中文摘要：

目的探讨抗癌生物活性肽-S（ACBP-S）对人胃癌细胞MGC-803细胞周期和凋亡的影响。方法（1）体外实验：以不同浓度ACBP-S处理人胃癌MGC-803细胞，采用二苯基溴化四氮唑蓝（MTY）法测定增殖抑制率；电镜下观察细胞凋亡现象；流式细胞术分析细胞周期与凋亡率；逆转录聚合酶链反应（RT-PCR）和免疫细胞化学方法检测p27基因mRNA和蛋白表达的变化。（2）动物体内实验：建立裸鼠胃癌移植瘤模型，每只裸鼠经尾静脉注射7峭ACBP．S，隔日给药，2周后处死，计算抑瘤率；HE染色观察肿瘤细胞形态变化；免疫组化法检测Bcl-2、Bax和增殖细胞核抗原（PCNA）的表达。结果（1）5．0、10．0和15．0μg／ml的ACBP．S均能抑制MGC-803细胞的生长。且随浓度增加和作用时间延长抑瘤率增加。电镜下可见，MGC-803细胞经15．0μg/ml ACBP-S作用48h后，呈现典型的凋亡特征。流式细胞术分析结果显示，5．0和20．0μg／ml ACBP-S作用MGC-803细胞24h的凋亡率较高，分别为（5．7±0．2）％和（13．9±0．6）％（P〈0．05）；20．0μg／ml ACBP-S可使G0／G1期MGC-803细胞的构成比明显上升。ACBP-S上调MGC-803细胞p27基因mRNA和蛋白的表达。（2）ACBP．S能抑制胃癌移植瘤的生长，抑制率达34．2％。镜下可见，治疗组肿瘤组织中出现大片坏死及大量凋亡细胞，异型细胞及核分裂相减少。免疫组化分析结果显示，治疗组Bcl-2和PCNA表达降低，Bax表达增高。结论ACBP—S能抑制人胃癌MGC-803细胞增殖，其作用机制与调控胃癌细胞的细胞周期和凋亡有关。

英文摘要：

Objective To explore the impact of anti-cancer bioactive peptide-S （ACBP-S） on ceil proliferation, cell cycle and apoptosis in human stomach cancer cell line MGC-803 cells. Methods （ 1 ） The cultured MGC-803 cells were treated with ACBP-S at various concentrations for 24, 48, 72 h, respectively. The inhibition rate of proliferation of MGC-803 cells were evaluated by MTT assay. Cell apoptosis was observed by transmission electron microscopy. Cell cycle and apoptosis were analyzed by flow cytometry （FCM）. RT-PCR was used to assay the changes of p27 mRNA expression. Immunocytochemistry was used to detect the changes of expression of p27, PCNA, Bax, Bcl-2 proteins, respectively. （2） a nude mouse xenograft model with gastric carcinoma cell was established. ACPB-S was administered into the tail vein of the mice in a dose of 7 μg, every other day, and the mice were killed after two weeks. The tumors were taken off for further analysis. Results （ 1 ） ACBP-S at concentrations of 5.0, 10.0 and 15.0 μg/ml inhibit the growth of MGC-803 cells in a concentration- and time-dependent manner. The concentration of ACBP-S at 20.0 μg/ml showed an inhibition rate of （86.6 ＋ 0. 1 ）%. Typical apoptotic changes were observed under the transmission electron microscope, the result of FCM in the range of 5.0 and 20. 0 μg/ml for 24 h showed higher early apoptosis rates, （5.7 ± 0. 2） % and （ 13.9 ± 0.6） %, respectively, with s significant difference compared with that of the control group （ P 〈 0. 05 ）. The ratio of G0/G1 was significantly increased with the increase of incubation time at 20 μg/ml. RT-PCR showed that the expression of p27 mRNA in MGC-803 cells was markedly increased after ACBP-S treatment. （2） After ACBP-S administration the tumor growth in nude mice was inhibited by 34.2%. More apoptotic and necrotic cells were observed in the mice of treatment group by histological examination with HE staining. The immunocytochemistry demonstrated that the expression of Bax protein was sig