Affiliations: [a] Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile | [b] Centro de Cáncer, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago, Chile
Correspondence:
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Corresponding author: Pilar Carvallo, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Casilla 114-D, Santiago, Chile. Tel.: +56 2 2686 2705; Fax: +56 2 2686 2349; E-mail:pcarvallo@bio.puc.cl
Abstract: BACKGROUND: Mechanisms that lead to the reduced expression of BRCA1 in
triple-negative breast cancer (TNBC) tumors are not fully understood. A
possible cause is overexpression of miR-146a and miR-638, which regulate
BRCA1 expression in other cancers. OBJECTIVE: To evaluate the expression of these microRNAs in relation to
BRCA1 expression in TNBC tumors. METHODS: Expression of both microRNAs was assessed by real time qPCR using
Taqman microRNA assays in TNBC tumors. Results were related to protein
expression of BRCA1 and patient's survival. RESULTS: miR-146a and miR-638 were overexpressed in 36% and 59% of
TNBC tumors, respectively. Overexpression was preeminent in BRCA1-deficient
tumors and significantly associated to a better overall survival. CONCLUSION: Both miRNAs are potential biomarkers for improved overall
survival in patients with BRCA1-deficient TNBC tumors.
Keywords: BRCA1, breast cancer, microRNA, miR-146a, miR-638, triple negative breast cancer
