Figure 1. Chemotherapy induces S100A10 expression in vitro and in vivo.

(A and B) Breast cancer cell lines were treated with vehicle (V), paclitaxel (P), or carboplatin (C) for 72 hours at IC₅₀. RT-qPCR (A) and immunoblot (B) assays were performed to analyze S100A10 mRNA and protein expression. mRNA levels were normalized to vehicle-treated MCF7 cells (mean ± SEM; n = 3). *P < 0.05, ***P < 0.001 vs. vehicle in each cell line (1-way ANOVA with Bonferroni’s post hoc test). (C–E) MDA-MB-231 cells were implanted into the mammary fat pad (MFP) of female SCID mice. When tumor volume reached 200 mm³ (day 0), mice were randomly assigned to treatment with vehicle or paclitaxel (10 mg/kg on days 0, 5, and 10). Tumors were harvested on day 13 for RT-qPCR (C; mean ± SEM; n = 3) and immunoblot (D and E) assays. Densitometric analysis of immunoblots (D) was performed and results (E) are presented as mean ± SEM (n = 3). *P < 0.05 vs. vehicle (Student’s t test). (F) MMTV-PyMT–transgenic mice were treated with vehicle or paclitaxel (5 mg/kg on days 0, 5, and 10) when tumors reached a cumulative volume of 150 mm³. Tumors were harvested on day 13 for reverse transcription (RT) and qPCR assay (mean ± SEM; n = 4). *P < 0.05 vs. vehicle (Student’s t test).