血管生成素
3 有待进一步解决的问题
Ang1和Ang2均参与肿瘤的血管生成。Ang1在肿瘤血管生成的作用尚未达成一致的意见，Ang1是促进还是抑制肿瘤的血管生成？Ang1受哪些因素或细胞因子的调节？是否在肿瘤形成的不同阶段Ang1发挥了不同的作用？有哪些调控机制？Ang2主要是由血管内皮细胞产生，部分肿瘤细胞也能分泌Ang2，那么，这些表达Ang2的内皮细胞和肿瘤细胞是否存在某种自分泌调节机制？Ang2对淋巴管的作用机制是什么？这些问题都有待于进一步研究。相信随着对Ang信号转导、基因表达调控等方面进一步深入的研究，有望为肿瘤的临床治疗提供一种新途径。
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