Abstract: Abstract：ObjectiveTo investigate the gene of YY1 in lung cancer tissues and discuss its function in cell proliferation，migration and invasion.Methods The mRNA of YY1 in 235 lung cancer tissues and 62 adjacent tumor tissues were determined by real-time quantitative PCR. NSCLC cell lines were transfected with YY1 over- vector and negative control vector using Lipofectamine 3000. Proliferation of cells were measured by MTT in control groups and YY1 over- groups after 24h, 48h and 72h of transfection in A549 and H1299 cells. Wound-healing assay and Transwell assay were performed to investigate the effect of YY1 over on the invasion and migration of lung cancer cells.Results Compared to normal adjacent tissues(5.80±0.58)，the of YY1 was significantly lower in lung cancer tissues(5.07±0.58)(P<0.01)．There were significant differences in the levels of YY1mRNAbetween gender, smoking status,histology subtypeor clinical stages(P＜0.05). Furthermore, compared to controls, the over- ofYY1 in H1299 cells was found to suppress proliferation for 48h and 72h (P<0.01) and A549 cell for 72h(P<0.05). Wound-healing assay and Transwell assay showed the over of YY1 inhibited migratory and invasive capability of lung cancer cells (P<0.05).Conclusion YY1mRNA level is lower in lung cancer tissue than normal adjacent tissue and YY1 suppresses lung cancer cell proliferation, migration and invasion.

Key words: lung cancer, YY1transcription factor, cell proliferation, cell migration, invasive ability