Published online Apr 14, 2017. doi: 10.3748/wjg.v23.i14.2511
Peer-review started: November 17, 2016
First decision: December 19, 2016
Revised: January 6, 2017
Accepted: March 2, 2017
Article in press: March 2, 2017
Published online: April 14, 2017
To investigate the effects of berberine on esophageal cancer (EC) cells and its molecular mechanisms.
Human esophageal squamous cell carcinoma cell line KYSE-70 and esophageal adenocarcinoma cell line SKGT4 were used. The effects of berberine on cell proliferation were evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. For cell cycle progression, KYSE-70 cells were stained with propidium iodide (PI) staining buffer (10 mg/mL PI and 100 mg/mL RNase A) for 30 min and cell cycle was analyzed using a BD FACSCalibur flow cytometer. For apoptosis assay, cells were stained with an Annexin V-FITC/PI apoptosis detection kit. The rate of apoptotic cells was analyzed using a dual laser flow cytometer and estimated using BD ModFit software. Levels of proteins related to cell cycle and apoptosis were examined by western blotting.
Berberine treatment resulted in growth inhibition of KYSE-70 and SKGT4 cells in a dose-dependent and time-dependent manner. KYSE-70 cells were more susceptible to the inhibitory activities of berberine than SKGT4 cells were. In KYSE-70 cells treated with 50 μmol/L berberine for 48 h, the number of cells in G2/M phase (25.94% ± 5.01%) was significantly higher than that in the control group (9.77% ± 1.28%, P < 0.01), and berberine treatment resulted in p21 up-regulation in KYSE-70 cells. Flow cytometric analyses showed that berberine significantly augmented the KYSE-70 apoptotic population at 12 and 24 h post-treatment, when compared with control cells (0.83% vs 43.78% at 12 h, P < 0.05; 0.15% vs 81.86% at 24 h, P < 0.01), and berberine-induced apoptotic effect was stronger at 24 h compared with 12 h. Western blotting showed that berberine inhibited the phosphorylation of Akt, mammalian target of rapamycin and p70S6K, and enhanced AMP-activated protein kinase phosphorylation in a sustained manner.
Berberine is an inhibitor of human EC cell growth and could be considered as a potential drug for the treatment of EC patients.
Core tip: Initial diagnosis of many esophageal cancer (EC) patients is made at an advanced stage of the disease, making surgery an undesirable option. Although advances in chemotherapy have been achieved, serious adverse effects usually limit clinical application. Exploring non-invasive strategies to prevent the growth of EC is urgently needed. The current research showed that berberine is an inhibitor of human EC cell growth and could be considered as a potential source of drugs for the treatment of EC patients.