Induction of apoptosis by acyclic retinoid in the human hepatoma-derived cell line, HuH-7.

HuH-7 cells, a human hepatoma-derived cell line, underwent apoptosis in response to all-trans 3, 7, 11, 15-tetramethyl- 2, 4, 6, 10, 14-hexadecapentaenoic acid, or acyclic retinoid. The retinoid-induced apoptosis was verified by a characteristic step-wise fragmentation of genomic DNA and chromatin condensation. The induction of apoptosis was detected as early as 8 hrs after the addition of the retinoid and was concentration dependent (0.1-10 microM). Neither the natural retinoid all-trans retinoic acid nor 9-cis retinoic acid induced apoptosis. These data strongly indicate that the antitumor activity of the acyclic retinoid may be partly explained by the induction of apoptosis in tumor cells.