[The effect of the murine stromal cell line MS-5 on the proliferation and apoptosis of human erythromyeloid leukemic cell line K562].
Effects of stromal environment on human leukemic cell apoptosis and proliferation have been investigated. The MS-5 cell line (kindly provided by Dr.Itoh) capable of supporting human hemopoietic cells and the K562 human erythromyeloid leukemic cell line were used. The total increment of cultured leukemic cells was lower than in control due to their co-cultivation with stromal cells, 96% of cells remaining viable. Colony formation by K562 cells appeared to be significantly lower, too (7.2 vs. 22 colonies per 10(3) cells). Inhibition by stromal cells was reproduced when stromal and leukemic cells were separated by a 0.5% agar layer as well as when leukemic cells were cultured on an agar layer which contained a 50% condition medium. Morphological signs of apoptosis in 78.75 +/- 7.64% of leukemic cells, as a result of serum deprivation, were in evidence after 72 hr. while only 14.33 +/- 3.69% of cells co-cultured with MS-5 died. Only 4% of adherent cells showed morphological signs of programmed death. Since protein bcl-2 was not detected in K562 cells it may be suggested that apoptosis of leukemic cells co-cultured with stromal ones does not use the bcl-2 gene pathway. Stromal cell-mediated inhibition of proliferation may be effected through humoral mechanisms.
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D000818:Animals; D017209:Apoptosis; D002455:Cell Division; D006412:Hematopoietic Stem Cells; D006801:Humans; D007951:Leukemia, Myeloid / Q000473:pathology*; D051379:Mice; D014407:Tumor Cells, Cultured
Vliianie myshinoĭ stromal'noĭ linii MS-5 na proliferatsiiu i apoptoz éritroleĭkemicheskoĭ linii k562.