The semaphorins were initially characterized as repulsive axon guidance factors. However, they are currently also recognized as important regulators of diverse biological processes which include regulation of immune responses, angiogenesis, organogenesis, and a variety of additional physiological and developmental functions. The semaphorin family consists of more than 20 genes divided into seven subfamilies, all of which contain the sema domain signature. They usually transduce signals by activation of receptors belonging to the plexin family, either directly, or indirectly following the binding of some semaphorins to receptors of the neuropilin family which subsequently associate with plexins. Additional receptors which form complexes with these primary semaphorin receptors are also frequently involved in semaphorin signalling, and can strongly influence the nature of the biological responses of cells to semaphorins. Recent evidence suggests that semaphorins play important roles in the etiology of multiple forms of cancer. Some semaphorins such as some semaphorins belonging to the class-3 semaphorin subfamily, have been found to function as bona fide tumor suppressors and to inhibit tumor progression by various mechanisms. Because these class-3 semaphorins are secreted proteins, these semaphorins may potentially be used as anti-tumorigenic drugs. Other semaphorins, such as semaphorin-4D, function as inducers of tumor progression and represent targets for the development of novel anti-tumorigenic drugs. The mechanisms by which semaphorins affect tumor progression are diverse, ranging from direct effects on tumor cells to modulation of accessory processes such as modulation of immune responses and inhibition or promotion of tumor angiogenesis and tumor lymphangiogenesis. This review focuses on the diverse mechanisms by which semaphorins affect tumor progression.

信号量最初被表征为排斥轴突的指导因子。但是，它们目前也被认为是多种生物过程的重要调节剂，包括调节免疫应答，血管生成，器官发生以及各种其他生理和发育功能。semaphorin家族由20多个基因组成，分为七个亚家族，所有这些亚家族均包含sema域签名。它们通常通过激活某些信号蛋白与随后与丛蛋白相关的神经菌素家族的受体结合，直接或间接地激活属于丛蛋白家族的受体来转导信号。与这些主要信号量受体形成复合物的其他受体也经常参与信号量信号传导，并可以强烈影响细胞对信号量的生物学反应的性质。最近的证据表明，信号量在多种癌症的病因中起着重要作用。已经发现一些信号量蛋白，例如属于第3类信号量蛋白亚家族的一些信号量蛋白，可以作为真正的肿瘤抑制剂，并通过各种机制抑制肿瘤的进展。由于这些3类信号量蛋白是分泌的蛋白质，因此这些信号量可能会被用作抗致瘤药物。其他信号量，例如semaphorin-4D，可作为肿瘤进展的诱导剂，并代表开发新型抗肿瘤发生药物的靶标。信号量影响肿瘤进展的机制多种多样，从对肿瘤细胞的直接作用到调节辅助过程，例如调节免疫应答以及抑制或促进肿瘤血管生成和肿瘤淋巴管生成，范围广泛。这篇综述着重于信号量影响肿瘤进展的各种机制。