DSCAM-AS1 promotes tumor growth of breast cancer by reducing miR-204-5p and up-regulating RRM2.

Abstract

Breast cancer (BC) is a common malignancy worldwide. More than 3 700 000 women die of BC every year. DSCAM-AS1 was overexpressed several kinds of cancer and miR-204-5p was lowly expressed, which indicated that miR-204-5p had anti-tumor activity and DSCAM-AS1 had pro-tumor activity. We intended to analyze DSCAM-AS1, miR-204-5p, and ribonucleotide reductase M2 (RRM2). Microarray analysis and quantitative Real Time fluorescence Polymerase Chain Reaction (qRT-PCR) were employed to determine DSCAM-AS1 and miR-204-5p expression. Luciferase reporter assay was applied to examine the target relationship between DSCAM-AS1, miR-204-5p, and RRM2. Cell Counting Kit-8 (CCK-8 assay), transwell assay, and flow cytometry were used to detect cell proliferation, invasion, and apoptosis. The expression of DSCAM-AS1, miR-204-5p, and RRM2 were confirmed by Western blot. We also conducted in vivo assay to verify the effect of DSCAM-AS1. DSCAM-AS1 was up-regulated, while miR-204-5p was down-regulated in BC tissues and cells. DSCAM-AS1 directly targeted miR-204-5p. DSCAM-AS1 promoted the proliferation and invasion of BC cells by reducing miR-204-5p and inhibiting miR-204-5p expression. DSCAM-AS1 expression was related to the expression of RRM2, and miR-204-5p could reverse the function of DSCAM-AS1. RRM2 was up-regulated in BC cells, and miR-204-5p inhibited RRM2 expression by targeting RRM2. Overexpression of RRM2 stimulated proliferation and cell invasion and impeded apoptosis. In vivo experiments showed that knockdown of DSCAM-AS1 decreased the tumorigenesis of BC cells, increased the expression of miR-204-5p. DSCAM-AS1 promoted proliferation and impaired apoptosis of BC cells by reducing miR-204-5p and enhancing RRM2 expression. DSCAM-AS1/miR-204-5p/RRM2 may serve as novel therapeutic targets for BC.