Tetrandrine Inhibits the Intracellular Calcium Ion Level and Upregulates the Expression of Brg1 and AHNAK in Hep-2 Cells.

BACKGROUND

Tetrandrine has been found to inhibit the growth of various types of tumor cells, but the underlying molecular mechanism remains to be determined. We aimed to investigate the effects of tetrandrine on human laryngeal carcinoma Hep-2 cells.

METHODS

Cell viability was tested using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The cell cycle was analyzed using flow cytometric analysis. The intracellular Ca2+ concentration was monitored using the membrane-permeable Ca(2+)-sensitive fluorescent probe fluo-3 acetoxymethyl ester-AM (Fluo3-AM). The mRNA and protein expression of Brgl and AHNAK were evaluated by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and immunocytochemistry, respectively.

RESULTS

Tetrandrine significantly inhibited the proliferation of Hep-2 cells as indicated by an IC50 value of 13.28 μg/mL. Tetrandrine induced cell cycle arrest at the G1 phase and decreased the intracellular concentration of Ca2+ in a concentration dependent manner. Intriguingly, tetrandrine upregulated Brg1 expression in a dose-and time-dependent pattern and elevated the expression of AHNAK in Hep-2 cells.

CONCLUSIONS

Our results suggest that tetrandrine may inhibit the growth of Hep-2 cells by decreasing the intracellular concentration of Ca2+ and upregulating the expressions of Brg1 and AHNAK.