RNAi技术沉默子宫颈癌HeLa细胞中HPA基因的表达对细胞侵袭力的影响

Effect on invasion ability of cervical cancer cells after silence heparanase gene expression in HeLa cells

目的 利用RNA干扰（RNAi）技术沉默宫颈癌细胞系HeLa细胞中乙酰肝素酶（HPA）基因的表达,并探讨其对宫颈癌细胞侵袭力的影响.方法 根据GenBank数据库提供的HPA基因核苷酸序列,设计4对针对HPA基因的短发夹状RNA（shRNA）特异性寡核苷酸序列（即shRNA-HPA-592、shRNA-HPA-995、shRNA-HPA-1351、shRNA-HPA-1658）,并设计1条随机无关序列作阴性对照,分 别克隆到pYr-1.1质粒中.用脂质体法将上述质粒转染入HeLa细胞,以未转染质粒者为空白对照,采用逆转录（RT）-PCR技术、免疫荧光法分别检测转染后HeLa细胞中HPA mRNA和蛋白的表达,筛选出其中对HPA基因沉默效果最佳的质粒.将该质粒转染入HeLa细胞,采用穿膜（transwell）小室体外侵袭实验检测转染后HeLa细胞侵袭力的变化.结果 RT-PCR技术检测显示,转染shRNA-HPA-592、shRNA-HPA-995、shRNA-HPA-1351、shRNA-HPA-1658质粒后,HeLa细胞中HPA mRNA的表达水平分别为0.54±0.05、0.89 ±0.18、0.82±0.22、0.91 ±0.47,阴性对照和空白对照细胞中HPAmRNA的表达水平分别为1.31 ±0.72和1.09±0.16；免疫荧光法检测显示,转染上述不同质粒后HeLa细胞的胞质中均可见绿色荧光,HPA蛋白均呈阳性表达,其中转染shRNA-HPA-592质粒后HeLa细胞的胞质中绿色荧光强度最弱.故筛选出的对HPA基因沉默效果最佳的质粒即为shRNA-HPA-592质粒.体外侵袭实验检测显示,转染shRNA-HPA-592质粒后HeLa细胞的穿膜细胞数为（44±4）个,明显低于空白对照、阴性对照[分别为（182±6）、（258±17）个],差异有统计学意义（P＜0.01）；而阴性对照与空白对照比较,差异无统计学意义（P＞0.05）.结论 本研究成功筛选出了靶向HPA基因的shRNA表达质粒,转染宫颈癌HeLa细胞后可高效抑制其HPA基因的表达,明显降低宫颈癌细胞的侵袭力,为进一步研究HPA基因的表达与宫颈癌侵袭的机制奠定了基础.

Objective Design and synthesize short hairpin RNA （shRNA） expression vector of RNA for specific silencing of heparanase （HPA） gene,screened plasmid which silence effects is the best.Observe the function of ceil invasion after inhibiting the expression of HPA in cervical carcinoma cell lines （HeLa）.Methods The genomic sequence of HPA gene was retrieved from GenBank database.Designed four pairs of specific oligonucleotide sequences and a negative control according to the shRNA design principles.They were inserted into the vector pYr-1.1,vectors,and transfected into HeLa cells via lipofectamine.Reverse transcription （RT）-PCR and immunofluorescence were employed to detect the expression of HPA gene in the transfected cells at the mRNA and protein levels,respectively.The plasmid were screened and transfected into HeLa cells,then transwell small room stromal invasion experiment were employed to observe the cervical carcinoma cell invasion.Results RT-PCR results of transfected HeLa cells shown that the mRNA amplification multiples were 0.54 ±0.05 in the HPA-592 group,0.89 ±0.18 in HPA-995 group,0.82 ±0.22 in the HPA-1351 group,0.91 ±0.47 in HPA-1658 group.While,they were 1.31 ±0.72 and 1.09 ±0.16 in negative control and blank control group,respectively.Green fluorescence was visible in the cytoplasm,which indicated that the HPA protein was expressed in the cytoplasm,of them the weakest green fluorescence in the HPA-592 group.The relative numbers of invasive cells among the HeLa cells were as follows：182 ±6 in the blank control group,258 ± 17 in the negative control group,and 44 ± 4 in the HPA-592-specific interference group（P 〈 0.01）.Conclusion Successfully screened shRNA vector targeting human HPA,efficiently inhibit expression of HPA gene when transfected into HeLa cells,and significantly reduced the invasion capacity of cervical carcinoma cells.