OBJECTIVE:To study induction effect of euphornin on the apoptosis of cervical cancer Hela cells and its mechanism. METHODS:The cervical cancer Hela cells were divided into blank control group,cisplatin group(positive control, 10 mg/L) and euphornin low-dose,medium-dose and high-dose groups (50,100,200 mg/L). They were treated with relevant medicine. The inhibitory effect of Hela cells proliferation was tested by MTT assay after 24,48,72 h of medicine treatment. The apoptotic rate of Hela cells was measured by flow cytometry after 48 h of medicine treatment. Morphology of nucleus was detected by Hoechst 33258 staining. The protein expression of Cyt-C,Bcl-2,Bax,Caspase-3,Caspase-8,Caspase-9 and Caspase-10 were detected by Western blot assay. RESULTS:Compared with blank control group,inhibitory rate of cell proliferation and cell apoptosis rate were increased significantly in cisplatin group and euphornin groups(P＜0.05 or P＜0.01),and obvious staining, deformation,shrinking,fragmentation or apoptotic bodies was found in nucleus. Compared with blank control group,the protein expression levels of Cyt-C,Caspase-8 and Caspase-9 in euphornin low-dose,medium-dose and high-dose groups were increased significantly,while the protein expression level of Bcl-2 and Bcl-2/Bax ratio were decreased significantly(P＜0.05 or P＜0.01);the protein expression levels of Bax,Caspase-3 and Caspase-10 in euphornin medium-dose and high-dose groups were increased significantly(P＜0.05 or P＜0.01). CONCLUSIONS:Euphornin can significantly inhibit the proliferation of Hela cell and promote cell apoptosis,the effect of which will be achieved by activating the Caspase-dependent mitochondrion apoptosis pathway.

[Abstract] Objective: To investigate whether AP1903, a small-molecule chemical inducer, can terminate the cytotoxicity of CD19CAR-T cells over-expressing iCasp9 suicide gene in vivo and in vitro. Methods: CD19CAR-T cells over-expressing iCasp9 (iCasp9-CD19CAR-T) were constructed and co-incubated with AP1903. Then, the cell phenotype and apoptosis were detected by Flow cytometry, and the iCasp9/CID suicide gene system was verified on K562 and T cells, respectively. The cytotoxicity of iCasp9-CD19CAR-T cells was detected in vivo (survival rate of NCG mice bearing Raji cell transplanted xenograft) and in vitro (cell killing function was detected by Flow cytometry) under the administration of AP1903. Results: Compared with CD19CAR-T cells, iCasp9-CD19CAR-T cells showed in significant difference in proliferation, phenotype and cytotoxicity both in vitro and in vivo (all P>0.05). At 2 h after AP1903 administration, the apoptosis rates of K562 and T cells co-expressing iCasp9 and CD19CAR were (33.8±0.9)% and (27.95±0.35)%, respectively; and at 24 h after AP1903 administration, the apoptosis rates reached 100% in both cell lines. The in vitro cytotoxicity of iCasp9-CD19CAR-T cells induced by AP1903 was significantly lower than that without AP1903 treatment (P<0.01); the 60-day survival rate of mice bearing Raji cell transplanted tumor treated with AP1903-induced iCasp9-CD19CAR-T cells was also significantly lower than those treated with iCasp9-CD19CAR-T cells alone (P<0.01). Conclusion: AP1903 can effectively terminate the cytotoxicity of CD19CAR-T cells over-expressing iCasp9 suicide gene in vitro and in vivo.