目的：观察携带hIFN-γ基因的内皮祖细胞（endothelial progenetor cells carrying hIFN-γ, EPC-hIFN-γ）在肿瘤化疗后维持治疗的效果。方法：LoVo大肠癌细胞加入喜树碱-11（camptothecin-11, CPT-11），再分别加入 hIFN-γ或（和）西妥苷单抗（cetuximab, C225)，MTT法观察其对LoVo细胞的抑制作用。荷Lovo大肠癌细胞移植瘤裸鼠在给药CPT-11后，再给予EPCs-hIFN-γ或（和）C225，观察对肿瘤的抑制作用和对裸鼠生存期的影响。结果：在体外，肿瘤细胞中加入CPT-11后再加入hIFN-γ或（和）C225可进一步抑制肿瘤细胞的生长。荷瘤裸鼠在给予CPT-11 50 mg/kg后，分别给予EPCs-hIFN-γ、C225或者EPCs-hIFN-γ + C225，均可以进一步抑制肿瘤的生长\[肿瘤平均体积(2 024.28±1 048.40) mm3 vs (764.94±720.14) mm3、(233.85±186.97) mm3、(186.95±133.43) mm3、(163.9±173.39) mm3，P＜005)，均可进一步延长荷瘤裸鼠的生存期（中位生存期34.2 d vs 39.4 d、44.5 d、48.5 d、51.3 d，P<0.05或P＜001）；其中以CPT-11+EPCs-hIFN-γ+C225的治疗效果最好。结论：EPCs-hIFN-γ用于化疗后维持治疗可以抑制肿瘤细胞生长，延长荷瘤小鼠的生存。

Objective:To observe the efficacy of endothelial progenitor cells carrying hIFN-γ (EPCs-hIFN-γ) in cancer maintenance therapy after chemotherapy. Methods: MTT was used to examine the inhibitory effects of hIFN-γ and/or C225 against colorectal cancer LoVo cells after treatment with CPT-11. The in vivo inhibitory effects of EPCs-hIFN-γ and/or C225 on LoVo tumors and their effects on survival of LoVo tumor-bearing nude mice were investigated after mice had been treated with CPT-11. Results: In vitro, hIFN-γ and/or C225 further inhibited the growth of cancer cells after CPT-11 treatment. In vivo, after 50 mg/kg CPT-11 treatment, EPCs-hIFN-γ，C225 and EPCs-hIFN-γ+C225 inhibited the growth of tumors in LoVo tumor-bearing nude mice (mean tumor volumes: \[2024.28±1048.40\] mm3 vs \[764.94±720.14\], \[233.85±186.97\], \[186.95±133.43\], \[163.9±173.39\] mm3; P＜0.05). EPCs-hIFN-γ, C225 and EPCs-hIFN-γ+C225 treatment also increased the survival of tumor-bearing mice (median survival: 34.2 d vs 39.4, 445, 48.5, 51.3 d; P<0.05 or P<0.01). Conclusion: EPC-hIFN-γ can inhibit the tumor growth and prolong the survival of tumor-bearing mice in cancer maintenance therapy after chemotherapy.

全军“十一五”科技攻关项目（No. 06G140）