Cell cultures U937 cells

A2. Aderka, D., Le, J., and Vilcek, J., IL-6 inhibits lipopolysaccharide-induced tumor necrosis factor production in cultured human monocytes U937 cells, and in mice. J. Immunol. 143, 3517-352) (1989). 

Calf serum was added to the medium for cell culture to 10% concentration. T98G or U937 cells were seeded onto 25 cm2 flasks for cell culture (Nunc, Denmark). Cells were cultivated for 72 h without serum, with 10% of intact serum or 10% serum after 6 h of photodynamic treatment. After the incubation period cells were harvested with chymotrypsine and their number was calculated in a hemocy-tometer chamber. 

Twenty years ago, a high-affinity-binding site for uPA was demonstrated on the surface of peripheral blood monocytes and cultured cells of the human histiocytic lymphoma cell line, U937 [46]. The expression of uPAR on the cell surface of many cell types has since then been demonstrated, including a variety of neoplastic cell lines as well as nonneoplastic cells such as neutrophils, macrophages, keratinocytes, placental trophoblasts, endothelial, and smooth muscle cells [7, 33, 47-51]. The human uPAR gene has been mapped to chromosome 19ql.3 [52]. 

Apart from the presence of proteins, several other factors can influence NM behavior in culture media, including the salt composition, the pH, or the buffer capacity. Using gold nanoparticles (AuNP) of three sizes Maiorano et al. [24] demonstrated that the nanoparticle-protein interactions are differendy mediated when AuNP are suspended in two common cell culture media (DMEM and RPMI) supplemented with fetal bovine serum. An increased protein coating and different size distribution were observed in AuNP suspended in DMEM in comparison to RPMI. Most impor-tantiy, differences were also found in the biological responses of two cell lines (HeLa and U937), as the intracellular internalization and cytotoxicity were higher in cells exposed to AuNP in RPMI, where the protein corona was less abundant. 

U937 cells (human monocyte like, hystiocytic lymphoma cells) were grown in RPMI-1640 (Hyclone, Logan, UT, USA) and, supplemented with 10% fetal bovine serum, 1% Pen-Strep at 37 °C in a 5% C02 atmosphere. Cells were plated in 150 mm Petri dishes at a density of 0.5 million cells per mL in a total of 250 mL culture medium. Concentrated PMA in DMSO was added to U937 cell cultures to a final concentration of 150 nM and cells were incubated with PMA for 1 h. 

Concerning NO implication in hematopoietic cancer cells apoptosis, the situation is less clear. In U937 and HL60 cells, NO effects are very different although both cell lines have been established in culture from promyelocytic leukemia. NO-induced apoptosis in U937 cells (p53 negative cells) is a p53 and caspase independent pathway but is controlled by Bcl-2 [124]. In these cells NO inhibits caspase 3 by S-nitrosation... 

NO induces the differentiation of promyelocytes in monocytes, talking about established culture cells (HL-60, U937, THP-1) or freshly leukemic isolated cells. Cell differentiation is shown by the inhibition of cell proliferation and cell adhesion, induction of marker expression (CD 14) and cytokines production (IL-ip and TNFa). This effect is due to NO donors and NO gaz [146], due to iNOS induction by CD23 ligation [112]... 

Teruya, T., Konishi, T., Uechi, S., Tamaki, H., and Tako, M. (2007). Anti-proliferative activity of oversulfated fucoidan from commercially cultured Cladosiphon okamuranus TOKIDA in U937 cells. Int. J. Biol. Macromol. 41, 221-226. 

PDE4 in primary blood macrophage cultures and in a human monocyte cell line THP-1, whereas in cultured U937 mononuclear cells, PDE4 PDE3. 

Cr supplementation prevented the increase in TNF-a levels and oxidative stress caused by high levels of glucose (30 mM) in cultured U937 monocytic cells (Jain and Kannan 2001). Similarly, chromium supplementation prevented elevated TNF-a secretion and lipid peroxidation levels in H202-treated U937 cells. 

Determination of [ H]-AA release. Aliquots (1 ml) of [ H]-AA-prelabelled U937 cells were placed in sterile 8 ml polystyrene tubes (Falcon) and test substances dissolved in cold serum-free RPMI were added at graduated concentrations. Control cells received an appropriate volume of RPMI without test substances. Cell cultures were kept for 1 hr at 4°C, after which the temperature was raised to 37°C. The cells were further incubated for 1 hr (dose-response relationship). After incubation, [ H]-AA was determined in the 200 g supernatants of cultures by liquid scintillation counting (liquid scintillation counter, Wallac 1410, Wallac Oy, Turku, Finland). Three experiments were carried out in every given series. All assays were performed in triplicate. 

Although DC maturation can be used to detect sensitizing capacity, major concerns remain on this assay (i) the limited reproducibility within and between laboratories due to inter-donor variability and variations in cell isolation and culture techniques (ii) the lack of sensitivity and dynamic range [122]. To circumvent interdonor variability cell lines such as THP-1, U937, KG-1 and MUTZ-3 have been used. 

Fig. 11 Comparison of the effect of nickel ion concentration on cell proliferation among five cell lines. Nickel chloride was used for the nickel ion supplier. Closed circles indicate the standardized viable cell number of PC-12. Open circles indicate the standardized viable cell number of MOLT-3. Triangles indicate the cultured standardized viable cell number of Hep G2. Squares indicate the standardized viable cell number of V79. Diamonds indicate the standardized viable cell number of U937 (n = 3). No addition of nickel chloride was used for the control culture condition...

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