ABSTRACT
AIM:To clarify the effect of miR-519d-3p on high glucose-induced human retinal microvascular endothelial cells(HRMEC)dysfunction and angiogenesis, and to elucidate the regulatory mechanism of miR-519d-3p on hypoxia inducible factor 1 subunit alpha(HIF-1α).METHODS: The normal glucose(NG)and high glucose(HG)cell models were established by inducing HRMEC with 5 and 30 mmol/L glucose, respectively. Control group: HG cell model was transfected with negative control mimics; mannitol group: the control group was added with 25 mmol/L mannitol; miR-519d-3p overexpression group: HG cell model was transfected with miR-519d-3p mimics; miR-519d-3p combined with HIF-1α overexpression group: HG cell model was co-transfected with miR-519d-3p mimics and HIF-1α overexpression vector. The expression of miR-519d-3p in each group was tested by real-time fluorescence quantitative PCR. The expression of HIF-1α protein in each group was tested by Western blotting. The binding sites between miR-519d-3p and HIF-1α were detected by luciferase reporter gene assay. The cell proliferation of each group was detected by CCK-8. The cell apoptosis of each group was tested by Hoechst 33342 staining. The protein expression of extracellular fluid inflammatory factors tumor necrosis factor-α(TNF-α), interleukin(IL)-1β and IL-6 in each group was tested by ELISA. The formation of new capillary lumen-like structures was detected by tubule formation assay.RESULTS: Compared with the NG, miR-519d-3p expression was significantly reduced in the HG cell model, while HIF-1α protein expression was significantly increased in the HG(all P<0.01). Compared with the control group, HIF-1α protein expression was significantly reduced in the miR-519d-3p overexpression group(P<0.01). The “CGUGAAA” sequence of miR-519d-3p could specifically bind to the “GCACUUU” sequence of HIF-1α 3'-untranslated region(3'-UTR). Compared with the control group, the miR-519d-3p overexpression group showed a significant increase in 24, 48 and 72h absorbance values, a significant decrease in cell apoptotic rate, a significant decrease in the concentrations of TNF-α, IL-1β and IL-6, and a significant decrease in the number of new capillary lumen-like structures(all P<0.01). Compared with the miR-519d-3p overexpression group, the miR-519d-3p combined with HIF-1α overexpression group showed a significant decrease in 24, 48 and 72h absorbance values, a significant increase in cell apoptotic rate, a significant increase in the concentrations of TNF-α, IL-1β and IL-6, and a significant increase in the number of new capillary lumen-like structures(all P<0.01). There was no difference between the control group and mannitol group in the comparison of the above indicators(all P>0.05).CONCLUSION: miR-519d-3p expression is down-regulated while HIF-1α protein expression is up-regulated in high glucose induced HRMEC model. HIF-1α is a target gene of miR-519d-3p. The miR-519d-3p targets HIF-1α to increase cell proliferation and reduce cell apoptosis and inflammation, thereby alleviating high glucose-induced HRMEC dysfunction and inhibiting angiogenesis.
ABSTRACT
@#[Abstract] Objective: To explore the effect of lncRNA HOTAIR/miR-519d-3p/cyclin D1 (CCND1) axis on the proliferation and metastasis of breast cancer cells and its underlying mechanism. Methods: A total of 50 pairs of breast cancer tissues and corresponding para-cancer tissues resected from breast cancer patients in the Department of Breast Surgery, the Third Hospital of Nanchang from March 2017 to February 2019 were collected for this study. The expression level of HOTAIR in breast cancer tissues and paired paracancer tissues was detected by qPCR, in addition, the expressions of HOTAIR and miR-519d-3p in normal breast epithelial cells and breast cancer cell lines were also detected. Breast cancer SKBR3 cells were divided into NC group (without any treatment), si-HOTAIR group, mir-519d-3p mimics group, miR-519d-3p mimic+pcHOTAIR group, miR-519d-3p mimic+pcCCND1 group, and si-HOTAIR+ pcCCND1 group. The proliferation ability of SKBR3 cells was detected by CCK-8. Invasion and migration of SKBR3 cells were detected by Transwell. The expression levels of E-cadherin, N-cadherin, Vimentin and CCND1 in SKBR3 cells were detected by Western blotting. The targeting relationship between HOTAIR and miR-519d-3p, miR-519d-3p and CCND1 was detected by Dualluciferase reporter gene system. Results: HOTAIR was highly expressed in breast cancer tissues and cell lines, with the highest expression in SKBR3 cells. HOTAIR knockdown significantly inhibited the proliferation, invasion and migration of SKBR3 cells, as well as increased the expression level of E-cadherin and decreased the expression levels of N-cadherin and Vimentin. Dual-luciferase reporter gene assay showed that HOTAIR targetedly down-regulated the expression of miR-519d-3p, and miR-519d-3p targetedly downregulated the expression of CCND1. Further studies showed that knockout of HOTAIR inhibited the EMT, proliferation, invasion and migration of SKBR3 cells through enhancing the inhibitory effect of miR-519d-3p on CCND1 expression (all P<0.05). Conclusion: HOTAIR knockdown inhibits proliferation and metastasis of SKBR3 cells by regulating the axis of miR-519d-3p/CCND1.
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Aim To determine whether 8-bromo-7-me-thoxychrysin ( BrMC) inhibits in vitro carcinogenicity via up-regulating miR-519d expression and down-regu-lating Twist1 expression in liver cancer stem-like cells ( LCSLCs) derived from SMMC-7721 cell line. Meth-ods The second generation spheroids derived from SMMC-7721 cell line were obtained by sphere-forming assay and were considered as LCSLCs . Then LCSLCs were treated with various concentrations ( 1.0, 3.0, 10.0 μmol·L-1) of BrMC. The expression level of miR-519d was detected using real-time PCR. And in vitro carcinogenicity was investigated by sphere-forming assay and clone-forming assay in agar. The transcrip-tional activity and protein expression of Twist1 were an-alyzed using luciferase reporter assay and Western blot. Moreover, the molecular mechanism of BrMC was elucidated via miR-519 mimic transfection and Twist1 gene transduction, respectively. Results Compared with SMMC-7721 cells, miR-519d-3p was low-ex-pressed and Twist1 was over expressed in LCSLCs. And the sphere-forming ratio and the clone-forming ra-tio decreased by treatment with BrMC ( 1.0, 3.0, 10.0 μmol·L-1) in a dose-dependent manner. Fur-thermore, luciferase reporter assay demonstrated miR-519d could directly target the 3′ untranslated region of Twist1 mRNA and regulate protein expression. miR-519d mimic enhanced the effects of BrMC (3.0 μmol ·L-1) . However, Twist1 gene transduction effective-ly reversed the effects of BrMC ( 3.0 μmol·L-1) . Conclusion BrMC inhibits in vivo carcinogenicity via regulating miR-519/Twist1 signal axis in LCSLCs de-rived from SMMC-7721 cell line.
ABSTRACT
The late T cell activation gene, 519, is expressed in antigen specific, growth factor dependent T cell lines and clones but not in T or B cell tumors, other hematopoietic cells, tonsil, muscle, lung, or liver. Resting peripheral blood lymphocytes (PBLs) express little or no 519mRNA, but levels increase dramatically 5~7 days after activation with alloantigen or mitogen. Four alternatively spliced transcripts of the gene exist. 520 cDNA, the predominate gene transcript, encodes a protein of 144 amino acids and has a potentially cleavable hydrophobic leader of 15 amino acids at the amino terminus. The 519 transcript encodes a 129 amino acid product. An polyclonal antiserum was produced by immunizing a rabbit with a synthetic peptide corresponding to the second hydrophobic region common to both 519 and 520. 14.3 and 15.5kD protein bands were immunoprecipitated (IP) from radiolabled in-vitro translated products, 519 and 520 respectively. A protein of 14.3kD was detected by IP of in-vivo 35S cysteine and methionine radiolabled cytotoxic T lymphocytes (CTL) cells. Western blotting of lysates from a CTI line and a B cell tumor line revealed a distinct band at 14.3kD only in CTL lanes. Both CTL and peripheral blood lymphocytes expressed the greatest amount of 519/520 protein in cells 5~7 days after stimulation. Western blotting of differential centrifugation samples localized 519/520 protein to the granule layer. Comparison of 519/520 proteins with other known protin sequences identified homology with surfactant associated and sphyngolipid activating proteins. A homologous gene(NKC5) is present in natural killer cells (NK). The increase in the amount of the 519/520 protein product in CTL and PBL parallel increases in mRNA expression. 519/520 and related gene products are present in CTL, PBL and NK cells, have structural similarity with lipid associating proteins.