Effects of lentivirus-mediated RWDD3 silencing on proliferation and invasion of human glioma U251 cells

AIM: To investigate the effect of RWDD3 gene silencing on the biological characteristics of human glioma U251 cells.METHODS: A lentiviral vector expressing RWDD3 shRNA was constructed and transfeeted into the U251 cells. The expression of RWDD3 at mRNA and protein levels was detected by real-time PCR and Western blot, respectively. The cell activity was determined by MTT assay. The colony formation ability was detected by the colony formation assay. The cell proliferation ability was detected by BrdU incorporation assay. The cell invasion and migration were evaluated by Transwell assay. Flow cytometry was used to monitor the changes of cell cycle distribution and apoptosis.RESULTS: Recombinant lentivirus was successfully transfected into U251 cells. Compared with the cells transfected with the scrambled shRNA and control cells, the cell activity, colony formation ability, and the invasive and migratory activities were inhibited, the cell cycle was arrested in G₀/G₁ phase, and the apoptosis was increased in the U251 cells transfected with RWDD3 shRNA(P<0.05).CONCLUSION: RWDD3 plays a vital role in proliferation and invasion of glioma cells. It may serve as a potential target of gene therapy for glioma.     

桉树微芽繁殖有效芽长度与继代周期的选择

以速生桉树品系为材料,比较研究了继代培养过程中不同长度有效芽的增殖率和扩繁效果,结果表明无性系GU1和DH33-9采用1～3 mm的有效芽,分别以21 d和28 d为继代周期进行培养,可以获得较高的增殖率和扩繁速度.采用小规格的有效芽继代扩繁能够充分利用材料,节约生产成本,提高桉树微芽繁殖体系建立初期的生产效率,使优良无性系的生产量迅速满足生产推广的需求,但适合小芽扩繁培养的生产技术还需要进一步探讨.     

茜草蒽醌对肝癌SMMC-7721细胞增殖的抑制作用

目的探讨茜草提取物蒽醌单体对人肝癌SMMC-7721细胞增殖的抑制作用.方法采用MTT法、形态学、集落形成法,检测蒽醌对人肝癌细胞增殖的抑制结果.结果MTT法显示各个浓度的蒽醌对肝癌SMMC-7721细胞的增殖均有抑制作用,呈现出与药物浓度、作用时间的依赖性;生长曲线由＂S＂型逐渐变得低平;倒置显微镜下可见药物组细胞数减少,间隙增大,细胞间出现＂接触性抑制＂;集落形成率降低（P〈0.01）,集落中细胞数减少.结论茜草蒽醌对人肝癌SMMC-7721细胞生长具有抑制作用;蒽醌有可能成为抗肝癌新药,为抗癌新药的开发提供理论与实验依据.     

2,4-D对大豆体细胞胚胎发生及增殖的影响

研究不同浓度的2,4-D对不同基因型大豆体细胞胚胎发生及增殖的影响.结果表明:不同基因型大豆体细胞胚胎发生率存在显著差异,在供试的6种基因型中,以CH21141和黑农40体细胞胚胎发生率最高,黑农35诱导率最低;大豆体细胞胚胎发生及继代增殖的最佳2,4-D浓度为10～20 mg·L~(-1),继代扩繁系数为3~n(n为继代培养次数).     

PPI1在裸鼠体内抑制人宫颈癌细胞HeLa生长的研究

探讨PPI1基因在裸鼠体内对人宫颈癌细胞生长的抑制作用。首先将稳定表达PPI1野生型和突变活化型基因的人宫颈癌细胞HeLa进行裸鼠体内致瘤,观察PPI1对肿瘤生长的影响;其次构建野生型HeLa细胞宫颈癌裸鼠模型,通过在体电脉冲技术,将PPI1野生型和突变活化型基因导入瘤体内进行基因治疗,观察裸鼠的存活情况;FACS分析移植瘤的细胞周期分布;免疫组化法检测移植瘤中的PPI1、cyclin B1、p53和p21的表达水平。在致瘤实验中,稳定表达PPI1突变活化型基因的HeLa细胞组的瘤结节生长缓慢,瘤结节明显小于对照组;在基因治疗实验中,PPI1突变活化型基因治疗组的裸鼠生存期明显延长,瘤组织中的肿瘤细胞呈现G2/M期停滞,cyclin B1和p21的表达水平明显增强,而突变型p53的表达明显减弱。PPI1活化型突变体对裸鼠HeLa移植瘤生长有明显的抑制作用。     

水稻胚乳细胞增殖动态分析及其与籽粒生长的关系

以一中熟粳稻品种和两个中熟籼型三系杂交稻为材料,观察了不同粒位籽粒胚乳的细胞增殖动态和细胞充实过程,在以Ｒｉｃｈａｒｄｓ方程模拟的基础上进行生长分析,结果表明：胚乳的细胞增殖速率的变化呈单峰曲线,但相对增速率在增殖始期最高,强势粒起始分裂势高,花后２．８￣３．５天即达最高增殖速率,分裂强度大,活跃分裂期短,为２．８９￣３．６３天,分裂终止期在花后６￣８天,弱势粒胚乳细胞增殖起始期迟,分裂速率的变化     

虎耳草及其组培快繁技术

综述了虎耳草的生物、生态学特性，用途，研究和开发利用现状等。组培繁殖试验结果表明，以虎耳草成熟植株的茎段为外植体，在无激素培养基MS上诱导出芽；在MS 6-BA0．2mg／L(单位下同) IBA0．1培养基上继代和增殖培养，繁殖系数可达4～5；在培养基1／2MS 15g/L糖的培养基上进行根系诱导及生长，生根率可达100％，开始生根时间3d，根系生长完成时间14～15d，生根整齐，同步性高。上述培养务件为本试验的最佳配方。虎耳草组培再生植株的移栽成活率可达85％以上。     

Knock-down of NEDD1 expression inhibits lung adenocarcinoma cell proliferation and migration

AIM: To explore the role of neural precursor cell expression developmentally down-regulated protein 1 (NEDD1) in the development and progression of lung cancer. METHODS: The differences of NEDD1 expression levels between lung cancer tissues and tumor-adjacent tissues were analyzed by the method of immunohistochemistry and TCGA database. Kaplan-Meier curve was used to analyze the correlation between lung cancer prognosis and the expression level of NEDD1. The proliferation of A549 cells was tested by plate colony formation experiment after knock-down of NEDD1 expression. The apoptosis rate and cell cycle distribution were examined by flow cytometry. The migration ability of the A549 cells was detected by Transwell assay. The protein levels of cell cycle-related molecules were determined by Western blot. Database analysis was performed to evaluate the relationship between the expression of NEDD1 and cyclin-dependent kinases 2 (CDK2). RESULTS: Compared with the tumor-adjacent tissues, the expression level of NEDD1 in the lung cancer tissues was increased, so as the database analysis, and the higher expression of NEDD1 showed a poorer prognosis. Under light microscope, the A549 cells showed a low proliferation rate after silencing the NEDD1 expression, and the colony formation ability of the cells was also reduced; knock-down of NEDD1 expression induced the apoptosis and inhibited the cell migration; knock-down of NEDD1 expression blocked the cells in G₁/S phase, and the protein levels of p-Rb and cyclinD1 were decreased, while the protein levels of p-Chk1, p-Chk2 and p-p53 were increased (P<0.05). A positive correlation between the expression of NEDD1 and CDK2 was noted by database analysis. CONCLUSION: NEDD1 plays an crucial role in promoting cell proliferation via inhibiting apoptosis and accelerating cell cycle, high expression of NEDD1 in lung adenocarcinoma tissue is related to poor prognosis, thus NEDD1 may be used as a candidate marker molecule for the diagnosis and prognosis of lung cancer.     

In vitro embryo germination and proliferation of pistachio (Pistacia vera L.)

In vitro development of isolated embryos and axillary bud proliferation were studied in Pistacia vera L. Different regulator-free nutrient media were compared to determine the effects of the mineral solution, agar and sucrose concentrations on seedling development from mature embryos. Nutrient-rich MS [Murashige, T., Skoog, F., 1962. A revised medium for rapid growth and bioassays with tabacco tissue cultures. Physiol. Plant. 15, 473–479] and DKW [Driver, J.A., Kuniyuki, A.M., 1984. In vitro propagation of Paradox walnut rootstock. HortScience 19, 507–509] mineral solutions were more efficient for the development of aerial parts than nutrient-poor KN [Knop, W., 1884. Bereitung einer concentrierten nährstofflosung für pflanzen. Landwersuhssat 30, 292–294] and WT [Withe, P.R., 1936. Plant tissue cultures. Bot. Rev. 2, 419–437] solutions. Reducing the agar concentration enhanced fresh matter production and balanced seedling development. When tested at different concentrations, sucrose was found to orient mature embryo development, with the best results obtained at concentrations of 2–4%, whereas high concentrations (6 and 12%) mainly inhibited elongation of the aerial parts. Plantlets obtained previously from in vitro cultured embryos were propagated by axillary budding. High bud proliferation (six shoots per explant) was achieved when using 17.8 μM benzyladenine (BA) combined with 0.5 μM indole-3-butyric acid (IBA). The addition of 2.9 μM gibberellic acid (GA₃) to the propagation medium did not improve axillary shoot yields and on average, media with GA₃ produced 2.3–2.6 elongated stems per cultured explant. Shoots were rooted in vitro in half-strength MS medium containing 12.3 μM IBA.