Lotem J, Sachs L
Department of Molecular Genetics, Weizmann Institute of Science, Rehovot, Israel.
Apoptosis. 1999 Jun;4(3):187-96. doi: 10.1023/a:1009614723237.
Many cytokines have been isolated by their ability to induce growth and have been called growth factors. But these cytokines are also essential to induce cell viability, and cell viability and growth can be separately regulated. Using as examples myeloid hematopoietic cells, lymphocytes and neuronal cells, in vitro and in vivo studies have shown the role of cytokines in inducing viability of different cell types during development to mature cells. Some cytokines can act on more than one cell type. Cytokines induce viability of normal and cancer cells by suppressing the apoptotic machinery activated by wild-type p53, or by cytotoxic agents including irradiation and compounds used in cancer chemotherapy. Cytokines can be used to decrease apoptosis in normal cells and inhibition of cytokine activity may improve cancer therapy by enhancing apoptosis in cancer cells. The apoptosis suppressing function of cytokines is mediated by changing the balance in the activity of apoptosis inducing and suppressing genes. Apoptosis suppression is upstream of caspase activation in the apoptotic process. Cytokines can suppress multiple pathways leading to apoptosis, only some of which were suppressed by other agents such as some antioxidants, Ca(2+)-mobilizing compounds and protease inhibitors.
许多细胞因子因其诱导生长的能力而被分离出来，并被称为生长因子。但这些细胞因子对于诱导细胞活力也是必不可少的，而且细胞活力和生长可以分别受到调控。以髓系造血细胞、淋巴细胞和神经元细胞为例，体外和体内研究表明，细胞因子在不同细胞类型从发育到成熟细胞的过程中诱导细胞活力方面发挥着作用。一些细胞因子可以作用于不止一种细胞类型。细胞因子通过抑制野生型p53激活的凋亡机制，或通过包括辐射和癌症化疗中使用的化合物在内的细胞毒性剂，来诱导正常细胞和癌细胞的活力。细胞因子可用于减少正常细胞中的凋亡，而抑制细胞因子活性可能通过增强癌细胞中的凋亡来改善癌症治疗。细胞因子的凋亡抑制功能是通过改变凋亡诱导和抑制基因活性的平衡来介导的。凋亡抑制在凋亡过程中位于半胱天冬酶激活的上游。细胞因子可以抑制多条导致凋亡的途径，其中只有一些途径被其他试剂如一些抗氧化剂、钙动员化合物和蛋白酶抑制剂所抑制。
