Research Paper Advance Articles

Exosomal miRNA-205 promotes breast cancer chemoresistance and tumorigenesis through E2F1

M/T-Exo miRNA-205 enhances the tamoxifen resistance in vivo. (A) Tumor growth curves of mice injected with the negative control miRNA-205 inhibitor (NCi), miRNA-205 inhibitor (205i), or lentiviral vector carrying E2F1 (E2F1). (B) Tumor growth curves of mice injected with M/T-Exo when the tumor size was around 50 mm3. (C) Tumor growth curves of mice injected with tamoxifen when the tumor size was around 100 mm3. (D). Representative images of the tumor. (E) After all treatments, the expression of miRNA-205 in tumors of mice on day 9 post-tamoxifen treatment. (F–G). The mRNA and protein expressions of E2F1 in tumors of mice on day 9 post-tamoxifen treatment. (H). The protein expressions of cleaved caspase-9 and caspase-3, Akt, and the phosphorylation of Akt at Ser 473 (p-Akt Ser 473) in tumors of mice on day 9 post-tamoxifen treatment. Values are means ± SD. *P **P ***P

Figure 7. M/T-Exo miRNA-205 enhances the tamoxifen resistance in vivo. (A) Tumor growth curves of mice injected with the negative control miRNA-205 inhibitor (NCi), miRNA-205 inhibitor (205i), or lentiviral vector carrying E2F1 (E2F1). (B) Tumor growth curves of mice injected with M/T-Exo when the tumor size was around 50 mm3. (C) Tumor growth curves of mice injected with tamoxifen when the tumor size was around 100 mm3. (D). Representative images of the tumor. (E) After all treatments, the expression of miRNA-205 in tumors of mice on day 9 post-tamoxifen treatment. (FG). The mRNA and protein expressions of E2F1 in tumors of mice on day 9 post-tamoxifen treatment. (H). The protein expressions of cleaved caspase-9 and caspase-3, Akt, and the phosphorylation of Akt at Ser 473 (p-Akt Ser 473) in tumors of mice on day 9 post-tamoxifen treatment. Values are means ± SD. *P < 0.05, **P < 0.01, ***P < 0.001. At least three replicates were available for analysis in each treatment group.