L-securinine induced the human colon cancer SW480 cell autophagy and its molecular mechanism.

AIMS: To investigate the anti-tumor effects of L-securinine inducing colon cancer SW480 cell autophagy and explore its potential molecular mechanism.

MAIN

METHODS

MTT method was used to detect the antitumor effect of SW480 cells cultured with L-securinine in vitro. Light and electron microscopy were used to observe SW480 cells treated with L-securinine morphological changes. Flow cytometry was used to observe the apoptoticratio and cell cycle inducing with the L-securinine in SW480 cells, and the autophagic apoptosis ratio was determined by FITC-conjugated annexin V by flow cytometry (FCM). FCM was applied to analysis cell cycle; the expression of autophagy gene Beclin-1 was examined by reverse transcriptase polymerase chain reaction (RT-PCR).

KEY FINDINGS: The generation depression effects of SW480 cells cultured in vitro were detected byMTT method (Pb0.05), and there were dosage-time dependent relationships. Numerous autophagic vacuoles and empty vacuoles were observed in SW480 cells treated with 2.5 μM L-securinine for 48 h by electron microscopy, and the process of cell division that got less was observed.Through flow cytometry, a number of observed autophagic cells were obviously increased, and G1/S phase was retarded. L-Securinine tended to arrest cells at the G1 phase of the cell cycle. The percentage of the apoptotic cells increased as treatment duration and concentrations increased. Beclin-1 expression enhanced with L-securinine concentration increased.

SIGNIFICANCE: L-Securinine has an anti-tumor effect against colon cancer SW480 cell. The L-securinine can induce striking autophagy in SW480 cell in vitro. The autophagy induced by L-securinine is related with upregulating the expression of autophagy gene Beclin-1.