靶向性蛋白激酶B1和环氧合酶-2 shRNA腺病毒载体的构建和在人胃癌细胞的表达

目的 构建靶向性蛋白激酶B1(PKB1/Akt1)和环氧合酶-2(COX-2)的短发夹RNA(shRNA)腺病毒载体,观察其在人胃癌细胞株SGC-7901中的表达.方法 利用同源重组技术构建重组腺病毒载体pGSadeno-Akt1+COX-2(pGSadeno-A+C),经酶切及测序鉴定后转染人胚肾细胞HEK293包装成为重组rAd5-A+C腺病毒,并测定病毒的滴度.体外转染人胃癌细胞株SGC-7901后,Real-time PCR和蛋白印迹分别检测Akt1和COX-2 mRNA和蛋白质的表达.结果 成功构建rAd5-A+C重组腺病毒,测定包装的病毒滴度为1.0×1010pfu/ml.转染组Akt1和COX-2 mRNA表达明显下调,其△Ct值分别是(12.26±0.05)和(5.41±0.09),比rAd5-HK空载组(10.63±0.02)、(3.75±0.08)和对照组(10.57±0.02)、(3.73±0.08)增高(P<0.01),而空载组和对照组比较ΔCt值无明显变化(P>0.05).同样转染组Akt1和COX-2蛋白表达量与空载组和对照组比较分别下调70.5%和63.7%(P<0.01),空载组和对照组比较Akt1和COX-2蛋白表达差异无统计学意义(P>0.05).结论 靶向性Akt1和COX-2的shRNA腺病毒载体可以特异性抑制Akt1和COX-2的表达,可能成为胃癌靶向性Akt1和COX-2基因治疗的新策略.

Construction of a shRNA adenovirus vector targeting protein kinase B1 and cyclooxygenase-2 and expression in human gastric carcinoma cells

Objective To construct a short hairpin RNA (shRNA) adenovirus vector targeting protein kinase BI (PKB1/Akt1) and cyclooxygenase-2 (COX-2) and observe their expression in human gastric carcinoma cell line SGC-7901. Methods Akt1 and COX-2 shRNA expression frames were sub-cloned to pGSadeno adenovirus vector by homologous recombination technology to construct pGSadeno-Aktl + COX-2 ( pGSadeno-A + C) vector. Furthermore after screening and amplification,recombinant ade-novirus vector was digested with Pacl and transfected into HEK293 cells. The replication adenovirus rAd5-A + C was packed and amplified in the HEK293 cells, and its titer was detected. After human SGC-7901 cells in vitro were transfected by rAd5-A + C,Akt1 and COX-2 mRNA and protein expression levels were detected by real-time PCR and Western blot respectively. Compared with rAdS-A + C,SGC-7901 and gen-eral rAd5-HK were selected as the negative controls. Results The recombinant adenovirus rAd5-A + C was constructed successfully and its titer reached 1.0 ×1010 pfu/ml. Aktl and COX-2 mRNA expression was downregulated significantly, and their ACt values ( 12.26±0.05 and 5.41±0.09 respectively ) were higher than rAd5-HK group (10.63±0.02 and 3.75 +0.08 respectively) and control group (10.57± 0.02 and 3.73±0.08 respectively) (P <0.01 ). There was no significant difference between rAd5-HK and control groups (P >0.05). Aktl and COX-2 protein expression was downregulated by 70.5% and 63.7% respectively ( P < 0.01 ) in rAd5-HK group as compared with control group ( P > 0.05 ). Conclu-sion The shRNA aclenovirus vector targeting Akt1 and COX-2 can specifically inhibit Akt1 and COX-2 expression,and this may be a new strategy in gastric carcinoma gene therapy targeting Akt1 and COX-2.