目的 探究重楼皂苷Ⅱ（PPⅡ）对弥漫大 B 细胞淋巴瘤（DLBCL）细胞凋亡的作用及机制。方法 以 0、 0.25、0.5、1、2、4 µmol·L-1 PPⅡ干预人 DLBCL 细胞系 U2932、TMD-8 细胞 24 h；采用 CCK-8 法检测细胞 活力；Annexin V-FITC/PI 流式细胞术检测细胞凋亡情况；Hoechst 33342 染色法观察细胞核凋亡和细胞数量变 化。通过肿瘤基因组图谱数据库（TCGA）筛选 DLBCL 的差异表达基因（DEGs）并进行富集分析；通过 Swiss Target Prediction 数据库对 PPⅡ进行作用靶点预测；将预测到的 PPⅡ作用靶点与 DLBCL 的 DEGs 取交集，并 构建蛋白互作（PPI）网络，筛选关键靶点并进行分子对接验证；采用 Western Blot 实验验证 PPⅡ对关键靶点蛋 白表达的影响。结果 与对照组（0 µmol·L-1 ）比较，0.25、0.5、1、2、4 µmol·L-1 PPⅡ组的 U2932、TMD-8 细 胞活力均显著降低（P＜0.05，P＜0.01）；1、2 µmol·L-1 PPⅡ组的 U2932、TMD-8 细胞凋亡率均显著升高（P＜ 0.01）；随着 PPⅡ浓度增加，U2932、TMD-8 细胞出现细胞核凋亡现象越明显，可观察到细胞核碎块状染色， 0.5、1、2 µmol·L-1 PPⅡ组的 U2932、TMD-8 细胞数量均显著减少（P＜0.01）。共获得 6 250 个 DEGs，富集分 析发现 DLBCL 与细胞凋亡信号通路关系密切；筛选出 Caspase-9、Caspase-3、Caspase-7、Bax、Bcl-2 等 5 个 关键靶点；分子对接显示 PPⅡ与关键靶点 Caspase-9、Caspase-3、Caspase-7 均具有良好的结合活性； Western Blot 实验结果显示，与对照组比较，0.5、1、2 µmol·L-1 PPⅡ组 U2932、TMD-8 细胞中 Cleaved Caspase-9/Caspase-9、Cleaved Caspase-3/Caspase-3、Cleaved Caspase-7/Caspase-7 及 Bax/Bcl-2 蛋白表达均显 著上调（P＜0.05，P＜0.01）。结论 PPⅡ可抑制 DLBCL 细胞增殖，并通过诱导 Caspase 级联反应促进其凋亡。

Objective To investigate the role and mechanism of Polyphyllin Ⅱ （PP Ⅱ） in promoting apoptosis in diffuse large B-cell lymphoma （DLBCL） cells. Methods Human DLBCL cell lines U2932 and TMD-8 were treated with 0，0.25，0.5，1，2，and 4 µmol·L-1 PPⅡ for 24 hours. Cell viability was detected using the CCK-8 assay； apoptosis was measured by Annexin V-FITC/PI flow cytometry；and nuclear apoptosis and cell count were observed using Hoechst 33342 staining. Differentially expressed genes （DEGs） in DLBCL were screened and enriched using The Cancer Genome Atlas （TCGA） database. The Swiss Target Prediction database was used to predict the targets of PPⅡ. The intersection of predicted PPⅡ targets and DLBCL DEGs was identified，and a protein-protein interaction （PPI） network was constructed to screen key targets， followed by molecular docking validation. Western Blot was used to verify the effects of PPⅡ on the expression of key target proteins. Results Compared with the control group （0 µmol·L-1 ），the viability of U2932 and TMD-8 cells in the 0.25，0.5，1，2，and 4 µmol·L-1 PPⅡ groups was significantly reduced （P＜0.05，P＜0.01）. The apoptosis rate of U2932 and TMD-8 cells in the 1 and 2 µmol·L-1 PPⅡ groups was significantly increased （P＜0.01）. As the concentration of PPⅡ increased，nuclear apoptosis in U2932 and TMD-8 cells became more evident，with fragmented nuclear staining observed. The number of U2932 and TMD-8 cells in the 0.5， 1， and 2 µmol·L-1 PP Ⅱ groups was significantly reduced （P＜0.01）. A total of 6 250 DEGs were identified， and enrichment analysis revealed a close relationship between DLBCL and apoptosis signaling pathways. Five key targets， including Caspase-9， Caspase-3， Caspase-7， Bax， and Bcl-2， were screened. Molecular docking showed that PP Ⅱ had good binding activity with the key targets Caspase-9， Caspase-3， and Caspase-7. Western Blot results showed that， compared with the control group， the protein expressions of Cleaved Caspase-9/ Caspase-9， Cleaved Caspase-3/Caspase-3， Cleaved Caspase-7/Caspase-7， and Bax/Bcl-2 in U2932 and TMD-8 cells in the 0.5，1，and 2 µmol·L-1 PPⅡ groups were significantly upregulated （P＜0.05，P＜0.01）. Conclusion PP Ⅱ can inhibit the proliferation of DLBCL cells and promote their apoptosis by inducing the Caspase cascade reaction.

R285.5

山东省自然科学基金青年基金项目(ZR2022QH168)；江苏省新药研究与临床药学重点实验室开放课题（XZSYSKF2021033）