Effect of long non-coding RNA MEG3 on invasion and migration of colorectal cancer cells

AIM: To investigate the expression of long non-coding RNA maternally expressed gene 3(MEG3) in colorectal cancer(CRC) cells, and to observe the effect of MEG3 on the invasion and migration of CRC cells. METHODS: The levels of MEG3 in human normal colon cell NCM460 and CRC cells SW48 and LoVo were detected by real- time PCR. MEG3 was over-expressed by plasmid transfection, and the effects of MEG3 on the invasion and migration of SW48 and LoVo cells were analyzed by Transwell assay and wound healing assay. The expression of matrix metalloproteinase(MMP) family proteins was determined by Western blotting. RESULTS: The level of MEG3 was down-regulated in CRC cells compared with normal colon cell NCM460. The invasion and migration of CRC cells were reduced after MEG3 over-expression. Transwell invasion and migration assays showed that the numbers of transmembrane SW48 and LoVo cells were smaller in MEG3 over-expression group than control group(CONCLUSION: The expression of MEG3 is down-regulated in CRC cells. Over-expression of MEG3 inhibits the invasion and migration of CRC cells. TIMP-2, MMP-2 and MMP-9 might play an important role in this regulation.     

Role of 17-AAG in inducing apoptosis and cell cycle arrest of HCT-15 cells

AIM: To investigate the effects of 17-AAG on apoptosis and cell cycle of HCT-15 cells and to clarify the related mechanisms. METHODS: MTT method was employed to evaluate the inhibitory effects of 17-AAG with Aifferent time and different doses on the proliferation of HCT-15 cells. The cells were stained with Annexin V-FITC/propidiumiodide and measured by flow cytometry. The expression of STAT3, cyclin D1, Cyt C, caspase 9 and caspase 3 at mRNA and protein levels was determined by RT-PCR and Western blotting. RESULTS: Treatment with 17-AAG at concentration of 1.25~20 mg/L for 24 h and 48 h significantly inhibited the activity of HCT-15 cells at both time-and concentration-dependent manners. Treatment with 17-AAG at concentrations of 0.425, 0.85 and 1.7 mg/L for 48 h significantly induced apoptosis and cell cycle arrest of HCT-15 cells. The exposure of 17-AAG at concentrations of 0.425, 0.85 and 1.7 mg/L for 48 h to the HCT-15 cells significantly down-regulated the expression of STAT3 and cyclin D1 at mRNA and protein levels, but up-regulated Cyt C, caspase 9 and caspase 3 mRNA and protein in a concentration-dependent manner. CONCLUSION: 17-AAG inhibits the cell activity, induces apoptosis and G₁ arrest by down-regulating the expression of cyclin D1, and promoting the mitochondria apoptosis through STAT3 pathway.     

Hsa-miR-218 inhibits growth of cervical cancer HeLa cells by targeting to LASP1

AIM: To study the effect of hsa-miR-218 on cervical cancer HeLa cell growth and the underlying molecular mechanism.METHODS: The lentivirus expression vector pmiR-218 targeting to hsa-miR-218 was constructed. pmiR-218 was transfected into HeLa cells. The number of viable HeLa cells was counted by the method of Trypan blue exclusion. The inhibitory rate of cell activity was detected by WST-8 assay. The expression of LIM and SH3 protein 1(LASP1) at mRNA and protein levels was determined by real-time PCR and Western blot. The interaction between miR-218 and LASP1 was examined using a luciferase reporter assay.RESULTS: The lentivirus expression vector pmiR-218 targeting to hsa-miR-218 was constructed successfully and confirmed by DNA sequencing. Over-expression of miR-218 inhibited the activity of HeLa cells with the inhibitory rates of 15%, 26% and 65% at 24 h, 48 h and 72 h, respectively. The difference between transfection group and blank control/negative control group was statistically significant. The luciferase activity was reduced when co-transfection with miR-218 mimics and LASP1-3,UTR plasmid. The relative expression of miR-218 was increased after transfection with pmiR-218. Over-expression of miR-218 down-regulated the LASP1 expression at mRNA and protein levels by 25% and 75% respectively. Compared with blank control group and negative control group, the difference was statistically significant(P<0.05).CONCLUSION: pmiR-218 effectively inhibits the growth of HeLa cells in a time-dependent manner. miR-218 targets to the 3,UTR of LASP1, thus down-regulating the expression of LASP1 in HeLa cells.     

Expression of Jagged2/Notch3 signaling molecules in pulmonary hypertensive rats induced by monocrotaline

AIM: To study the expression of Jagged2/Notch3 signaling molecules in pulmonary vascular wall of pulmonary hypertensive rats induced by monocrotaline. METHODS: SD rats were randomly divided into normal control group (C group,n=15), solvent control group (S group,n=15) and monocrotaline model groups (M group,n=15). The model of pulmonary hypertension was established by a single subcutaneous injection of monocrotaline (50 mg/kg). The rats in S group were given a single subcutaneous injection of the same dose of solvent. After 4 weeks, the pulmonary vascular remodeling was assessed by HE staining, and the mean pulmonary artery pressure (mPAP) and right ventricular systolic pressure (RVSP) were determined by right heart catheterization. The expression of Jagged2/Notch3/Hes5 molecules in the pulmonary vascular wall was detected by immunohistochemical method and real-time PCR. RESULTS: Compared with S group and C group, the percentage of medial wall thickness of smaller arteries in model group increased significantly (P<0.01). The levels of mPAP and RVSP in M group were significantly higher than those in S group and C groups (P<0.01). The results of real-time PCR showed that the expression of Jagged2, Notch3 and Hes5 was significantly increased in M group compared with S group and C group. The data from immunohistochemical detection indicated that Jagged2 mainly expressed in the intima of small lung artery, Notch3 and Hes5 mainly expressed in the medial smooth muscle cells. Compared with S group and C group, the expression of Jagged2 and Notch3 was significantly increased in the lung small arteries of M group. CONCLUSION: The activation of Jagged2/Notch3 signaling pathway might play an important role in the formation of pulmonary hypertension.     

Integration of transgenes into sexual polyploidization schemes for potato (Solanum tuberosum L.)

Most potato transgenic research has focused on development of resistance to pathogens and modification of potato physiology. Many transgenes, particularly those conferring pathogen resistance, could substantially lower potato production costs in developing countries. However, transgenes have not been reported in sexually propagated 4x-2x potato hybrids commonly grown in developing countries. Two transgenes,the Bacillus thuringiensis cry3Aa endotoxin protein gene and the PVY°coat protein gene, were engineered intodiploid and tetraploid potato using Agrobacterium tumefaciens-mediated transformation. Cry3Aa was produced at high levels in several lines while the PVY° coat protein was not expressed. Diplandroid and tetraploid genotypes were crossed to produce transgenic 4x-2x hybrids. Genetic transformation had no discernable effect on fertility ofthe primary transformants, germination of4x-2x seed derived from the transformants and agronomic performance(tuber set, average tuber weight and total tuber yield) of the 4x-2xhybrids. The transgenic 4x-2xhybrids produced non-viable pollen and could only be crossed as female parents. Results suggest that transgenes, such ascry3Aa, could be expressed in 4x-2x hybrids to lower costs of production with no significant effect on plant phenotype. This revised version was published online in July 2006 with corrections to the Cover Date.     

尾叶香茶菜种子发芽特性研究

研究温度、光照、贮藏时间及GA3处理对尾叶香茶菜种子发芽特性的影响。结果表明：尾叶香茶菜种子存在休眠期，度过休眠期后发芽率迅速增加，到达峰值后如果不采取科学的贮藏手段，发芽率将迅速下降；GA3处理可以提高种子的发芽率，其适宜的浸种浓度为50mg／L；光线对尾叶香茶菜种子萌发没有影响；其适宜发芽温度为20～30℃。     

Virtual Studio System Technology

Virtual studio system (VSS), a new technology based on virtual reality, develops fast in recent years. Virtual studio concept replaces real background sets with computer generated 3D synthetic and combines real foreground action, with computer generated backgrounds. As VSS need not construct real background sets and has little limitness of time and space, it is regarded as a revolution in TV programs. This paper mainly discusses about the background, technology feature, application and future.     

小鼠ES细胞在不同饲养层上培养nanog基因的 表达水平与生长行为

观察小鼠ES-D3细胞在MEF、新生牛睾丸支持细胞(nBTSCs)和新生兔睾丸支持细胞(nRTSCs)饲养层上生长4 d nanog基因的表达水平和生长行为。RT-PCR分析显示，MEF饲养层上培养4d的ES-D3 nanog基因含量高；nBTSC饲养层上培养nanog基因表达较低；而RTSC饲养层上培养nanog基因表达最低。结果显示：不同饲养层上的ES-D3细胞集落形态和培养4d分化程度有差异。在MEF饲养层上的ES-D3细胞培养4d，集落形态仍然很规则，细胞间紧密，集落表面少见大细胞，AKP染色强阳性。在nBTSC饲养层上的ES-D3细胞，集落界限清晰，AKP染色显示，集落大部分细胞呈阳性，少数的细胞集落为弱阳性，可见集落表面分散有较多的大细胞。在nRTSC饲养层上的饲养层上的ES-D3，集落隆起不明显，集落界限不清晰，大部分集落形态不太规则，AKP染色显示集落中部分细胞呈阳性，少数的细胞集落为全阴性，集落表面有较少的大细胞，集落周围有伸出的成纤维细胞。     

“Ch型”谷子显性核不育的遗传及其应用研究（Setaria italica）

通过对“Ch型”谷子显性核不育的遗传研究,证实“Ch型”的不育性与“澳大利亚谷”的细胞质无关,其育性是受两对显性连锁基因Ms-和Rf-上位互作控制的。其中Ms是显性不育基因,Rf是显性上位基因,当二者共同存在时,显性上位基因能抑制显性不育基因的表达,从而使不育表现可育。这种由杂交而来,并能找到“恢复系”的显性核不     

磷化氢环流熏蒸技术在高大房式仓中的应用

在高大房式仓中进行了磷化氢环流熏蒸试验，同时研究了不同仓型和不同熏蒸方式存在的差异。结果表明，在仓房容量、风道设置、环流设置配置合理的条件下，能在较短时间内使磷化氢气体在仓内各部位分布均匀，最低浓度与最高浓度比值最小为0．5，大部分比值在0．8－0．9之间，均高于国外资料推荐的PH3环流熏蒸浓度均匀性标准，即大于0．25。保持有效杀虫浓度的时间长，能够杀死仓内粮堆中的储粮害虫，取得了良好的杀虫效果。