RESUMO
<p><b>OBJECTIVE</b>To investigate the effects of T lymphoma invasion and metastasis inducing factor 1 antisense oligodeoxynucleotides (Tiam 1 ASODN) transfection on the morphology and invasive migration potential of gastric cancer cells.</p><p><b>METHODS</b>The higher invasive and migratory subgroup (M(H)) were separated from human gastric cancer cell line MKN-45 (M(0)) by laminin adhesion method in vitro. Tiam 1 ASODN was transfected into M(H) cells with liposome, and the expression of Tiam 1 mRNA and protein was determined by RT-PCR and flowcytometry respectively. The changes in morphology, the invasive and migratory potential between Tima 1 ASODN transfected M(H) cells and no transfected M(H) cells were observed by HE stain, cytoskeletal protein stain, scanning electronic microscope (SEM) and Boyden chamber test.</p><p><b>RESULTS</b>Compared with the control, the expression of Tiam 1 mRNA and protein in M(H) cells was significantly decreased after transfected with 0.43 micromol/L ASODN(P< 0.01). The invasive and migratory potential of M(H) cells in vitro was also much more decreased than that of no transfected cells (P< 0.05 or P< 0.01). At the same time, transfected M(H) cells had less membrane surface projections, fewer or shorter pseudopodia, less irregular cytoskeletal network and less spotted-like actin bodys than no transfected M(H) cells did.</p><p><b>CONCLUSION</b>Tiam 1 ASODN transfection can effectively suppress the expression of Tiam 1 in gastric cancer cells and impair its invasive and migratory potential in vitro, which may be fulfilled through modulating the reconstruction of cytoskeleton and decreasing the deforming and migratory potential of gastric cancer cells.</p>