High-Throughput Process Development for Biopharmaceuticals

PTH2R is related to cell proliferation and migration in ovarian cancer: a multi-omics analysis of bioinformatics and experiments

Background

Ovarian cancer is a common gynecological disease and seriously endangers women's health. Currently, there is still a lack of effective molecular markers for the diagnosis and treatment of ovarian cancer. The present study aimed to investigate the molecular markers associated with ovarian cancer.

Methods

The molecular and gene related to ovarian cancer were extracted from GEO database and TCGA database by bioinformatics, and the related genes and functions were further analyzed. The results were verified by qPCR, WB, CCK-8 and Transwell experiments.

Results

Data analysis showed that PTH2R gene was highly expressed in tumors, and 51 HUB genes were obtained. Finally, experimental verification showed that PTH2R gene was highly expressed in ovarian cancer, and PTH2R gene was involved in the proliferation, invasion and metastasis of ovarian cancer cells.

Conclusions

After experimental verification, we found that knocking down the expression of PTH2R can inhibit the proliferation, invasion and migration of tumor cells.PTH2R is expected to become a new molecular marker for ovarian cancer.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-022-02566-2.

Process development exploiting competitive adsorption-based displacement effects in monoclonal antibody aggregate removal-A new high-throughput screening procedure for membrane chromatography

High-throughput screening (HTS) approaches are commonly used to accelerate downstream process development. Although most HTS approaches use batch isothermal data (K_P screen) or bind and elute mode as screening procedure, different or new process designs are rarely investigated. In this paper, a mechanistic model case study for the separation of two different two-component solutions was conducted and confirmed prior evidence. With these outcomes, a novel HTS screening procedure was developed including the determination of competitive adsorption-based displacement effects and key parameter identification. The screening procedure employing an overload bind and elute (OBE) mode is presented in a case study dealing with IgG aggregate removal in a typical monoclonal antibody purification step, applying a Sartobind® S membrane adsorber (MA). Based on a MA scale down device, the OBE mode allows the determination of classical process parameters and dynamic effects, such as displacement effects. Competitive adsorption-based displacement effects are visualized by introducing a displacement identifier leading to a displacement process map. Based on this map, the approach is transferred to and confirmed by the OBE recycle experiments with 4.6 and 8.2 ml benchtop scsale devices resulting in 45% reduced IgG monomer and 88% increased higher molecular weight species binding capacities.

A proline metabolism selection system and its application to the engineering of lipid biosynthesis in Chinese hamster ovary cells

Chinese hamster ovary (CHO) cells are the leading mammalian cell host employed to produce complex secreted recombinant biotherapeutics such as monoclonal antibodies (mAbs). Metabolic selection marker technologies (e.g. glutamine synthetase (GS) or dihydrofolate reductase (DHFR)) are routinely employed to generate such recombinant mammalian cell lines. Here we describe the development of a selection marker system based on the metabolic requirement of CHO cells to produce proline, and that uses pyrroline-5-carboxylase synthetase (P5CS) to complement this auxotrophy. Firstly, we showed the system can be used to generate cells that have growth kinetics in proline-free medium similar to those of the parent CHO cell line, CHOK1SV GS-KO™ grown in proline-containing medium. As we have previously described how engineering lipid metabolism can be harnessed to enhance recombinant protein productivity in CHO cells, we then used the P5CS selection system to re-engineer lipid metabolism by over-expression of either sterol regulatory element binding protein 1 (SREBF1) or stearoyl CoA desaturase 1 (SCD1). The cells with re-engineered proline and lipid metabolism showed consistent growth and P5CS, SCD1 and SREBF1 expression across 100 cell generations. Finally, we show that the P5CS and GS selection systems can be used together. A GS vector containing the light and heavy chains for a mAb was super-transfected into a CHOK1SV GS-KO™ host over-expressing SCD1 from a P5CS vector. The resulting stable transfectant pools achieved a higher concentration at harvest for a model difficult to express mAb than the CHOK1SV GS-KO™ host. This demonstrates that the P5CS and GS selection systems can be used concomitantly to enable CHO cell line genetic engineering and recombinant protein expression.

We have engineered a proline P5CS metabolism selection system in CHO cells

P5CS proline selection was used to engineer lipid metabolism in CHO cells

P5CS selection was stable for at least 100 generations

P5CS and GS selection systems were used together to engineer lipid and mAb expression

Lipid metabolism P5CS engineered CHO cells give enhanced recombinant protein expression

High throughput solubility and redissolution screening for antibody purification via combined PEG and zinc chloride precipitation

As upstream product titers increase, the downstream chromatographic capture step has become a significant "downstream bottleneck." Precipitation becomes more attractive under these conditions as the supersaturation driving force increases with the ever-increasing titer. In this study, two precipitating reagents with orthogonal mechanisms, polyethylene glycol (PEG) as a volume excluder and zinc chloride (ZnCl₂ ) as a cross linker, were examined as precipitants for two monoclonal antibodies (mAbs), one stable and the other aggregation-prone, in purified drug substance and harvested cell culture fluid forms. Manual batch solubility and redissolution experiments were performed as scouting experiments. A high throughput (HTP) liquid handling system was used to investigate the design space as fully as possible while reducing time, labor, and material requirements. Precipitation and redissolution were studied by systematically varying the concentrations of PEG and ZnCl₂ to identify combinations that resulted in high yield and good quality for the stable mAb; PEG concentrations in the range 7-7.5 wt/vol% together with 10 mM ZnCl₂ gave a yield of 97% and monomer contents of about 93%. While yield for the unstable mAb was high, quality was not acceptable. Performance at selected conditions was further corroborated for the stable mAb using a continuous tubular precipitation reactor at the laboratory scale. The HTP automation system was a powerful tool for locating desired (customized) conditions for antibodies of different physicochemical properties.