[Mechanism of combined use of cyclopamine and hydroxycamptothecin in inducing the apoptosis of human oral squamous cell carcinoma cell line].

ABSTRACT

OBJECTIVE: To study the mechanism underlying the effect of combined use of cyclonpamine and hydroxycamptothecin in inducing the apoptosis of human oral squamous cell carcinoma cell line (OSCC) HSQ-89. METHODS: CCK8 assay was used to investigate the inhibitory effect of cyclopamine on HSQ-89 cells. Flow cytometry (FCM) was employed to examine the cell apoptosis following combined treatment with cyclonpamine and hydroxycamptothecin. Reverse transcription polymerase chain reaction (RT-PCR) was applied to detect the mRNA expressions of Bcl-2, Bcl-xl, and Bid in HSQ-89 cells after the treatments. RESULTS: Combined treatment with cyclonpamine and hydroxycamptothecin significantly inhibited the cell proliferation compared with hydroxycamptothecin treatment alone, also resulting in a significantly higher apoptosis rate of the cells (P<0.05). The mRNA level of Bcl-2 was significantly decreased after the treatments, especially after the combined treatment. Cyclopamine produced no significant effect on the mRNA levels of Bcl-xl and Bid in the cells. CONCLUSION: The combined use of cyclopamine and hydroxycamptothecin significantly down-regulates the expression on of bcl-2 to induce the apoptosis of human OSCC cell line HSQ-89.