Figure 1

Acquired chemoresistant cancer cells exhibit aberrant cell-autonomous Hh pathway activity. Representative data from three independent experiments are expressed as mean ± s.d. A, Expressions of Hh pathway ligands SHh, IHh and DHh in acquired chemoresistant cancer cells K562/A02 and KB/VCR compared to their respective parental cancer cells K562 and KB respectively by QT-PCR analysis. B, Gli luciferase reporter activity in chemoresistant K562/A02 and KB/VCR cancer cells and their respective parental cancer cells K562 and KB determined by luciferase reporter assay. The cells (4 × 104) seeded into 48-well plates were transfected with Gli luciferase reporter and pRL-Renilla luciferase plasmids. After transfectinos for 24 h, the cells (around 100% confluency of adherent cells) in culture medium with 10% serum were further treated with tomatidine (10 μM), Robo (10 μM) and cyc (3 μM) for 24 h. C, Expressions of the Hh pathway target genes Gli1 in acquired chemoresistant K562/A02 and KB/VCR cancer cells and their respective parental cancer cells K562 and KB. The cells (2 × 105) were seeded into 6-well plates. After 24 h, the cells (around 100% confluency of adherent cells) in normal culture conditions were treated with tomatidine (10 μM), Robo (10 μM) and cyc (3 μM) for 24 h were collected for examined by QT-PCR analysis. D, Treatment with the Robo circumvents the chemoresistance of K562/A02 cells and KB/VCR cells to Dox and VCR respectively. K562/A02 cells and KB/VCR cells were seeded into 96-well plates and incubated with Dox or VCR supplemented with or without various concentrations of Robo for 72 h.