The Application of Clinical Genetics (May 2024)

Functional Analysis of BRCA1 3’UTR Variants Predisposing to Breast Cancer

  • Sierra-Díaz DC,
  • Cabrera R,
  • Gonzalez-Vasquez LA,
  • Angulo-Aguado M,
  • Llinás-Caballero K,
  • Fonseca-Mendoza DJ,
  • Contreras-Bravo NC,
  • Restrepo CM,
  • Ortega-Recalde O,
  • Morel A

Journal volume & issue
Vol. Volume 17
pp. 57 – 62

Abstract

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Diana Carolina Sierra-Díaz,1 Rodrigo Cabrera,1,2 Laura Alejandra Gonzalez-Vasquez,1 Mariana Angulo-Aguado,1,3 Kevin Llinás-Caballero,1,4 Dora Janeth Fonseca-Mendoza,1 Nora Constanza Contreras-Bravo,1 Carlos Martin Restrepo,1 Oscar Ortega-Recalde,1,5 Adrien Morel1 1Center for Research in Genetics and Genomics (CIGGUR), Institute of Translational Medicine (IMT), School of Medicine and Health Sciences, Universidad Del Rosario, Bogotá, Colombia; 2Laboratorio de Biología Molecular y Pruebas Diagnósticas de Alta Complejidad, Fundación Cardioinfantil-Instituto de Cardiología, Bogotá, Colombia; 3Growth Factors, Nutrients and Cancer Group, Molecular Oncology Programme, Centro Nacional Investigaciones Oncológicas (CNIO), Madrid, Spain; 4Institute for Immunological Research, University of Cartagena, Cartagena, Colombia; 5Departamento de Morfología, Facultad de Medicina, Universidad Nacional de Colombia, Bogotá, D.C, ColombiaCorrespondence: Adrien Morel, School of Medicine and Health Sciences, Center for Research in Genetics and Genomics (CIGGUR), Institute of Translational Medicine (IMT), Universidad Del Rosario, Cra 24# 63c - 69, Bogotá, 111221, Colombia, Tel +57-6012970200, Email [email protected]: Breast Cancer (BC) is the main female cancer diagnosed worldwide, and it has been described that few genes, such as BRCA1, have a high penetrance for this type of cancer. In this manuscript, we were interested in evaluating the effect of 3’UTR variants on BRCA1 expression.Patients and Methods: To accomplish this objective, Whole Exome Sequencing (WES) data of 400 patients with unselected BC was used to filter variants located in the region of interest of BRCA1 gene, finding two of them (c.*36C>G and c.*369_373del). miRGate and miRanda in silico tools were used to predict microRNA (miRNA) interaction.Results: The two variants (c.*36C>G, c.*369_373del) were predicted to affect miRNA interaction. After cloning of BRCA1 3’UTR into pMIR-Report vector, the construct was transfected into two BC cell lines (MDA-MB-231 and MCF-7), and the variant c.*36C>G evidenced overexpression of reporter gene luciferase, showing that the transcript was not being degraded by the miRNA in MDA-MB-231 cells.Conclusion: The variant seems to protect against Triple Negative BC probably due to the expression level of miRNA in this particular cell line (MDA-MB-231). This is consistent with the clinical history of the patients who harbor BC Hormone Receptors positive (HR+).Keywords: miRNA, 3’UTR variant, breast cancer, BRCA1

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