黄芪-莪术联合顺铂诱导肝癌细胞凋亡及其对miR-122a,miR-221,miR-151表达的影响

目的:探讨黄芪-莪术联合顺铂(DDP)抗肝癌的作用机制。方法:构建人肝癌裸鼠原位移植瘤模型。成瘤后,将其随机分为模型组、顺铂组(DDP,2 mg·kg-1,ip),黄芪-莪术高、中、低剂量(H,M,L,12,6,3 g·kg-1·d-1,ig)组,黄芪-莪术高剂量+顺铂组(H+DDP),黄芪-莪术中剂量+顺铂组(M+DDP),黄芪-莪术低剂量+顺铂组(L+DDP),每组8只。采用Td Tmediated d UTP nick end labeling(TUNEL)法观察黄芪-莪术联合顺铂对人肝癌细胞Hep G2的原位诱导凋亡作用,采用酶联免疫吸附法(ELISA)检测其对凋亡相关蛋白B淋巴细胞瘤-2(Bcl-2)的影响,采用实时荧光定量聚合酶链式反应(Real-time PCR)观察人肝癌裸鼠肿瘤组织中microRNA(miR)-122a,miR-221,miR-151的表达。结果:H,H+DDP,M+DDP,L+DDP组均有肿瘤细胞凋亡,镜下观察肿瘤细胞核内呈棕黄色,核高度凝聚,部分细胞脱落,与模型组比较有明显的凋亡现象发生(P0.05,P0.01),以H+DDP组诱导凋亡作用最为显著。与模型组比较,H,M,H+DDP,M+DDP,L+DDP组血清中Bcl-2含量均显著降低(P0.01),以H+DDP组降低最为显著。与DDP组比较,H,M,L,H+DDP,M+DDP,L+DDP均能显著上调miR-122a的表达(P0.01),H+DDP对miR-221,miR-151的表达有显著抑制作用(P0.01)。结论:黄芪-莪术能显著诱导人肝癌细胞Hep G2凋亡,且诱导凋亡作用与剂量有一定的正相关性,其机制可能与显著下调Bcl-2表达,上调miR-122a,下调miR-221,miR-151的表达有关,与DDP合用表现为协同增效作用。

Effects of Astragali Radix-Curcumae Rhizoma and Combined with Cisplatin on Apoptosis of Hepatocellular Carcinoma Cells and Expressions of miR-122a, miR-221 and miR-151

Objective: To investigate the action mechanism of Astragali Radix-Curcumae Rhizoma combined with cisplatin (DDP) for hepatic cancer. Method: Human hepatocarcinoma cells HepG2 were transplanted into nude mice to establish models, and the modeled mice were randomly divided into 8 groups:model group, cisplatin (DDP) group (2 mg · kg^-1, ip), Astragali Radix-Curcumae Rhizoma high dose, middle dose and low dose groups (H, M, L, 12, 6, 3 g · kg^-1 · d^-1, ig), Astragali Radix-Curcumae Rhizoma high dose+cisplatin group (H+DDP), middle dose+cisplatin group (M+DDP), and low dose+cisplatin group (L+DDP), n=8 in each group. The effects of Astragali Radix-Curcumae Rhizoma combined with cisplatin on apoptosis of human hepatocellular carcinoma cells HepG2 were observed by TdT-mediated dUTP nick end labeling(TUNEL). The apoptosis related protein B-cell lymphoma-2(Bcl-2) was detected by enzyme linked immunosorbent assay (ELISA). Expressions of microRNA(miR)-122a, miR-221 and miR-151 in transplanted tumor tissues were determined by Real-time PCR. Result: As compared with the model group, the apoptosis of tumor cells was obvious, the tumor cell nucleus was brown yellow under the microscope, tumor cell nucleus was highly condensed and some cells were detached from the nucleus in H, H+DDP, M+DDP, and L+DDP groups (P<0.05, P<0.01). The apoptosis was most significant in H+DDP group. ELISA results showed that the contents of Bcl-2 in H, M, M+DDP, H+DDP and L+DDP groups were significantly decreased as compared with the model group(P<0.01), and the decrease extent was most significant in H+DDP group. The Real-time PCR results showed that the expressions of miR-122a could be significantly up-regulated in H, M, L, H+DDP, M+DDP, and L+DDP groups (P<0.01) and expressions of miR-221, miR-151 were significantly inhibited in H+DDP group (P<0.01) as compared with DDP group. Conclusion: Astragali Radix-Curcumae Rhizoma can significantly induce apoptosis of human hepatocellular carcinoma cells HepG2 in positive correlation with dosage.The mechanism may be related to significantly down-regulating the expression of Bcl-2, up-regulating the expression of miR-122a and down-regulating the expression of miR-221 and miR-151.The combination of Astragali Radix-Curcumae Rhizoma and DDP showed synergistic effect.