摘要: Objectives Abnormal activation of NF-kappa B signalling is a major mechanism of apoptosis resistance in glioblastoma multiforme (GBM). Therefore, better understanding of the regulation of NF-kappa B signalling has a significant impact for GBM therapy. Here, we uncovered a critical role of the small GTPase RND3 in regulating the p65 subunit of NF-kappa B and NF-kappa B signalling in GBM. Materials and methods Human GBM samples, GBM cells and a human orthotopic GBM-xenografted animal model were used. The mechanisms of RND3 in regulation of NF-kappa B signalling and GBM cell apoptosis were examined by luciferase assay, quantitative PCR, immunostaining, immunoblotting, immunofluorescence, coimmunoprecipitation, TUNEL staining, JC-1 analysis and flow cytometry. Results Overexpression of RND3 led to reduced p65 activity in GBM-cultured cells and a GBM animal model, indicating that the NF-kappa B pathway is negatively regulated by RND3 in GBM. Mechanistically, we found that RND3 bound p65 and promoted p65 ubiquitination, leading to decreased p65 protein levels. Furthermore, RND3 enhanced cleaved caspase 3 levels and promoted apoptosis in GBM cells, and RND3 expression was positively correlated with cleaved caspase 3 and IL-8 in human GBM samples. The effect of RND3 on promoting apoptosis disappeared when p65 ubiquitination was blocked by protease inhibitor carfilzomib or upon co-expression of ectopic p65. Conclusions RND3 binds p65 protein and promotes its ubiquitination, resulting in reduced p65 protein expression and inhibition of NF-kappa B signalling to induce GBM cell apoptosis.

摘要: Objectives Growth differentiation factor 11 (GDF11), an emerging secreted member of the TGF-beta superfamily, plays essential roles in development, physiology and multiple diseases; however, its role during adipogenic differentiation and the underlying mechanisms remains poorly understood. Materials and methods Bone marrow-derived human mesenchymal stem cells (hMSCs) and 3T3-L1 pre-adipocytes were induced with adipogenic culture medium supplementing with different concentrations of recombinant GDF11 (rGDF11 0, 10, 50, 100 ng mL(-1)). Oil Red O staining, qRT-PCR analysis, Western blot analysis and immunofluorescence staining were performed to assay adipogenesis. Results For both hMSCs and 3T3-L1 pre-adipocytes, the presence of rGDF11 leads to a dose-dependent reduction of intracellular lipid droplet accumulation and suppressed adipogenic-related gene expression. Mechanically, GDF11 inhibits adipogenesis by activating Smad2/3-dependent TGF-beta signalling pathway, and these inhibitory effects could be restored by SB-431542, a pharmacological TGF-beta type I receptor inhibitor. Conclusions Taken together, our data indicates that GDF11 inhibits adipogenic differentiation in both hMSCs and 3T3-L1 pre-adipocytes by activating Smad2/3-dependent TGF-beta signalling pathway.

摘要: Objectives Wnt1-inducible signalling pathway protein 3 (WISP3/CCN6) belongs to the CCN (CYR61/CTGF/NOV) family of proteins, dysregulation of this family contributed to the tumorigenicity of various tumours. In this study, we need to explore its role in hepatocellular carcinoma that remains largely elusive. Materials and Methods The expression of WISP3/CCN6 was analysed by qRT-PCR and Western blotting. Effects of WISP3 on proliferation and metastasis of HCC cells were examined, respectively, by MTT assay and Boyden Chamber. Roles of WISP3 on HCC tumour growth and metastatic ability in vivo were detected in nude mice. Related mechanism study was confirmed by immunofluorescence and Western blotting. Results The expression of WISP3 was significantly downregulated in HCC clinical samples and cell lines, and reversely correlated with the tumour size. Forced expression of WISP3 in HCC cells significantly suppressed cell growth and migration in vitro as well as tumour growth and metastatic seeding in vivo. In contrast, downregulation of WISP3 accelerated cell proliferation and migration, and promoted in vivo metastasis. Further study revealed that WISP3 inhibited the translocation of beta-catenin to the nucleus by activating glycogen synthase kinase-3 beta (GSK3 beta). Moreover, constitutively active beta-catenin blocked the suppressive effects of WISP3 on HCC. Conclusions Our study showed that WISP3 suppressed the progression of HCC by negative regulation of beta-catenin/TCF/LEF signalling, providing WISP3 as a potential therapeutic candidate for HCC.

摘要: Objectives Tumour-targeted gene therapy is a promising approach for effective control of gastric cancer cell proliferation. Our study aims to develop a cancer therapy which combines tumour-targeting promoters with cytotoxins. Methods The expression of globotriaosylceramide (Gb3), which is a Shiga-like toxin I (Stx1) receptor, was verified in gastric cancer compared with normal stomach tissues as assessed by flow cytometry and immunohistochemical analysis. We therefore constructed the recombinant pFZD7-Stx1 plasmid vectors with tumour-preferential Frizzled-7 promoter and Stx1. pFZD7-Stx1 was used to treat gastric cancer in vitro and in vivo. The gastric cancer cell proliferation and tumour growth were identified after the transfection with the pFZD7-Stx1. Results Globotriaosylceramide was obviously increased in gastric cancer compared with normal stomach. The gastric cancer cell proliferation and tumour growth decreased significantly after the transfection with the pFZD7-Stx1. Conclusion Frizzled-7 promoter is preferentially active, and Gb3 is abundant in gastric cancer cells. Frizzled-7 promoter and Stx1 may be used to determine a novel and relatively specific and potent gastric cancer therapeutic strategy.

摘要: Objectives Topographic cues can modulate morphology and differentiation of mesenchymal stem cells. This study aimed to determine how topographic cues of a novel bilayered poly (lactic-co-glycolic acid) (PLGA) scaffold affect osteogenic/odontogenic differentiation of dental pulp stem cells (DPSCs). Methods The surface morphology of the scaffolds was visualized by scanning electron microscope, and the surface roughness was measured by profilometry. DPSCs were cultured on each side of the scaffolds. Cell morphology, expression of Yes-associated protein (YAP) and osteogenic/odontogenic differentiation were analysed by immunohistochemistry, real-time polymerase chain reaction, and Alizarin Red S staining. In addition, cytochalasin D (CytoD), an F-actin disruptor, was used to examine the effects of F-actin on intracellular YAP localisation. Verteporfin, a YAP transcriptional inhibitor, was used to explore the effects of YAP signalling on osteogenic/odontogenic differentiation of DPSCs. Results The closed side of our scaffold showed smaller pores and less roughness than the open side. On the closed side, DPSCs exhibited enhanced F-actin stress fibre alignment, larger spreading area, more elongated appearance, predominant nuclear YAP localization and spontaneous osteogenic differentiation. Inhibition of F-actin alignments was correlated with nuclear YAP exclusion of DPSCs. Verteporfin restricted YAP localisation to the cytoplasm, down-regulated expression of early osteogenic/odontogenic markers and inhibited mineralization of DPSCs cultures. Conclusions The surface topographic cues changed F-actin alignment and morphology of DPSCs, which in turn regulated YAP signalling to control osteogenic/odontogenic differentiation.