Dihydrotanshinone I (DHTS) was previously reported to exhibit the most potent anti-cancer
activity among several tanshinones in colon cancer cells. Its cytotoxic action was reactive oxygen species
(ROS) dependent but p53 independent.
Purpose: To further study the anti-cancer activity of DHTS and its molecular mechanisms of action in colon
cancer both in vitro and in vivo.
Methods: Caspase activity was detected by fluorescence assay. Apoptosis was detected by flow cytometry and
TUNEL assay. Protein levels were analyzed by western blotting. Knockdown of target gene was achieved by
siRNA transfection. Formation of LC3B puncta and activation of caspase-3 were detected by confocal fluorescence
microscope. In vivo anti-colon cancer activity of DHTS was observed in xenograft tumors in NOD/SCID
mice