Background and purpose: The transcription factor PAX6 is primarily expressed in embryos. PAX6 is also expressed in several tumors and plays oncogenic or tumor suppressor role. This study aimed to investigate the expression of PAX 6 in non-small cell lung cancer (NSCLC) tumor samples and cell lines; and evaluate the effects of PAX6 on the proliferation and invasion of tumor cells and the expression level of cyclin E and p38. Methods: Western blot was carried out to detect the PAX6 protein level in 86 NSCLC tumor tissues

paired adjacent normal tissues and 2 cell lines. PAX6 siRNA was transfected into human lung cancer A549 cell line. Anchorage-independent growth and invasiveness of tumor cells were measured by MTT and transwell cell invasion assay

respectively. Cyclin E and p38 protein level before and after transfection were detected by western blot. Results: Comparison with tumor adjacent tissues and normal human bronchial epithelial cells 16HBE

PAX6 in NSCLC tissues and A549 cell lines was significantly higher expression. After transfection with efficient sequence of PAX6 siRNA for A549 cell lines

the down expression of PAX6 inhibits tumor cell proliferation

the proportion of cells in G1 phase increased

the cell invasion and migration decreased remarkably. Cyclin E and p38 activity was inhibited in PAX6 knockdown cells. Conclusion: PAX6 accelerate cell cycle progression by activating cyclin E and p38. PAX6 is a potential target for diagnosis and therapy.