Effects of cell proliferation and apoptosis of L-carnitine combined with epirubicin on different human lung adenocarcinoma cells

Objective To investigate the effect of L-carnitine (LCNT) combined with epirubicin (EPI) on cell proliferation and apoptosis of two lung adenocarcinoma cell lines (GLC-82 and A549). Methods GLC-82 and A549 cells were divided into control group, EPI group, LCNT group and EPI+LCNT group, respectively. The cell proliferation rate was examined by MTT assay 24 h after the treatment, and the cell cycle and cell early apoptosis were analyzed by flow cytometry. The expression of P53 and Bcl-2 proteins were detected by Western Blot. Results Compared with the control group, the proliferation rate of GLC-82 and A549 cells was 37.56%(P 0.05) after 24 hours of 20.00 μg/ml LCNT treatment indicating LCNT could promote the proliferation of GLC-82 cells. Compared with the EPI group, EPI+LCNT had smaller inhibitory effect on the proliferation of GLC-82 cells, and the inhibition rate of the EPI+LCNT group was 12.14% lower than that of EPI group (P 0.05). Conclusions Comparing with the EPI, the combination of LCNT and EPI has less proliferation inhibition and apoptosis induction on GLC-82 cells, and without significant effect on A549 cells. LCNT can promote the proliferation of GLC-82 cells and block the cell cycle at G0/G1 phase. This mechanism may be related to down-regulation of P53 protein and up-regulation of Bcl-2 protein expression. Key words: Lung neoplasms; Adenocarcinoma; Cell proliferation; Cell apoptosis; L-carnitine; Epirubicin