Anti-Phosphotyrosine monoclonal antibody, clone QZ30 [HRP]

The application of anticancer drugs during pregnancy is associated with placenta-related adverse pregnancy outcomes. Therefore, it is important to study placental toxicity of anticancer drugs. The aim of this study was to compare effects on viability and steroidogenesis in placental tissue explants and trophoblast cell lines. Third trimester placental tissue explants were exposed for 72 h (culture day 4-7) to a concentration range of doxorubicin, paclitaxel, cisplatin, carboplatin, crizotinib, gefitinib, imatinib, or sunitinib. JEG-3, undifferentiated BeWo, and syncytialised BeWo cells were exposed for 48 h to the same drugs and concentrations. After exposure, tissue and cell viability were assessed and progesterone and estrone levels were quantified in culture medium. Apart from paclitaxel, all compounds affected both cell and tissue viability at clinically relevant concentrations. Paclitaxel affected explant viability moderately, while it reduced cell viability by 50% or more in all cell lines, at 3-10 nM. Doxorubicin (1 mu M) reduced viability in explants to 83 +/- 7% of control values, whereas it fully inhibited viability in all cell types. Interference with steroid release in explants was difficult to study due to large variability in measurements, but syncytialised BeWo cells proved suitable for this purpose. We found that 1 mu M sunitinib reduced progesterone release to 76 +/- 6% of control values, without affecting cell viability. While we observed differences between the models for paclitaxel and doxorubicin, most anticancer drugs affected viability significantly in both placental explants and trophoblast cell lines. Taken together, the placenta should be recognized as a potential target organ for toxicity of anticancer drugs.

l-Tyrosine is a versatile compound used in the fine chemical, pharmaceutical, and functional food industries. Here, we report a bi-enzymatic cascade involving alanine racemase (ALR) and d-amino acid oxidase (DAAO) to produce pyruvate, as co-substrate for l-tyrosine production, from the cheap substrate l-alanine. The BpALR (ALR from Bacillus pseudofirmus) was used as a whole-cell biocatalyst, converting l-alanine to d, l-alanine. The FsDAAO (DAAO from Fusarium solani) was immobilized to oxidize the d-alanine generated in the first step to pyruvate. Both systems were combined as a continuous-flow reactor for maximized l-alanine-to-pyruvate conversion rates. The optimal parameters and appropriate conditions for FsDAAO immobilization were investigated. The pyruvate concentration of 86.6 g/L was achieved within 17 h. Subsequently, a whole-cell biocatalyst system for l-tyrosine production, catalyzed by the tyrosine phenol-lyase (TPL) from Erwinia herbicola (EhTPL), was developed, and a fed-batch approach was applied with phenol and the pyruvate produced with the ALR/DAAO system mentioned above. The concentration of phenol and pyruvate in the reactor should not exceed 7.5 g/L and 10 g/L, respectively. Significantly, the l-tyrosine concentration of 152.5 g/L was achieved within 10 h, demonstrating the great potential for high-efficiency production of l-tyrosine through the approach we established in this paper.