E1B-55kDa缺陷腺病毒dl1520联合DDP抗鼻咽癌作用的实验研究

Inhibitory Effect of E1B-deleted Adenovirus dl1520 Combined with Cisplatin on Nasopharyngeal Carcinoma

目的:探讨E1B-55kDa缺陷腺病毒dl1520与顺铂(DDP)联合应用对鼻咽癌的抑制作用。方法:采用MTT法测定体外dl1520联合DDP对鼻咽癌的细胞毒作用;在鼻咽癌裸鼠移植瘤上进行抗瘤实验,并用免疫组化检测腺病毒六邻体抗原的表达,分析dl1520在肿瘤内的复制情况。结果:在体外,dl1520能明显抑制CNE-2鼻咽癌细胞的生长,当感染复数(MOI)为0.032、0.160、0.800、4.000、20.000、100.000时,dl1520对CNE-2细胞的抑制率分别为2.78%、7.41%、10.19%、24.07%、45.37%和67.59%;当同时加入1μg/ml顺铂时,抑制率分别为29.63%、32.41%、40.74%、52.78%、66.67%和74.07%,而单独顺铂对CNE-2的抑制率为24.07%,联合组与单用dl1520组和单用DDP组比较均存在显著差异(P<0.01)。在动物实验中,dl1520单独及联合较低剂量DDP能显著抑制裸鼠移植瘤的生长,抑瘤率分别为35.71%和55.13%,与对照组比较,P值分别小于0.01和0.001;联合组与单独DDP组(抑瘤率为21.65%)比较也存在显著差异(P<0.05)。免疫组化结果证实,在dl1520组和联合组的肿瘤组织内存在大量腺病毒的复制,而对照组和DDP组中未见。结论:E1B-55kDa缺陷腺病毒dl1520对鼻咽癌具有一定的抑制作用,而dl1520与DDP联合应用可显著增强其抗癌效果。

Objective: To evaluate the antitumor effect of E1B 55kDa deleted adenovirus dl1520 combined with cisplatin (DDP) on nasopharyngeal carcinoma (NPC). Methods: The cytotoxicities of dl1520 alone or combined with DDP were detected by MTT assay in vitro; xenograft model in nude mouse was used to determine the antitumor effect in vivo, and the expression of virus hexon protein were detected by immunohistochemistry to evaluate propagation of dl1520 in tumor tissue. Results: In vitro, dl1520 alone or combined with DDP inhibited the growth of NPC cells. The cell viability repression rates were 2.78%, 7.41%, 10.19%, 24.07%, 45.37%,and 67.59%,respectively,while CNE 2 cells treated with dl1520 alone at 0.032, 0.16, 0.8, 4, 20,and100 MOIs (multiple of infection); the repression rate was 24.07% when treated with 1 μg/ml DDP; but when treated with dl1520 combined with DDP (1 μg/ml), the repression rates were 29.63%, 32.41%, 40.74%, 52.78%, 66.67%,and 74.07% respectively. There was significant difference between the two groups (P< 0.01). Compared with control, dl1520 alone or combined with DDP effectively inhibited the growth of tumor xenografts in vivo, which inhibition rates were 35.71% (P< 0.01) and 55.13% (P< 0.001); the combination of dl1520 and DDP showed more marked antitumor effect, compared with DDP alone, which inhibition rate was 21.65% (P< 0.05). Virus replication was detected on a large scale in tumor tissues treated with dl1520 alone or combined with DDP, but not in tumors of other groups. Conclusion: dl1520 can inhibit distinctly the growth of nasopharyngeal carcinoma in vitro and in vivo, and its antitumor efficacy can be augmented by chemotherapeutic agent DDP.