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ISSN 1672-9145 Acta Biochim Biophys Sin 2004, 36(8): 537–540 CN 31-1940/Q

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Antisense Tiam1 Down-Regulates the Invasiveness of 95D Cells in Vitro

Min HOU, Li TAN, Xia WANG, and Yun-Song ZHU*

Department of Molecular Genetics, Shanghai Medical College, Fudan University & Key Laboratory of Molecular Medicine, Ministry of National Education, Shanghai 200032, China

Abstract As a specific guanine nucleotide exchange factor of Rac1, Tiam1 (T-lymphoma invasion and metastasis inducing protein 1) is involved in a number of cellular events, such as cytoskeleton reorganization, cell adhesion, and cell migration. Since Tiam1 was implicated in the invasion and metastasis of T-lymphoma cells and breast tumor cells, we compared the expression level of Tiam1 in two human giant-cell lung carcinoma cell strains with high or low metastasis potential, and found that Tiam1 expression level in high-metastatic 95D cells was higher than that in low-metastatic 95C cells. To further confirm the role of Tiam1 in invasion and metastasis, we constructed the antisense Tiam1 expression plasmid (pcDNA3-anti-Tiam1), which was transfected into 95D cells. A stable transfected clone with decreased Tiam1 expression was screened and selected for further research. Transwell assay showed that down-regulation of endogenous Tiam1 by anti-Tiam1 can reduce the in vitro invasiveness of 95D cells. Our results suggested that Tiam1 signaling contributed to the invasion and metastasis of the human giant-cell lung carcinoma cells.

Key words T-lymphoma invasion and metastasis inducing protein 1 (Tiam1); invasion and metastasis

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Received: May 11, 2004 Accepted: June 23, 2004

The work was supported by a grant from the National Natural Science Foundation of China (No. 30170398)

*Corresponding author: Tel, 86-21-54237278; E-mail, [email protected]