RESUMEN
Objective:To investigate the effect of miR-27b-3p on radiation resistance of breast cancer cells.Methods:The relative expression levels of miR-27b-3p in normal tissues and breast cancer tissues were analyzed through GEO database and verified by the qRT-PCR assay. Cloning formation, immunofluorescence, and EDU assay were used to assess the functions of miR-27b-3p on radioresistance of breast cancer cells. The luciferase reporter assay was used to verify whether miR-27b-3p directly targeted PLK2 mRNA. A rescue experiment was performed to identify the influence of PLK2 overexpression on miR-27b-3p regulated radioresistance.Results:The expression level of miR-27b-3p in both breast cancer tissues ( t=2.99, P<0.01) and breast cancer cells ( t=21.21, 32.88, P<0.05) was significantly higher than those in normal breast tissues and cells, especially, it was elevated in radioresistant MCF-7R cells ( t=25.63, P<0.05). Overexpression of miR-27b-3p enhanced the cloning efficiency of MCF-7 cells ( t=10.32, P<0.05), and had a protective effect on the proliferation of irradiated MCF-7 cells ( t=8.77, 8.26, 8.03, P<0.05). But interference of miR-27b-3p reduced the cloning efficiency and proliferation of MCF-7R cells ( t=40.00, P<0.05) after irradiation with different doses( t=8.54, 8.32, 8.23, P<0.05). Moreover, PLK2 was verified to be a direct target of miR-27b-3p, and overexpression of PLK2 inhibited miR-27b-3p-mediated radioresistance of breast cancer cells (MCF-7: t=9.66, P<0.05; MCF-7R: t=6.42, P<0.05). Conclusions:miR-27b-3p contributes to the radioresistance of breast cancer cells by targeting PLK2.
RESUMEN
Objective: To investigate the potential role of plasmatic microRNA-27b-3p (miR-27b-3p) as a biomarker in early diagnosis of gastric cancer (GC). Methods: The expressions of miR-27b-3p in plasma from 46 GC patients and 40 age- and gender-matched healthy controls were detected by real-time fluorescent quantitative-PCR (RFQ-PCR). The expression of miR-27b-3p in peripheral blood cells from 12 GC patients and 12 healthy controls were also detected by RFQ-PCR. The association of plasmatic miR-27b-3p level with the clinicopathological features of GC was statistically analyzed. The sensitivity and specificity of miR-27b-3p for diagnosis of GC were evaluated by receiver operating characteristic (ROC) curve and area under the curve (AUC). Results: The level of plasmatic miR-27b-3p in GC patients was significantly lower than that in the healthy controls (P 0.05). The downregulation of plasmatic miR-27b-3p level was correlated to the differentiation of GC (P 0.05). The ROC curve analysis showed that AUC value was 0.724, and the sensitivity and specificity of plasmatic miR-27b-3p used for differential diagnosis of GC were 60.0% and 76.1%, respectively. Conclusion: Downregulation of plasmatic miR-27b-3p level may indicate the occurrence of GC. MiR-27b-3p may be a potential biomarker for early diagnosis of GC.