Anti nc

miR-10a mimic, miR-10a inhibitor (anti-miR-10a), miRNA mimic negative control (miR-NC), and miRNA inhibitor negative control (anti-NC) were designed and synthesized by Shanghai GenePharma, Ltd. (Shanghai, China). The sequences were as follows: miR-10a mimic sense, 5′-CAAAUUCGGAUCUACAGGGUAUU-3′ and anti-sense, 5′-UACCCUGUAGAUCCGAAUUUGUG-3′; miR-NC sense, 5′-UUCUCCGAACGUGUCACGUTT-3′ and anti-sense, 5′-UACCCUGUAGAUCCGAAUUUGUG-3′; anti-miR-10a, 5′-CACAAAUUCGGAUCUACAGGGUA-3′; anti-NC, 5′-CAGUACUUUUGUGUAGUACAA-3′. Cells were cultured to ~60–70% confluency, following which Lipofectamine^® 2000 RNAiMAX reagent (Thermo Fisher Scientific, Inc.) was used to transfect the MDA-MB-231 and MCF-7 cells with miR-10a mimic, miR-NC, anti-miR-10a or anti-NC (all 100 nM) for 48 h at 37°C according to the manufacturer's protocol.

miR-634 mimic (5-AACCAGCACCCCAACUUUGGACGGTATTCGCACTGGATACGACGAACTTT-3), miR-negative control (NC; 5-ACUACUGAGUGACAGUAGA-3), miR-634 inhibitor (5-CACUACUUUUGUGUCCCACUU-3) and antiNC (5-CAGUACUUUUGUGUAGUACAA-3) were purchased from Guangzhou RiboBio Co., Ltd. (Guangzhou, China). The open reading frame of heat shock-related 70 kDa protein 2 (HSPA2) was inserted into pcDNA3.1 vector (Invitrogen; Thermo Fisher Scientific, Inc.) to generate the pcDNA3.1/HSPA2 overexpression vector. A total of 5×10⁵ cells were transfected with 2.5 µg NC, miR-634 mimic, antiNC, miR-634 inhibitor, empty vector or HSPA2 overexpression vector using Lipofectamine 2000 reagent (Invitrogen; Thermo Fisher Scientific, Inc.) according to the manufacturer's protocol. Overexpression efficiency was analyzed via western blot analysis. After 48 h of transfection, the cells were harvested and used for further experiments.