| With the deep research of the carbon nano-materials, especially the graphene was firstly discovered since2004, it has gradually become a "superstar material" in the region of materials science. Nano-graphene and the graphene derivatives are two dimensional structures of carbon. Due to their unique physical and chemical properties, super hydrophobic surface, a better modification surface and unique optical properties, they have been widely used in biomedical, electronic devices and composite materials research fields. They also have a very bright application prospects, such as:biosensors, biological imaging, and gene delivery, photothermal therapy of tumor and cancer, hydrophobic anticancer drugs, and antibacterial materials and organization of material and other fields.In recent years, with the crossover study of the biological technology and other subjects, and the rapid development of material of biology, it has brought a great impact on biological medicine, food safety, energy and environment, and aerospace, information industry and other technical field. As more and more of nanotechnology and nano materials were applied in various fields, which require us not only to pay attention to the beneficial effects of nano-materials in our lives, but also we should consider which materials may bring the potential effects on environment and health. We should also pay much attention on trie cause and effects of the nano-materials on the bio-compatibility and bio-medicine.One of the most important impacts on physiological pathology is the transfer of tumor invasion. This process is called Epithelial-Mesenchymal transition (EMT). The process mainly occurred in the polarity of epithelial cells, which will be changed into mesenchymal cells and they have invasiveness and migration capability. It exists in multiple physiological and pathological processes in human body. Many studies have shown that EMT and tumor cell invasion and metastasis are closely related. We adopt the carbon materials graphene which we called "star material" as the research object, and study its effect on EMT cell. This research provides the possibility of material modified drug targeting delivery probability, and at the same time it can lead to the study of the mechanisms of tumor, new therapeutic methods for inhibiting tumor metastasis. In this study, we mainly focuses on the nano size (about100nm) of nano-graphene oxide (GO). To observe the direct interaction in the epithelial cell line treated by TGF-β1(transforming growth factor-P) or GO, and the epithelial cell line directly observe whether they cause epithelial-mesenchymal cells, and the possibility of transformation of cell growth factor TGF-β1induced tumor epithelial-mesenchymal in the role transformation of mesenchymal cells. We choose the mouse mammary epithelial cells (NMuMG) as the main object of study, to explore the unmodified nano-graphene oxide (NGO) effects on epithelial cell line, we tested the direct and indirect effects of graphene, observation of cytotoxic effects and the induction of the occurrence of EMT, in order to provide certain theoretical basis for the mechanism of biological effects of graphene oxide.(1) We chose the nano-graphene oxide and some epithelial cells line from different species as the study objects in the experiment. The dose (concentration:0、5、10、15、20and40ug/ml) and different times (24h、48h and96h) were processed, after we selected the low toxicity screening of effective concentration and observed the obvious effect of cell lines in the form in the shortest time. At first, We used induced EMT model by TGF-β1, we found the obvious biological effects of cell lines of mouse mammary epithelial cells (NMuMG) screened for GO and TGF-β1(2) We divided into three groups:1) control group;2) graphene treatment group,3) the TGF-β1group and4) graphene&TGF-β1group. Then we had an experiment of the capability of morphology and cell migration assay through24h and48h. After the experiment, we only found the TGF-β1cells which showed morphological changes to the evolution of the spindle sample mesenchymal cells. It has the strongest migration ability, so we think the induceed cells is the typical EMT. While the GO alone treated cells did not change, and healing ability began weak. In the graphene&TGF-β1group, there were only a handful of fibrotic phenomenon happened, so we can draw the conclusion that graphene oxide on TGF-β1induced has played a certain inhibition.(3) We applied the Real-time PCR and Western blotting to detect the level of genes expression and level of the relative protein. Finally, we found that after the induction of TGF-β1, the expression of marker gene(E-cadherin) of epithelial cell decreased, whereas Mesenchymal cells marker gene(FN) expressed increased. This result also suggests after the induction of the TGF-β1, the process EMT also occurred. However, after the graphene oxide was upregulated, we observed the expression of TGF-β1after induction of EMT appears associated markers in different degrees of inhibition. From the above-mentioned changes in the expression of genes, we preliminarily concluded that graphene oxide also participates in the regulation of TGF-β1EMT process. According to the EMT process, the relative signal pathway may cause us to verify GO respectively from TGF-betal/Smad pathway and MAPK (ERK and p38) pathways directly and indirectly involved in the mechanism of cell biological effects NMuMG-EMT. |
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