HepG2细胞在模拟微重力条件下的生长研究——体外细胞三维生长模型构建

Studies on HepG2 Growth Under Simulated Microgravity:to Establish a Method for Three-dimensional Cultivation In vitro as an Research Model

将人肝癌细胞(HepG2)接种于生物可降解支架聚羟基乙酸(polyglycolicacid,PGA)上,采用模拟微重力方法,在具有低剪应力和适宜气体扩散的旋转细胞培养系统(RCCS)中培养,构建体外三维培养模型.通过扫描电镜、透射电镜、RT-PCR、流式细胞术等方法观察分析.结果表明,细胞在此模型中生长良好,细胞呈多面体,含有丰富的微绒毛、线粒体以及胞间有紧密连接形成.该系统有利于细胞形成三维结构,更接近于体内细胞实际生长状况.另外,通过黏附分子表达分析,表明该模型重现了肝癌细胞某些体内侵袭转移特征.一些在肿瘤细胞侵袭和转移过程中具有重要作用的细胞黏附分子(celladhesionmolecules,CAMs)表达有了显著的变化,其中E-钙粘素(E-cadherin)表达降低,CD44、细胞间黏附分子-1(intercellularadhesionmolecule-1,ICAM-1,CD54)以及整合素β1(integrinβ1,CD29)表达增高.在体外实验中,对实验模型的适当选择是得到理想客观实验结果的必要前提,采用模拟微重力的方法构建的体外细胞三维培养模型,将为肿瘤生物学研究、药物敏感性试验等提供更为理想的研究模型.

Human hepatocarcinoma cells, HcpG2 were cultured onto biodegradable polyglycolic acid （PGA） polymer scaffolds, which were cultured in a rotating cell culture system （RCCS） to form a three-dimensional （3D） multicellular culture in vitro. The RCCS can simulate microgravity effects with low shear stress and well exchanging for gas. Then the growth characteristics and some mechanism of the cells in RCCS were detected by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, RT-PCR and flow cytometry （FCM）. The results indicate that the cells grew well with polyhedron morphology and lots of microvilli, mitochondria and tight junctions in this system, which means that this system is useful for cells to form 3D structure to mimic cell status in vivo. The expression of some cell adhesion molecules （CAMs） were changed markedly, which arc closely associated with cancer invasion and metastasis. The characters of increased expression of integrin β1 （CD29）, CD44, intercellular adhesion molecule-1 （CD54） and depressed expression of E-cadherin presumably show that the HepG2 cells cultured in RCCS could recur some characters of primary liver cancer in vivo, the capacity of invasion and metastasis. It is necessary for acquiring perfect and external results to select an appropriate research model for studying in vitro. This 3D culture in vitro under simulated microgravity can provide a useful and reasonable model for oncology, anticancer drugs research and other research.