J Clin Invest.
Autophagy is essential for cannabinoid antitumoral action.
(A) Effect of peritumoral THC administration on the growth of
Atg5+/+ (upper panel) and
Atg5–/– (lower panel)
RasV12/T-large antigen MEF tumor xenografts generated in nude mice
(mean ± SD; n = 7 for each condition). Photographs
show representative images of vehicle- and THC-treated tumors. (B)
Left: Effect of THC administration on LC3 immunostaining (green) and apoptosis as
determined by TUNEL (red) in Atg5+/+ and
Atg5–/– MEF tumor
xenografts. Representative images from 1 vehicle-treated and 1 THC-treated
Atg5–/– tumors are
shown. Right: Bar graphs show the percentage of TUNEL-positive nuclei and cells
with TUNEL-positive nuclei and LC3 dots relative to the total number of nuclei in
each section (mean ± SD). Eighteen sections were counted from 3
dissected tumors for each condition (vehicle-treated and THC-treated). Scale bar:
50 μm. (C) Schematic of the proposed mechanism of
THC-induced cell death (see text for details). **P < 0.01
compared with vehicle-treated tumors.