Furthermore, miR-342, miR-520 for triple negative and hormone receptor-positive types of breast cancer, respectively in collaboration with two detected distinct cluster of miRNAs for different breast cancer cell lines can be applied for more dedicated miRNA-based individualized targeted therapy.
In addition, miR-15/107/182-mediated downregulation of BRCA1 interrupt DNA repair and may change the course of BC therapy. miR-146a and miR-146-5p silencing BRCA1 may trigger formation of triple-negative and basal-like sporadic BC cases. miR-182 might effect the therapy outcome. miR-21 targeted therapy might be useful for the treatment of BRCA2 mutation carriers. miR-342 overexpression and the absence of functional BRCA1 gene might cause synthetic lethality, which might be used as a base for future therapies.
Together, our findings suggest a tumor-suppressive function of miR-342 that could be exploited in the treatment of a subset of BRCA1-mutant hereditary breast cancers.