Similarly, the upregulation of circRNA_103809 could also arrest more MDA-MB-231 cells at the G2/M stage (28.0%) relative to OE-vector group (16.4%) (Figures 3DCF). western blotting data for the protein of E-ca, N-ca and Vimentin in circRNA_103809-overexpressing MDA-MB-157 cells (A) and MDA-MB-231 cells (B) after the overexpression of miR-532-3p. All experiments were repeated at least three times. ???< 0.001. Data_Sheet_1.docx (410K) GUID:?0DF8FC3B-FF3D-41BF-80F7-448736437404 Data Availability StatementAll datasets generated for this study are included in the article/Supplementary Material. Abstract Breast malignancy has become one of the most serious disease threatening mankind health in the world. Accumulating studies indicated that circRNAs played an important role in the occurrence and progression of breast malignancy, however, the functions Z-FA-FMK of circRNA_103809 in breast cancer progression remain unclear. Therefore, in this study, we aimed to clarify the potential role and regulatory mechanism of circRNA_103809 in the development of breast cancer. Firstly, the expression level of circRNA_103809 and microRNA-532-3p (miR-532-3p) in breast cancer tissues and normal tissues were detected with the quantitative real-time polymerase chain reaction (RT-qPCR). In addition, the cell proliferation ability, metastasis ability and related pathways were recognized by Cell Counting Kit-8 (CCK-8), circulation cytometry, and western blot, respectively. Furthermore, the connection between circRNA_103809 and miR-532-3p was detected by dual-luciferase reporter assay. Then, our data showed that circRNA_103809 was down-regulated in breast cancer Z-FA-FMK tissues in contrast to adjacent non-tumor tissues, and the relative expression level of circRNA_103809 was closely associated with distant metastasis size, TNM stage, HER-2 status and overall survival time. In addition, our assays showed that this overexpression of circRNA_103809 could significantly inhibit epithelial-mesenchymal transition (EMT) pathway, then suppress breast malignancy cell proliferation and metastasis ability. Moreover, we also found that the antitumor effect induced by circRNA_103809 could be reversed with the addition of miR-532-3p mimics. Taken together, this study showed that circRNA_103809 could inhibit cell proliferation and metastasis in breast malignancy by sponging miR-532-3p, and circRNA_103809 might be a prospective target of breast malignancy therapy. experiments to further confirm the biological role and potential mechanism of circRNA_103809 in breast cancer. Moreover, based on the results of bioinformatic analysis, we hypothesized that miR-532-3p might be the downstream gene of circRNA_103809 based. Above all, our data exhibited that circRNA_103809 might be a encouraging treatment target for breast malignancy. Materials and Methods Z-FA-FMK Tissue Samples Breast cancer and paired non-tumor tissues of 65 breast cancer cases were collected at Nanfang Hospital, and the patients had not been previously treated with radio- or chemotherapy. The inclusion criteria were as follows: (1) Age older than 18 and more youthful Z-FA-FMK than 80 years; (2) Written informed consent; and (3) Main ovarian cancer confirmed pathologically by experienced pathologists. Z-FA-FMK In addition, the exclusion criteria were as follows: (1) Patients with other malignant diseases and (2) Patients with previous neoadjuvant chemotherapy or radiotherapy. All of the tissue samples was evaluated by experienced pathologists at Nanfang Hospital. Furthermore, this research was approved by the Medical Ethics Committee at our center, and all of the included patients signed informed consent voluntarily. Cell Culture The human breast malignancy cell lines (MDA-MB-157, MCF-7, MDA-MB-231, MDA-MB-468, T47D, BT20) and normal breast epithelial cell collection (MCF-10A) were purchased from ATCC (Shanghai, China), and cultured with RPMI-1640 (Gibco) made up of 1% penicillin/streptomycin (Gibco) and 10% FBS (HyClone, Logan, UT, United States). RNA Transfection Lentiviruses [multiplicity of contamination (MOI) of 30] made up of pcDNA3.1 plasmids were used to upregulate the expression of circRNA_103809 in two breast malignancy cell lines. Then, the treated cells including the circRNA_103809-overexpressing group (OE-circRNA_103809) and the unfavorable control group (OE-vector) were also transfected with a negative control p44erk1 sequence (miR-532-3p NC) and miR-532-3p mimics via Lipofectamine 2000 Transfection Reagent (Thermo Fisher, United States). Target sequences are shown in Table 1. TABLE 1 Sequences of oligomers and primers used in the present research. method (Khare.