Objective:To observe the effect of MARK2 expression on cell polarity and proliferation in He La cells

and to investigate the underlying mechanisms. Methods:A stable He La cell line highly expressing MARK2 protein was established by using G418 selection. Cell polarity was observed with TRITC-Phalloidin staining. Cell proliferation was examined with plate colony formation assay.Proportions of cells in different phases of cell cycle were analyzed by flow cytometry. Levels of total Rb protein and phosphorylated Rb protein were analyzed by Western blot. Results:High expression of MARK2 in Hela stable cells led to phenotypic changes consistent with reversed epithelial polarity. Decreased cell proliferation

increased G1-phase cell proportion

reduced S-phase cell proportion and inhibited Rb phosphorylation were observed in He La stable cells. Conclusion:Enforced expression of MARK2 protein in He La cells leads to decreased Rb phosphorylation

arrests cell cycle at G1-stage thus inhibits cell proliferation. MARK2 can reconstruct epithelial polarity of He La cells

and modulate both signaling pathways regulating cell polarity and cell proliferation.