A comparison of the NK cell cytotoxicity with effects of TNF-alpha against K-562 cells, determined by LDH release assay.
Effects of r h TNF-alpha as a single cytotoxic mediator against K-562 cells was examined by LDH release and compared with NK cell cytotoxicity. The mean values of the percentage of LDH release (x = 6.25 +/- 3.68%, for ten individual experiments) from K-562 cells cultured for 2 h with r h TNF-alpha 100 U/ml of culture medium did not give significant difference in comparison with mean values of percentage LDH release (x = 6.43 +/- 2.97%, for 37 individual experiments) from K-562 cells which were cultured without r h TNF-alpha (Student's t-test, P > 0.05). The results also showed, that in the presence of increasing concentrations of r h TNF-alpha there was no significant increase of LDH release through the cell membrane in these short term incubations. However, significant difference in LDH release from K-562 cells was found after 6 h between cultures treated for 30 min with or without r h TNF-alpha (Mann-Whitney test, P < 0.05). Since TNF-alpha alone shows a lower degree of K-562 cell membrane damage than NK effectors, this suggested that TNF-alpha is neither an only nor a major mediator of cell destruction, based on determination of LDH release.
Jurisić
V
V
Institute for Oncology and Radiology of Serbia, Belgrade, Bosnia & Hercegovina.
Spuzić
I
I
Konjević
G
G
D000328:Adult; D006801:Humans; D020014:K562 Cells / Q000187:drug effects; D007694:Killer Cells, Natural / Q000276:immunology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism*; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D014409:Tumor Necrosis Factor-alpha; D007770:L-Lactate Dehydrogenase