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Objective MicroRNA-145 (miR-145) is underexpressed in breast cancer. The study aimed to explore the regulatory effect of miR-145 on breast cancer MCF-7 cells by investigating the association of miR-145 with ADAM17 and EGFR. Methods The MCF-7 breast cancer cells were divided into three groups: the transfection group (transfected with microRNA-145 mimics), the control group (without transfection) and the nonsense sequence group (transfected with nonsense microRNA). MTT, transwell and real-time quantitative fluorescence polymerase chain reaction(qPCR) were respectively used to detect the proliferative capacity, invasive ability and expression of MCF-7 breast cancer cells after the transfection of miR-145 in three groups. ADAM17 and EGFR mRNA and protein levels in three groups of breast cancer MCF-7 cells were detected by qPCR and western blot. Results The results of qPCR showed that the relative expression of miR-145 was significantly higher in transfection group (13964.33±1265.30) than those in control group (1.00±0.05) and nonsense sequence group (1.03±0.15) and the difference was statistically significant (P<0.01); the expression of ADAM17 mRNA in transfection group (1.71±0.08) was significantly higher than that in control group (1.00±0.07) and the difference was statistically significant (P<0.01). Compared with the nonsense sequences at 24 h, 48 h, and 72 h, the inhibition rate of MCF-7 in transfection group was significantly increased (P<0.01). The results of transwell invasion showed that the number of transmembrane cells in transfection group [(56.20±2.17)/field] was significantly lower than those in control group [(92.80±3.90)/field] and nonsense sequence group [(91.80±4.97)/field of view ] (P < 0.01). Western blot results showed that the protein content of ADAM17 and EGFR in transfection group was significantly lower than those in the control group and the nonsense sequence group (P<0.01). Conclusion MiR-145 inhibits the proliferation and invasion of breast cancer MCF-7 cell line by acting on the ADAM17-EGFR signaling pathway.
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Objective To investigate the effects and mechanisms of a disintegrin and metalloproteinase 17 (ADAM17) on high-glucose mediated permeability,proliferation and migration in human retinal microvascular endothelial cells (HRMECs).Methods HRMECs were divided into 4 groups:normal group (5 mmol · L-1 glucose),high glucose group (25 mmol · L-1 glucose),NC (Negative control for siRNA) + high glucose group and siADAM17 (ADAM17 siRNA) + high glucose group.The expression of ADAM17 was detected using real time PCR and Western blot.Horseradish Peroxidase (HRP) was used to detect the permeability of HRMECs.Cell Counting Kit-8 (CCK-8)and BrdU were used to evaluate cell proliferation.Cell migration was determined using Transwell assay.In addition,the expression of p-EGFR,p-ERK and MMP9 was assayed using Western blot.Results Compared with normal group,the mRNA and protein levels of ADAM17 were increased in high glucose group (P ＜ 0.01).ADAM17 expression of siADAM17 + high glucose group was markedly reduced compared with NC + high glucose group.High glucose increased the permeability of HRP comparison to normal group,whereas in siADAM17 + high glucose group the permeability of HRP was reduced compared with NC + high glucose group.The optical density of HRMECs was decreased in siADAM17 + high glucose group 1.53 ± 0.29 in comparison with NC + high glucose group 2.43 ± 0.25,as well as the content of BrdU-incorporation(P ＜ 0.05).The number of migrated cells in high glucose group,NC + high glucose group,siADAM17 + high glucose group and normal group were 157.00 ± 7.93,169.00 ± 10.12,121.00 ± 9.28,110.00 ±8.25,respectively.Moreover,the expression of p-EGFR,p-ERK and MMP9 in siADAM17 +high glucose group was decreased compared with NC + high glucose group (all P ＜0.01).Conclusion SiADAM17 can reduce the cell permeability,suppressed and migration induced by high glucose via EGFR/ERK/MMP9 signaling pathway.
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Aim To study the role of TNF-α/NF-κB signaling in matrix metalloproteinase ( MMP)-9 expres-sion induced by lipopolysaccharide ( LPS ) in airway epithelial cells, and to investigate the effects of lenti-virus mediated RNAi targeting a disintegrin and metal-loproteinase 17 ( ADAM17 ) gene on MMP-9 expression induced by LPS. Methods The ADAM17 siRNA ex-pression vector was constructed, and packaged to re-combinant lentivirus in 293T cells. The HBE4-E6/E7 cells were pretreated for 30 min by NF-κB inhibitor ( PDTC) and a recombinant human TNFR p75-Fc fu-sion protein ( Etanercept) , or infected by the recombi-nant lentivirus for 72 h, and then stimulated for 24 h by LPS or TNF-α. The release of TNF-α was detected by ELISA. The mRNA and protein levels of MMP-9 were analyzed respectively by RT-PCR and Western blot. NF-κB activity was detected by electrophoretic mobility shift assay. Results LPS and TNF-α signifi-cantly increased MMP-9 mRNA and protein expressions and the activation of NF-κB in HBE4-E6/E7 cells ( P0. 05 ) . And PDTC significantly inhibited MMP-9 mRNA and protein expressions and the activation of NF-κB induced by TNF-α ( P <0. 05 ) . Conclusions TNF-α/NF-κB signaling partic-ipates in the regulation of MMP-9 expression induced by LPS in airway epithelial cells, and lentivirus-media-ted RNAi targeting ADAM17 plays an important role in that signaling pathway upstream by regulating TNF-αrelease.