rAd-p53 的抑癌作用及体外转染后抑癌蛋白的表达

 目的 为了了解重组人p53腺病毒注射液（商品名“今又生”）对大肠癌-174细胞株的体外抑制作用及其半数致死量（IC50），更好地指导临床应用。方法 通过体外细胞培养、利用MTT法对比检测重组人p53腺病毒注射液与5-氟脲嘧啶、替加氟、顺铂、奥沙利铂、丝裂霉素以及紫杉醇等大肠癌常用化疗药物的IC50，明确重组人p53腺病毒注射液体外抑瘤活性的强弱；利用免疫组化检测技术检测重组人p53腺病毒体外转染大肠癌-174细胞株后，细胞凋亡、生长抑制与细胞内p53蛋白表达情况之间的关系。结果 重组人p53腺病毒注射液具有良好的体外抑瘤效应，IC50为5．73×10^11VP，且有剂量和时间依赖性；但其单用时的体外抑癌远远逊于经典的化疗药物如丝裂霉素、5-氟脲嘧啶和顺铂等；五种不同滴度的重组人p53腺病毒注射液在体外大肠癌-174细胞株转染过程中皆出现了阳性染色结果，最早的阳性染色结果出现在p53基因转染24小时后，而空白对照组的免疫组化染色皆为阴性。结论 重组人p53腺病毒注射液具有明确的体外抑瘤效应，且有剂量和时间依赖性；但其单用时的体外-174细胞株的作用低于丝裂霉素、5-氧尿嘧啶和顺铂。

The Expression of p53 in Posttransfectioncells with rAd-p53 Gene and Inhibition Activity in Vitro

Objective 　To understand the inhibition and IC₅₀ (50 % inhibiting concent ration) of the recombinant adenoviral p53 gene ( rAd-p53) for the colorectal cancer cells in vitro and to guide clinical practice. Methods 　We evaluate the efficiency ( IC ₅₀ ) of the rAd2p53 and six kind of anti-cancer drugs (5-fluorouracil , tegafur , mitomycinc , cisplatin , oxaliplatin , paclitaxel) for human colorectal cancer cell line-174 through the cell culture and MTT chemosensitivity assay to make sure the anti-cancer capability of rAd-p53. Expression of p53 protein in t ransfection cells of colorectal cancer line-174 with rAd-p53 was evaluated by immunohistochemical stain. Results 　The rAd-p53 has good anti-cancer efficacy for the colorectal cancer cell line-174 in vitro , its IC₅₀ is 5. 73 ×10 ¹¹VP (viral particles) and it is dose-dependent and timedependent . But it s anti-cancer efficacy can′t be compared with the classical chemical medicine mitomycinc , 5-fluorouracil and cisplatin et al when it used alone. The immunohistochemistry stain in blank control group is negative. However five different density of rAd-p53 are all appeared positive result in infected colorectal cancer cells with rAd-p53 and earliest positive result presented at 24 hours after infection. Conclusion 　The rAd-p53 has good anti-cancer efficacy for the colorectal cancer cell line-174 in vitro , it is dose and time-dependent manner. But its anti-cancer efficacy worse than those of the classical chemical medicine mitomycinc , 5-fluorouracil and cisplatin etc. when it was used alone.