MicroRNA-301a Promotes Cell Proliferation and Resistance to Apoptosis through PTEN/PI3K/Akt Signaling Pathway in Human Ovarian Cancer.
MicroRNAs are endogenous small noncoding RNAs, which play a critical role in regulating various biological and pathologic processes. Furthermore, miR-301a has been detected to be overly expressed in tumorigenic progression of ovarian cancer. However, the effects of miR-301a on ovarian cancer are still unclear.
The objective of this study is to investigate the molecular mechanisms of miR-301a in epithelial ovarian cancer cells.
The miR-301a expression in ovarian cancer cells was detected. Then, cell proliferation, cell cycle, and apoptosis of the miR-301a-mimic-transfected ovarian cancer cells were determined, as well as the effects of the miR-301a mimic on the PTEN/phosphoinositide 3-kinase (PI3K) signaling pathway were explored.
We found that the miR-301a expression levels were markedly upregulated in ovarian cancer tissues and cells, and upregulation of miR-301a-promoted cell viability and proliferation. Our results also showed that the miR-301a-mimic accelerated cell cycle progression of ovarian cancer cells by targeting the CDK4/Cyclin-D1 pathway but not the CDK2/Cyclin-E pathway. Moreover, transfection of the miR-301a mimic into ovarian cancer cells could decrease the PTEN expression while increasing the PI3K and Akt phosphorylation, as compared with the miR-301a inhibitor group and the negative control group.
Therefore, miR-301a should be an oncogene in ovarian cancer, and overexpression of miR-301a promoted proliferation of ovarian cancer cells by modulating the PTEN/PI3K/Akt signaling pathway.
Ni J
,Chen Y
,Fei B
,Zhu Y
,Du Y
,Liu L
,Guo L
,Zhu W
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MicroRNA-21 promotes glioma cell proliferation and inhibits senescence and apoptosis by targeting SPRY1 via the PTEN/PI3K/AKT signaling pathway.
Our study aims to investigate the effect of microRNA-21 (miR-21) on the proliferation, senescence, and apoptosis of glioma cells by targeting SPRY1 via the PTEN/PI3K/AKT signaling pathway.
Glioma tissues and brain tissues were collected for this study after surgical decompression for traumatic brain injury. RT-qPCR was employed to measure mRNA levels of miR-21, SPRY1, PTEN, PI3K, and AKT, and Western blotting was conducted to determine protein levels of SPRY1, PTEN, PI3K, AKT, p-AKT, Caspase-3, Caspase-9, P53, GSK3, and p-GSK3. Human glioma U87 cells were assigned into the blank, negative control (NC), miR-21 mimics, miR-21 inhibitors, siRNA-SPRY1, and miR-21 inhibitors + siRNA-SPRY1 groups, with human HEB cells serving as the normal group. Cell proliferation, cell cycle, and apoptosis were determined by MTT and flow cytometry, respectively.
Compared with control group, an increased expression of miR-21, PI3K, AKT, p-AKT, P53, and p-GSK3, and a decreased expression of SPRY1, PTEN, Caspase-3, and Caspase-9 were observed in the glioma group, and no significant differences were found in the expression of GSK3. SPRY1 was verified to be the target gene of miR-21. Compared with the blank and NC groups, levels of PI3K, AKT, p-AKT, P53, and p-GSK3 increased while levels of SPRY1, PTEN, Caspase-3, and Caspase-9 decreased in the miR-21 mimics and siRNA-SPRY1 groups; the miR-21 inhibitors group reversed the tendency; furthermore, the miR-21 inhibitors group showed decreased cell proliferation but promoted apoptosis, which were opposite to the results of the miR-21 mimics and siRNA-SPRY1 groups.
MicroRNA-21 might promote cell proliferation and inhibit cell senescence and apoptosis of human glioma cells by targeting SPRY1 via the PTEN/PI3K/AKT signaling pathway.
Chai C
,Song LJ
,Han SY
,Li XQ
,Li M
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Repression of microRNA-21 inhibits retinal vascular endothelial cell growth and angiogenesis via PTEN dependent-PI3K/Akt/VEGF signaling pathway in diabetic retinopathy.
Diabetic retinopathy (DR) is a microvascular complication of diabetes and one of the most common causes of blindness in active stage. This study is performed to explore the effects of microRNA-21 (miR-21) on retinal vascular endothelial cell (RVEC) viability and angiogenesis in rats with DR via the phosphatidylinositiol 3-kinase/protein kinase B (PI3K/Akt)/vascular endothelial growth factor (VEGF) signaling pathway by binding to phosphatase and tensin homolog (PTEN). Sprague Dawley (SD) rats were used for establishment of DR models. Target relationship between miR-21 and PTEN was assessed by bioinformatics prediction in combination with dual-luciferase reporter gene assay. Identification of expression of miR-21, PTEN and PI3K/Akt/VEGF signaling pathway-related genes in the retinal tissues was then conducted. In order to assess the contributory role of miR-21 in DR, the RVECs were transfected with mimic or inhibitor of miR-21, or siRNA-PTEN, followed by the detection of expression of PTEN and PI3K/Akt/VEGF-related genes, as well as the measurement of cell viability, cell cycle and apoptosis. Increased expression of miR-21 and PI3K/Akt/VEGF related genes, along with a reduced expression of PTEN was observed in the retinal tissues of DR rats. PTEN was targeted and negatively regulated by miR-21, while the PI3K/Akt/VEGF signaling pathway was activated by miR-21. RVECs transfected with miR-21 inhibitor exhibited promoted viability and angiogenesis, and inhibited apoptosis. To conclude, our results indicated that miR-21 overexpression could potentially stimulate RVEC viability and angiogenesis in rats with DR through activation of the PI3K/Akt/VEGF signaling pathway via repressing PTEN expression, highlighting the potential of miR-21 as a target for DR treatment.
Lu JM
,Zhang ZZ
,Ma X
,Fang SF
,Qin XH
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