中文摘要：

为了研究载体介导的RNAi（RNAinterference）技术特异地抑制K-RASAsn12。（K-RAS第12位密码子突变形式为GAT）在胰腺癌细胞中的表达，合成两条编码针对K-RASAsn12。突变特异性短发夹RNA（shorthairpinRNA，shRNA）序列的单链DNA，并将其克隆到pSilenCircle栽体中，构建含目的基因片段的重组质粒pSC-K-RASAsn12。同法构建含GFP基因片断的重组质粒pSC-GFP做为对照。用其分别瞬时转染人胰腺癌AsPC-1细胞和BxPC-3细胞后，经半定量RT-PCR和Westernblot检测K-RAS的表达水平。结果表明构建的针对K-RASAsn12的编码突变特异性shRNA的质粒表达载体可特异的抑制胰腺癌细胞的K-RASAsn12。表达，但对野生型的K-RAS（K-RASwT）表达无影响。

英文摘要：

To silence the expression of K-RASAsn12 in human pancreatic cancer cell line by vector-based RNAi（RNA interference） technique, two single-strand DNA sequences encoding mutant-specific shRNA （short haipin RNA） for K-RASAsn12 were synthesized and then inserted into pSilenCircle. The recombinant plasmid was called pSC-K-RASAsn12. According to the same method, pSC-GFP encoding shRNA for GFP was gained. Both recombinant plasmids were transfected into human pacreatic cancer cell line AsPC-1 and BxPC-3. The expression level of K-RASAsn12 was detected by semi-quantitative RT-PCR and Western blot. The result indicated that the recombinant plasmid edcoding mutant-specific shRNA for K-RASAsn12 can inhibit significantly the expression of K- RASAsn12, without affection of wild-type K-RAS（K-RASWT） in Human Pancreatic Cancer Cell Line.