[Effect of leukoreduction on tumor-associated cytokine accumutation in supernatant of stored packed red cells and its effect on tumor cell proliferation in vitro].

Objective: This study was to investigate whether prestorage leukoreduction could decrease the accumulative concentration of tumor-associated cytokines in supernatant of stored packed red blood cells (pRBC) and to study the effect of prestorage leukoreduction on proliferation of HepG2 tumor cells by in vitro. The leukoreduced (LR) and non-leukoreduced (NLR) pRBC were equally obtained from one donation and were stored under 2 °C-6°C. The supernatants of pRBC in these two group were performed by centrifugation with 1 006×g for 10 min at day 0 and 35 d. The enzyme-linked immunosorbent assay (ELISA) was used to detect the expression of normal T cells and secretory factor (RANTES/CCL5), as well as the accumulative concentrations of tumor-necrosis factor (TNF-α), platelet derived growth factor (PDGF), vascular endothelial growth factor (VEGF) and monocyte chemotactic protein-1 (MCP-1) in pRBC supernantant of above-mentioned two groups. After HepG2 cells was cultured with the supernatant of NLR-pRBC and LR-pRBC at the end of day 35 together for 48 hours, the methyl thiazolil tetracolium (MTT) method was used to measure the proliferation of tumor cells in vitro.

Results: The accumulative concentration of 5 cytokines in supernatants of above menthioned two groups increased in different degrees along with the prolongation of storage time,that is, the accumulative concentrations of 5 cytokines at 35 d were higher than that at day 0, in which the change of VEGF accumu-lative concentration showed statistical significance, its accumulative concentration in NLR group at day 35 elevated to 549.61 ± 299.43 pg/ml, and was higher than that in LR group (95.46 ± 110.87 pg/ml) (P < 0.05). The experiment of HepG2 cell proliferation indicated that the supernatant of LR pRBC group produced less proliferation of tumor cells with OD value 0.40 (95% CI, 0.38-0.42) than that of NLR pRBC group with OD value 0.49 (95% CI, 0.43-0.55) (P < 0.05).

Conclusion: The prestorage leukoreduction has been confirmed to decrease the accumulative level of cytokines, particalarly decrease the accumulative level of VEGF, moreover, it may be a factor for inhibiting the proliferation of tumor cells in vitro.