[Anti-hepatoma effects of Smac analogue Birinapant and its related molecular mechanism].

OBJECTIVE

To investigate the effects of Birinapant on hepatocellular carcinoma cells and its related molecular mechanisms.

METHODS

Human hepatocellular carcinoma cells QGY-7701 were treated with 0, 1, 5, 25 and 125 nmol/L Birinapant for 24, 48 and 72 hours respectively, each experiment 3 wells.The proliferation activity of cells, the apoptosis levels, the cells nuclear type, the mitochondrial membrane potential, the transcription and expression levels of genes and the cytotoxicity of Birinapant were analyzed.At the same time, 4-week-old male BALB/C mice were randomly divided into 5 groups, with 20 mice in each group.The mice were inguinal injected with QGY-7701 cells, and then subcutaneous injected with Birinapant (concentrations ranging from 0, 1, 5, 25, 125 μg/kg) in each group after two days, once every other day.On 18 day since first Birinapant injection, 10 mice were killed in each group to weigh tumor tissue and survival time was recorded from the remaining 10 mice.The effects of Birinapant on the growth of the tumor and the survival time of tumor-bearing mice were observed.

RESULTS

Compared with the negative control (NC) group, the proliferation activity of QGY-7701 was inhibited significantly after Birinapant treatment and the apoptosis levels were increased significantly (<0.01).The cell mitochondrial membrane potential was decreased and the karyotype was changed (<0.01).At the same time, the transcription and expression levels of genes cellular inhibitor of apoptosis protein 1(cIAP-1), cellular inhibitor of apoptosis protein 2(cIAP-2), ras, raf, mek and erk were significantly decreased (<0.01), while the expression levels of caspase-3 and caspase-9 genes were up-regulated (<0.01).Compared with the model group (MG), the growth of the tumor was inhibited significantly and the survival time of the tumor-bearing mice was prolonged after Birinapant treatment (<0.01).

CONCLUSIONS

Birinapant can inhibit the expression of cIAP-1, cIAP-2 and the proteins of Ras-Raf-MEK-ERK signal pathways, so as to activate the mitochondria mediated endogenous apoptosis pathway.Birinapant shows a certain inhibitory effect on liver cancer.