Growth Rate Changes in CHO Host Cells Are Associated with Karyotypic Heterogeneity
Growth Rate Changes in CHO Host Cells Are Associated with Karyotypic Heterogeneity
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DOI：
10.1002/biot.201700230
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发表时间：
2018-03-01
影响因子：
4.7
通讯作者：
Lee, Kelvin H.
中科院分区：
文献类型：
--
作者：
Baik, Jong Youn;Lee, Kelvin H.
中国仓鼠卵巢（CHO）细胞系的不稳定性和克隆性问题可能会影响细胞培养表型，如细胞生长、生产率或产品质量，并且仍然是生物制药制造的挑战。虽然已努力表征CHO生产细胞系中的细胞系不稳定性，但尚未确定CHO宿主细胞中预先存在的细胞系不稳定性水平。在这项研究中，细胞系的不稳定性和宿主，CHO-DUK细胞系的染色体异质性，报告通过使用核型分析方法。CHO-DUK细胞的长期培养和核型分析显示，在较晚的传代培养物中生长速率较高，与含有mar3染色体的群体比例增加相关。为了进一步研究生长速率和核型之间的相关性，通过有限稀释法对CHO-DUK细胞进行亚克隆，并测定每个亚克隆的生长速率和核型。含有mar3染色体的亚克隆比没有mar3染色体的亚克隆表现出更高的细胞生长速率。最后，核型分析表明，CHO-DUK细胞，以及有限稀释的亚克隆，表现出核型异质性人口，表明染色体重排发生自发和频繁，甚至在非工程化的宿主细胞。这些结果证明了CHO宿主细胞系的不稳定性，并表明染色体不稳定性和核型变化与克隆性受损（异质性）相关，影响CHO宿主细胞中的细胞系稳定性。
Chinese hamster ovary (CHO) cell line instability and clonality issues can affect cell culture phenotypes such as cell growth, productivity, or product quality and remain challenges for biopharmaceutical manufacturing. While there have been efforts for characterizing cell line instability in CHO production cell lines, a pre-existing level of cell line instability in CHO host cells has not been determined. In this study, cell line instability and chromosomal heterogeneity of the host, CHO-DUK cell line, is reported by using a karyotyping approach. Long-term cultures and karyotype analysis of CHO-DUK cells revealed that the growth rate was higher in later passage cultures, correlating with an increase in the population ratio containing the mar3 chromosome. To further investigate a correlation between growth rate and karyotype, CHO-DUK cells are subcloned by limiting dilution and the growth rate and karyotype of each subclone are determined. Subclones containing the mar3 chromosome exhibit higher cell growth rates than subclones without the mar3 chromosome. Finally, karyotype analysis indicate that CHO-DUK cells, as well as limiting-diluted subclones, exhibit a karyotypically heterogeneous population, suggesting that chromosomal rearrangements occur spontaneously and frequently even in non-engineered host cells. These results demonstrate CHO host cell line instability and suggest that chromosomal instability and karyotypic changes are associated with compromised clonality (heterogeneity), affecting cell line (in)stability in CHO host cells.