表达Tie2的单核细胞在肿瘤研究中的进展

表达Tie2的单核细胞(TEM)仅存在于外周血及肿瘤组织中,在肿瘤血管生成中发挥重要作用.TEM能够被血管生成素2(Ang2)及缺氧化学信号募集进入肿瘤组织,分化成表达Tie2的巨噬细胞,通过旁分泌作用参与肿瘤血管生成.肝癌、结肠癌、乳腺癌、恶性胶质瘤等肿瘤中检测到TEM水平升高,这对于肿瘤的诊断及预后判断有一定的提示作用.近年研究发现,TEM可用于抗肿瘤药物的靶向递送,能有效抑制肿瘤的生长和转移,同时TEM也是抗肿瘤治疗的潜在靶点.然而TEM在肿瘤微血管密度、临床分级及预后判断中的作用并不明确,目前针对TEM具体功能的探究引起了学者的广泛关注.

Tie2 expressing monocytes in cancer research

Tie2 expressing monocytes (TEMs) only present in human circulating blood and tumor organs, and have an important role in tumor angiogenesis and progression. TEMs are effectively recruited to tumors by angiopoietin 2 （Ang2） and hypoxia and then differentiate into macrophages, which promote the angiogenesis in experimental tumor models by providing paracrine support to nascent blood vessels. Studies show that TEMs are up-regulated in hepatocellular carcinoma, colorectal cancer, breast cancer, malignant glioma and other human cancers, which suggests that TEMs are conducive to diagnosis and prognosis of tumors. With the further research, TEMs are applied to deliver drugs which can obtain significant anti-tumor responses and inhibit metastasis with the ability of tumor-homing. Meanwhile, TEMs may also be a potential target for the anticancer drugs. However, the present researches indicate that the effects of TEMs in tumor microvessel density, clinical stage and prognosis are still questionable. Current works that aim at describing and predicting the concrete function of TEMs have attracted significant attention from researchers.