XIANG Yinzhou,LI Xuejun,ZOU Yuhua, et al. The effects of L-mimosine on apoptosis and DNA damage-related protein expression in human pharyngeal squamous cell carcinoma FaDu cells[J]. JOURNAL OF WEZHOU MEDICAL UNIVERSITY, 2020, 50(7): 557-562.
Abstract：Objective: To explore the effect of L-mimosine on FaDu cells apoptosis and DNA damage related protein expression in human pharyngeal squamous cell carcinoma. Methods: The growth of FaDu cells after treating with L-mimosine at different time was observed by an inverted microscope. Flow cytometry was used to detect the apoptosis effects after different concentrations of L-mimosine and ammonium ferric citrate treating FaDu cells. Cell growth proliferation activity was examined by CCK-8 method after different concentrations of L-mimosine and ammonium ferric citrate processing FaDu cells. The expressions of p-Histone-H2AX, p-ATR, p-ATM and p-mTOR proteins related to DNA damage in FaDu cells were detected by western-blot after different concentrations of L-mimosine treating FaDu cells. Results: Different concentrations of L-mimosine inhibited the growth of FaDu cells at different times. Ferric ammonium citrate of 100 µmol/L could inhibit the apoptosis of FaDu cells, while deficient or excessive iron could promote the apoptosis of tumor cells. Compared with the control group, the apoptosis rate of FaDu cells was found between L-mimosine group (200 µmol/L) was the most significant. No significant difference was found between L-mimosine (200 µmol/L)+ammonium ferric citrate (50 µmol/L) group and L-mimosine (200 µmol/L)+ammonium ferric citrate (100 µmol/L) group. Meanwhile the apoptosis rate of FaDu cells in the ferric ammonium citrate group (50, 100 µmol/L) was significantly reduced. The effect on the proliferation activity of FaDu cells, ranging from strong to weak, were L-mimosine (200 µmol/L) group, L-mimosine (200 µmol/L)+ammonium ferric citrate (50 µmol/L) group and L-mimosine (200 µmol/L)+ ammonium ferric citrate (100 µmol/L) group. Compared with the control group, the difference was significant (P<0.05). With the increase of L-mimosine concentration, the expression of p-ATR protein decreased, while p-Histone-H2AX, p-ATM, p-mTOR in FaDu cells increased. Conclusion: L-mimosine cause DNA double strand damage and lead to tumor cell apoptosis via interference with iron metabolism of FaDu cells to regulate Akt/mTOR and other signaling pathways.
