Exosomes Derived from Brain Metastatic Breast Cancer Cells Destroy the Blood-Brain Barrier by Carrying lncRNA GS1-600G8.5

Figure 4

Exosomal lncRNA GS1-600G8.5 promotes BBB passage of breast cancer cells. (a) Volcano plot of differentially expressed lncRNAs between brain metastatic and nonbrain metastatic breast cancer cells. Data were obtained from the GSE79540 database [10]. The red dots represent upregulated lncRNAs and the blue dots represent downregulated lncRNAs in the brain metastatic breast cancer cells compared to the nonbrain metastatic breast cancer cells. (b) The top five upregulated lncRNAs were verified by real-time PCR, in MDABR3 high brain metastatic breast cancer cells and MDA231 parental cells (, -test). (c) The top five upregulated lncRNAs were verified by real-time PCR in exosomes derived from MDABR3 and parental MDA231 cells (, -test). (d) The interference effect of GS1-600G8.5 was verified by real-time PCR in exosomes derived from MDABR3 cells transfected with siRNA. The siRNA-2 with the best interference effect was used for further study. One-way ANOVA. (e) GS1-600G8.5-deficient MDABR3 exosomes and control exosomes were added to the BBB system, and the change in the TEER value was detected after 24 h. One-way ANOVA comparison was done. NC: BBB system without any treatment; siNC-Exo: BBB system treated with exosomes derived from MDABR3 cells that were transfected with siRNA NC; silnc-Exo: BBB system treated with exosomes derived from MDABR3 cells that were transfected with siRNA GS1-600G8.5. (f) Permeability was detected in the BBB system. One-way ANOVA comparison was used. (g) BBB system was treated with exosomes for 24 h, MDA231 (PFG-labeled) cells were added to BBB model, and the number of MDA231 cells crossing the BBB was counted after 48 h. Magnification ×200. One-way ANOVA. (h) Western blot was used to detect the expressions of tight junction and adhesive proteins in the BMECs treated with GS1-600G8.5-deprived exosomes and control exosomes. One-way ANOVA comparison was used; , , and .

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