TGF-β1在人支气管上皮细胞恶性转化中的作用

The mechanism of TGF-β1 in radiation-induced human bronchial epithelium tumorigenesis

目的 研究人支气管上皮细胞恶性转化过程中 ,TGF β1表达水平的变化及其对细胞生长、增殖的影响 ,为进一步研究辐射诱发肿瘤发生的机理奠定基础。方法 在 2 4孔板中按 5× 10 4细胞 /孔分别接种对数生长期的BEP2D及BERP35T 2细胞 ,用一定浓度的TGF β1处理 ,计数 ,绘制细胞生长曲线 ,同时于光镜下观察细胞形态及生长状况。用westernblot方法检测胞浆内及分泌到培养液中的TGF - β1的丰度。 结果 两种细胞胞浆内的TGF β1表达水平无明显差异 ,但BERP35T 2细胞分泌到培养液中的TGF β1丰度约为BEP2D细胞的 5倍。TGF β1对两种细胞的生长均有抑制作用。在相同的浓度下 ,TGF β1对BERP35T 2细胞的生长抑制作用较BEP2D细胞弱。 结论 在辐射诱发人支气管上皮细胞恶性转化过程中TGF β1对其生长抑制作用减弱。

Objective To study the mechanism of radiation-induced tumorigenesis,the authors analyzed the expression of TGF-β1 in a human bronchial epithelium cell line BEP2D and its α-particle-induced malignantly transformed cell line BERP35T-2 cells,determined the influence of its expression on the cell growth and proliferation,and investigated the effect of exogenous TGF-β1 on these cells. Methods To determining the cell growth rate,5×10 4 cells were plated into 24-well culture plates and treated with 1 ng/ml or 2 ng/ml TGF-β1.The number of cells in three wells was counted with a hemocytometer every day.Proteins were extracted from BEP2D and BERP35T-2 cells or from the supernatant.The abundance of TGF-β1 was examined with Western blot. Results When analyzed the abundance of TGF-β1 in the cytoplasm,TGF-β1 in BERP35T-2 cells was not significantly higher than that in BEP2D cells ( P>0.05 ).As the abundance of TGF-β1 secreted into the culture medium was compared,TGF-β1 from BERP35T-2 cells was significantly higher than that from BEP2D cells( P <0.01).When treated with TGF-β1,inhibitory effect on growth and proliferation of both BEP2D and BERP35T-2 cells was showed. But,the effect of TGF-β1 on BERP35T-2 cells was weaker than that on BEP2D cells. Conclusion In the malignant transformation process of human bronchial epithelial cells induced by radiation,the inhibitory effect of TGF-β1 on cell growth decreased. ;