Effects of miR-599 targeting YAP1 on proliferation, invasion and apoptosis of bladder urothelial carcinoma cells

The aim of this study was to investigate the effects of microRNA (miR)-599 targeting Yes-associated protein 1 (YAP1) on the proliferation, invasion and apoptosis of bladder urothelial carcinoma cell line J82. J82 cells cultured in vitro were divided into miR-nc group (transfected with analog negative control miR-NC), miR-599 group (transfected with miR-599 analog), miR-599 + pcDNA3.1 group (co transfected with miR-599 analog and pcDNA3.1 empty vector), miR-599 + pcDNA3.1-YAP1 group (co transfected with miR-599 analog and pcDNA3.1-YAP1 over expression vector), the targeting relationship between miR-599 and YAP1 was detected by double luciferase reporter gene assay, the expression level of miR-599 was detected by real-time fluorescence quantitative PCR, the expression of YAP1 was detected by Western blot, cell proliferation was detected by MTT method, cell invasion was detected by Transwell's cell experiment, and apoptosis was detected by flow cytometry. The miR-599 was able to bind to YAP1 targetingly; compared with those in miR-NC group, miR-599 expression level and apoptosis rate in miR-599 group were significantly higher, however, the expression level of YAP1 protein and the abilities of cell proliferation and invasion were significantly lower (P < 0.05); there was no significant difference in the above indexes between miR-599 group and miR-599 + pcDNA3.1 group (P > 0.05); compared with those in miR-599 + pcDNA3.1 group, the expression level of YAP1 protein and the abilities of cell proliferation and invasion in miR-599 + pcDNA3.1-YAP1 group were significantly higher, while the apoptotic rate was significantly lower (P < 0.05). MiR-599 may inhibit the proliferation, invasion and promote apoptosis of bladder urothelial carcinoma J82 cells by targetingly regulating YAP1.

MicroRNA-559 plays an inhibitory role in the malignant progression of glioblastoma cells by directly targeting metadherin

Purpose: Several microRNAs (miRNAs) that are aberrantly expressed in glioblastoma multiforme (GBM) play a significant role in GBM formation and progression. The expression profile and functions of miR-559 in GBM remain unclear. Here, we quantified the expression and investigated the involvement of miR-559 in the oncogenicity of GBM cells in vitro and in vivo.

Material and methods: Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) was carried out to determine miR-559 expression in GBM tissues and cell lines. A series of functional assays was performed to evaluate the effects of miR-559 overexpression on GBM cell proliferation, apoptosis, migration, and invasion in vitro and on GBM tumor growth in vivo. The regulatory mechanisms of miR-559 action in GBM cells were then explored.

Results: The expression of miR‑559 was lower in GBM tissues and cell lines and significantly correlated with the Karnofsky performance score and tumor size among patients with GBM. Exogenous miR‑559 expression inhibited GBM cell proliferation, migration, and invasion and promoted apoptosis. MiR-559 overexpression decreased tumor growth in vivo. Mechanistic experiments confirmed metadherin (MTDH) as a direct target gene of miR-559 in GBM. Silencing of MTDH induced effects similar to those of miR-559 upregulation in GBM cells, whereas MTDH expression restoration attenuated the antitumor effects of miR‑559 in GBM cells. Protein kinase B (AKT) in the phosphatase and tensin homolog (PTEN)–AKT signaling pathway was found to be deactivated in GBM cells after upregulation of miR-559 both in vitro and in vivo.

Conclusion: MiR-559 acts as a tumor suppressor in GBM cells in vitro and in vivo, at least in part through the downregulation of MTDH and inhibition of AKT in the PTEN–AKT pathway. Therefore, targeting the miR-559–MTDH axis may be a promising therapeutic strategy for patients with GBM.