Résumé
<p><b>OBJECTIVE</b>To evaluate the relationship between mammalian target of rapamycin (mTOR) signaling pathway and histone acetylation in cell survival, cell cycle, gene expression and protein level on human gastric cancer cells.</p><p><b>METHODS</b>Human gastric cancer cell lines, MKN45 and SGC7901 were treated with trichostatin A, rapamycin and/or LY294002, a PI3K inhibitor. Cell viability was analyzed by methylthiazolyl tetrazolium. Cell cycle distribution was evaluated by flow cytometry. The transcription level of p21(WAF1) gene was detected by using real-time polymerase chain reaction. Proteins were detected by Western blotting.</p><p><b>RESULTS</b>Cell viability remarkably reduced after treatment by more than two drugs (P< 0.01). Through flow cytometry assessment, MKN45 cells were arrested in G2 phase (P< 0.05), while SGC7901 cells were in G2 or G1 phase (P< 0.05) whether treated with single or more than two drugs. The expression of p21(WAF1) mRNA was remarkably increased in the gastric cancer cells treated with conjoined drugs (P< 0.01). Phosphorylation of Akt, p70S6K and 4E-BP1 was significantly reduced in cells treated with conjoined drugs (P< 0.01). And histone acetylation of H4/H3 was also increased in cells treated with conjoined drugs (P< 0.01).</p><p><b>CONCLUSION</b>mTOR singnaling pathway has an important relationship with histone acetylation in gastric cancer cell lines. There is a co-effect of mTOR inhibitor and histone deacetylase inhibitor on gastric cancer cells.</p>
Sujets)
Humains , Acétylation , Protéines adaptatrices de la transduction du signal , Métabolisme , Technique de Western , Cycle cellulaire , Lignée cellulaire tumorale , Survie cellulaire , 4H-1-Benzopyran-4-ones , Pharmacologie , Inhibiteur p21 de kinase cycline-dépendante , Génétique , Cytométrie en flux , Histone , Métabolisme , Acides hydroxamiques , Pharmacologie , Morpholines , Pharmacologie , Phosphoprotéines , Métabolisme , Phosphorylation , Réaction de polymérisation en chaîne , Protein kinases , Métabolisme , Protéines proto-oncogènes c-akt , Métabolisme , ARN messager , Génétique , Métabolisme , RT-PCR , Ribosomal Protein S6 Kinases, 70-kDa , Métabolisme , Transduction du signal , Physiologie , Sirolimus , Pharmacologie , Tumeurs de l'estomac , Métabolisme , Anatomopathologie , Sérine-thréonine kinases TORRésumé
<p><b>OBJECTIVE</b>To investigate the role of endotoxin receptor expression in the activation of hepatic stellate cells (HSCs).</p><p><b>METHODS</b>HSCs were isolated from normal rats and the expression of endotoxin receptors on quiet HSCs and in vitro activated HSCs was determined using RT-PCR and immunocytochemical staining methods. A rat model of liver fibrosis and cirrhosis was established. The expressions of CD14 and alpha-SMA in liver tissues were detected by immunohistochemical staining.</p><p><b>RESULTS</b>Freshly isolated HSCs had a low level of CD14 mRNA expression and no expression of TLR4 mRNA was detected. The in vitro activated HSCs had increased expressions of CD14 mRNA and TLR4 mRNA and LPS up-regulated the expression of endotoxin receptors. Immunocytochemical staining showed cytoplasmic and nucleolus staining for CD14 in the cultured HSCs. LPS played a further role on CD14 protein expression. In the development of liver fibrosis, the number of CD14-positive cells in the livers was increased and these cells were distributed along the sinusoids. In the later stage of liver fibrosis, the CD14-positive cells were gathered in the fibrotic septae, which also contained alpha-SMA positive cells.</p><p><b>CONCLUSION</b>The activated HSCs expressed endotoxin receptors. The endotoxin receptors may be involved in the role in which HSCs played in the inflammatory process and liver fibrosis development.</p>
Sujets)
Animaux , Rats , Actines , Métabolisme , Cellules cultivées , Cellules étoilées du foie , Métabolisme , Antigènes CD14 , Métabolisme , Cirrhose du foie , Métabolisme , Anatomopathologie , ARN messager , Génétique , Rat Wistar , Récepteurs immunologiques , Génétique , Métabolisme , RT-PCRRésumé
<p><b>OBJECTIVE</b>To investigate the effect of T-cell vaccination in murine experimental autoimmune hepatitis (EAH).</p><p><b>METHODS</b>To induce the EAH model, the syngeneic S-100 antigen emulsified in complete Freud's adjuvant was injected intraperitoneally to C57Bl/6 at day 1 and day 7. For T-cell vaccination, splenocytes were removed from animal 2 weeks after induction of EAH and from control animals, and activated in vitro by mitogen stimulation with Concanavalin A (Con A), then inactivated by mitomycin and injected at 5 10(7) cells per animal as T-cell vaccination at 14 and 7 days before first induction of EAH.</p><p><b>RESULTS</b>The histological grade and serum ALT level of the mice who received T-cell vaccination were decrease significantly, compared with that of model group (1.44+/-0.88 vs. 2.33+/-0.87, t=2.24, P<0.05; 63.0U/L+/-23.4U/L vs. 115.0U/L1+/-39.6U/L, t=2.37, P<0.01, respectively); there was no significant change in mice who received irrelevant T-cell vaccination.</p><p><b>CONCLUSION</b>T-cell vaccination with T cells from EAH animals, but not with irrelevant T cells, was able to protect animals from EAH.</p>