| BACKGROUND/OBJECTIVESTumor metastasis is an extremely complex process involving multi-genes, multi-factors and multi-steps, in which neoplastic cells must escape from the primary tumor, degrade the extracellular matrix, migrate to distant sites, arrest in the capillaries, and migrate through the basement membrane and underlying connective tissue to the metastatic site. The essential events of the process are detachment, intravasation, circulation, arrest, extravasation, angiogenesis and proliferation, which come down to interactions of neoplastic cells with host cells and extracellular matrix -governed by adhesion, migration, invasion, proteaselysis, and the complicated signal transduction. In view of signaling play the leading roles in the cell function, signal transduction system and its mechanisms in the tumor metastasis are the key to understanding of essence of the process and exploring new anti-metastasis techniques. Considering similarities between tumor metastasis and the migration of progenitor cells in embryonic tissue development, HGF/SF-c-met signaling pathway may be very important to the tumor metastasis just as it to the migration of embryo primitive cells. HGF/SF-c-met signaling is a pathway by stimulation of c-Met via its ligand hepatocyte growth factor /scatter factor (HGF/SF), leads toa plethora of biological and biochemical effects in the cell. HGF/SF, a multifunction cell growth factor yielded by interstitial cell (fibroblasts, neuroglial cells, glial cells fat-storing cells, macrophages), primarily as specific to the liver, proved to be have mitogen, motogen, morphogen activity for nearly all epithelial cells. HGF/SF, having a magic scatter effect to tumor cells, named as scatter factor, promotes adhesiveness, invasiveness, motion and metastasis and stimulates blood vessel growth for cancer cells. c-Met, only presented in the epithelial cells, is a receptor tyrosine kinase shown to be over-expressed and mutated in a variety of malignancies. HGF/SF-c-met signaling may play an important or critical causal role in tumor progression and invasion and metastasis. However, little is known about the target molecules, molecules links to invasion, migration and metastasis, and gene expression profiles by which it exerts biological function through start-up transcriptional gene expression.This paper aims to explore the transcriptional gene expression profiles by activating HGF/SF-c-met signaling in colorectal carcinoma cells by using the microarray technology which can detect thousands of genes in the same time, and to construct c-met and S100A6 antisense eukaryotic expression vector for blockage of HGF/SF-c-met signaling and to find a new way for antisense gene therapy, and to probe into anti-metastasis effect and mechanisms of 3 , 4 , 5-trihydroxystibene-3- P -mono-D-glucoside (THMG, a Chinese drug extract).METHODS1. Cell biological techniques to detect cell growth curve, adhesion rate, migration, invasiveness, cell cycle, gene and protein expression were used for estimation of in vitro effects by stimulation of HGF/SF, Coastar Transwell Culture System for migration and invasiveness, PI stain flow cytometry for cellcycle analysis, and SABC Immune fluorescence technique and FCM for protein expression detection, and P -actin semi-quantitative RT-PCR for analysis of gene expression of c-met and HGF/SF.2. HGEC-40S microarray (Biostar, Shanghai) containing 4096 cDNA spots, fluorescent probe Labelled by Cy3-dUTP and Cy5-dUTP, derived from cDNA reverse-transcripted from RNA, extracted from human colorectal adenocarcinoma cell LoVo by HGF/SF stimulating experiments, were applied to exploring differential gene expression profiles between with and without HGF/SF stimulation. GenePix 4000B scanner was for scanning the microarray, and GenePix Pro 3. 0 software for analysis of intensity and ratio of Cy5/Cy3.3. Bioinformatic technology was used to optimize object gene sequences for antisense therapy. The c-met and S100A6 sequences was amplified from Hela cells by RT-PCR,...
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