DNA Transfer into Animal Cells Using Stearylated CPP Based Transfection Reagent.

Mammalian transient expression systems enable flexible and rapid production of proteins. They're ideal for expression of human or other mammalian proteins because these systems generate recombinant proteins with more native folding and post-translational modifications-such as glycosylation-than expression systems based on hosts such as E. coli, yeast, or insect cells.Here we describe transient protein production using QMCF Technology (Icosagen, Estonia) that uses specific suspension-adapted mammalian cell lines (QMCF cells), appropriate QMCF episomal expression vector, a chemically defined animal origin-free, serum-free medium, and Reagent 007™ (Icosagen, Estonia) for efficient delivery of nucleic acids for transfection of mammalian cells in comparison with PEI MAX™ (Transfection Grade Linear Polyethylenimine Hydrochloride, Polysciences).

Potentiation of luteolin cytotoxicity by flavonols fisetin and quercetin in human chronic lymphocytic leukemia cell lines.

Despite numerous studies chronic lymphocytic leukemia (CLL) still remains an incurable disease. Therefore, all new compounds and novel strategies which are able to eradicate CLL cells should be considered as valuable clues for a potential future remedy against this malignancy. In the present study, the cytotoxic profiles of natural flavonoids were described in two human CLL cell lines, HG-3 and EHEB, indicating the flavone luteolin as the most potent flavonoid with half-maximal inhibitory constants (IC50) of 37 µM and 26 µM, respectively. Luteolin significantly increased the apoptotic cell population in both cell lines by increasing the activities of caspases-3 and -9 and triggering the intrinsic apoptotic pathway. Two flavonols, fisetin and quercetin, were somewhat less efficient in suppressing cellular viability, whereas baicalein, chrysin, (+)-catechin and hesperetin exerted only a small or no response at doses as high as 100 µM. Both fisetin and quercetin were able to augment the cytotoxic activity of luteolin in both cell lines by reducing the IC50 values up to four fold. As a result of this, luteolin displayed cytotoxicity activity already at low micromolar concentrations that could potentially be physiologically achievable through oral ingestion. No other tested flavonoids were capable of sensitizing CLL cells to luteolin pointing to a specific binding of fisetin and quercetin to the cellular targets which interfere with the signaling pathways induced by luteolin. Although further molecular studies to unravel this potentiating mechanism are certainly needed, this phenomenon could contribute to future remedies for prevention and treatment of chronic lymphocytic leukemia.