Fig. 3

Cytotoxic effect of H₂O₂ on HT1376_T and HT1376_sT cells. a: cells were treated with 5 mM H₂O₂ or mock-treated as described in Methods and counted. Data of six experiments are reported. The HT1376_sT cells are more susceptible to the toxic effect of H₂O₂ (**p = 0.005 according to Student’s t test). b: phase contrast micrograph of representative fields of the two cell populations treated as described above, showing the stronger cytotoxic effects of H₂O₂ on HT1376_sT. Scale bar: 100 μm