Trace metal optimization in CHO cell culture through statistical design of experiments.

A majority of the biotherapeutics industry today relies on the manufacturing of monoclonal antibodies from Chinese hamster ovary (CHO) cells, yet challenges remain with maintaining consistent product quality from high-producing cell lines. Previous studies report the impact of individual trace metal supplemental on CHO cells, and thus, the combinatorial effects of these metals could be leveraged to improve bioprocesses further. A three-level factorial experimental design was performed in fed-batch shake flasks to evaluate the impact of time wise addition of individual or combined trace metals (zinc and copper) on CHO cell culture performance. Correlations among each factor (experimental parameters) and response variables (changes in cell culture performance) were examined based on their significance and goodness of fit to a partial least square's regression model. The model indicated that zinc concentration and time of addition counter-influence peak viable cell density and antibody production. Meanwhile, early copper supplementation influenced late-stage ROS activity in a dose-dependent manner likely by alleviating cellular oxidative stress. Regression coefficients indicated that combined metal addition had less significant impact on titer and specific productivity compared to zinc addition alone, although titer increased the most under combined metal addition. Glycan analysis showed that combined metal addition reduced galactosylation to a greater extent than single metals when supplemented during the early growth phase. A validation experiment was performed to confirm the validity of the regression model by testing an optimized setpoint of metal supplement time and concentration to improve protein productivity.

Exosome CTLA-4 Regulates PTEN/CD44 Signal Pathway in Spleen Deficiency Internal Environment to Promote Invasion and Metastasis of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the most common primary cancers, and its pathogenesis is complicated and difficult to screen. Currently, there is no effective treatment. In traditional Chinese medicine, a large proportion of patients with HCC have been diagnosed with spleen deficiency (SD) syndrome and treated with tonifying traditional Chinese medicine, which has significant clinical efficacy. However, the role and molecular mechanism of SD in HCC remain unclear. In this study, 40 mice were randomly divided into four groups: control, SD, HCC, and SD-HCC groups. The liver cancer model of SD was established by reserpine induction and orthotopic transplantation. The effects of SD on the proliferation, apoptosis, invasion, and metastasis of HCC cells were studied by cell proliferation, cell apoptosis, cell scratch, and transwell assay. We found that compared with the HCC group, the protein expressions of cytotoxic T lymphocyte antigen 4 (CTLA-4), programmed cell death protein 1 (PD-1), phosphatase and tensin homolog (PTEN), and AKT (also known as protein kinase B or PKB) in the exosomes of the SD-HCC group were upregulated. In addition, the metastases and self-renewal of exosomes in the SD-HCC group were more aggressive than those in the HCC group, which could be partially reversed with the addition of CTLA-4 inhibitors. Further studies showed that in the internal environment of SD, CTLA-4 promoted tumor invasion and metastasis by regulating the PTEN/CD44 pathway. In conclusion, our findings suggest that during SD in the internal environment, exosome CTLA-4 regulates the PTEN/CD44 signal pathway to promote the proliferation, self-renewal, and metastasis of liver cancer.

An Integrative Analysis Reveals the Potential Mechanism between Herbal Medicine Yinchen and Immunoregulation in Hepatocellular Carcinoma.

Aims. Abundant evidences in traditional Chinese medicine (TCM) supported the therapeutic value of herbal medicine Yinchen in hepatocellular carcinoma (HCC), but the underlying mechanism remains to be investigated. Main Methods. The intersection of immune gene set, module genes, HCC-associated genes, and target genes of Yinchen was employed for further analyses. The module genes were identified by weighted gene coexpression network analysis, and the other three gene sets were obtained from public databases. Subsequently, we further explored the clinical value and immunoregulation of the hub gene of intersection. The relevant pathways related to hub gene expression were investigated by gene set enrichment analysis. Finally, the interaction of active compounds and target genes was validated by molecular docking. Key Findings. Thirteen active compounds and 90 target genes of Yinchen were included. After constructing the network among Yinchen, target genes, and HCC, BIRC5 was identified as the hub gene. Significant difference was found between the high-expressed group and the low-expressed group in survival and stage. Different immune subtypes also presented significant difference in BIRC5 expression. Moreover, NK cell and T cell (CD4+ effector memory and CD4+ memory resting) were negatively correlated with BIRC5 expression, while CTLA4 and LAG3 were positively correlated. The results of molecular docking further validated a good binding activity of quercetin-BIRC5 interaction. Significance. In summary, our research identified for the first time a novel underlying association among herbal medicine Yinchen, BIRC5, immunotherapy, and HCC. We speculated that Yinchen may target the immune checkpoints (CTLA4 and LAG3) and activate the immune cells by suppressing BIRC5.