Fig. 2.

FSIP1 deficiency promotes chemoresistance in TNBC. (A) MDA-MB-231 and MDA-MB-468 cells expressing shFSIP1 or control (Ctl) shRNA, as well as FSIP1-KO MDA-MB-231 cells, were cultured overnight in 96-well plates (1 × 10³ cells per well) and treated with vehicle, doxorubicin (0.2 µg/mL), or docetaxel (20 µg/mL) (n = 3 per group). MDA-MB-231 cells expressing shFSIP1 or Ctl were also treated with 5-fluorouracil (10 µM) or cyclophosphamide (500 nM). Cell viability was determined after 24 or 48 h (MTS assay). (B) BALB/c nude mice were injected with 1 × 10⁶ Ctl or shFSIP1 MDA-MB-231 cells into their flanks (n = 8 per group). When s.c. tumors grew to 100 to 200 mm³, the mice were randomized and injected i.p. with vehicle or docetaxel (10 mg/kg) on days 1, 7, and 14. Tumor sizes were measured twice a week. On day 21, mice were killed and tumors were dissected and weighed. Docetaxel reduced the size and weight of Ctl, but not FSIP1-silenced, MDA-MB-231 tumors. Mean ± SEM; one-way ANOVA followed by post hoc Newman-Keuls test; *P < 0.05, **P < 0.01.