Expression of Foxo3a in non-Hodgkin's lymphomas is correlated with cell cycle inhibitor p27kip1

Objective: Cell cycle arrest by FOXO transcription factors involves in transcriptional activation of p27(kip1), although the exact mechanism remains unclear. And it has been evidenced that reduced level of p27(kip1) which is frequently occurred in human cancers has been associated with poor prognosis. In this study, our purpose is to investigate the clinical relevance of altered patterns of Foxo3a and p27(kip1) expression in Chinese patients with localized non-Hodgkin's lymphomas (NHL). Methods: We analyzed the Foxo3a and p27(kip1) expression of Chinese NHL patients by immunohistochemistry and protein levels using Western Blot. Results: There was a direct relationship between the low level of Foxo3a and the rapid proliferation in immunohistochemical analyses. We also found a positive correlation between Foxo3a and p27(kip1) in immunohistochemical analyses and cell culture. Additionally we revealed that activation of Foxo3a could induce the accumulation of p27(kip1) at protein levels when cell cycle was arrested. Conclusions: The expression of Foxo3a may be correlated with patients' survival.