Figure 3.

The antiproliferative effect of the Δ-Ru1/Dox combination in MCF-7 cells and multicellular tumor spheroids (MCTSs). Cells were treated with Δ-Ru1 (20 μM) alone, Dox (2 μM) alone or in combination for 24 h. (A) Viability of MCF-7 cells observed by fluorescence microscopy after incubating with Calcein AM (λ ex = 488 nm, λ em = 520 ± 20 nm). Scale bar 200 μm. (B) MCF-7 MCTSs imaged with the dye Calcein AM after drug treatment for 24 h. MCF-7 cells in a total of 1 × 10⁴ cells cultured for 72 h. Scale bar 200 μm. (C) MCTSs incubated with the drug by increasing days. The MCTSs incubated with Δ-Ru1 (20 μM) alone, Dox (2 μM) alone, or the Δ-Ru1/Dox combination observed under fluorescence microscope. Scale bar 200 μm. (D) Relative diameter change of MCTSs. The MCTSs diameter on the day of the initial treatment was set as 100%. *p < 0.05, **p < 0.01.