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Objective To investigate the molecular mechanism of SNHG5 regulating the proliferation, invasion and apoptosis of glioblastoma multiforme (GBM) cells by targeting miR-421. Methods Real-time quantitative PCR test was performed to detect the expression levels of SNHG5 and miR-421 in 31 cases of GBM tissue samples and 32 cases of normal brain tissue samples. After increasing or decreasing SNHG5 expression in U87 cell lines by lentivirus or plasmid transfection, the changes of miR-421 expression were measured by real-time quantitative PCR, to explore the correlation between SNHG5 and miR-421 in GBM. The dual-luciferase reporter test was performed to explore the target interaction of SNHG5 and miR-421. The plasmids with low expression of SNHG5 and miR-421 were cotransfected into U87 cells for the rescue experiment. CCK-8 test, Transwell test, flow cytometry and tumor cell xenograft in nude mice were used to verify molecular mechanism of SNHG5 regulating the proliferation, invasion and apoptosis of GBM in vitro and vivo. Results The expression level of miR-421 was decreased in U87 cell line after SNHG5 upregulation. In addition, the expression level of miR-421 was increased in U87 cell line after SNHG5 downregulation (P < 0.05). The expression level of SNHG5 was correlated negatively with the expression of miR-421 in GBM and U87 cell line. The result of luciferase reporter tests indicated SNHG5 targetedly interacted with miR-421. Rescue experiment results showed that compared with si-SNHG5+miR-421-inhibitor group, the proliferation, invasion and anti-apoptosis ability of U87 cells were significantly inhibited in the si-SNHG5+control-inhibitor group, the expression levels of BAX and p21 were significantly higher, the expression levels of CyclinD1 and Bcl-2 were lower remarkably (P < 0.05). Conclusion SNHG5 promotes the proliferation, invasion and anti-apoptosis of GBM by targeting miR-421 and regulating the expression of CyclinD1, p21, BAX and Bcl-2. Downregulation of miR-421 is related to SNHG5 overexpression in GBM.
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Purpose To detect the expression of miR-421 in serum and tissues of prostate cancer ( PCa) and its clinical value inPCa. Methods 62 cases of PCa and 46 cases of benign prostatic hyperplasia (BPH) were enrolled in the Department of Urology, the First Affiliated Hospital of Anhui Medical Universi-ty from December 2015 to December 2016. Another 42 cases of paraffin-embedded sections of PCa and 37 cases of BPH were al-so used in this study. The expression of miR-421 in serum was detected by real-time PCR (qRT-PCR). The expression of miR-421 in tissues was detected by in situ hybridization. Results The expression of miR-421 in serum of patients with PCa and BPH was ( 2. 52 ± 1. 70 ) and ( 0. 82 ± 0. 65 ), respectively. Compared with the expression of BPH, the expression of miR- 421 in serum of PCa was increased (P＜0. 05). The expression of miR-421 in serum and tissues of patients with PCa was corre-lated with Gleason score, TNM clinical stage, and bone metasta-ses (P＜0. 05). It was not related to the patient's age, preop-erative PSA level and other factors ( P＞0. 05). Conclusion miR-421 is more abundant in PCa patients than that in patients with benign prostatic hyperplasia, and is expected to become a diagnostic marker for PCa.
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AIM:To investigate the molecular mechanism of inhibition of miR-421 expression promoting radiosensitivity in the cervical cancer cells.METHODS:Cervical cancer lines HeLa, SiHa, C33A and CaSki were transfected with miR-421 inhibitor or negative control nucleotide using Lipofectamine 2000 kit, and the levels of miR-421 expression in the cervical cancer lines and endometrial epithelium cell line ESC were detected by real-time PCR.These cells with transfection were exposed to various doses of X-ray (0, 2, 4, 6 and 8 Gy).After 48 h, the cell viability, LDH leakage rate and apoptotic rate were measured respectively by MTT assay, ELISA and flow cytometry with Annexin V-FITC/PI staining.The protein levels of cleaved caspase-9, caspase-9, cleaved PARP, PARP, Bcl-2 and Bax were monitored by Western blot.RESULTS:Low miR-421 levels was found in the ESC cells, while high miR-421 levels were observed in the HeLa, SiHa, C33A and CaSki cells.The level of miR-421 in the cells transfected with miR-421 inhibitor was significantly lower than that in negative control group (P<0.05).The viability and LDH leakage rate of the cervical cancer cells with low miR-421 expression were notablely lower than those in negative control group, and the apoptotic rate at 72 h was remarkablely increased (P<0.05) under the same conditions.The results of Western blot indicated that, after exposure to ionizing radiation, the protein levels of cleaved caspase-9, cleaved PARP and Bcl-2 were significantly increased, while the protein level of Bax was significantly decreased in the cervical cancer cells with low miR-421 expression compared with negative control group (P<0.05).CONCLUSION:miR-421 is lowly expressed in the normal endometrial epithelial cells, but highly expressed in the cervical cancer cells.Down-regulation of miR-421 expression significantly inhibits the growth and enhances the radiosensitivity of cervical cancer cells at least partly via activating caspase-9 apoptosis pathway, thus promoting Bcl-2 and inhibiting Bax expression.