Matrine inhibits the migratory and invasive properties of nasopharyngeal carcinoma cells

Abstract

Matrine is a widely used Chinese herbal medicine that has historically been used in the treatment of inflammation and cancer. However, the antimetastatic effects and associated molecular mechanisms of matrine on nasopharyngeal carcinoma (NPC) remain to be elucidated. Therefore, the aims of the present study were to assess the antimetastatic effects of matrine on NPC, and identify the underlying mechanisms. Matrine inhibited the proliferation of NPC cells in vitro and in vivo. Furthermore, matrine inhibited the migration and invasion of NPC tumor cells at doses below the toxic range. Following treatment with matrine for 24 h, there was a decrease in the protein expression levels and activities of matrix metalloproteinase (MMP)‑2 and MMP‑9 in NPC‑039 cells. In addition, matrine markedly reduced the expression levels of p65 and p50 in the nuclei. Combined treatment of matrine with helenalin, a nuclear factor‑κB (NF‑κB) inhibitor resulted in a synergistic reduction in MMP‑2 and MMP‑9 expression levels, and the invasive capabilities of the NPC‑039 cells were also reduced. In conclusion, matrine inhibits NPC cell migration and invasion by suppressing the NF‑κB pathway. These results suggest that matrine may be a potential therapeutic agent for NPC.

Figure 1

Cellular viability of NPC-039 and CNE-2Z nasopharyngeal carcinoma cells treated with matrine. (A) NPC-039 and (B) CNE-2Z cells were treated with matrine, and incubated for 24, 48 and 72 h, after which the cell viability was measured using an 3-(4, 5-dimethylthiazol-2-yl) 2, 5-diphenyltetrazolium bromide assay. The data represent the mean ± standard deviation of three independent experiments, each performed in triplicate. ^*P<0.05 and ^**P<0.01, compared with the untreated control group at 24 h; ^#P<0.05 and ^##P<0.01, compared with the control group at 48 h; ^&P<0.05 and ^&P<0.01, compared with the control group at 72 h.

Figure 2

Effects of matrine on the in vitro invasion of NPC-039 nasopharyngeal carcinoma cells. (A) NPC-039 cells underwent a migration assay. Cells were cultured in media supplemented with 2% fetal bovine serum (FBS) and treated with various concentrations of matrine (0, 12.5, 25 and 50 μg/ml). Images were captured at 0 and 24 h. (B) Rate of migration was expressed as a percentage of the control (0 μg/ml). (C) NPC-039 cells underwent an invasion assay. Cells pre-incubated with various concentrations of matrine (0, 12.5, 25 and 50 μg/ml) were plated onto the upper wells of a chamber. FBS (10%) was added to the bottom wells for 24 h, to induce cell invasion. Following a 24 h incubation, the cells on the bottom side of the filter were fixed, stained in crystal violet and measured. Spontaneous migration in dimethyl sulfoxide was designated as control (magnification, ×100). (D) The rate of invasion was expressed as a percentage of the control (0 μg/ml). The data represent the mean ± standard deviation of three independent experiments. ^*P<0.05 and ^**P<0.01, compared with the control group.

Figure 3

Matrine suppresses the expression of matrix metalloproteinase (MMP)-2 and MMP-9 in NPC-039 nasopharyngeal carcinoma cells. (A) NPC-039 cells were treated with matrine (0, 12.5, 25 and 50 μg/ml) for 24 h and then subjected to western blotting, to analyze the protein expression levels of MMP-2 and MMP-9. (B) Quantification of the protein expression levels of MMP-2 and MMP-9 in NPC-039 cells. (C) Effects of matrine on the acivities of MMP-2 and MMP-9. (D) Quantification of the activities of MMP-2 and MMP-9 in NPC-039 cells. The data represents the mean ± standard deviation of three independent experiments, performed in triplicate. ^*P<0.05 and ^**P<0.01, compared with the control group.

Figure 4

Expression levels of nuclear factor (NF)-κB-related proteins following treatment with matrine, and the effects of the NF-κB inhibitor helenalin and matrine on cell invasion and matrix metaloproteinase (MMP)-2 and MMP-9 protein expression in NPC-039 nasopharyngeal carcioma cells. (A) Inhibitory effects of matrine on p50 and p65 nuclear translocation. Cells were pretreated with matrine for 12 h. Nuclear and whole cell lysate proteins were prepared and analyzed by western blotting, with Histone H1 serving as a loading control. (B) Quantification of p50 and p65 nuclear translocation. (C) Cells were pretreated with helenalin (5 μM) for 30 min and then incubated in the presence or absence of matrine (25 μg/ml) for 24 h. Cellular invasiveness was measured using a Boyden chamber invasion assay and cells were stained with crystal violet. Control group, cells were left untreated (magnification, ×100). (D) The rate of invasion was expressed as a percentage of control. (E and F) NPC-039 cells were treated and then subjected to western blotting to analyze the protein expression levels of MMP-2 and MMP-9. The data represents the mean ± standard deviation of three independent experiments, performed in triplicate. ^*P<0.05 and ^**P<0.01, compared with the control group.

Figure 5

In vivo growth inhibition of implanted NPC-039 nasopharyngeal carcinoma cells in nude Balb/c mice by matrine. NPC-039 cells were implanted subcutaneously into nude mice. Mice were treated with or without matrine by intraperitoneal injection (60 mg/kg/day). (A) The relative tumor volume and (B) final tumor weight of control and matrine-treated mice impanted with NPC-039 cells. ^*P<0.05 and ^**P<0.01, compared with vehicle treatment.