摘 要 目的: 探讨重组人P53腺病毒(recombinant human adenovirus P53，rAdP53)对不同P53状态肝癌细胞生长的抑制和放射增敏作用。 方法: 以重组人P53腺病毒分别感染突变型P53肝癌细胞PLC/PRF/5和野生型P53肝癌细胞SMMC7721， Western blotting检测肝癌细胞P53蛋白表达，MTT法检测细胞存活率，台酚蓝染色绘制细胞生长曲线。肝癌细胞感染rAdP53 48 h后照射不同剂量的X射线，克隆形成法检测放射增敏比，TUNEL法检测细胞凋亡。 结果: 50 MOI rAd-P53转染PLC/PRF/5和SMMC7721细胞后转染效率分别为89.37%和87.53%，转染48 h可见P53蛋白高表达，MTT法显示细胞存活率分别为341%和35.44%，细胞生长曲线显示感染后第5天两种细胞生长抑制率分别为41.91%和17.03% (P<0.01)，PLC/PRF/5细胞的凋亡率\[(8.8±1.4)%\]显著高于SMMC7721 [(4.1±1.1)%] (P<0.01)。应用20 MOI的rAd-P53转染细胞48 h后加X射线(4 Gy)照射，PLC/PRF/5细胞的凋亡率为(26.9±5.6)%，显著高于SMMC7721细胞凋亡率(16.4±29)% (P<0.01)；20 MOI的rAdP53转染后加照射PLC/PRF/5和SMMC7721，细胞的放射增敏比SER(Dq)值分别为1.30和1.16；SER(D0)值分别为1.57和1.25。 结论: rAdP53能显著抑制人肝癌细胞生长、诱导细胞凋亡并提高细胞的放射敏感性，其对PLC/PRF/5细胞作用显著强于SMMC7721细胞；表明不同内源性P53状态的肝癌细胞对rAdP53治疗及其协同的放疗敏感性可能不同。

Abstract Objective:To investigate the inhibitory effect of recombinant human adenovirus P53(rAdP53) against human hepatocellular carcinoma cell lines with different P53 statuses and its enhancing effect on radiosensitivity. Methods: 〖WTBZ〗Two human hepatocellular carcinoma cell lines with different P53 genetic statuses, PLC/PRF/5 (MT P53) and SMMC7721 (WT P53) were infected with recombinant adenovirus carrying wildtype P53 gene (rAdP53) with increasing multiplicities of infection (MOI). P53 protein expression was detected by Western blotting assay; cell survival was evaluated by MTT; radiosensitivity was evaluated using a clonogenic assay; and cell apoptosis was assayed by TUNEL. Results: Infection efficiency of 50 MOI values of rAdP53 to PLC/PRF/5 and SMMC7721 cells were 89.37% and 86.53%, respectively. The expression of P53 protein was significantly increased in both cell lines 48 h after infection, and cell survival rates of PLC/PRF/5 and SMMC7721 cells were 3.41% and 35.44%, respectively. Inhibitory rates of PLC/PRF/5 and SMMC7721 cells 5 d after infection were 41.91% and 17.03%, respectively. Cells were treated with rAdP53 at 20 MOI for 48 h and then cells were irradiated (4 Gy); the apoptotic rates in PLC/PRF/5 and SMMC7721 cells were (269±5.6)% and (16.4±2.9), respectively (P<0.01). Clone formation assay showed that rAdP53 enhanced sensitivity of PLC/PRF/5 and SMMC7721 cells to radiotherapy, and SER (sensitive enhancement ratio) of Dq were 1.30 and 1.16, respectively, and SER of D0 were 1.57 and 1.25, respectively. Conclusion: rAdP53 can greatly inhibit proliferation, induce l apoptosis and increase radiosensitivity of human hepatocellular carcinoma cells. But the aforesaid efficacy of rAdP53 in PLC/PRF/5 cells is stronger that in SMMC7721 cells, which suggests that hepatocellular carcinoma cells with different P53 statuses responds differently to treatment with rAd-P53 or combination of rAdP53 and irradiation.

国家自然科学基金资助项目(No.30872975)