospective study of 473 Chilean GBC patients and 2137 population‐based controls to develop and internally validate three GBC risk prediction models. The Baseline Model accounted for gallstones while adjusting for sex and birth year. Enhanced Model I also included the non‐genetic risk factors: body mass index, educational level, Mapuche surnames, number of children and family history of GBC. Enhanced Model II further included Mapuche ancestry and the genotype for rs17209837. Multiple Cox regression was applied to assess the predictive performance, quantified by the area under the precision‐recall curve (AUC‐PRC) and the number of cholecystectomies needed (NCN) to prevent one case of GBC at age 70 years. The AUC‐PRC for the Baseline Model (0.44%, 95%CI 0.42‐0.46) increased by 0.22 (95%CI 0.15‐0.29) when non‐genetic factors were included, and by 0.25 (95%CI 0.20‐0.30) when incorporating non‐genetic and genetic factors. The overall NCN for Chileans with gallstones (115, 95%CI 104‐131) decreased to 92 (95%CI 60‐128) for Chileans with a higher risk than the median according to Enhanced Model I, and to 80 (95%CI 59‐110) according to Enhanced Model II. In conclusion, age, sex and gallstones are strong risk factors for GBC, but consideration of other non‐genetic factors and individual genotype data improves risk prediction and may optimize allocation of financial resources and surgical capacity.</jats:p>
5Scopus© Citations 16
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Validation of an NGS Panel Designed for Detection of Actionable Mutations in Tumors Common in Latin America
(2021)
Mauricio Salvo
;
Evelin González-Feliú
;
Jessica Toro
;
Iván Gallegos
;
Ignacio Maureira
<jats:p>Next-generation sequencing (NGS) is progressively being used in clinical practice. However, several barriers preclude using this technology for precision oncology in most Latin American countries. To overcome some of these barriers, we have designed a 25-gene panel that contains predictive biomarkers for most current and near-future available therapies in Chile and Latin America. Library preparation was optimized to account for low DNA integrity observed in formalin-fixed paraffin-embedded tissue. The workflow includes an automated bioinformatic pipeline that accounts for the underrepresentation of Latin Americans in genome databases. The panel detected small insertions, deletions, and single nucleotide variants down to allelic frequencies of 0.05 with high sensitivity, specificity, and reproducibility. The workflow was validated in 272 clinical samples from several solid tumor types, including gallbladder (GBC). More than 50 biomarkers were detected in these samples, mainly in BRCA1/2, KRAS, and PIK3CA genes. In GBC, biomarkers for PARP, EGFR, PIK3CA, mTOR, and Hedgehog signaling inhibitors were found. Thus, this small NGS panel is an accurate and sensitive method that may constitute a more cost-efficient alternative to multiple non-NGS assays and costly, large NGS panels. This kind of streamlined assay with automated bioinformatics analysis may facilitate the implementation of precision medicine in Latin America.</jats:p>
2Scopus© Citations 13
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ADAR1 Transcriptome editing promotes breast cancer progression through the regulation of cell cycle and DNA damage response
(2020)
Eduardo A. Sagredo
;
Alfredo I. Sagredo
;
Alejandro Blanco
;
Pamela Rojas De Santiago
;
RIVAS VERA, SOLANGE VERÓNICA
Scopus© Citations 28 2
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Immune-related IncRNA LINC00944 responds to variations in ADAR1 levels and it is associated with breast cancer prognosis
(2021)
Pamela R. de Santiago
;
Alejandro Blanco
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Fernanda Morales
;
Katherine Marcelain
;
Olivier Harismendy
2Scopus© Citations 38
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Identification of Circulating lncRNAs Associated with Gallbladder Cancer Risk by Tissue-Based Preselection, Cis-eQTL Validation, and Analysis of Association with Genotype-Based Expression
(2022)
Alice Blandino
;
Dominique Scherer
;
Trine B. Rounge
;
Sinan U. Umu
;
Felix Boekstegers
<jats:p>Long noncoding RNAs (lncRNAs) play key roles in cell processes and are good candidates for cancer risk prediction. Few studies have investigated the association between individual genotypes and lncRNA expression. Here we integrate three separate datasets with information on lncRNA expression only, both lncRNA expression and genotype, and genotype information only to identify circulating lncRNAs associated with the risk of gallbladder cancer (GBC) using robust linear and logistic regression techniques. In the first dataset, we preselect lncRNAs based on expression changes along the sequence “gallstones → dysplasia → GBC”. In the second dataset, we validate associations between genetic variants and serum expression levels of the preselected lncRNAs (cis-lncRNA-eQTLs) and build lncRNA expression prediction models. In the third dataset, we predict serum lncRNA expression based on individual genotypes and assess the association between genotype-based expression and GBC risk. AC084082.3 and LINC00662 showed increasing expression levels (p-value = 0.009), while C22orf34 expression decreased in the sequence from gallstones to GBC (p-value = 0.04). We identified and validated two cis-LINC00662-eQTLs (r2 = 0.26) and three cis-C22orf34-eQTLs (r2 = 0.24). Only LINC00662 showed a genotyped-based serum expression associated with GBC risk (OR = 1.25 per log2 expression unit, 95% CI 1.04–1.52, p-value = 0.02). Our results suggest that preselection of lncRNAs based on tissue samples and exploitation of cis-lncRNA-eQTLs may facilitate the identification of circulating noncoding RNAs linked to cancer risk.</jats:p>
12Scopus© Citations 8
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Increase in ADAR1p110 activates the canonical Wnt signaling pathway associated with aggressive phenotype in triple negative breast cancer cells
(2022)
Fernanda Morales
;
Paola Pérez
;
Julio C. Tapia
;
Lorena Lobos-González
;
José Manuel Herranz
2Scopus© Citations 12
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Ski Is Required for Tri-Methylation of H3K9 in Major Satellite and for Repression of Pericentromeric Genes: Mmp3, Mmp10 and Mmp13, in Mouse Fibroblasts
(2020)
Claudio Cappelli
;
Hugo Sepulveda
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Solange Rivas
;
Víctor Pola
;
Ulises Urzúa
Scopus© Citations 2 5
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Concordance Analysis of ALK Gene Fusion Detection Methods in Patients with Non–Small-Cell Lung Cancer from Chile, Brazil, and Peru
(2021)
Gonzalo Sepúlveda-Hermosilla
;
Matías Freire
;
Alejandro Blanco
;
Javier Cáceres
;
Rodrigo Lizana
1Scopus© Citations 6

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