(A) Quantification of primary tumor volume of cocultures injected in the mammary fat pads of NOD/SCID mice treated with vehicle (–) or with PTX 10 mg/kg every 3 days i.p. for 20 days (n = 3–4 per group). (B) Primary mammary tumors in A were subjected to quantitative fluorescence multiplex immunostaining for pan-CK and FAP to quantify the percent of pan-CK⁺/FAP⁺ hybrid cells. Shown are representative images of vehicle- or PTX-treated tumors. Scale bar: 50 µm. (C) Number of spontaneous lung metastasis per mice per group of mice in A assessed by histopathology. (D) Luc–GFP-231 (1.0 × 10⁵) alone or cocultured with DsRed-MSCs for 72 hours (1.5 × 10⁵ cells) were injected intracardially in NOD/SCID mice. At day 20, mice were treated with DOXO (4 mg/kg every 3 days) or vehicle for 1 week (n = 3-4 per group). Shown are representative images of GFP⁺ lung metastases and bioluminescence images of distant metastases at necropsy in mice treated with DOXO or vehicle. Quantification of the number of metastases in mice using GFP pixels. Scale bar: 20 µm. (E) Schematic illustrating that Luc–GFP-CCN6–KO BCCs (1.0 × 10⁵) alone or with DsRed-MSC were cultured for 5 days and treated with Navitoclax (5 μM for 48 hours). Cells (1 × 10⁵) were intracardially injected in FVB mice. After 2 days control mice were treated with vehicle or PTX 10 mg/kg for 10 days and followed using bioluminescence imaging (BLI). (F) Representative bioluminescence images of metastases at indicated conditions (n = 6–14 per group). For all panels, data are presented as individual values with mean ± SEM. In A–C, the 2-tailed unpaired Student’s t test was employed; in D, 1-way ANOVA with post hoc Tukey HSD/Tukey-Kramer was used; in F, 2-way ANOVA with Tukey’s multiple comparison test was used. *P < 0.05; **P < 0.005; ***P < 0.0005.