Abstract
Purpose: To observe the apoptotic effects of NSMF on human hepatoma cells and to investigate the mechanisms. Materials and methods: Human hepatoma cell line Bel-7402 and Hep G-2 were treated by 0.2 T rotary NSMF (30 min/d) with 250 Hz, 400 Hz and 500 Hz for 3 d and 6 d, respectively. Apoptosis was analyzed with flow cytometry. Cell proliferation was measured with XTT assay. Expression of Bcl-2, caspase3/8/9 was analyzed with ELISA. Results: After 6 d treatment, significant apoptosis was induced by 400 Hz in Bel-7402 cells. Slight cell apoptosis was observed at 250 Hz, while Hep G-2 cells exhibited slight apoptosis at 250 Hz and 400 Hz. After 3 d treatment, no apoptosis exhibited in both cell types. Compared with control group, expression of Bcl-2 and Caspase 8 in treated Bel-7402 cells were significantly reduced (p < 0.01), while Caspase 3 and Caspase 9 were significantly upregulated (p < 0.01). Conclusions: NSMF upregulates caspase 9 and downregulates Bel-2 expression, which results in higher level of active caspase 3 to trigger apoptosis in cells. Different cell types require different NSMF factors like rotary frequency and treatment time to induce apoptosis.
Acknowledgements
This work was supported by National Natural Science Foundation of China (81171636) and Tianjin Natural Science Foundation (12JCZDJC21800).