ISSN: 0034-8376
eISSN: 2564-8896



Whole Sequencing of the MitochondWhole Sequencing of the Mitochondrial Genome of Breast Cancer Tissue in Mexican-Mestizo Postmenopausal Women with Different Body Mass Indexrial Genome of Breast Cancer Tissue in Mexican-Mestizo Postmenopausal Women with Different Body Mass Index



Nishi Adams-Reyes, Obesity Research Unit, Faculty of Medicine, Universidad Nacional Autónoma de México; Obesity Clinic, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
Ramón M. Coral-Vázquez, Postgraduate and Research Section, Escuela Superior de Medicina, Instituto Politécnico Nacional; Sub directorate of Teaching and Research, Centro Médico Nacional 20 de Noviembre, Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado, Mexico City, Mexico
Juan P. Méndez, Obesity Research Unit, Faculty of Medicine, Universidad Nacional Autónoma de México; Obesity Clinic, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán; Mexico City, Mexico
Alberto Tenorio, Instituto de Enfermedades de la Mama, FUCAM, Mexico City, Mexico
Juan Carlos Zenteno, Genetics Department Research Unit, Instituto de Oftalmología Conde de Valenciana and epartment of Biochemistry, Faculty of Medicine, Universidad Nacional Autónoma de México, Mexico City, Mexico
Vanessa Villegas-Ruiz, Genetics Department, Research Unit, Instituto de Oftalmología Conde de Valenciana, Mexico City, Mexico
Patricia Canto, Obesity Research Unit, Faculty of Medicine, Universidad Nacional Autónoma de México; Obesity Clinic, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico


Background: Mitochondrial and oxidative stress has been related to obesity and breast cancer being this cancer more frequent and more aggressive in postmenopausal women with obesity. Objective: The objective of this study was to investigate whether Mexican-Mestizo postmenopausal women with breast cancer and obesity present different somatic mutations in the mitochondrial DNA (mtDNA) when compared to women with normal body mass index (BMI). Subjects and Methods: We included six Mexican-Mestizo postmenopausal women bearing breast cancer and who underwent mastectomy or breast-conserving surgery. BMI was determined in each case. Patients’ genomic DNA was isolated from blood leukocytes and tumor tissue samples. Whole mtDNA sequence was determined by MitoChip v2.0 mitochondrial resequencing array, and data were analyzed using the GeneChip Sequence Analysis Software. Tumor mtDNA sequence was compared with matched leukocyte mtDNA sequence. Results: Three women had a normal BMI and three presented obesity. Overall, we found 64 genetic variants: 53.1% were somatic mutations and 46.9% were polymorphisms; 44.1% were in the non-coding region and 55.9% were in genes that encode for mitochondrial proteins. Among the somatic mutations, 67.7% were in patients with normal BMI and 32.3% in patients with obesity. Conclusions: We did not find a higher frequency of mitochondrial somatic mutations in postmenopausal women with breast cancer and obesity compared to those with normal BMI. However, results could be due to the small number of women studied. (REV INVEST CLIN. 2019;71:237-45)



Keywords: Breast cancer. Body mass index. Mexican-Mestizo postmenopausal women. Mitochondria genome. Somatic mutations.