Inhibition of Nonsmall Cell Lung Cancer Cell Migration by Protein Arginine Methyltransferase 1-small Hairpin RNA Through Inhibiting Epithelial-mesenchymal Transition,Extracellular Matrix Degradation, and Src Phosphorylation In Vitro

Background：Protein arginine methyltransferases 1 （PRMT1） is over-expressed in a variety of cancers,including lung cancer,and is correlated with a poor prognosis of tumor development.This study aimed to investigate the role of PRMT1 in nonsmall cell lung cancer （NSCLC） migration in vitro.Methods：In this study,PRMT1 expression in the NSCLC cell line A549 was silenced using lentiviral vector-mediated short hairpin RNAs.Cell migration was measured using both scratch wound healing and transwell cell migration assays.The mRNA expression levels of matrix metalloproteinase 2 （MMP-2） and tissue inhibitor ofmetalloproteinase 1,2 （TIMP l,2） were measured using quantitative real-time reverse transcription-polymerase chain reaction.The expression levels of protein markers for epithelial-mesenchymal transition （EMT） （E-cadherin,N-cadherin）,focal adhesion kinase （FAK）,Src,AKT,and their corresponding phosphorylated states were detected by Western blot.Results：Cell migration was significantly inhibited in the PRMT1 silenced group compared to the control group.The mRNA expression of MMP-2 decreased while TIMP 1 and TIMP2 increased significantly.E-cadherin mRNA expression also increased while N-cadherin decreased.Only phosphorylated Src levels decreased in the silenced group while FAK or AKT remained unchanged.Conclusions：PRMT1-small hairpin RNA inhibits the migration abilities of NSCLC A549 cells by inhibiting EMT,extracellular matrix degradation,and Src phosphorylation in vitro.

Effect of Tuina along“bladder meridian”alleviating intervertebral disc degeneration by regulating the transforming growth factor-β1/Smad signaling pathway in a rabbit model

OBJECTIVE:The aim of this study was to investigate the protective effects of Tuina(a traditional Chinese massage therapy)on intervertebral disc(IVD)degeneration and the regulatory mechanisms of the transforming growth factor-β1(TGF-β1)/small mothers against decapentaplegic(Smad)signaling pathway.METHODS:Thirty New Zealand white rabbits were randomized into five groups:the control group,model group,model+Tuina group(Tuina group),model+TGF-β1 group(TGF-β1 group),and model+TGF-β1 inhibitor SB431542 group(SB431542 group).The model was established by posterolateral annulus fibrosus puncturing(AFP).Recombinant TGF-β1 and inhibitor SB431542 was injected into the TGF-β1 group and SB431542 group with a microsyringe,respectively.The rabbits in the Tuina group received Tuina treatment along the bladder meridian for 4 weeks.Magnetic resonance imaging(MRI)was performed on rabbits before AFP and after 4 weeks of intervention.Lumbar IVDs(L2-L3 to L4-L5)were harvested after intervention.Histopathological changes in the IVDs were measured by hematoxylin and eosin(HE)staining.Type I collagen was analyzed by immunohistochemistry detection.The expression level of matrix metalloproteinase-3(MMP3)was determined by enzyme-linked immunosorbent assay.Cell apoptosis was evaluated by terminal deoxynucleotidyl transferasemediated nick end labeling and Western blotting.Realtime polymerase chain reaction and Western blotting were used to analyze the expression of TGF-β1 and Smad2/3/4 and a disintegrin and metalloproteinase with thrombospondin motifs 5.RESULTS:Posterolateral AFP induced IVD degeneration in rabbits with histopathological damage and noticeable changes in MRI images.Tuina alleviated histopathological changes and reversed the expression of extracellular matrix degeneration-related molecules and apoptosis-related proteins.Furthermore,AFP induced the activation of TGF-β1 and Smad2/3/4,whereas Tuina therapy markedly reduced the protein expression of Smad2/3 and the gene expression of TGF-β1 and Smad2/3/4.Additionally,the TGF-β1/Smad signaling pathway was activated in the TGF-β1 group,while the TGF-β1/Smad signaling pathway was inhibited in the SB431542 group.CONCLUSION:Posterolateral AFP induced disc degeneration as determined by MRI assessment and histological analysis.Tuina alleviated disc degeneration,possibly by inhibiting the fibrotic response mediated by the TGF-β1/Smad pathway,thus alleviating extracellular matrix degeneration and reducing cell apoptosis.