中期因子在肿瘤发生和组织再生中的作用

中期因子(midkine,MK）是一种肝素结合性生长因子.在胚胎期，MK在组织中广泛分布.在成人体内其表达降低，仅局限于某些特定部位.MK受体种类繁多，信号通路复杂多样，这就决定了MK功能的多样化，它能促进很多种类细胞的生长、存活、分化和迁移，具有抗细胞凋亡的作用，不仅与肿瘤发生密切相关，而且在很多组织的发育形成及损伤后的修复再生过程均有参与.MK已成为恶性肿瘤在内的多种疾病治疗中颇具前景的分子靶点.本文中对MK的基因及蛋白结构、受体及相关信号通路、分子功能及作用机制等进行了全面的综述，并对其在肿瘤发生和发育与组织再生等方面的生物学功能及研究意义进行了深入的探讨.

Midkine in Tumorigenesis and Tissue Regeneration

Midkine (MK) is one of the heparin-binding growth factors that strongly expressed during embryogenesis, where the level and distribution is restricted in adults. Multiple kinds of MK receptors attribute to its various functions via different downstream signaling pathways. MK has an anti-apoptotic activity and is known to promote the growth, survival, differentiation and migration of many cell types .It is vigorously involved in development and regeneration of normal tissues, as well as in tumorigenesis. In this review, we will illustrate MK from the aspects of molecular structure, receptors, related signaling pathways, biological functions, and mechanisms of its activities.