特异性溶瘤重组腺病毒KH901对荷瘤鼠肿瘤生长的抑制作用和表达GM-CSF的研究

Effects of KH901, A Tumor-specific Oncolytic Recombinant Adenovirus, on Antitumor and Expressing GM-CSF in Xenograft Tumor Models

目的探讨特异性溶瘤重组腺病毒KH901的抗肿瘤效果及表达人粒细胞-巨噬细胞集落刺激因子(GM-CSF)的水平。方法裸鼠皮下接种人肝细胞癌(Hep3B)细胞或人前列腺癌(LNcap)细胞,建立相应裸鼠移植瘤模型。KH901瘤体内注射给药,同时设阳性对照〔5-氟尿嘧啶(5-FU)或顺铂尾静脉注射〕和阴性对照〔生理盐水(NS)尾静脉注射〕,以相对肿瘤增殖率(T/C%)和抑瘤率观察抗肿瘤效果;建立人肺癌(A549)裸鼠移植瘤模型,瘤体内注射KH901,分别于首次给药后第2、7、11、14、18、36d各取3只动物眶静脉采血并摘取肿瘤,以ELISA法测定血清和肿瘤匀浆液上清中GM-CSF含量。结果1在Hep3B裸鼠抑瘤实验中,KH901高剂量(3×1010VP/鼠)组的T/C%和抑瘤率分别为7.31%、93.61%,与KH901低剂量(3×108VP/鼠)组(40.27%、68.76%)和5-FU组(37.33%、61.49%)相比显示出较强的抑瘤效果(P<0.05)。2在LNcap裸鼠抑瘤实验中,KH901多次给药(3×1010VP/鼠×3)组的T/C%和抑瘤率分别为5.47%、95.29%,其抑瘤效果强于顺铂组(25.47%、71.93%),但与KH901单次给药(3×1010VP/鼠×1)组(12.94%、87.94%)相比差异无统计学意义。3在A549裸鼠移植瘤模型中,肿瘤和血清中的GM-CSF分别在第7d〔(47.72±9.21)ng/mg〕和第11d〔(92.45±18.64)ng/mL〕出现高峰,随后,GM-CSF表达量逐渐降低。结论KH901有明显的抗肿瘤作用,在体内肿瘤中表达高水平的GM-CSF,并渗入血管到循环系统,形成血液GM-CSF的高峰。

Objective Conditionally replicating oncolytic adenovirus KH901 was engineered with a genetically modified telomerase reverse transcriptase promoter and a cDNA of human granulocyte macrophage colony stimulating factor （GM-CSF）. The objective of this study was to evaluate the anti-tumor efficacy and the selective GM-CSF expression of KH901 in xenograft tumor models. Methods After intratumoral administration of KH901, the rates of Relative Tumor Growth （T/C%） and inhibition in Hep3B and LNcap xenograft models were measured for observing the KH901 antitumor efficacy. At various time points, the GM-CSF expression levels in tumor tissues and the blood of A549 xenograft model were determined by ELISA method. Results In both Hep3B and LNcap xenograft models, KH901 showed the significantly higher restraint tumor rates at high dose （3 × 10^10 VP, P〈0. 05） compared to 5-FU or Cisplatin. Even at the low dose （3×10^8 VP）, the KH901 antitumor effect was similar to 5-FU （P〉0. 05）. In A549 xenograft model, the level of GM-CSF was continuously elevated and the peak values were found on day 7 in the blood and on day 11 in the tumor tissues. Then GM-CSF expression gradually reduced in both blood and tumor tissues. Conclusion KH901 can significantly inhibit the tumor growth in xenograft tumor model, and also express a high level of human GM-CSF in tumor tissue and release to circulating system to form a CM-CSF peak value in the blood.