In several cancers, microRNA (miRNAs) play vital roles in tumor initiation, drug resistance, and metastasis. The aim of this study was to examine the expression levels of miR-4301 in human breast cancer and investigate whether its potential roles involved targeting Dopamine receptor D2 (DRD2). Real-time quantitative reverse transcription polymerase chain reaction (qRT-PCR) was also used to examine the expression levels of miR-4301 in human breast cancer cell lines MDA-MB-231, MCF-7, and SKBR3. In these cell lines, MTT assay, immunofluorescence staining, caspase assay, proliferation assay, and flow cytometry were conducted to explore the potential functions of miR-4301. The effects of modulating miR-4301 on transcription levels of DRD2 were subsequently confirmed via qRT-PCR. miR-4301 expression levels were significantly decreased in human breast cancer specimens and cell lines (P < 0.05). Transfection of miR-4301 in breast cancer cells suppressed cell proliferation and induced apoptosis. Expression analysis indicated that miR-4301 was inversely correlated with DRD2 expression in breast cancer specimens. qRT-PCR showed that miR-4301 negatively regulated DRD2 expression. Downregulation of DRD2 expression in MDA-MB-231, MCF-7, and SKBR3 cells suppressed cell proliferation and promoted apoptosis.
Keywords: DRD2; apoptosis; breast cancer; miR-4301.
© 2018 Wiley Periodicals, Inc.