['We have previously reported the crucial roles of oncogenic Kirsten rat sarcoma viral oncogene homolog (KRAS) in inhibiting apoptosis and disrupting cell polarity via the regulation of phosphodiesterase 4 (PDE4) expression in human colorectal cancer HCT116 cells in three-dimensional cultures (3DC). Herein we evaluated the effects of resveratrol, a PDE4 inhibitor, on the luminal cavity formation and the induction of apoptosis in HCT116 cells.', 'Apoptosis was detected by immunofluorescence using confocal laser scanning microscopy with an antibody against cleaved caspase-3 in HCT116 cells treated with or without resveratrol in a two-dimensional culture (2DC) or 3DC.', 'Resveratrol did not induce apoptosis of HCT116 cells in 2DC, whereas the number of apoptotic HCT116 cells increased after resveratrol treatment in 3DC, leading to formation of a luminal cavity.'] Does resveratrol induce luminal apoptosis of human colorectal cancer HCT116 cells in three-dimensional culture?