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目的 研究干扰素(Interferon-γ,IFN-γ)对MGC-803胃癌细胞株的抗增殖和诱导凋亡作用,并 探讨其诱导凋亡作用的机制。方法 应用MTT法检测IFN对MGC-803胃癌细胞株的抗增殖作用的影响及细 胞毒活性;通过MTT染色法、HE染色、扫描电镜观察凋亡细胞的形态学改变;应用(TdT-mediateddUTPnick endlabeling)TUNEL法定量检测IFN γ诱导凋亡的情况;通过免疫细胞化学法测定P53、P16、C-myc、Bcl-2、Bax 的阳性表达率。结果 IFN-γ在1250～10000u/ml范围内对MGC-803胃癌细胞均有抑制作用(P<0.05), MTT染色法观察:正常肿瘤细胞着色均匀,凋亡细胞缩小成深蓝色,死亡细胞空泡样,不着色。扫描电镜及 TUNEL法均观察到实验组细胞体积变小,可见凋亡小体突出于肿瘤细胞表面。凋亡率随作用时间和浓度增加而 升高,实验组P53、P16、C-myc蛋白表达没有明显变化(P>0.05),Bcl-2蛋白表达下降,Bax蛋白表达上调,与对 照组相比均有显著性差异(P<0.01)。结论 IFN-γ可抑制MGC-803胃癌细胞增殖,诱导肿瘤细胞凋亡。其 作用机制可能是与通过上调肿瘤细胞Bax蛋白表达,下调Bcl-2蛋白表达有关。
Objective To investigate the antiproliferative and apoptosis-inducing effects of Interferon-γ (IFN-γ) on MGC-803 gastric cancer cell lines and to explore its mechanism of apoptosis. Methods MTT assay was used to detect the effect of IFN on the proliferation of MGC-803 gastric cancer cell lines and its cytotoxicity. The morphological changes of apoptotic cells were observed by MTT staining, HE staining and scanning electron microscopy. TdT-mediated dUTPnick end labeling TUNEL method was used to quantitatively detect IFNγ-induced apoptosis. The positive rates of P53, P16, C-myc, Bcl-2 and Bax were determined by immunocytochemistry. Results IFN-γinhibited the MGC-803 gastric cancer cells in the range of 1250 ~ 10000u / ml (P <0.05). The MTT staining showed that the normal tumor cells were stained evenly, the apoptotic cells were reduced to dark blue, and the dead cells were empty Bubble, no coloring. Scanning electron microscopy and TUNEL method were observed in the experimental group cells became smaller, we can see apoptotic bodies protruding from the tumor cell surface. The apoptotic rates increased with time and concentration. There was no significant change in the expression of P53, P16 and C-myc in the experimental group (P> 0.05), the expression of Bcl-2 decreased and the expression of Bax increased compared with the control group There was significant difference (P <0.01). Conclusion IFN-γ can inhibit the proliferation of MGC-803 gastric cancer cells and induce tumor cell apoptosis. Its mechanism may be related to upregulation of Bax protein expression in tumor cells and downregulation of Bcl-2 protein expression.