Downregulation of miR‑505 promotes cell proliferation, migration and invasion, and predicts poor prognosis in breast cancer

Abstract

microRNAs are involved in the tumor progression of various cancer types. The present study aimed to determine the prognostic significance of microRNA-505 (miR-505) in patients with breast cancer and investigate the functional role of miR-505 in BCa progression. The expression of miR-505 was estimated using reverse transcription-quantitative polymerase chain reaction. Kaplan-Meier survival curves and Cox regression analysis were used to evaluate the prognostic value of miR-505 in patients with BCa. Cell experiments were performed to assess the biological function of miR-505 during BCa progression. A significant downregulated expression level of miR-505 was observed in BCa tissues and cells compared with the corresponding controls (P<0.001). The expression of miR-505 was significantly associated with distant metastasis status (P= 0.013) and Tumor-Node-Metastasis staging (P= 0.002). Furthermore, the overall survival time was significantly shorter for patients with low miR-505 expression compared with those with high miR-505 expression (P<0.001). In addition, miR-505 was identified as an independent prognostic factor for BCa. The results of cell experiments revealed that an overexpression of miR-505 could significantly inhibit BCa cell proliferation, migration and invasion, whereas a downregulation of miR-505 significantly enhanced BCa cell proliferation, migration and invasion (P<0.05). In summary, all data indicated that a low miR-505 expression level is associated with a poor prognosis for patients with BCa and promotes tumor cell proliferation, migration and invasion. Therefore, the aberrant expression of miR-505 may serve as a therapeutic target for BCa.

Circular RNA SERPINE2 promotes development of glioblastoma by regulating the miR-361-3p/miR-324-5p/BCL2 signaling pathway

“…The downregulated expression level of miR-505 has been implicated in breast cancer progression. 33 Also, the restored expression of miR-324-5p significantly mitigated gallbladder carcinoma cell migration, invasion, and epithelial-mesenchymal transit (EMT) in vitro , 14 while the overexpression of miR-361-3p fosters migration and invasion of pancreatic cancer cell in vitro. 10 In our study, the predicted circSERPINE2 target miRNAs, miR-361-3p and miR-324-5p, were found to be remarkably downregulated in GM tumor tissues.…”

A Novel TCGA-Validated, MiRNA-Based Signature for Prediction of Breast Cancer Prognosis and Survival

“…In addition, hsa-miR-210 and hsa-miR-221 have been linked with BC invasion and poorer prognosis of patients with BC ( Volinia et al, 2012 ). Other miRNAs associated with prognosis in BC include hsa-miR-155, hsa-miR-206, hsa-miR-133b, hsa-miR-10b, let-7b, hsa-miR-30a, and hsa-miR-505 ( Chen et al, 2012 ; Cheng et al, 2012 ; Ma et al, 2014 ; Parrella et al, 2014 ; Quan et al, 2018 ; Wang et al, 2019 ; Yao et al, 2019 ). However, many previous studies have been limited by small numbers of participants or a lack of extensive study scope, which has limited the translation of their findings into clinical application; for instance, the research results of the hsa-miR-30a only apply to triple-negative breast cancer ( Cheng et al, 2012 ), and the study of the hsa-miR-10b has scarce representation in the population of cases classified as low risk by the Nottingham Prognostic Index ( Parrella et al, 2014 ).…”

<p>lncRNA PART1 Promotes Breast Cancer Cell Progression by Directly Targeting miR-4516</p>

“…miRNAs are a kind of small non-coding RNAs that negatively regulate the mRNA translation at the post-transcriptional level. 14,15 Many kinds of research have demonstrated that lncRNAs often target miRNAs directly to exert their role in promoting the progression of cancer. 16 miR-4516 has been proven to regulate the progression of many cancers, including glioblastoma, hepatocellular carcinoma, papillary thyroid carcinomas and so on.…”