In vitro analysis of angiogenesis-potentiated overgrowth of primary erythroleukemic cells. (A) Using the cytokine array findings as a reference, primary erythroleukemic cells, seeded at a density of 1 × 10⁴/mL, were cultured in standard medium with the addition of exogenous VEGF-A, MCP-5, IL-6 (□); VEGF-A and MCP-5 (▪); IL-6 and VEGF-A (○); or media alone (•) as per “Materials and methods.” (B) In separate experiments, erythroleukemic cells were cultured in LDSAC-conditioned media (•) with the addition of neutralizing antibodies to VEGF-A (□), MCP-5 (○), and TNF-α (▪), or in various combinations; only combined inhibition of VEGF-A and MCP-5 (▴) is shown for simplicity. Scoring of live cells occurred every 24 hours by trypan blue exclusion over a 72-hour time course with significance considered between all tested groups to reflect P < .05 (^*). Error bars represent ± standard deviation.