Effects of tumor-associated macrophages on the biological behavior of A375 human malignant melanoma cells / 中华皮肤科杂志

ABSTRACT

Objective To evaluate the effects of tumor-associated macrophages on the proliferation,invasion and migration of human cutaneous malignant melanoma cells.Methods Cultured U937 human monocytic cells at logarithmic phase were classified into three groups to be pretreated with phorbol ester for 48 hours followed by 48-hour activation by phorbol ester (M polarization),lipopolysaccharide (LPS) at 25 mg/L (M1 polarization),and interleukin (IL)-4 at 15 μg/L (M2 polarization) respectively.Then,enzyme-linked immunosorbent assay (ELISA) was performed to determine the levels of IL-12p70 and IL-10 in the supernatant of these activated cells.A375 human malignant melanoma cells were divided into four groups to be cultured alone or with M-,M1-and M2-polarized macrophages respectively.After additional culture for different durations (24,48 and 72 hours),methyl thiazolyl tetrazolium (MTT) assay was conducted to estimate the proliferative activity,and Transwell assay to evaluate the invasion and migration activity,of the A375 cells.Results The proliferation of A375 cells was accelerated by coculture with M-and M2-polarized macrophages,but inhibited by that with M1-polarized macrophages,with significant differences among the four groups in the proliferative activity at 48 and 72 hours (all P ＜ 0.05),but not at 24 hours (P ＞ 0.05).Invasion assay showed that the number of A375 cells that migrated through Transwell chambers was significantly larger in M2 and M groups (147.00 ± 7.92 and 113.22 ± 8.15 respectively),but smaller in the M1 group (56.44 ± 7.55),than in the control group (84.11 ± 6.07,all P ＜ 0.05).Similarly,migration assay revealed a significant increase in the number of A375 cells that migrated through Transwell chambers in the M2 and M(p) groups (198.33 ± 8.22 and 156.00 ± 8.83 respectively),but a significant decrease in the M1 group (97.11 ± 6.75) as compared with the control group (123.89 ± 7.01,all P＜ 0.05).Conclusions The proliferation,invasion and migration of A375 cells can be accelerated by IL-4-activated M2-polarized macrophages,but decelerated by LPS-activated M1-polarized macrophages.Phorbol ester tends to induce monocytic cells to differentiate into M2-polarized macrophages.