Chondrosarcoma are the second primary malignant bone tumor group. Surgical resection remains the primary therapy for chondrosarcoma. This mesenchymal malignancies have a poor prognosis due to the absence of an effective adjuvant therapy. Berberine has been reported to be useful in the treatment and prevention of cancer. Electrical stimulation could enhance anti-proliferation effect of chemotherapy drug. The aim of our study was to detect that electrical stimulation could enhance programmed cell death of berberine-treated chondrsarcoma cell lines and investigate the mechanism.
The JJ cells were intervened with berberine and various frequencies of electrical stimulation, followed with incubated for 48 hours. In order to examine the effects of this intervention on cell proliferation, cell cycle, apoptosis and necrosis, we performed trypan blue exclusion assay, 4,6-diamidino-2-phenylindole dihydrochloride assays (DAPI stain)and flow cytometry analysis. Western blot was used to examine the protein levels of Bax, Bcl-2, Capsase-3 and PARP which are associated with apoptosis. Flow cytometric analysis showed that berberine with electrical stimulation significantly induced cell cycle to arrest in G2/M phase. Induction of apoptosis via ER stress involved an increase cellular Ca2+, and hyperpolarization of mitochondrial membrane and activation of associated protein before culminating in apoptosis
In conclusion, we have demonstrated that electrical stimulation with berberine inhibits cell growth via the induction of cell cycle arrest at the G2/M phase and may induce apoptosis through the ER stress pathway in human JJ cells.
