Chen Kaiming, Li Dong, Li Hongwen, Li Bing, Li Jie, Huang Lei, Li Renhao, Xu Xiaoqing, Jiang Lingxiao, Jiang Cizhong, Gu Hua, Fang Jianmin
School of Life Sciences and Technology, Tongji University, Shanghai, China.
Shanghai Tongji Hospital, Tongji University, Shanghai, China.
Appl Microbiol Biotechnol. 2017 Jul;101(14):5785-5797. doi: 10.1007/s00253-017-8331-4. Epub 2017 May 24.
Chinese hamster ovary (CHO) cells have been widely used for production of recombinant proteins and therapeutic antibodies. However, owing to the instability and heterogeneity of CHO cells, the development of stable and high-expression recombinant CHO cell lines is often time-consuming. To investigate the mechanisms associated with heterogeneity in protein productivity, we performed transcriptome analysis on the subclones derived from a stable parental CHO clone. Two high-expression subclones and one low-expression subclone were selected based on their similar genomic background and subjected to RNA-seq analysis. Over 100 differentially expressed genes were identified between the subclones with high and low productivity. The molecular functions of the differentially expressed genes were enriched for translational elongation, sterol biosynthetic process, and regulation of secretion. In addition, analyses of the two subclones with high protein expression levels identified over 300 differentially expressed genes involved in DNA metabolic processes, cellular macromolecule catabolic processes, cell cycle, protein catabolic processes, and RNA processing and transcription. A subset of the differentially expressed genes was overexpressed in CHO cells to identify their effects on protein production. Together, these results indicate that transcriptome variation can cause significant inter-cellular heterogeneity in CHO cells and a better understanding of the molecular mechanism underlying heterogeneity might help to improve the production of recombinant proteins by CHO cells.
中国仓鼠卵巢（CHO）细胞已被广泛用于重组蛋白和治疗性抗体的生产。然而，由于CHO细胞的不稳定性和异质性，稳定且高表达的重组CHO细胞系的开发往往耗时较长。为了研究与蛋白质生产力异质性相关的机制，我们对来自一个稳定亲本CHO克隆的亚克隆进行了转录组分析。基于相似的基因组背景，选择了两个高表达亚克隆和一个低表达亚克隆，并进行RNA测序分析。在高生产力和低生产力亚克隆之间鉴定出100多个差异表达基因。差异表达基因的分子功能在翻译延伸、甾醇生物合成过程和分泌调节方面得到富集。此外，对两个高蛋白表达水平的亚克隆进行分析，鉴定出300多个参与DNA代谢过程、细胞大分子分解代谢过程、细胞周期、蛋白质分解代谢过程以及RNA加工和转录的差异表达基因。在CHO细胞中过表达一部分差异表达基因，以确定它们对蛋白质生产的影响。总之，这些结果表明转录组变异可导致CHO细胞间显著的异质性，更好地理解异质性背后的分子机制可能有助于提高CHO细胞重组蛋白的产量。
