Ⅲ型干扰素信号通路诱导肺癌细胞凋亡的机制研究

Research on mechanism of IFN λ-induced apoptosis in human lung cancer cells

目的研究半胱氨酸蛋白酶(Caspase)激活方式,探讨Ⅲ型干扰素(IFNλ)信号通路诱导凋亡的机制。方法用IFNλ刺激人肺癌细胞A549,或用IL-10刺激表达复合受体FL-10R1/λR1的A549/FL-10R1/λR1细胞。用流式细胞分析检测Caspase3、Caspase8和Caspase9的激活程度。用Caspase抑制剂Z-VAD-FMK抑制Caspase,用流式细胞分析检测Caspase的激活情况,并通过末端转移酶标记术观察其对细胞凋亡的影响。结果 IFNλ信号通路可以上调Caspase3、Caspase8和Caspase9活化水平(5.5、3.5和4.5倍)并诱导凋亡。Z-VAD-FMK抑制Caspase3和Caspase8激活(60.0%和57.9%),但是提高了Caspase9的激活水平(35.1%),且不能阻止凋亡。结论 IFNλ信号可以激活不同的Caspase,通过激活死亡受体通路和线粒体通路来诱导凋亡,但是Caspase不是IFNλ诱导凋亡所必需的。

Objective To investigate the activation pattern of caspases by type Ⅲ interferon （IFNS） in apoptosis induction. Methods IFN λ stimulated lung cancer cell line A549 or IL-10 stimulated A549/FL-10R1/λR1, respectively. And the activation of caspase 3, caspase 8 and caspase 9 was determined by flow cytometry. Pancaspase inhibitor Z-VAD-FMK was used to inhibit caspase activation, and activated caspase levels were tested by flow cytometry. The level of apoptosis was tested by counting viable cells, Results IFN λ, signaling could activate caspase 3, caspase 8 and caspase 9 by 5.5, 3.5 and 4.5 times, respectively, and induce apoptosis. Z-VAD-FMK inhibited the activation of caspase 3 and caspase 8 by 60.0% and 57.9%, respectively, but activated caspase 9 by 35.1%. h could not stop apoptosis induced by IFNλ signaling. Conclusion IFNλ signaling activates various caspases, and induces both death receptor-mediated and mitochondria--mediated apoptotic pathways, which lead to apoptosis. But caspases are not necessary to this apoptosis induction.