Department of Biotechnology, University of New South Wales, Kensington, NSW, 2052, Australia.,
Cytotechnology. 1998 Nov;28(1-3):91-100. doi: 10.1023/A:1008073513948.
Previously, we described the genetic construction Super- CHO, a cell line capable of autocrine growth under fully defined protein-free conditions. Super-CHO cells constitutively express insulin growth factor-I (IGF-I) and transferrin in sufficient amounts to support long-term, stable growth without the addition of exogenous growth factors, thus making it an ideal host for the production of recombinant biopharmaceuticals. although IGF-I has been successfully expressed in Chinese Hamster Ovary (CHO) cells, the long term effects of recombinant IGF-I expression have not been explored. In particular, the expression of the endogenous IGF-I receptor in response to IGF-I production has not been reported. We report here the transcriptional induction of the type I IGF receptor gene in Super-CHO. In addition, we examined the conditioned medium for the presence of IGF-I binding proteins. Ligand blot analysis reveals the presence of IGF binding proteins present in the medium conditioned by Super-CHO cells as well as CHO cells incubated in the presence of IGF-I. Furthermore, immunoaffinity reveals that Super-CHO expresses IGF binding protein-3 in response to IGF-I production. These results suggest the autocrine growth of Super-CHO involves a complex interaction of cell type specific factors which regulate its utility of IGF-I.
先前，我们描述了 Super-CHO 细胞系的基因构建，这是一种能够在完全无蛋白条件下进行自分泌生长的细胞系。Super-CHO 细胞持续表达足够量的胰岛素样生长因子-I（IGF-I）和转铁蛋白，足以支持长期稳定的生长，无需添加外源性生长因子，因此是生产重组生物制药的理想宿主。虽然 IGF-I 已在中华仓鼠卵巢（CHO）细胞中成功表达，但重组 IGF-I 表达的长期影响尚未得到探索。特别是，内源性 IGF-I 受体对 IGF-I 产生的反应的表达尚未报道。我们在这里报告了 Super-CHO 中 I 型 IGF 受体基因的转录诱导。此外，我们检查了条件培养基中是否存在 IGF-I 结合蛋白。配体印迹分析显示，Super-CHO 细胞和在 IGF-I 存在下孵育的 CHO 细胞的条件培养基中存在 IGF 结合蛋白。此外，免疫亲和法显示 Super-CHO 表达 IGF 结合蛋白-3 以响应 IGF-I 的产生。这些结果表明 Super-CHO 的自分泌生长涉及调节其 IGF-I 利用的细胞类型特异性因素的复杂相互作用。
