Novel lncRNA PSMG3­AS1 functions as a miR­143­3p sponge to increase the proliferation and migration of breast cancer cells.

Long non­coding RNAs (lncRNAs) are considered to be important regulators in breast cancer. In the present study, the potential mechanisms and functional roles of lncRNA PSMG3­antisense (AS)1 were investigated in vivo and in vitro. The relative expression levels of lncRNA PSMG3­AS1 and microRNA (miR)­143­3p were determined using reverse­transcription quantitative PCR. The protein expression levels of collagen type 1 alpha 1 (COL1A1) and proliferating cell nuclear antigen (PCNA) were obtained using western blot analysis. Bioinformatics analysis was used to identify the relationship between PSMG3­AS1, miR­143­3p and COL1A1. Colony forming and Cell Counting Kit­8 assays were used to detect cell proliferation. Transwell and wound­healing assays were used to determine cell migration. The results of the present study demonstrated that PSMG3­AS1 expression was increased in breast cancer tumor tissues and cell lines, and that of miR­143­3p was decreased. Knockdown of PSMG3­AS1 increased the level of miR­143­3p expression, which led to the mitigation of proliferation and migration capacity in breast carcinoma cells. Additionally, PSMG3­AS1 knockdown was demonstrated to reduce the mRNA and protein expression levels of COL1A1. miR­143­3p mimic transfection reduced proliferation and migration in MDA­MB­231 and MCF­7 cell lines. Furthermore, miR­143­3p inhibition significantly increased the proliferation and migration of breast cancer cells compared with the negative control group. The mRNA and protein expression levels of PCNA were reduced in the MCF­7 cell line when transfected with miR­143­3p mimics and si­PSMG3­AS1. However, PCNA expression was increased in cells transfected with a miR­143­3p inhibitor. In conclusion, the results of the present study identified a novel lncRNA PSMG3­AS1, which serves as a sponge for miR­143­3p in the pathogenesis of breast cancer. PSMG3­AS1 may be used as a potential therapeutic target gene in breast cancer treatment.