Effect Of RGD Peptide On The Invasion And Metastasis Of Tb Cell Line

Lingual squamous cell carcinoma is the most encountered malignance in oral cavity and has a high metastatic ability. It has a high incidence , rapid spreadability, earlier metastasis and a high mortality. Therefore,it is a important task for the researchers of tumor to find a effective therapeutic scheme. A metastatic cell line from brain metastasis which is named as Tb is a special case from Tca8113 cell line discovered by Wu Junzheng through nude mice experiment. It has not only the characteristics of Tca8113,but also the potential of multiplication, recrudescence and metastasis. Therefore, it can be counted as the model of highly metastatic cells for experiment research. The establishment of Tb cell line not only do benefit to studying the pertinent molecular mechanism of tumor metastasis, but also do help to singling out the inhibitor of metastasis.Tumor metastasis is a very perplex course.It involves the interaction of the tumor cells, vascular endothelium cells, lymphoid endothelium cells and extracellularmatrix(ECM) and also does it include the aggregation of blood platelets. RGD(arginine- glycin- asparagine) is the common sequence which exists in ECM and cell membrane such as FN, VN, Collagen, vWF and Opn etc. It plays a great role in the course of tumor invasion. The man-made RGD peptides just simulate the mutual amino acid sequence and take precedence to interfere with the interaction of the tumor cells and ECM to attain the aim of inhibitting tumor invasion and metastasis.In 1986,Humphries first reported GRGDS could inhibit B16-F10 cells from adhering to FN in vitro and metastasizing to lung in vivo, while the peptide which didn' t contain RGD sequence didn' t have the function. Because it isn' t immune to human body,also doesn' t it could bring side-effects to body, it has become a hot topic for tumor metastasis reseach. But we haven' t found literatures about the application of RGD peptide on human tongue cancer heretofore. In this article, we will use Tb cell line as the highly metastatic tumor model to study its inhibiting effect on tongue cancer metastasis.1. With light microscope observation we found that the Tb cells and the Tb cells treated with RGDS had the similar morphological characteristics .They all looked like epidermoid cells and were polygonal in shape with the typical cobblestone growing pattern. They all had much nuclear cleavage and nuclear heteromorphosis.2. Immunohistochemical staining was carried out to detect 1-integrin expression in the Tb cells and their-6-counterparts which were treated with RODS. Tb cells showed positive staining on their cell membranes with the antibody of ,-integrin while the protein expression of 1-integrin decreased in the treated cells.3. MTT assay was applied to study the effects of different concentration of RGDS peptide on Tb cells' adhesive capability to Matrigel and Fibronectin. Different concentration of RGDS peptide showed inhibitory effects on the adhesion of Tb cells to Matrigel and Fibronectin.4. Cellular motility experiment was carried out to assay the inhibitory effects of RGDS peptide on Tb cells' motility on Matrigel and Fibronectin. It showed that RGDS could restrain Tb cells from moving on Matrigel and Fibronectin.5. The invasion experiment of chicken embryo' cardiac muscle was applied to study the restrainability of RGDS peptide on the invasion of Tb cells. Compared with the control, it distinctly inhibited the tumor cells from invading alive tissue (P<0. 01) .6. The electrophoresis of substrate SDS-PAGE gels containing gelatin was used to infer the relationship between RGDS and matrix metalloproteinase. The result of the electrophoresis indicated that RGDS peptide could partly limit the secretion of the matrix metalloproteinase which was induced by Fibronectin.7. The effect of anti-metastasis of the drug was observed in nude mice Tb cell model that would metastasize to lung. The Tb lung metastatic nodule number was decreased significantly in nude mice experiment.From the results above, we could conclude...