To summarize Notch, basic hel ix-loop-hel ix (bHLH) and Wnt gene signal transduction pathways in the process of differentiation and development of neural stem cells. Methods The l iterature on the gene signal transduction pathway in the process of differentiation and development of neural stem cells was searched and then summarized and analyzed. Results The formation of Nervous System resulted from common actions of multi-signal transduction pathways. There may exist a fixed threshold in the compl icated selective system among Notch, bHLH and Wnt gene signal transduction pathways. Conclusion At present, the specific gene signal transduction pathway of multi pl ication and differentiation of neural stem cells is still unclear.
ObjectiveTo observe the regulation of PTB-associated splicing factor (PSF) exerts on phosphatidylinositol 3 kinase (PI3K)/Akt signaling pathway in cultured retinal pigment epithelial (RPE) cells.
MethodsARPE-19 RPE cells were divided into five groups including PSF overexpression (0.25, 0.50, 1.00 μg of pEGFP-C2-PSF plasmid DNA), PSF overexpression control (pEGFP-C2 empty vector DNA), PSF inhibition (0.25, 0.50, 1.00 μg of pGenesil-PSF-RNAi plasmid DNA), PSF inhibition control (pGenesil-scramble-siRNA empty vector) and sham transfected group (treated with lipofactamine 2000 reagent, but without adding plasmid DNA) groups. After transfecting with plasmid DNA, the cells were stimulated with insulin-like growth factor-1 (IGF-1). IGF-1-stimulated ARPE-19 cells were also treated with Wortmannin and /or PSF over-expression. WST-1 assay was used to detect the proliferation rates, the VEGF mRNA levels were analyzed using real time polymerase chain reaction (PCR), the levels of phosphorylation Akt and total Akt expression were measured by western blotting.
ResultsAfter IGF-1 stimulation, the difference of the cell proliferation rates between PSF overexpression group, PSF overexpression control group and sham transfected group was statistically significant (F=29.728, P<0.05). The difference of the cell proliferation rates between PSF inhibition group, PSF inhibition control group and sham transfected was also statistically significant (F=14.121, P<0.05). Compared with control group, the VEGF mRNA levels was decreased in PSF overexpression group (P=0.000 3), but increased in PSF low expression group (P=0.030 9). Furthermore, overexpression of PSF could down-regulate the activation of pAkt after IGF-1 stimulation. When combined with Wortmannin treatment, the VEGF mRNA levels in PSF overexpression group was significantly lower than the control group (P<0.05).
ConclusionsAfter IGF-1 treatment, PSF plays a role in suppressing the proliferation and VEGF expression in RPE cells by inactivating PI3K/Akt signaling pathway.
ObjectiveTo summarize the therapeutic targets of pancreatic cancer (PC).
MethodsThe related literatures about the therapeutic targets of PC were reviewed.
ResultsPC was one of the most challenging tumor in worldwide, and was characterized as a highly aggressive disease with poor overall prognosis and a high mortality rate. The hallmark of PC was its poor response to radio-and chemo-therapy. Current chemotherapeutic regimens could not provide substantial survival benefit with a clear increase in overall survival. Recently, several new approaches which could significantly improve the clinical outcome of PC had been described, involving signal-transduction pathways, immune response, stroma reaction, and epigenetic changes.
ConclusionsMany therapeutic targets are involved in the treatment of PC. As current therapies failed to significantly improve the progression and the survival of PC, new therapeutic approaches and clinical studies are strongly required.
OBJECTIVE: To study the effect of overexpression of truncated type II TGF-beta receptor on transforming growth factor-beta 1(TGF-beta 1) autoproduction in normal dermal fibroblasts. METHODS: In vitro cultured dermal fibroblasts were treated with recombinant human TGF-beta 1(rhTGF-beta 1) (5 ng/ml) or recombinant adenovirus containing truncated type II TGF-beta receptor gene (50 pfu/cell). Their effects on regulating gene expression of TGF-beta 1 were observed with Northern blotting. RESULTS: rhTGF-beta 1 up-regulated the gene expression of TGF-beta 1 and type I procollagen. Overexpression of truncated receptor II down-regulated the gene expression of TGF-beta 1. CONCLUSION: Overexpression of the truncated TGF-beta receptor II decreases TGF-beta 1 autoproduction via blocking TGF-beta receptor signal. The results may provided a new strategy for scar gene therapy.
As an important intracellular genetic and regulatory center, the nucleus is not only a terminal effector of intracellular biochemical signals, but also has a significant impact on cell function and phenotype through direct or indirect regulation of nuclear mechanistic cues after the cell senses and responds to mechanical stimuli. The nucleus relies on chromatin-nuclear membrane-cytoskeleton infrastructure to couple signal transduction, and responds to these mechanical stimuli in the intracellular and extracellular physical microenvironments. Changes in the morphological structure of the nucleus are the most intuitive manifestation of this mechanical response cascades and are the basis for the direct response of the nucleus to mechanical stimuli. Based on such relationships of the nucleus with cell behavior and phenotype, abnormal nuclear morphological changes are widely used in clinical practice as disease diagnostic tools. This review article highlights the latest advances in how nuclear morphology responds and adapts to mechanical stimuli. Additionally, this article will shed light on the factors that mechanically regulate nuclear morphology as well as the tumor physio-pathological processes involved in nuclear morphology and the underlying mechanobiological mechanisms. It provides new insights into the mechanisms that nuclear mechanics regulates disease development and its use as a potential target for diagnosis and treatment.
ObjectiveTo explore the feasibility of co-transduction and co-expression of Nogo extracellular peptide residues 1-40 (NEP1-40) gene and neurotrophin 3 (NT-3) gene into neural stem cells (NSCs).MethodsNSCs were derived from the cortex tissue of Sprague Dawley rat embryo. The experiment included 5 groups: no-load lentiviral vector transducted NSCs (group A), NEP1-40 transducted NSCs (group B), NT-3 transducted NSCs (group C), NEP1-40 and NT-3 corporately transducted NSCs (group D), and blank control (group E). Target genes were transducted into NSCs by lentiviral vectors of different multiplicity of infection (MOI; 5, 10, 15) for different time (24, 48, 72 hours). Fluorescent microscope was used to observe the expression of fluorescence protein and acquire the optimum MOI and optimum collection time. Real-time fluorescence quantitative PCR and Western blot tests were utilized to evaluate the gene expressions of NEP1-40 and NT-3 in NSCs and protein expressions of NEP1-40 and NT-3 in NSCs and in culture medium.ResultsThe optimum MOI for both target gene was 10 and the optimum collection time was 48 hours. The real-time fluorescence quantitative PCR and Western blot results showed that the mRNA and protein relative expressions of NEP1-40 in groups B and D were significantly higher than those in groups A and C (P<0.05), but no significant difference was found between groups B and D, and between groups A and C (P>0.05). The mRNA and protein relative expressions of NT-3 in groups C and D were significantly higher than those in groups A and B (P<0.05), but no significant difference was found between groups A and B, and between groups C and D (P>0.05).ConclusionNEP1-40 and NT-3 gene can be successfully co-transducted into NSCs by the mediation of lentiviral vector. The expressions of the two target genes are stable and have no auxo-action or antagonism between each other.
Objective? To introduce the basic research and cl inical potential of the hair foll icle stem cells related signal transduction in prol iferation and differentiation. Methods The recent original articles about the hair foll icle stem cells were extensively reviewed. Results Many different signal pathways had been involved in the skin development and self-newals.The hair foll icle stem cells could play an important role in the skin self-renewal and regeneration which were modulated by several different signal pathways, which included bone morphogenetic protein/transforming growth factor β, Wnt, Notch and ectodysplasin A genes.? Conclusion The hair foll icle stem cells may be a future approach to repair cutaneous wounds as a cell therapy．
Objective To evaluate the effect of integrin-linked kinase (ILK) in the process of retinal neovascularization induced by vascular endothelial growth factor (VEGF). Methods The ILK activities of retinal choriodal endothelial cell line RF/6A were inhibited by LY294002 or siRNA knockdown. VEGF-induced changes of cell adhesion, proliferation, migration and endothelial cell tube-formation were measured then. The in-vivo effects of ILK were also assessed by intraperitoneal injection of LY294002 into an animal model of RNV. Results The cell adhesion measurements of control group, VEGF group, VEGF＋LY294002 group and VEGF＋siRNA group were 0.0726plusmn;0.01961, 0.1137plusmn;0.02631, 0.0837plusmn;0.01503 and 0.0853plusmn;0.02454 , respectively. The difference was statistically significant between VEGF group and control group（t =4.211，Plt;0.01）, and between (VEGF＋LY294002) group or (VEGF＋siRNA) group and control group (t =3.074, 2.91，Plt;0.01). The cell proliferation results of control group, VEGF group and VEGF＋LY294002 group were 0.4162plusmn;0.1392, 0.6412plusmn;0.2420, 0.4476plusmn;0.1834 , respectively. The difference was statistically significant between VEGF group and control group（t=2.608，Plt;0.05）, and between (VEGF＋LY294002) group and VEGF group（t=2.244，Plt;0.05）.The cell migration results of control group, VEGF group and VEGF＋LY294002 group were 83.66plusmn;30.283, 248plusmn;74.748, 138.5plusmn;38.167, respectively. The difference was statistically significant between VEGF group and control group（t=5.436，Plt;0.01）, and between (VEGF＋LY294002) group and VEGF group（t=3.682，Plt;0.01）. There was no obvious tube-formation after ILK activity was inhibited or knocked down. The non-perfusion areas were increased from （62798plusmn;16995.62）mu;m2 to （84722.65plusmn;10435.01）mu;m2 after intraperitoneal injection of LY294002 into animal model of RNV, the difference was statistically significant（t=3.476，Plt;0.01）. Conclusions ILK may play an important role in the process of VEGF-induced retinal neovascularization by regulating the cellular adhesion, proliferation, migration and tube-formation, as all those cellular functions were supressed obviously after the ILK activity was inhibited by LY294002 or the ILK expression was knocked down by siRNA.
Objective To probe into the roles of inositol 1, 4, 5-trisphosphate (IP3) and bcl-2 gene expression in inhabiting hepatocellular carcinoma of nude mice by quercetin. Methods Animals with hepatocellular carcinoma in quercetin group were treated with injection peritoneum of quercetin 50 mg/（kg·d ） for 3 weeks, while which in control group were treated with 0.4% DMSO of RPMI 1640 0.05 ml/（g·d）. Then the volume and the weight of tumors were measured, IP3, bcl-2 mRNA and bcl-2 protein were assayed by IP3-［3H］ Birtrak Assay, RT-PCR and Western blot respectively. Results The volume and weight of tumors in quercetin group were lower than those in control group 〔（15.8±10.1） mm3 vs. （52.3±26.5） mm3 in volume, （44.8±10.4） mg vs.（91.3±31.4） mg in weight， P＜0.01〕. Content of IP3 in quercetin group was lower than that in control group 〔（13.4±1.4） pmol/mg prot vs. （35.3±6.6） pmol/mg prot， P＜0.01〕. There was no significant difference in bcl-2 mRNA expression between quercetin group and control group 〔RI （the gray degree multiply area of bcl-2 /the gray degree multiply area of β-actin）： 0.55±0.05 vs. 0.79±0.19， P＞0.05〕， but the expression of bcl-2 protein in quercetin group was lower than that in control group (RI: 1.07±0.12 vs. 6.69±1.80, P＜0.01). Conclusion Quercetin can inhabit the growth of hepatocellular carcinoma tansplanted into liver of nude mice by reducing IP3 production and down-regulating bcl-2 gene expression.
【Abstract】Objective To investigate the apoptosis induced by TGF-β1 in human hepatic carcinoma cell lines and its relationship with p53 gene and Smad. Methods Three human hepatic carcinoma cell lines which involving in various status of the p53 gene were used in this study. TGF-β1-induced apoptosis in hepatic carcinoma cell lines was measured by the terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. To study the mechanism of TGF-β1-induced apoptosis, these cell lines were transfected with a TGF-β1-inducible luciferase reporter plasmid containing Smad 4 binding elements (SBE) and luciferase gene using Lipofectamine 2000, then treated with TGF-β1, relative luciferase activity was assayed. Results Of three cell lines studied with TUNEL assay, TGF-β1 induced apoptosis was observed in HepG2 cells (wild type p53). Huh-7 (mutant p53) and Hep3B (deleted p53) cell lines showed less apoptosis. Luciferase activity assay indicated that the response to TGF-β1 induction in HepG2 cells was increased dramatically but was not significant in Huh-7 and Hep3B cell lines. Conclusion HepG2 cells seem to be highly susceptible to TGF-β1-induced apoptosis compared with Hep3B and Huh7 cell lines. Smad 4 is a central mediator of the TGF-β1 signal transduction pathway.
