Abstract: Objective To investigate the function of Thy-1 gene, especially its possible roles in the migration of A549 cells as well as the possible mechanisms by which it works. Methods Construct recombinant expression plasmid vector of pcDNA3.0-Thy-1 and transfected it into A549 cells. These cell lines were further studied for the exogenous Thy-1 mRNA expression by RT-PCR and expression of endogenous Thy-1 protein by immunofluorescence assay. Then the transwell cell migrations were assayed. In order to study the possible mechanisms by which Thy-1 influences the invasiveness potential, microarray were used to screen out cell migrations associated genes. Results Eukaryotic expression vector pcDNA3.0-Thy-1 was constructed; Stable Thy-1 expressing cell line were established; Transwell assay showed that over expression of Thy-1 in A549 cell line resulted in reduced ability of cell migration (EM>P/EM><0.0001); and microarray suggested that the Thy-1 gene could influenced the expression level of 25 cell motility-related genes. In these genes， 11 genes expressions were up regulated, and 14 genes were down regulated. These results could be consistent when microarray and RT-PCR methods were used to detect the difference of gene expression.Conclusion Overexpression of Thy-1 leads to a less invasive phenotype of A549 cells and changes the expression level of many cell motility-related genes. This suggested that Thy-1 expression patterns in lung cancer tissue may be associated with the invasiveness of non-small cell lung cancer.

Key words: Thy-1, Lung cancer, A549 cell, Cell motility, Construction of vector, Microarray, Transwell, RT-PCR, Human