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研究発表を行った学会；
・第３０回日本分子生物学会年会・第８０回日本生化学会大会合同大会　BMB2007
　2007年12月11日~15日(横浜)

タイトル；Proteomic Analysis of molecular mechanisms in the development of highly metastatic human tongue cancer cells.
　
発表者；　ウイルソン 森藤 政代　氏
　　　（熊本大学　 大学院医学薬学研究部　腫瘍医学分野）
Abstract；
To study the pattern of heterogeneous cancer development in human tongue cancer, we used a mouse model in which cancer cell lines of different metastatic abilities were mixed and transplanted, followed by observation of their growth and metastatic behaviors. First, we prepared two fluorescent-labeled human tongue cancer cell lines: a nonmetastatic cell line which stably overexpressed dsRed fluorescent protein (RFP-SQUU-A), and a highly metastatic cell line which stably overexpressed green fluorescent protein (GFP-SQUU-B). After mixing the RFP-SQUU-A and GFP-SQUU-B cells, we transplanted the mixture into the right side of mouse tongues submucously and observed the changes in growth and localization of each cell type for 42 days. The RFP-cells gradually disappeared from the tumor center and ultimately localized to the marginal regions only, while the GFP-cells showed aggressive growth in the tumor center and lymph node metastasis.
To determine the cellular factors related to these phenomena, the cell lines were subjected to differential proteomic (iTRAQ) and transcriptomic (DNA chip) analyses, followed by a study of the biological association on their networks involved in metastasis through an in silico analysis of the combined mRNA and protein data comparing metastatic SQUU-B with nonmetastatic SQUU-A. In meteastatic SQUU-B, we detected the upregulation of genes that Glucose transporters (GLUT1, GLUT3), Glycolytic enzymes (Phosphoglycerate kinase 1, hexokinase-1), Heme oxygenase 2, Triosephosphate isomerase, Cytokeratins 8,18,19, and Cathepsin D precursor, which were downstream of HIF (Hypoxia inducible factor) signal transduction. In addition we detected both the downregulation of tumor suppressors such as VHL, TSC1, P53, and P63, which also suppress HIF-related cellular signals, as well as the upregulation of oncogenes such as Src, Ras etc. and growth factor signaling by IGF, HER-2, PI3K, which activates the HIF-related cellular signals. We also detected differences between SQUU-A and SQUU-B in vitro in the expression and transcriptional activity of HIF-1α.
These results suggested HIF and HIF-related cellular signals could be very important cellular factors in the aggressive growth of metastatic cells in heterogeneous cancer development, making them potential target molecules in metastatic cells.