ISA27 inhibits cell proliferation and induces apoptosis in tumor tissues.

<p>14 days from starting treatment, tumors were harvested from mice of different ISA27 treatment groups (IP = intraperitoneal treatment; IT = intratumor treatment) and processed for histological and Western blotting analysis. <i>A) Histological analysis:</i> apoptosis and cell proliferation were evaluated by analysis of cleaved caspase 3 and PCNA levels by immunohistochemistry in paraffin embedded sections of tumors. Upper panel shows representative images of immunohistochemistry analysis. ISA27-treated tumors show increased cleaved caspase 3 levels and reduced cell proliferation. Cleaved caspase 3 and PCNA levels in tumors were quantified from digital images. Results are shown in graph as percent of cleaved caspase 3 and PCNA expression respect to controls (*P<0.05 <i>vs</i> control). <i>B) Western blotting analysis:</i> apoptosis and cell proliferation were evaluated by analysis of cleaved caspase 3 and phosphorylated histone H3 (pH3) levels by Western blotting in whole lysates of tumors using specific antibodies. Densitometric analysis shows that ISA27 induced a significant increase in cleaved-caspase-3 levels and a significant reduction in pH3 levels (*P<0.05 <i>vs</i> control).