Ding Jing, Li Qin-Ying, Yu Jie-Zhong, Wang Xin, Lu Chuan-Zhen, Ma Cun-Gen, Xiao Bao-Guo
Institute of Neurology, Huashan Hospital, Institutes of Brain Science and State Key Laboratory of Medical Neurobiology, Fudan University, 12 Middle Wulumuqi Road, 200040, Shanghai, China.
Cell Biol Toxicol. 2015 Feb;31(1):29-38. doi: 10.1007/s10565-015-9292-y. Epub 2015 Feb 6.
Recombinant human erythropoietin (EPO), a glycohormone, is one of the leading biopharmaceutical products, while carbamylated erythropoietin (CEPO), an EPO derivative, is attracting widespread interest due to its neuroprotective effects without erythropoiesis in several cells and animal models. However, exogenous EPO promotes an angiogenic response from tumor cells and is associated with tumor growth, but knowledge of CEPO on tumor growth is lacking. Here we show that CEPO, but not EPO, inhibited Neuro-2a growth and viability. As expected, CEPO--unlike EPO--did not activate JAK-2 either in primary neurons or in Neuro-2a cells. Interestingly, CEPO did not induce GDNF expression and subsequent AKT activation in Neuro-2a cells. Before CEPO/EPO treatment, glial cell line-derived neurotrophic factor (GDNF) neutralization and GFR receptor blocking decreased the viability of EPO-treated Neuro-2a cells but did not influence CEPO-treated Neuro-2a cells. As compared to primary neurons, the expression of CD131, as a receptor complex binding to CEPO, is almost lacking in Neuro-2a cells. In BABL/C-nu mice, CEPO did not promote the growth of Neuro-2a cells nor extended the survival time compared to mice treated with EPO. The results indicate that CEPO did not promote tumor growth because of lower expression of CD131 and subsequent dysfunction of CD131/GDNF/AKT pathway in Neuro-2a cells, revealing its therapeutic potential in future clinical application.
重组人促红细胞生成素(EPO)是一种糖激素,是主要的生物制药产品之一,而促红细胞生成素的氨甲酰化衍生物(CEPO)因其在多种细胞和动物模型中具有无红细胞生成作用的神经保护效应而受到广泛关注。然而,外源性EPO会促进肿瘤细胞的血管生成反应并与肿瘤生长相关,但关于CEPO对肿瘤生长的影响尚缺乏了解。在此我们表明,CEPO而非EPO能抑制Neuro-2a细胞的生长和活力。正如预期的那样,与EPO不同,CEPO在原代神经元或Neuro-2a细胞中均未激活JAK-2。有趣的是,CEPO在Neuro-2a细胞中未诱导胶质细胞源性神经营养因子(GDNF)表达及随后的AKT激活。在CEPO/EPO处理之前,胶质细胞源性神经营养因子(GDNF)中和及GFR受体阻断降低了EPO处理的Neuro-2a细胞的活力,但不影响CEPO处理的Neuro-2a细胞。与原代神经元相比,作为与CEPO结合的受体复合物的CD131在Neuro-2a细胞中几乎缺乏表达。在BABL/C-nu小鼠中,与用EPO处理的小鼠相比,CEPO既未促进Neuro-2a细胞的生长,也未延长存活时间。结果表明,由于Neuro-2a细胞中CD131表达较低及随后的CD131/GDNF/AKT信号通路功能障碍,CEPO不会促进肿瘤生长,这揭示了其在未来临床应用中的治疗潜力。