RESUMO
Objective To investigate the inhibitory effect of Withaferin A ( WFA) on the growth of orthotopic xenograft tumor of hepatocellular carcinoma in nude mice and the mechanism of its antitumoral effect. Methods For in vivo model, anti-tumor efficacy of Withaferin A was evaluated in nude mice mod-els of human liver cancer orthotopic xenograft. The nude mice were randomly divided into model group, Sunitinib group,and Withaferin A groups [6, 3 mg/(kg·d)]. All mice were given intraperitoneal injec-tion for 14 days. Tumor volume and tumor weight were observed. Antiangiogenic effects were assessed in vi-vo by the tumor inhibition rate and microvessel density. Quantitative polymerase chain reaction ( QPCR) as-say was used to detect the mRNA expression of vascular endothelial growth factor ( VEGF) , basic fibroblast growth factor (bFGF), angiopoietin-2 (Ang-2), vascular endothelial growth factor receptor 2 (VEGFR2) from tumor tissues. For in vitro experiments, the cell count kit 8 ( CCK8 ) assay was used to detect the effect of Withaferin A on HepG2 cells proliferation. QPCR assay and enzyme-linked immunosorbent assay ( ELISA) were used to detect the mRNA expression of VEGF. Results Compared to the model group, the high-dose Withaferin A group and the Sunitinib group had a significantly lower tumor weight (P<0. 05). The tumor inhibition rate was 42. 69％ in the high-dose Withaferin A group, 20. 22％ in the low-dose With-aferin A group, and 49. 43％ in the Sunitinib group. The growth of HepG2 cells was significantly inhibited by different concentrations of Withaferin A,and the 50％ concentration of inhibition ( IC50 ) of Withaferin A were (2. 64 ± 0. 18)μmol/L at 24 h. Withaferin A (6,3 μmol/L) could inhibit the protein and mRNA ex-pression of VEGF ( P<0. 05 ) . Conclusions Withaferin A significantly reduces the growth of orthotopic xenograft tumor of hepatocellular carcinoma in nude mice via antiangiogenic effect. Downregulation of the protein and mRNA expression of VEGF by WFA may be one mechanism of its anti-liver cancer effect.
RESUMO
Objective Intercellular adhesion molecule-1 (ICAM-1) plays an important role in mediating pulmonary infiltration of neutrophils .The aim of the study was to observe the expression of ICAM-1 and its potential regulators MK 2/HuR in pulmonary micro-vascular endothelial cells ( PMVEC ) in mice with acute respiratory distress syndrome ( ARDS) induced by lipopolysaccharide ( LPS) . Methods Ten 6-8 weeks old healthy C57BL/6 mice were randomly divided into an LPS and a control group of equal number , the former injected intraperitoneally with LPS diluted in 100 μL PBS while the latter with PBS only , both at 5 mg per kg of the body weight .At 24 hours after injection , all the mice were sacrificed .Real-time PCR was used to determine the mRNA expressions of HuR and ICAM-1 in the PMVECs, Western bolt employed to detect the protein expressions of MK2, HuR and ICAM-1, and flow cytometry adopted to measure the ICAM-1 expression on the surface of the PMVECs and pulmonary infiltration of neutrophils . Results The W/D ratio in the lung tissue of the mice was significantly lower in the LPS than in the control group (3.61 ±0.28 vs 6.16 ±0.40, P<0.05), while the rate of neutrophil infiltration markedly higher in the former than in the latter ([13.92 ±3.23]%vs [3.24 ±1.24]%, P<0.05).The mRNA and protein expressions of ICAM-1 in the PMVECs were significantly elevated in the LPS group as compared with that in the control (P<0.05), and so was the mRNA expression of HuR (P<0.05).No remarkable changes were observed in the expressions of total MK 2 and HuR proteins, but phosphorylated MK2 (p-MK2) and cytoplasmic HuR were increased in the LPS-stimulated mice. Conclusion Specific blockage or reduction of the HuR expression in PMVECs may lower the expression of ICAM-1, reduce neutrophil infiltration , and lessen pathophysiological changes in mice with ARDS .