Expression of matrix metalloproteinase-28 in human normal cytotrophoblast cells and a choriocarcinoma cell line,JEG-3

There are striking similiarities present between the behavior of invasive placental cells and that of invasive cancer cells. Matrix metalioproteinases (MMPs) are one of the most important mediators. MMP-28, the new member ofMMPs, was sequenced and identified recently. Expression of MMP-28 mRNA and protein in the cytotrophoblast cells anda choriocarcinoma cell line, JEG-3 cell, was conducted by zymography, RT-PCR and Northern blot. There is MMP-28mRNA expression in both the cytotrophoblast cells and JEG-3 cells by RT-PCR. The activity of MMP-28 in cytotrophoblast cells was significantly weaker than that in JEG-3 (P < 0.01) by zymography. Furthermore, mRNA expression of MMP-28 was significantly stronger (P < 0.001) in JEG-3than in human cytotrophoblast cells in a time-dependent way by Northern Blot. Our results suggest that MMP-28 may play a role in some of the tissue-remodeling events associated with normal pregnancy and tumor progression.``     

Regulation of activin A in cell proliferation and hormone secretion by human normal trophoblast cells

Regulation of activin A in cell proliferation as well as hCG and progesterone secretion was investigated using primary cultured cytotrophoblast cells and normal placenta origin cytotrophoblast cell line-NPC cells in serum-free system. It was shown that activin A promoted hCG and progesterone secretion in primary cultured cytotrophoblast cells as well as progesterone secretion in NPC cells, while it had no effect on cell proliferation and hCG secretion in NPC cells. Important evidence is provided for the autocrine regulatory mechanism of activin A on hormone secretion in placental trophoblast cells at early pregnancy.     

蜂胶黄酮Pinobanksin-3-acetate对结肠癌HCT-116细胞增殖及凋亡的影响

 为探讨蜂胶黄酮(Pinobanksin-3-acetate, PB3A)对结肠癌HCT-116 细胞增殖及细胞凋亡的影响, 采用四甲基偶氮唑盐(MTT)比色法, 检测不同浓度、不同时间PB3A、5-氟尿嘧啶(5-FU)及两种药物联合作用对HCT-116 细胞生长所产生的影响, 倒置显微镜观察细胞的形态学变化特点, Annexin V-FITC/PI 双染色、流式细胞仪检测药物作用24 h 后的细胞凋亡率。结果显示, PB3A 对HCT-116 细胞增殖有明显的抑制作用, 并呈浓度和时间依赖性。其抑制活性与5-FU 几乎没有显著性差异, 联合用药具有协同效应; 在一定剂量范围内, 可见凋亡细胞明显增多。流式细胞仪分析结果表明, 细胞凋亡率明显上升, 呈剂量依赖性。PB3A 对HCT-116 细胞具有明显的增殖抑制和诱导细胞凋亡作用。     

H13对HT-29细胞周期和caspase-3蛋白表达的影响

探讨新型Topo I抑制剂H13对体外培养的人结肠癌细胞HT-29细胞周期和caspase-3表达的影响.以人结肠癌细胞HT-29为研究对象,PI染色,流式细胞仪检测H13处理48 h后细胞周期的分布;Western Blot法检测H13处理48 h后caspase-3表达的变化.2.5和5 g/mL H13处理的HT-29处理48 h后,G1期细胞百分率下降,S期细胞百分率上升,并且有剂量依赖性;2.5,5,10 g/mL H13处理的HT-29处理48 h后,caspase-3蛋白表达升高.H13对诱导HT-29细胞周期阻滞于S期,其机制可能与其上调caspase-3表达有关.     

Rho激酶抑制剂诱导PC12和PC12Adh细胞突起生长的差异比较

 PC12细胞是研究神经分化最常用的细胞之一.在rho激酶(ROCK)抑制剂的作用下,PC12细胞能够长出神经样突起.最近,美国菌种保存中心(ATCC)同时提供PC12细胞和PC12 Adh细胞.研究的主要目的是观察ROCK抑制剂诱导这2种细胞长突起是否存在差异.PC12细胞和PC12Adh细胞按照ATCC方法进行培养,用神经生长因子(NGF,1000ng/mL)或ROCK抑制剂(33μmol/L Y27632,33μmol/L法舒地尔)处理细胞1~4d.结果发现NGF能够诱导这2种细胞生长突起,而ROCK抑制剂只诱导PC12Adh细胞长突起,对PC12细胞不明显.因此,ROCK抑制剂诱导这2种细胞突起生长存在明显差异,PC12Adh细胞更适合用于ROCK抑制剂的神经诱导分化实验.     

Comparative study on the effect of integrin αvβ3 on secretion of matrix metalloproteinases in human normal and carcinoma trophoblasts

The invasion of cytotrophoblast cells into the maternal endometrium during embryonic implantation is very similar to the metastasis of carcinoma cells. However, the significant difference is that the former is a highly controlled process. In this report, the effects of integrin αvβ3 on the secretion of matrix metalloproteinase (MMP) were compared between normal cytotrophoblast cells and choriocarcinoma cells by RT-PCR, gelatin zymography and immunocytochemistry. The results reveal that both normal cytotrophoblast cells and choriocarcinoma cells can express integrin αvβ3. The secretion of MMPs in normal cytotrophoblast ceils is up-regulated by anti-αvβ3 antibody, whereas, decreased in choriocarcinoma cells. It was suggested that αvβ3 can modulate the expression of MMPs in trophoblasts, and this action is carried out through distinct mechanisms in normal and carcinoma cytotrophoblast cells.     

芒果苷对人肺腺癌A549细胞增殖的抑制作用及其机制研究

利用相差显微镜观察细胞形态变化情况;用MTT法测定芒果苷对A549细胞增殖作用的影响以及Western-Blot法检测芒果苷对Caspase-3、Caspase-8、Caspase-9蛋白分子表达水平的影响.结果显示,与对照组相比,芒果苷对人肺腺癌A549细胞的抑制率与浓度和时间均呈正相关性.在有效浓度为3μM,作用最佳时间为48h时,A549细胞的镜下形态和结构发生显著的变化;并且导致Caspase-3、Caspase-8、Caspase-9的活性以及它们的剪切小体数量增加.表明芒果苷对人肺腺癌A549细胞具有抑制增殖的作用,并且通过caspase依赖性途径诱导A549细胞凋亡.     

过表达蛋白合成与分泌相关蛋白提高CHO细胞anti-hLAG3产量

对比研究了过表达蛋白合成与分泌途径中的20种蛋白对瞬时表达细胞（ExpiCHO-S细胞）表达anti-hLAG3产量的影响,考察了转录因子XBP1s对ExpiCHO-S细胞生长、抗体产量和抗体亲和力的影响。结果表明,当所研究蛋白的表达质粒与anti-hLAG3质粒以1：4的质量比共转染时,XBP1s能够使抗体产量提高约30%,GADD34、NFKBIz、CERT、C/EBPα和mTOR的过表达则会明显降低抗体产量,其他14种蛋白对抗体产量的影响较小。随着XBP1s共转染比例的增加,其对anti-hLAG3生产的促进作用增强,当共转染比例提高到60%时,相对于共转染比例为60%的EGFP,可使转染后168 h的抗体产量提高到2.1倍。此外,XBP1s的过表达对活细胞密度和细胞活率以及抗体亲和力的影响均较小。以上结果表明XBP1s可作为细胞工程的一个有效靶标用于提高CHO细胞重组蛋白的生产性能。