RESUMO
Mussel-inspired approach was attempted to non-covalently functionalize the surfaces of boron nitride (BN) with self-polymerized dopamine coatings in order to reduce the interfacial thermal barrier and enhance the thermal conductivity of BN-containing composites. Compared to the polypropylene (PP) composites filled with pristine BN at the same filler content, thermal conductivity was much higher for those filled with both functionalized BN (f-BN) and maleic anhydride grafted PP (PP-g-ma) due to the improved filler dispersion and better interfacial filler-matrix compatibility, which facilitated the development of more thermal paths. Theoretical models were also applied to predict the composite thermal conductivity in which the Nielsen model was found to fit well with the experimental results, and the estimated effective aspect ratio of fillers well corresponded to the degree of filler aggregation as observed in the morphological study.
RESUMO
BACKGROUND: GC-binding factor 2 (GCF2) is a transcriptional regulator that represses transcriptional activity of the epidermal growth factor receptor (EGFR) by binding to a specific GC-rich sequence in the EGFR gene promoter. In addition to this function, GCF2 has also been identified as a tumor-associated antigen and regarded as a potentially valuable serum biomarker for early human hepatocellular carcinoma (HCC) diagnosis. GCF2 is high expressed in most HCC tissues and cell lines including HepG2. This study focused on the influence of GCF2 on cell proliferation and apoptosis in HepG2 cells. MATERIALS AND METHODS: GCF2 expression at both mRNA and protein levels in HepG2 cells was detected with reverse transcription (RT) PCR and Western blotting, respectively. RNA interference (RNAi) technology was used to knock down GCF2 mRNA and protein expression. Afterwards, cell viability was analyzed with a Cell Counting Kit-8 (CCK-8), and cell apoptosis and caspase 3 activity by flow cytometry and with a Caspase 3 Activity Kit, respectively. RESULTS: Specific down-regulation of GCF2 expression caused cell growth inhibition, and increased apoptosis and caspase 3 activity in HepG2 cells. CONCLUSIONS: These primary results suggest that GCF2 may influence cell proliferation and apoptosis in HepG2 cells, and also provides a molecular basis for further investigation into the possible mechanism at proliferation and apoptosis in HCC.
Assuntos
Apoptose , Carcinoma Hepatocelular/patologia , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Neoplasias Hepáticas/patologia , RNA Interferente Pequeno/genética , Proteínas de Ligação a RNA/metabolismo , Western Blotting , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Citometria de Fluxo , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Regiões Promotoras Genéticas/genética , RNA Mensageiro/genética , Proteínas de Ligação a RNA/antagonistas & inibidores , Proteínas de Ligação a RNA/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais CultivadasRESUMO
AIM: To construct the eukaryotic expression vector pEGFP-N1/ACRBP and stably express ACRBP in human hepatocarcinoma cells, providing functional clues for ACRBP. METHODS: A recombinant plasmid pMAL-C2/ACRBP was used as a template to amplify ACRBP cDNA. The PCR product was ligated into an eukaryotic expression vector pEGFP-N1 to construct a recombinant plasmid pEGFP-N1/ACRBP. Then the pEGFP-N1/ACRBP was transfected by Fugene HD into ACRBP-negative HepG2 cells. The stably transfected clones were selected by G418. RT-PCR and immunohistochemistry were used to detect the expression of ACRBP in HepG2 cells. RESULTS: The eukaryotic expression vector pEGFP-N1/ACRBP was constructed and confirmed by sequencing. The stably transfected HepG2 cells expressed ACRBP. CONCLUSION: The eukaryotic expression vector pEGFP-N1/ACRBP has been successfully constructed and transfected into HepG2 cells, resulting in stable expression of ACRBP.
Assuntos
Carcinoma Hepatocelular/genética , Proteínas de Transporte/genética , Vetores Genéticos/genética , Neoplasias Hepáticas/genética , Carcinoma Hepatocelular/metabolismo , Proteínas de Transporte/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Células Hep G2 , Humanos , Neoplasias Hepáticas/metabolismo , RNA Mensageiro/metabolismo , TransfecçãoRESUMO
A great variety of polymer/layered silicate (PLS) nanocomposites have been reported, however, there are few exfoliated PLS nanocomposites and their inorganic-organic interfaces are still a great problem, especially for the elastomers. In this research, a kind of exfoliated elastomer/silicate layer nanocompound was prepared and proved by XRD and TEM, in which 10 phr Na(+)-montmorillonite was dispersed in butadiene-styrene-vinyl pyridine rubber by latex compounding method with acidic flocculants. Moreover, a dynamic mechanical thermal analyzer (DMTA) suggested a strong interfacial interaction (interaction parameter B(H) = 4.91) between the silicate layers and macromolecules in addition to the weak inorganic-organic interfacial interaction, and solid state (15)N NMR indicated the formation of a strong ionic interface through the acidifying pyridine. Subsequently, a remarkable improvement of the dispersing morphology, mechanical performance and gas barrier property appeared, compared to that using calcium ion flocculants. This supports the formation of an exfoliated structure and an improved interfacial interaction.