目的了解载体携带的小干扰RNA（small interfering RNA, siRNA）对人胰腺癌细胞株PANC-1血管内皮生长因子（vascular endothelial growth factor, VEGF）表达的抑制作用以及对肿瘤细胞生长的影响。方法 设计并合成2对针对VEGF的siRNA 真核表达载体（PU-VEGF-siRNA1 组和 PU-VEGF-siRNA2 组，简称为重组质粒组），经脂质体Lipofectamine 2000 转染PANC-1 细胞，经G418 筛选后获得稳定转染细胞株，空载体转染组作为实验对照组，未转染组作为空白对照组。采用MTT法检测转染后PANC-1 细胞的增殖，流式细胞仪检测转染后PANC-1 细胞的凋亡率和细胞周期，逆转录聚合酶链反应（RT-PCR）检测转染后VEGF mRNA 表达情况。结果 与实验对照组和空白对照组比较，两重组质粒组PANC-1 细胞的增殖减慢，细胞凋亡率增加，VEGF mRNA 表达明显下降，差异均有统计学意义（Plt;0.05）； 细胞周期结果显示，两重组质粒组S 期细胞所占比例较两对照组明显减少（Plt;0.05）。 结论siRNA 能有效抑制胰腺癌细胞VEGF 的表达，并能在体外抑制人胰腺癌细胞株PANC-1 细胞的生长。
Objective To investigate the inhibitory effect of survivin antisense oligonucleotides (ASODN) on proliferation of pancreatic cancer cells PANC-1. Methods The ASODN and sense oligodeoxynucleotides (SODN) were complementary to survivin sequences. FAM-marked ASODN was transfected into PANC-1 cells mediated by positive ion liposome as ASODN group. Blank control group (normal cells), negative control group (normal medium)， and SODN group were established for comparison. The transfection efficiency was detected by flow cytometry (FCM) after transfection; MTT assay was used to detect cytotoxicity; Cell morphological changes were examined by transmission electron microscopy; The cell cycle and apoptotic rate were analyzed by FCM; Immunohistochemical staining techniques were used, and the expressions of survivin were observed under light microscopy, examined and analysed by computer image. Results ①The transfection efficiency was 31.9%, 37.4%, 41.4%, 52.6%, 24.2%, 11.4%, 16.1%, and 15.5% when the transfecting concentration of ASODN was 50, 100, 150, 200, 250, 400, 600, and 800 nmol/L, respectively; The transfection efficiency was 12.0%, 50.8%, and 11.2% when the inoculated cells was 2×104/well, 2×105/well, and 2×106/well, respectively; The transfection efficiency was 58.8%, 34.0%, and 23.6% when 2 μl, 3 μl, and 4 μl liposome was used during transfection, respectively. ②Cell gap was oversize, morphous was round, adherent cells were less after transfection under fluorescence microscope. ③The inhibition rate in the ASODN group was higher than that in each control group (Plt;0.05) on 24, 36, 48 h after treating by survivin ASODN, which increased as time prolonged (Plt;0.05). ④The apoptosis showed a ladder-shaped line in the ASODN group. ⑤Apoptotic morphology was demonstrated in the ASODN group, such as apoptotic cells with nuclear chromatin highly concentrated, crescent nuclear staining aggregated by the side nuclear membrane, nucleolus disappeared by AO and EB stains. ⑥The apoptotic rate 〔（38.1±3.4）%〕 in the ASODN group was higher than that in the SODN group 〔（4.16±1.7）%〕, Plt;0.05. ⑦G2/M cell cycle arrested in the ASODN group. ⑧After transfection, the expression of survivin protein in the ASODN group was significantly lower than that of each control group (Plt;0.05). Conclusions The optimal transfection conditions are as following: the cell count of 2×105/well, concentration of ASODN 200 nmol/L, and cationic liposome oligofectamine 2 μl, respectively. Survivin ASODN can inhibit the proliferation of pancreatic cancer cells and induce their apoptosis.