THC induces apoptosis in primary ALL cells in vitro.

(A) The effect of THC on primary ALL cell viability was determined by culturing the cells for 2 hours in serum-free medium in the presence of various concentrations of THC (1, 5, and 10 μM) or the vehicle. The viable cell number was determined by trypan blue dye exclusion. (B) The effect of THC on the induction of apoptosis in primary ALL cells was determined by TUNEL assay, as described in Figure 2. Tumor cells were cultured as described above with THC (filled histogram) or the vehicle (empty histogram). Apoptosis was quantified using the TUNEL method, and the cells were analyzed using a flow cytometer. The percentage of apoptotic cells following THC exposure is depicted in each histogram.