Objective: Spleen tyrosine kinase (Syk) is closely related to tumor invasion and metastasis, and has been shownto have potential inhibitory effects in tumors. In this study, we constructed a eukaryotic expression vector forSyk and analyzed its effects on invasive ability of the A549 non-small cell lung cancer cell line in vitro. Methods:A fragment of Syk was obtained by RT-PCR from human lung cancer cells and cloned into the expression vectorpLNCXSyk. After restriction endonuclease digestion, PCR and DNA sequencing confirmation, the recombinantSyk expression plasmid was transfected into A549 human lung cancer cells using lipofectamine protocols. Afterselection, the cells stably expressed Syk. Detection of Syk expression of the cells by RT-PCR, and invasive abilitywere examined. Results: The eukaryotic expression plamid pLNCXSyk was constructed and expressed stablyin the A549 human lung cancer cells. The RT-PCR results showed that Syk mRNA expression was upregulatedsignificantly (P<0.05). Lower invasion through a basal membrane were apparent after transfection (P<0.05). Conclusions: A eukaryotic expression plasmid to cause Syk expression in lung cancer cells can obviously inhibittheir invasive ability in vitro.
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