Apoptosis inducing effect of tanshinone ⅡA on human nasopharyngeal carcinoma CNE cells

OBJECTIVE: To investigate anticancer effect and potential mechanism of tanshinone II(A) (Tan II(A)) on human nasopharyngeal carcinoma cell line CNE cells. METHOD: Antiproliferative effect of Tan II(A) on CNE cells was evaluated by morphological examination, cell growth curves, colonial assay and MTT assay. Apoptosis detection was carried out using Hoechest 33258 and PI double-dyeing method. Intracellular Ca2+ concentration and mitochondria membrane potential were detected by fluorospectrophotometer. Bad and MT-1A transcript analysis in CNE cells was analyzed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). RESULT: Tan II(A) could inhibit CNE cells proliferation in dose- and time-dependent manner. 50% inhibiting concentration of Tan II(A) on CNE cells in 24, 48, 72 h was 45.7, 24.8, 3.3 mg x L(-2), respectively. Typical apoptotic morphology such as chromatin aggregation was observed in CNE cells with Tan II(A) treated for 24 h, and the apoptotic inducing effect was in a dose-dependent manner. After treated with Tan II(A), intracellular Ca2+ concentration of CNE cells was increased, mitochondria membrane potential of the cells was decreased, relative mRNA level of Bad and MT-1A was up-regulated. CONCLUSION: Tan II(A) had anticancer effect on CNE cells through apoptosis via calcineurin-dependent pathway and MT-1A downregulation.