Insight into single cell cloning in serum-free media

Chinese hamster ovary (CHO) cells have been used as host cells for the manufacturing of therapeutic recombinant proteins over the past decade. It is thought that the development of high performance cell lines, which satisfy both productivity and regulatory expectations, is one of the key success drivers to establish good manufacturing processes. The cell line for the clinical and commercial productions should be derived from a single progenitor or clone, and so the single cell cloning is an essential step during the cell line development. Recently serum-free media have been widely applied for this step. But under such conditions, the cloning efficiency varies significantly among the clones. This might be because the serum-free conditions can be stressful for the CHO cells exposed to such an unexpected cloning process. In this study, we performed re-cloning from two pre-cloned cell lines to evaluate the impact of serum-free cloning on the resulting cell line characteristics; various parameters such as cell growth, productivity, fed-batch culture performance, product quality and cell stability were evaluated. As a result, most of the clones showed exactly the same performance before and after the cloning process, but some clones did not. The detail of these results will be presented and also the proper evaluation to be needed during cell line development, especially after the single cell isolation, will be discusse

The neutrophil-to-lymphocyte ratio as a novel independent prognostic factor for multiple metastatic lung tumors from various sarcomas

Purpose Sarcomas are among the most refractory malignant tumors and often recur as pulmonary metastasis. Although the presence of a high neutrophil-to-lymphocyte ratio (NLR) has been associated with the prognosis of several malignancies, the relationship between the NLR and sarcoma with pulmonary metastasis is unclear. We investigated the impact of the NLR in patients who underwent surgical resection for metastatic lung tumors from various sarcomas. Methods The subjects of this retrospective study were 158 patients with metastatic lung tumors from various sarcomas, who underwent initial pulmonary metastasectomy between 2006 and 2015. We examined the clinicopathological variables, including the NLR and the characteristics of surgical procedures. Survival was estimated by the Kaplan–Meier method and prognostic factors were evaluated by multivariate analysis. Results Multivariate analysis revealed significantly better survival of the group with an NLR  2 years, and 3 or more pulmonary metastasectomies. Conclusion The NLR immediately before the most recent pulmonary metastasectomy is a novel independent prognostic factor, which may be helpful when considering repeated pulmonary metastasectomy