Figure 2

DNP-induced NPC cell metastasis in vitro and vivo . A, To determine DNP-induced invasion and motility, a Matrigel-coated Boyden chamber was used to measure 6-10B cell invasion, and an uncoated chamber for measuring cell motility. The cells invading to the lower surface of Boyden chamber membrane were fixed with methanol and stained with hematoxylin and eosin. a, 6-10B treated with 0.01% DMSO-PBS in Matrigel-coated Boyden chamber; b, 6-10B cells treated with DNP (6 μM) in Matrigel-coated Boyden chamber; Scale bar, 5 μm; c, 6-10B cells treated with 0.01% DMSO-PBS in the uncoated chamber; d, 6-10B cells treated with DNP in the uncoated chamber. Scale bar, 10 μm. Arrows, The invading cells. B, In concentration-course assays, 6-10B cells were treated with 2, 4, 6, and 8 μM DNP for 24 h. The motility and invasion of the treated cells were analyzed. Random fields were counted to determine the number of invaded cells under a light microscope. a, Invasion of 6-10B cells at various concentrations; b, Motility of 6-10B cells at various concentrations. The results were statistically analyzed by one-way analysis of variance (ANOVA) with post-hoc Dunnett’s test (*, p < 0.05). C, In animal experiments, 20 nude mice were randomly divided into 2 groups with 10 mice per group. One group was injected with DNP-treated 6-10B cells in Matrigel through the tail vein (1 × 10⁴ cells/mouse). The other group was injected with untreated 6-10B cells. After 60 days, metastatic tumors nodes in the lungs were observed under the microscope (*, p < 0.05).