2026-04-18T03:51:39Zhttps://recercat.cat/oai/request

oai:recercat.cat:2445/1757752025-12-05T09:34:09Zcom_2072_1057col_2072_478799col_2072_478917

00925njm 22002777a 4500 dc Pasculli, Barbara author Barbano, Raffaela author Fontana, Andrea author Biagini, Tommaso author Viesti, Maria Pia Di author Rendina, Michelina author Valori, Vanna Maria author Morritti, Maria author Bravaccini, Sara author Ravaioli, Sara author Maiello, Evaristo author Graziano, Paolo author Murgo, Roberto author Copetti, Massimiliano author Mazza, Tommaso author Fazio, Vito Michele author Esteller, Manel author Parrella, Paola author 2021-03-25T16:17:36Z 2021-03-25T16:17:36Z 2020-08-12 2021-03-25T16:17:36Z miR-155-5p is a well-known oncogenic microRNA, showing frequent overexpression in human malignancies, including breast cancer. Here, we show that high miR-155-5p levels are associated with unfavorable prognostic factors in two independent breast cancer cohorts (CSS cohort, n = 283; and TCGA-BRCA dataset, n = 1,095). Consistently, miR-155-5p results as differentially expressed in the breast cancer subgroups identified by the surrogate molecular classification in the CSS cohort and the PAM50 classifier in TCGA-BRCA dataset, with the TNBC and HER2-amplified tumors carrying the highest levels. Since the analysis of TCGA-BC dataset also demonstrated a significant association between miR-155-5p levels and the presence of mutations in homologous recombination (HR) genes, we hypothesized that miR-155-5p might affect cell response to the PARP-1 inhibitor Olaparib. As expected, miR-155-5p ectopic overexpression followed by Olaparib administration resulted in a greater reduction of cell viability as compared to Olaparib administration alone, suggesting that miR-155-5p might induce a synthetic lethal effect in cancer cells when coupled with PARP-1-inhibition. Overall, our data point to a role of miR-155-5p in homologous recombination deficiency and suggest miR-155-5p might be useful in predicting response to PARP1 inhibitors in the clinical setting. Càncer de mama Inhibidors enzimàtics Oncogens Breast cancer Enzyme inhibitors Oncogenes Hsa-miR155-5p up-regulation in Breast Cancer and its relevance for treatment with Poly [ADP-ribose] polymerase 1 (PARP-1) inhibitors