Our results showed that the doxorubicin treatment alters the proper functioning of the cell cycle by modulation not only the expression of this miRNA family but also some of its theoretically targeted genes: doxorubicin exposure reduced the expression of the aforementioned genes, except E2F1, E2F3, and CDK2, in MDA-MB-231 and E2F1 in MDA-MB-468, both triple negative breast cancer cell lines. This evidence concerns the gene CDK2 and triple-negative breast carcinoma.