两性聚丙烯酰胺冰胶对蛋白质分子印迹的广泛适用性

选择溶菌酶、胃蛋白酶、卵清蛋白、牛血红蛋白和γ-球蛋白为模板,考察两性聚丙烯酰胺冰胶的分子印迹功能。预聚溶液中除了丙烯酰胺、甲叉双丙烯酰胺外,还含有作为功能单体的丙烯酸和烯丙基胺,因此所得聚合物中既有酸性基团,也有碱性基团,有助于在分子水平上识别同样是两性物质的蛋白质。上述蛋白质的分子量、等电点差异显著,且涵盖了很宽的范围。利用同一单体溶液即可合成对所有蛋白质均有印迹效果的聚合物,其分子量和等电点无影响。模板分子在毛细管印迹柱中的保留时间大于非印迹柱中的保留时间。溶菌酶的印迹因子高达7.0,γ-球蛋白最小(2.0),其它蛋白质介于二者之间。本研究结果表明,两性聚丙烯酰胺冰胶是印迹各种蛋白质的理想材料,在蛋白质的识别、纯化和去除方面具有极大的潜力。

Plant Genomic Imprinting and Its Effect on Seed Development

Genomic imprinting is the epigenetic phenomenon by which certain genes are expressed in a parent-of-origin-specific manner, and was first discovered in mammalian embryos. Recent studies have shown that it also occurs in developing plant seeds, and is now becoming a hot topic of biology of plant seed development. According to the previous studies on imprinted genes, imprinting mechanism and their roles in plant seed development, the current progress of genomic imprinting in plant seed development was summarized and possible strategies were proposed to deal with the problems, which could provide helpful information for further research.

长链非编码RNA在喉癌中的研究进展

喉癌是较常见的恶性肿瘤之一,目前的治疗手段大多会影响患者的生存质量,如何尽早发现并治疗该疾病是当前面对的重要难题。如长链非编码RNA(LncRNA),广泛存在于细胞间质与细胞器中,其长度为200~1 000 bp,可以在特定的生理状态和生物过程中表达,参与遗传修饰的调控,LncRNA在转录和转录后水平参与了细胞的发生、发展过程,部分LncRNA也可作为喉癌早期诊断指标或评价喉癌预后的标志物。因此,LncRNA可作为肿瘤治疗新的靶点,并有助于为患者预后做出准确判断。

Heme oxygenase-1 prevents liver fibrosis in rats by regulating the expression of PPAR_γ and NF-_κB

AIM:To investigate the effects of heme oxygenase(HO)-1 on liver fibrosis and the expression of peroxisome proliferator-activated receptor gamma(PPARγ) and nuclear factor-kappa B(NF-κB) in rats.METHODS:Sixty Wistar rats were used to construct liver fibrosis models and were randomly divided into 5 groups:group A(normal,untreated),group B(model for 4 wk,untreated),group C(model for 6 wk,untreated),group D [model for 6 wk,treated with zinc protoporphyrin Ⅸ(ZnPP-Ⅸ) from week 4 to week 6],group E(model for 6 wk,treated with hemin from week 4 to week 6).Next,liver injury was assessed by measuring serum alanine aminotransferase(ALT),aspartate aminotransferase(AST) and albumin levels.The degree of hepatic fibrosis was evaluated by measuring serum hyaluronate acid(HA),type Ⅳ collagen(Ⅳ-C) and by histological examination.Hydroxyproline(Hyp) content in the liver homogenate was determined.The expres-sion levels of alpha-smooth muscle actin(α-SMA) in liver tissue were measured by real-time quantitative polymerase chain reaction(RT-PCR).The expression levels of PPARγ and NF-κB were determined by RT-PCR and Western blotting.RESULTS:The expression of HO-1 increased with the development of fibrosis.Induction of HO-1 by hemin significantly attenuated the severity of liver injury and the levels of liver fibrosis as compared with inhibition of HO-1 by ZnPP-Ⅸ.The concentrations of serum ALT,AST,HA and Ⅳ-C in group E decreased compared with group C and group D(P < 0.01).Amount of Hyp and α-SMA in the liver tissues in group E decreased compared with group C(0.62 ± 0.14 vs 0.84 ± 0.07,1.42 ± 0.17 vs 1.84 ± 0.17,respectively,P < 0.01) and group D(0.62 ± 0.14 vs 1.11 ± 0.16,1.42 ± 0.17 vs 2.56 ± 0.37,respectively,P < 0.01).The expression of PPARγ at levels of transcription and translation decreased with the development of fibrosis especially in group D;and it increased in group E compared with groups C and D(0.88 ± 0.15 vs 0.56 ± 0.19,0.88 ± 0.15 vs 0.41 ± 0.11,respectively,P < 0.01).The expression of NF-κB increased with the development of fibrosis especially in group D;and it decreased in group E compared with groups C and D(1.43 ± 0.31 vs 1.89 ± 0.29,1.43 ± 0.31 vs 2.53 ± 0.54,respectively,P < 0.01).CONCLUSION:Our data demonstrate a potential mechanism that HO-1 can prevent liver fibrosis by enhancing the expression of PPARγ and decreasing the expression of NF-κB in liver tissues.

长链非编码RNA与鼻咽癌发生发展的研究进展

长链非编码RNA(long non-coding RNA,lncRNA),即长度大于200nt的RNA分子,被发现在转录及转录后水平参与调控基因表达,参与遗传修饰的调控,部分lncRNA在鼻咽癌的发生发展中起到一定调控作用,并可能成为鼻咽癌预后的标志物。本文就肿瘤相关lncRNA在鼻咽癌中的作用进行简单综述。

Astragalus polysaccharides can regulate cytokine and P-glycoprotein expression in H22 tumor-bearing mice

AIM:To investigate the adjunct anticancer effect of Astragalus polysaccharides in H22 tumor-bearing mice.METHODS:To establish a solid tumor model,5.0 × 10 6 /mL H22 hepatoma cells were inoculated subcutaneously into the right armpit region of Kunming mice(6-12 wk old,18-22 g).When the tumors reached a size of 100 mm 3,the animals were treated as indicated,and the mice were randomly assigned to seven groups(n = 10 each).After ten days of treatment,blood samples were collected from mouse eyes,and serum was harvested by centrifugation.Mice were sacrificed,and the whole body,tumor,spleen and thymus were weighed immediately.The rate of tumor inhibition and organ indexes were calculated.The expression levels of serum cytokines,P-glycoprotein(P-GP) and multidrug resistance(MDR) 1 mRNA in tumor tissues were detected using enzyme-linked immunosorbent assay,Western blotting,and quantitative myeloid-derived suppressor cells reverse transcription-polymerase chain reaction,respectively.RESULTS:The tumor inhibition rates in the treatment groups of Adriamycin(ADM) + Astragalus polysaccharides(APS)(50 mg/kg),ADM + APS(100 mg/kg),and ADM + APS(200 mg/kg) were significantly higher than in the ADM group(72.88% vs 60.36%,P = 0.013;73.40% vs 60.36%,P = 0.010;77.57% vs 60.36%,P = 0.001).The spleen indexes of the above groups were also significantly higher than in the ADM group(0.65 ± 0.22 vs 0.39 ± 0.17,P = 0.023;0.62 ± 0.34 vs 0.39 ± 0.17,P = 0.022;0.67 ± 0.20 vs 0.39 ± 0.17,P = 0.012),and the thymus indexes of the ADM + APS(100 mg/kg) and ADM + APS(200 mg/kg) groups were significantly higher than in the ADM group(0.20 ± 0.06 vs 0.13 ± 0.04,P = 0.029;0.47 ± 0.12 vs 0.13 ± 0.04,P = 0.000).APS was found to exert a synergistic antitumor effect with ADM and to alleviate the decrease in the sizes of the spleen and thymus induced by AMD.The expression of interleukin-1α(IL-1α),IL-2,IL-6,and tumor necrosis factor-α(TNF-α) was significantly higher in the ADM + APS(50 mg/kg),ADM + APS(100 mg/kg) and ADM + APS(200 mg/kg) groups than in the ADM group;and IL-10 was significantly lower in the above groups than in the ADM group.APS could increase IL-1α,IL-2,IL-6,and TNF-α expression and decrease IL-10 levels.Compared with the ADM group,APS treatment at a dose of 50-200 mg/kg could downregulate MDR1 mRNA expression in a dose-dependent manner(0.48 ± 0.13 vs 4.26 ± 1.51,P = 0.000;0.36 ± 0.03 vs 4.26 ± 1.51,P = 0.000;0.21 ± 0.04 vs 4.26 ± 1.51,P = 0.000).The expression level of P-GP was significantly lower in the ADM + APS(200 mg/kg) group than in the ADM group(137.35 ± 9.20 mg/kg vs 282.19 ± 20.54 mg/kg,P = 0.023).CONCLUSION:APS exerts a synergistic anti-tumor effect with ADM in H22 tumor-bearing mice.This may be related to its ability to enhance the expression of IL1α,IL-2,IL-6,and TNF-α,decrease IL-10,and downregulate MDR1 mRNA and P-GP expression levels.

Detection of eukaryotic translation initiation factor 4E and its clinical significance in hepatocellular carcinoma

AIM:To study the expression of eukaryotic translation initiation factor 4E(eIF4E),which is closely correlated with malignant tumors,and its relationship to prognosis in hepatocellular carcinoma. METHODS:Western blotting was performed to quantify the elF4E protein expression in the normal human liver cell line L02 and the hepatoma cell lines Hep3B, HepG2,and Huh7.Forty-six hepatocellular carcinoma samples with complete clinical data were obtained from Changzheng Hospital during the period of December 2008 to July 2009.The expression of eIF4E in the tumor samples and their adjacent tissues were detected by immunohistochemistry.The relationship between the test results and hepatocellular carcinoma(HCC) prognosis was statistically analysed by using a COX proportional hazard model. RESULTS:Western blotting analysis showed that there were distinct eIF4E protein bands in all three of the hepatoma cell lines.In particular,the HepG2 cell line had the highest level of eIF4E protein expression.The L02 cell group had a low eIF4E expression.Immunohistochemical assay showed that there were 32 cases in which the tumour tissue expression was higher than their adjacent tissues,accounting for 69.57%.There were also 14 cases in which the tumour tissue expression was lower or no significant difference was found, accounting for 30.43%.COX proportional hazards model analysis showed that HCC prognosis was related to the depth of invasion,the overexpression of eIF4E and p53, possibly as independent HCC prognostic predictors. CONCLUSION:In summary,eIF4E expression is associated with liver cancer,and patients with high eIF4E expression levels have a higher risk of recurrence.

HCMV Infection Depress NGF Expression in Human Glioma Cells

Human cytomegalovirus （HCMV） is the most common cause of congenital infection, resulting in birth defects such as microcephaly. In this study, RT-PCR and Western Blotting were performed to quantify the regulation of endogenic nerve growth factor expression in neuroglia ceils by HCMV infection. The results showed that basal, endogenous NGF expression in U251 was unchanged during early HCMV infection. NGF expression is strongly down-regulated during the latent phase of infection. These results suggest that HCMV can depress the NGF expression in U251 cells.

Toxicarioside A inhibits SGC-7901 proliferation,migration and invasion via NF-κB/bFGF signaling

AIM:To investigate the inhibitory role of toxicarioside A on the gastric cancer cell line human gastric cancer cell line(SGC-7901) and determine the underlying molecular mechanism.METHODS:After SGC-7901 cells were treated with toxicarioside A at various concentrations(0.5,1.5,4.5,9.0 μg/mL) for 24 h or 48 h,cell viability was determined by 3-(4,5-dimethyl-thiazol-2-yl)-2,5-diphenyl2H-tetrazolium bromide assay,and the motility and invasion of tumor cells were assessed by the Transwell chamber assay.Immunofluorescence staining,reverse transcription polymerase chain reaction and Western blotting were performed to detect the expression of basic fibroblast growth factor(bFGF) and fibroblast growth factor receptor-1(FGFR1),and nuclear factorkappa B(NF-κB) activation was examined by electrophoretic mobility shift assay.RESULTS:The results showed that toxicarioside A was capable of reducing cell viability,inhibiting cell growth,and suppressing cell migration and invasion activities in a time-and dose-dependent manner in SGC-7901 cells.Further analysis revealed that not only the expression of bFGF and its high-affinity receptor FGFR1 but also the NF-κB-DNA binding activity were effectively blocked by toxicarioside A in a dose-dependent manner compared with the control group(P < 0.05 or P < 0.01).Interestingly,application of the NF-κB specific inhibitor,pyrrolidinedithiocarbamate(PDTC),to SGC-7901 cells significantly potentized the toxicarioside A-induced down-regulation of bFGF compared with the control group(P < 0.05).CONCLUSION:These findings suggest that toxicarioside A has an anti-gastric cancer activity and this effect may be achieved partly through down-regulation of NF-κB and bFGF/FGFR1 signaling.

姜黄素分子印迹聚合物的制备与表征及其吸附性能的研究

目的制备姜黄素的分子印迹聚合物(MIP)。方法以姜黄素为模板分子、乙二醇二甲基丙烯酸酯为交联剂、偶氮二异丁腈为引发剂,模板分子-功能单体-交联剂的摩尔比为1∶4∶20;采用本体聚合法,通过优化条件获得了对姜黄素有特异选择性吸附的MIP;采用红外光谱仪、扫描电镜和热重分析仪对聚合物进行结构表征,并研究MIP的吸附性能。结果制备MIP的最优条件是以甲基丙烯酸为功能单体,溶剂为丙酮;该聚合物的印迹因子为1.27,符合拟二级动力学模型(r2=0.9970)。结论制备的MIP可用于分离、纯化和富集姜黄素。