Figure 5. 3T3-A-EXO promotes 3LL tumor cell metastasis in vivo via MMP3/MMP9 axis.

(A, B) 3LL cells were treated with 30 μg/ml 3T3-EXO or 3T3-A-EXO for 4 h. Then, 1×10⁶ tumor cells were intravenously injected into mice, and these mice were euthanized 15 days later. Lung tumor foci were statistically analyzed (n = 6) (A). The weights of lungs were statistically analyzed (n = 6) (B). (C, D) 3LL cells were treated with 30 μg/ml NC 3T3-A-EXO or MMP3KD 3T3-A-EXO for 4 h. Then, 1×10⁶ tumor cells were intravenously injected into mice, and these mice were euthanized 15 days later. Lung tumor foci were statistically analyzed (n = 6) (C). The weights of lungs were statistically analyzed (n = 6) (D). (E) MMP9 protein levels in 3LL cells stably transfected with NC or MMP9 shRNA were detected by Western blot. (F, G) 3LL cells stably transfected with MMP9 shRNA were treated with 30 μg/ml 3T3-EXO or 3T3-A-EXO for 4 h. Then, 1×10⁶ tumor cells were intravenously injected into mice, and these mice were euthanized 15 days later. Lung tumor foci were statistically analyzed (n = 6) (F). The weights of lungs were statistically analyzed (n = 6) (G). (A-D, F, G) The results are shown as the mean ± SEM of three independent experiments. (E) One representative of three independent experiments is shown. P-values were generated by one-way ANOVA, followed by Tukey-Kramer multiple comparisons test; **p< 0.01; ***p< 0.001; NS, not significant. Control indicates 3LL cells treated with PBS in (A-D) and 3LL cells with MMP9 KD treated with PBS in (F, G), respectively.