Figure 6.

Downregulation of DDIT4‐AS1 improves sensitivity of breast cancer cells to paclitaxel in vivo. a,b) MDA‐MB‐231 cells with stable expression of a DDIT4‐AS1‐targeted shRNA or a nontargeting shRNA were subcutaneously injected into nude mice. The mice were randomly divided into four groups: shNT+vehicle, shNT+ paclitaxel, shDDIT4‐AS1+vehicle, shDDIT4‐AS1+PTX, and 10 mg kg⁻¹ PTX was given intraperitoneally once every 3 days, and tumor volumes were measured on the days as indicated. After 2 weeks, the mice were sacrificed and tumor weights were examined. The values are presented as mean ± s.d. (n = 5), *p < 0.05, **p < 0.01; two‐way ANOVA. c) The effect of treatment on mice body weight. d,e) qPCR analysis of DDIT4‐AS1 and DDIT4 mRNA expression in the MDA‐MB‐231 xenografts following the indicated treatment. β‐actin was the internal control. *p < 0.05. f) WB analysis of the indicated protein expression in the MDA‐MB‐231 xenografts following the indicated treatment. ***p < 0.001. g) Representative Ki67, DDIT4, and LC3 staining and quantitative analysis of orthotopic xenograft sections from DDIT4‐AS1 downregulation and control groups treated with or without PTX. Scale bar, 200 µm. *p < 0.05, ***p < 0.001.