Our results indicated that the overexpression of a miRNA (miR-1) could destroy mitochondria of cancer stem cells. miR-1 was downregulated in melanoma stem cells (MSCs) and breast cancer stem cells (BCSCs) compared with cancer non-stem cells.
Moreover, the miR-1 status was demonstrated using multivariate analysis as an independent worse prognostic factor for both disease-free and breast cancer-specific survival.
MicroRNA-206 (miR-206), as a homolog of miR-1, plays important roles in tumorigenesis and tumor progression of various human malignancies, including breast cancer, endometrial endometrioid carcinoma, rhabdomyosarcoma, glioma, lung cancer, and laryngeal cancer.
In particular, the most differentially expressed miRNAs were validated by qRT-PCR, such that miR-200a-3p and miR-96-5p were up-regulated and miR-1-3p and miR-486-3p were down-regulated in patients with breast cancer with SLN metastasis.
Our further analysis detected substantial involvement of the miRNAs miR-324, miR-93, miR-615 and miR-1 in breast cancer, which was not known previously.