Valrubicin (AD-32) (AD 32) inhibits TPA- and PDBu-induced PKC activation (IC50s: 0.85 and 1.25 μM) and has antitumor and anti-inflammatory activity.

PKC (PDBu-induced):1.25 μM, PKC (TPA-activated):0.85 μM

UMSCC5 cells exposed to Valrubicin (2 μM for 3 h), a single dose of radiation (400 cGy), or the combined treatment are cultured for a further 12, 24, or 48 hours. At these times, the cells are collected by trypsinization (0.25%), washed in PBS, and fixed at 5 × 10^6 cells/mL with 95% ethanol. Cells are incubated with ribonuclease (50 μg; 70-90 Kunitz units/mg for 30 min), and the resulting pellet resuspended in and incubated with propidium iodide (0.05 mg/mL for 10 min). The DNA content of the samples is determined by flow cytometry according to standard technique [2].

Hamsters with cheek pouch tumors of 100 mm2 are randomly assigned to one of five treatment groups. Momentarily anesthetized animals each receives once a week × 3 injections (27 g × 0.5-inch needle: 0.1 mL administered slowly to the base of the lesion) of Valrubicin (3, 6, or 9 mg) or drug vehicle (Cremophor: alcohol;1:1 by volume; NaCl diluent 12). A further group of animals receives anesthesia but no direct tumor treatment (control). Individual tumor sizes are measured with calipers at weekly intervals for 4 weeks, at which time the animals are sacrificed [2].