Effect of α-bisabolol on migration and invasion of glioblastoma cells

Objective To study the effect of α-bisabolol on migration and invasion of glioblastoma cells and explore its possible mechanism. Methods Human glioblastoma cell lines U251 and U87 were cultured in vitro. CCK8 colorimetric assay was used to detect the changes of cell viability at 24 hours after treatment with different concentrations of α-bisabolol (0 µmol/L, 1.25 µmol/L, 2.5 µmol/L, 5 µmol/L, 10 µmol/L); Cell scratch test, Transwell assay and Western blotting were used to detect the changes of cell migration and invasive ability and changes in the expression of MMP-2, MMP-9 and c-Met protein at 24 hours after treatment with different concentrations of α-bisabolol (0 µmol/L, 1.25 µmol/L, 2.5 µmol/L); U251 cells were divided into four groups: group A(blank plasmid), group B (blank plasmid +2.5 µmol/L α-bisabolol), group C (c-Met over-expressing plasmid) and group D (c-Met over-expressing plasmid +2.5 µmol/L α-bisabolol). At 24 hours after plasmid transfection, 2.5 µmol/L of α-bisabolol was added to group B and D, Cell scratch test, Transwell assay and Western blotting were used to detect cell migration, invasion and expression of c-Met, MMP-2, and MMP-9 proteins in the four groups. Results The cell survival rate of 5 µmol/L, 10μmol/L group was lower than that of 0 µmol/L, 1.25 µmol/L, 2.5μmol/L group (U251: 61.22%±5.08%, 29.48%±4.84% vs 100%±0.00%, 98.16%±5.71%, 96.89±7.30%, P=0.00, U87: 55.72%±8.17%, 19.66%±4.82% vs 100%±0.00%, 97.86%±5.41%, 95.31%±5.42%, P=0.00).The percentage of scratch closure in the 0μmol/L, 1.25μmol/L and 2.5μmol/L groups was 49.36%±5.44%, 35.08%±3.79%, 23.89%±4.51% for U251, and 46.64%±4.83%, 33.42%±3.10%, 22.35%±3.62% for U87. The number of cells invaded the lower chamber was 248.67±14.94, 171.11±17.91, 87.11 ±15.49 for U251, and 202.44±16.98, 145.44±11.91, 71.98±9.32 for U87, the differences between three groups were statistically significant (all P=0.000). c-Met, MMP-2, and MMP-9 protein expression levels were: U251 (c-Met: 1.00±0.00, 0.70±0.09, 0.33±0.08, MMP-2: 1.00±0.00, 0.70±0.08, 0.32±0.10, MMP-9: 1.00±0.00, 0.69±0.09, 0.24±0.07), U87 (c-Met: 1.00±0.00, 0.71±0.08, 0.27±0.08, MMP-2: 1.00±0.00, 0.71±0.10, 0.29±0.04, MMP-9:1.00±0.00, 0.72±0.08, 0.23±0.04), the differences between three groups were statistically significant (all P=0.000). After transfection of c-Met overexpression plasmid, the percentage of scratch closure in group D was significantly higher than that in group B (35.61%±4.70% vs 13.11%±2.99%, P=0.00). The number of cells invaded the lower chamber in group D was significantly higher than that in group B (209.44±18.13 vs 91.33±14.46, P=0.00). The expression of c-Met, MMP-2, and MMP-9 in group D was higher than that in group B (c-met: 0.60±0.04 vs 0.39±0.04; MMP-2: 0.71±0.10 vs 0.49±0.08; MMP-9: 0.73±0.11 vs 0.45±0.07), and the differences were statistically significant (all P=0.000). Conclusion α-Bisabolol can inhibit migration and invasion of glioblastoma cells by down-regulating c-Met.