Effect of miR-181b on cell proliferation and expression of Bcl-2 and SP1 in HepG2 cells

AIM: To investigate the role of miR-181b in the expression of Bcl-2 and SP1 at mRNA and protein levels in the human hepatoma G2 cells (HepG2), and to explore the effect of miR-181b on the regulation of HepG2 cell proliferation. METHODS: The synthetic double-strand complementary DNA based on the sequence of miR-181b was inserted into the vector of miRNASelect^TM pEGP-miR. The microRNA high-expression plasmid was cloned, and the sequences were identified. The miR-181b plasmid was transfected into HepG2 cells with liposomes. The stable cell line was screened by puromycin. The mRNA and protein levels of Bcl-2 and SP1 were measured by RT-PCR and Western blotting, respectively. Methyl thiazolyl tetrazolium (MTT) method was used to analyze the proliferation of HepG2 cells. RESULTS: The Western blotting results showed that miR-181b inhibited the protein expression of Bcl-2 and SP1. The result of RT-PCR also indicated that the mRNA expression of Bcl-2 and SP1 was suppressed. Compared with the control, the growth rate of HepG2 with high expression of miR-181b was significantly decreased.CONCLUSION: miR-181b inhibits the proliferation of HepG2, which may be related to the down-regulation of Bcl-2 and SP1.     

科技期刊引文的分布与评价效用的分析与思考

目的 通过对中国30种科技期刊中外引文的数量及其各种分布情况的调查,揭示引文数量和质量与不同学术水平期刊之间的对应关系以及对中国科技期刊的评价效用。方法 采用统计分析方法,对不同学术水平期刊中外引文的数量和质量指标进行比较和分析。结果 学术期刊的引文数量和质量均高于普通期刊,而普通期刊由于中文引文比例大,对中国科技期刊学术评价的贡献度大于学术期刊,但学术评价效用不高。结论 引文作为论文的重要组成部分和学术质量的保证,应该纳入中国科技期刊综合评价指标体系中的独立指标,中国科学引文数据库来源期刊应进行适当调整,注重质量,可吸收一些相关的国际期刊。     

Shikonin reverses HGF-induced resistance to gefitinib in lung cancer cells HCC827

AIM: To investigate the effect of shikonin on reversing hepatocyte growth factor(HGF)-induced resistance to gefitinib in lung cancer HCC827 cells, and to explore its possible mechanisms.METHODS: The gefitinib-resistant HCC827 cells induced by HGF were treated with shikonin and gefitinibthe alone or in combination. The inhibition rates of cell viability were determined by MTT assay. The invasive ability of HCC827 cells with HGF-induced resistance to gefitinib was determined by Transwell assay. The protein levels of epithelial-mesenchymal transition (EMT) and related signaling pathway in the HCC827 cells were detected by Western blot.RESULTS: The results of MTT assay showed that the cell activity of HCC827 cells was significantly inhibited by shikonin in a dose dependent manner. The IC₅₀ of shikonin in HCC827 cells was 3.06 μmol/L. And the IC₅₀ of gefitinib in HCC827 cells was 0.51 μmol/L. Under the condition of combined treatment with shikonin and gefitinib in the presence of HGF (20 μg/L), the IC₅₀ of gefitinib was 7.36 μmol/L, significantly lower than that treated with gefitinib alone (P<0.01), so did the result of the cell migration (P<0.01). HGF induced EMT, while shikonin reversed this effect. The protein expression level of p-AKT was significantly up-regulated by HGF, while markedly down-regulated treatment with shikonin and gefitinib compared with gefitinib alone (P<0.01).CONCLUSION: Shikonin reverses HGF-induced resistance to gefitinib in lung cancer HCC827 cells, and the mechanism may be likely related to the preventon of EMT and the inhibition of HGF-induced activation of p-AKT signaling pathway.     

金雀异黄素对雌性大鼠体内促性腺激素及胰岛素样生长因子表达的影响

本试验旨在研究金雀异黄素(genistein,GEN)对雌性大鼠体内促性腺激素及胰岛素样生长因子表达的影响。选取40只SD雌性大鼠[体重(200±20)g],随机分为5组,分别为阴性对照(NC)组、GEN低(L)、中(M)、高剂量(H)组及阳性对照(PC)组,每组8只,NC组灌胃花生油(其他组灌胃试剂以此为溶剂);L、M、H组分别灌胃15、30、60 mg/(kg BW·d)GEN,PC组灌胃己烯雌酚0.5 mg/(kg BW·d)。试验期30 d。采用酶联免疫吸附试验(ELISA)法检测血清中卵泡刺激素(FSH)、黄体生成素(LH)、胰岛素样生长因子-1(IGF-1)、胰岛素样生长因子结合蛋白-1(IGFBP-1)含量;实时定量PCR法检测卵巢IGF-1、IGFBP-1 mRNA表达水平。结果表明:与NC组比较,试验组血清中FSH、LH含量有升高趋势,但差异不显著(P0.05),作用效果与PC组一致;试验组血清IGF-1含量略有降低,但差异不显著(P0.05),PC组显著降低(P0.05);试验组血清IGFBP-1含量显著或极显著升高(P0.05或P0.01),PC组显著升高(P0.05);试验组卵巢组织中IGF-1、IGFBP-1 mRNA表达水平均升高,其中M、H组显著升高(P0.05),与PC组变化一致。由此可见,GEN能够提高雌性大鼠血清FSH、LH含量、降低血清IGF-1含量、提高血清IGFBP-1含量,同时提高卵巢中IG FBP-1、IG F-1 mRNA的表达水平,这些指标协同作用于卵巢,能够促进卵泡的成熟,调节卵巢功能。     

几种工程措施对黄土区陡峭边坡植被盖度的影响及其机理

陡削以兰州新区的一段陡峭边坡作为试验地点,通过分析在植被重建初期经人工整地后形成的4种微地形(大圆形坑、小圆形坑、条形坑和原状坡面)的植被盖度特征及环境因子(土壤硬度和水分、地表和空气温度、坡位、无纺布)对植被盖度的影响,探寻能有效提高植被盖度的几种工程改造措施。研究表明:①铺设了无纺布坡面的植被盖度显著大于对照坡面;陡峭边坡不同坡位的植被盖度:下坡位>中坡位>上坡位(P<0.05),这与自然坡面植被盖度分布规律一致。②3种微地形的植被盖度均显著大于陡峭坡面,其中条形坑的土壤水分和植被盖度最大,最大盖度维持的时间最长。③微地形和坡面的植被盖度均与土壤水分呈显著正相关,与空气温度、地表温度均呈显著负相关;微地形的土壤硬度(3kg·cm^-2)适宜植物生长,大于该值会对植被生长产生抑制作用;铺设无纺布有利于促进上坡位的植被生长,使坡面植被分布更均匀。研究结果表明,在陡峭边坡坡度、坡位和温度等无法改变的情况下,选择对压实的坡面进行整地翻耕处理,增加长条坑的数量并铺设无纺布等有效的工程改造措施,能显著增加植被盖度,促进植被恢复。     

Comparative analysis of MAPK and PI3K/AKT pathway activation and inhibition in human and canine melanoma

The lack of advanced animal models of human cancers is considered a barrier to developing effective therapeutics. Canine and human melanomas are histologically disparate but show similar disease progression and response to therapies. The purpose of these studies was to compare human and canine melanoma tumours and cell lines regarding MAPK and PI3K/AKT signalling dysregulation, and response to select molecularly targeted agents. Pathway activation was investigated via microarray and mutational analysis. Growth inhibition and cell cycle effects were assessed for pathway inhibitors AZD6244 (MAPK) and rapamycin (PI3K/AKT) in human and canine melanoma cells. Human and canine melanoma share similar differential gene expression patterns within the MAPK and PI3K/AKT pathways. Constitutive pathway activation and similar sensitivity to AZD6244 and rapamycin was observed in human and canine cells. These results show that human and canine melanoma share activation and sensitivity to inhibition of cancer‐related signalling pathways despite differences in activating mutations.     

牦牛EPF的原核表达及多克隆抗体制备

本试验旨在制备牦牛早孕因子(early pregnancy factor,EPF)多克隆抗体,为牦牛妊娠早期高效快速诊断技术研究奠定基础.采用RT-PCR方法,从牦牛胎盘和卵巢组织中提取RNA,反转录为模板后进行EPF基因扩增,并将其克隆到改造后的载体pET28-His10-Sumo上,构建pET28-His10-Su...     

Characterization of sulfonylurea-resistant Schoenoplectus juncoides having a target-site Asp376Glu mutation in the acetolactate synthase

Schoenoplectus juncoides, a noxious weed for paddy rice, is known to become resistant to sulfonylurea (SU) herbicides by a target-site mutation in either of the two acetolactate synthase (ALS) genes (ALS1 and ALS2). SU-resistant S. juncoides plants having an Asp₃₇₆Glu mutation in ALS2 were found from a paddy rice field in Japan, but their resistance profile has not been quantitatively investigated. In this study, dose–response of the SU-resistant accession was compared with that of a SU-susceptible accession at in vivo whole-plant level as well as at in vitro enzymatic level.     

Farmers' Attitudes to the Benefits and Barriers of Adopting Automation for Surface Irrigation on Dairy Farms in Australia

The study reports farmers' attitudes andperceptions towards the ``barriers' and ``benefits' of automaticirrigation systems. Factor analysis was used to identify perceived ``barriers' and ``benefits' andthe impact of these on farmers' priority to adopt automation wasexamined. Results suggest that farmers'attitudes, particularly with respect to ``cost' and``lifestyle' influenced the priority given to adopting automaticirrigation systems. The area under pasturecultivation was also an importantdeterminant in the farmers' priority foradopting automatic irrigation systems.