Immunohistochemistry of i.c. tumor tissue for H&E, Ki67, TK1 and active caspase-3 expression after 2 days of treatment.

<p><b>A.</b> Tumor tissue sections were stained for H&E, Ki67, TK1 and active caspase-3 after 2 days of DMSO or 25 mg/kg TMZ treatment. Scale bars = 50 µm. <b>B.</b> Quantification of Ki67, TK1 and active caspase-3 staining. Differences between the treated (black triangles) and control (white triangles) groups were tested for significance using T-Test or Mann-Whitney Rank Sum Test (**: <i>P</i><0.01, NS: not significant). Ki67 positive cells were less numerous in tumors treated with TMZ vs. DMSO. No significant difference could be observed on the TK1 staining. Active caspase-3 was induced in TMZ treated tumors.