Basic research on anti-tumor effects of Interferon-α on hepatocellular carcinoma

【目的】本研究探讨IFN-α亚型对人肝癌细胞株体外生长的影响; IFN-α和5-Fu对人肝癌细胞株体外生长的抑制作用; IFN-α诱导人肝癌细胞株凋亡的机制; IFN-α单独或联合5-Fu对人肝癌细胞株裸鼠移植瘤生长的影响。[结果] 1.本实验观察了α1、α2、α5、α8、α10五种重组α干扰素亚型（浓度0-1024 IU/mL，24-96 h）对13株人肝癌细胞株生长的影响，结果表明：α5亚型干扰素的抗增殖作用最强，其次为α8、α10、α2、α1。2. IFN-α和5-Fu同时加入肝癌细胞培养液中，无协同抑制作用。3.天然人IFN-α可不同程度地诱导IFN-α诱导的凋亡敏感细胞系中caspase-3、caspase-7、caspase-8和caspase-9的活化以及PARP的蛋白水解。此外，细胞色素C和Smac/Diablo从线粒体释放到细胞质中，在IFN-α处理的细胞中具有时间依赖性。这些结果提示线粒体凋亡诱导途径参与了IFN-α诱导的细胞凋亡。4.皮下注射IFN-α Con 1（0.01、0.1、1μg/mouse/day; 0.01 μg/mouse =临床剂量）连续14 d呈剂量和时间依赖性抑制裸鼠肝癌生长。最后，接受0.01、0.1和1 μg/只IFN-α Con 1的小鼠的肿瘤体积分别降低至对照肿瘤体积的约60%、25%和0- 10%。随着IFN-α Con 1剂量的增加，凋亡细胞数明显增加，血管数明显减少。5. IFN-α与5-Fu对裸鼠移植瘤有协同作用。[结论]本研究结果为IFN-α在肝癌防治中的临床应用提供了依据。

[Purpose] In this study, we examined that the effects of IFN-α subtypes on the growth of human liver cancer cell lines in vitro ; growth inhibitory effects of IFN-α and 5-Fu in vitro ; mechanisms of apoptosis induction by IFN-α; and the effects of IFN-α alone or IFN-α plus 5-Fu on the growth of human liver cancer cell lines transplanted In nude mice.[Results] 1. When we examined the effects of five kinds of recombinant IFN-α subtypes (α1, α2, α5, α8, α10; concentrations: 0-1024 IU/mL; 24-96 hours) on the growth of 13 human liver cancer cell lines, the strongest anti-proliferative effects was noted In IFN-α5 subtype, and followed by α8, α10, α2, α1. 2. No synergistic growth Inhibitory effects could be recognized when IFN-α and 5-Fu were simultaneously added t o the culture of liver cancer cells. 3. Natural human IFN-α induced activation of caspase-3, -7, -8, and -9, and proteolysis of PARP in IFN-α-induced apoptosis-sensitive cell lines at various degrees. In addition, release of cytochrome C and Smac/Diablo from mitochondria into cytoplasm was identified in IFN-α-treated cells time-dependently. These findings suggest mitochondria apoptosis induction pathway is involved in the IFN-α-induced apoptosis. 4. Subcutaneous IFN-αCon1 injection (0.01, 0.1, 1μg/mouse/day; 0.01 μg/mouse = clinical dosesage) for consecutive 14 days dose-and time-dependently suppressed the HCC tumor growth in nude mice. Finally, the tumor volumes of mice received 0.01, 0.1, and 1 μg/mouse of IFN-αCon1 decreased to about 60%, 25%,and 0-10%, respectively, of control tumor volumes. The number of apoptotic cells significantly Increased and the number of blood vessels significantly decreased with the increase of IFN-αCon1 dose. 5. Synergistic effect of IFN-α plus 5-Fu was identified In nude mouse tumors. [Conclusions] These data Indicate the potential clinical application of certain types of IFN-α in the prevention and treatment of HCC.