Analysis of flavonoids and antitumor activity of transgenic Saussurea involucrate / 中国中药杂志

The aim of this paper was to investigate the flavonoids of callus of transgenic and non-transgenic Saussurea involucrate and its antitumor activity on the esophageal cancer CaEs-17 cells. The species and content of mono-phenols were detected by high performance liquid chromatography. The growth of human esophageal cancer CaEs-17 cells was detected using CCK-8 assay, apoptosis morphology observation and flow cytometry. Expression of related apoptotic genes Bax and Bcl-2 were determined by qPCR. The results showed that the content of total flavonoids in the transgenic callus was 2.72 times that of the non-transgenic callus. The cyanidin-galactoside was detected in the transgenic callus, but not in the non-transgenic callus. The inhibitory effect of the extracts from the transgenic callus on CaEs-17 cells was more significant than that of the non-transgenic callus, and the IC₅₀ value had a decreased of 26.4%. Flow cytometry analysis results showed that the apoptosis induction effect of the extracts from the transgenic callus on CaEs-17 cells was significantly better than that of the non-transgenic callus. Fluorescence quantitative PCR analysis results showed that the extracts from the transgenic callus could up-regulate the expression of proapoptotic gene Bax and down-regulate the expression of apoptotic gene Bcl-2, and the regulation effect of the transgenic callus was more significant. Therefore, compared with the non-transgenic callus, the antitumor activity of the extracts from the callus of transgenic S. involucrate on the esophageal cancer CaEs-17 cells was significantly increased, which was closely related to the accumulation of cyanidin-galactoside and its metabolism-related flavonoid compounds in the transgenic callus.

ShRNA-mediated silencing of MDM2 inhibits growth of HepG2 hepatocellular carcinoma cells xenografted in nude mice / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To construct a short hairpin (sh)RNA targeting the gene encoding the MDM2 oncoprotein in order to investigate its role in human hepatocellular carcinoma (HCC) and its potential for use as a gene therapy strategy to inhibit HCC growth in vivo.</p><p><b>METHODS</b>Small interfering (si)RNAs were designed targeting the MDM2 gene (siMDM2-1 and siMDM2-2) and unrelated sequences (negative control) and cloned into the expression plasmid pGCSilencer-U6-neo-GFP. A HCC mouse model was established by subcutaneous inoculation of HepG2 cells (2 x 10(6) in 0.2 ml) into 20 nude mice. The inoculated mice were divided into four equal groups for tumor-localized injections of saline, negative control siRNA plasmid, siMDM2-1 plasmid, and siMDM2-2 plasmid. Tumor growth was observed daily (by caliper measurement) for one month, when mice were sacrificed by cervical dislocation. The tumor mass was resected for analysis of tumor inhibition rate (% = [(average tumor weight of control group - average tumor weight of treatment group) / average tumor weight of control group x 100]) and effects on MDM2 and p53 mRNA and protein expression (by reverse transcription- PCR and western blotting, both normalized to beta-actin). Significance of between-group differences was assessed by one-way ANOVA or LSD test; pairwise comparisons were made by the Chi-squared test.</p><p><b>RESULTS</b>siMDM2-1 and siMDM2-2 suppressed the xenografted tumor growth remarkably (60.6% and 54.6% inhibition rates, respectively), significantly reduced the expression ofMDM2 gene (62.8% and 61.6%) and protein (60.7% and 59.5%), and significantly increased p53 gene (47.1% and 45.6%) and protein (45.9% and 44.3%) (all, P < 0.05).</p><p><b>CONCLUSION</b>shRNA-mediated silencing of the MDM2 gene effectively inhibits HCC tumorigenesis of subcutaneously xenografted HepG2 cells in nude mice, and the mechanism may involve p53.</p>

Effect of 90Sr-90Y ophthalmic applicator on corneal neovascularization after alkali burn / 中华实验眼科杂志

Background Corneal neovascularization ( CNV ) is a complication of many ocular surface diseases.It often worsen the pathological course.Effective therapy for CNV is still researching. Objective This study was to investigate the inhibitory effect of irradiation on CNV. Methods CNV models were established in 70 right eyes of 70 clean Wistar rats by corneal alkali burning.The models were randomized into β ray 10 Gy once irradiation group( 2 eyes),β ray 7 Gy multiple irradiation group( 17 eyes),β ray 10 Gy multiple irradiation group( 17 eyes),1％ cyclosporin A ( CsA ) eye drops group ( 17 eyes) and model group ( 17 eyes),and 6 matched normal rats were used as normal controls.All treatments started from the first day of the corneal alkali burning.CNV length and area were measured under the slit lamp every day.Corneal samples and homogenate were prepared 3,5,7 days after corneal alkali burning.The expressions of bcl-2,bax,vascular endothelial growth factor(VEGF) in rat corneas were detected by immunochemistry,VEGF proteins and VEGF mRNA were detected by Western blot and reverse transcription polymerase chain reaction (RT-PCR),respectively. Results Corneal ulceration was found in the βray 10 Gy once irradiation group and β ray 10 Gy multiple irradiation group.CNV length and area were much less in the β ray 7 Gy multiple irradiation group and 1％ CsA eye drops group compared with the model group on the seventh day after experiment( length:q=14.40,24.20,P＜0.01 ;area:q=17.80,14.00,P＜0.01 ).Immunochemistry revealed that compared with the model group,expressions of bcl-2 and VEGF proteins were weaker,but the expression of bax protein was stronger in the β ray 7 Gy multiple irradiation group and 1％ CsA eye drops group.RT-PCR showed that the expression of VEGF mRNA in cornea was lower in the β ray 10 Gy multiple irradiation group,β ray 7 Gy multiple irradiation group and 1％ CsA eye drops group in comparison with that in model group,and the results from Western blot showed the same pattern as RT-PCR. Conclusions Low dose irradiation of 90Sr-90Y ophthalmic applicator inhibits CNV formation after alkali burn.The study provide a new understanding of the irradiation for the treatment of CNV.

Therapeutic effects of small interfering RNA targeting MDM2 on human osteosarcoma cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the inhibitory effect of the small interfering RNA targeting mdm2 gene on the growth of osteosarcoma cells.</p><p><b>METHODS</b>PGCsilencerTM-mdm2 siRNA was constructed and transfected into the osteosarcoma cell line U2OS cells. The inhibitory effects on mdm2 were determined by RT-PCR and Western blot analysis. The cell growth activity was determined by MTT assay, and the cell apoptosis was examined by flow cytometry. The therapeutic effects of simdm2 was assessed on the nude mouse model of transplanted tumor.</p><p><b>RESULTS</b>The simdm2 plasmid was successfully constructed. After simdm2 being transfected into the U2OS cells, the expressions of mdm2 gene and protein were significantly inhibited. The ability of cell growth activity decreased greatly and cell apoptosis occurred apparently. There was no significant difference between the negative control group and non-transfected group. The growth of xenograft tumor in simdm2 transfected nude mice was inhibited and the expressions of mdm2 gene and protein were down-regulated remarkably.</p><p><b>CONCLUSION</b>siRNA targeting mdm2 gene inhibits the mdm2 expression in osteosarcoma U2OS cells and the growth of osteosarcoma in nude mice.</p>