Expression of Notch signaling transduction pathway in lung cancer stem cells

Abstract

Objective To explore the expression of Notch transduction signaling pathway in lung cancer stem cells and the effect on the cellular growth in vitro after blocking Notch signaling pathway. Methods Lung cancer stem cells and general tumor cells were isolated from human lung adenocarcinoma cell line A549 by the high speed sorting of flow cytometry based on surface marker of CD133. Expression of Notch transduction signaling pathway in lung cancer stem cells and general tumor cells were detected by real-time fluorescent quantitative polymerase chain reaction(FQ- PCR)and Western blotting.The proliferation of lung cancer stem cells and general tumor cells in vitro was detected by cell counting kit-8 (CCK-8)respectively, and the growth curves of lung cancer stem cells and general tumor cells were described and compared.After blocking the Notch transduction signaling pathway by γ- secretase Inhibitor (DAPT), a γ- secretase inhibitor, cellular growth in lung cancer stem cells and general tumor cells was both observed and analyzed. Results CD133 positive cells(served as lung cancer stem cell)occupied(0.40±0.11)% of all A549 cells before the high speed sorting by flow cytometry, while the percentage of CD133 positive cells reached to(95.00±0.63)% after the high speed sorting of flow cytometry, with significant difference(P 0.05).However,after 48 h of DAPT intervention, variant inhibitions of growth were shown.Compared to general tumor cells[(21.5±3.4)%], growth inhibitory rate of cancer stem cells[(33.7±1.9)%]increased obviously, indicating a statistically significant difference(P< 0.05). Conclusion Conclusion Inhibitory effect on the growth of lung cancer stem cells was more significant. It may be related to overexpression of Notch inhibited by DAPT and its negative feedback effect on lung cancer cells. Key words: Notch pathway; Tumor stem cell; Growth inhibition; CD133