Figure 7. Combination of arginine deprivation with canavanine does not induce apoptosis in normal colon epithelial cells in 3-D organoid/colonosphere culture.

(A) Representative, deconvoluted z-stack phase contrast images of normal colonospheres before and after 3 days of exposure to the indicated treatment conditions; −Arg environment was achieved by supplementation of the regular for colonospheres cell culture medium with 2 U/ml rhARG. Cit and Cav were supplemented to final concentrations of 0.05 mM and 0.1 mM, respectively. Scale bar = 200 μm. (B) Western blots of protein samples extracted from HT29 and normal colonosphere cultures treated as described in (A); protein extracts were probed with anti-c-PARP and anti-ASS1 antibodies; GAPDH was used as loading control.