Halenaquinone, a novel phosphatidylinositol 3-kinase inhibitor from a marine sponge, induces apoptosis in PC12 cells.
In nerve growth factor-treated PC12 cells, 12b-methyl-(S)-1H-benzo[6,7]phenanthro[10,1-bc]furan-3,6,8,11(2H,12bH)-tetrone (halenaquinone) caused cytotoxicity in a concentration-dependent manner (EC(50) value; 10 microM). Gel electrophoretic DNA analysis of PC12 cells treated with halenaquinone (10 microM) and 11-(acetyloxy)-1,6b,7,8,9a,10,11,11b-octahydro-1-(methoxymethyl)-9a,11b-dimethyl-[1S-(1 alpha,6b alpha,9a beta,11 alpha,11b beta)]-3H-furo[4,3,2-de]indeno[4,5-h]-2-benzopyran-3,6,9-trione (wortmannin) (3 microM) showed a typical apoptotic DNA ladder. In the flow cytometric analysis, halenaquinone caused apoptosis in a concentration- and time-dependent manner (EC(50) value; 10 microM), whereas 2,3-dihydro-12b-methyl-(S)-1H-benzo[6,7]phenanthro[10,1-bc]furan-6,8,11(12bH)-trione (xestoquinone) with the methylene group at the C-3 position failed to cause apoptosis, suggesting that the carbonyl group at the C-3 position in halenaquinone is important for exerting apoptotic effects in PC12 cells. Phosphatidylinositol 3-kinase was inhibited by halenaquinone (IC(50) value; 3 microM) as well as wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase. Halenaquinone inhibited phosphatidylinositol 3-kinase activity at lower concentrations than those at which it induced apoptosis in PC12 cells. These results suggest that halenaquinone causes the death of PC12 cells through an apoptotic process and that the mechanism of halenaquinone-induced apoptosis may be partially explained by the inhibition of phosphatidylinositol 3-kinase activity.
Fujiwara
H
H
Department of Pharmaceutical Molecular Biology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Aramaki, Aoba-ku, Sendai 980-8578, Japan.
Matsunaga
K
K
Saito
M
M
Hagiya
S
S
Furukawa
K
K
Nakamura
H
H
Ohizumi
Y
Y
D000111:Acetylcysteine / Q000494:pharmacology; D000730:Androstadienes / Q000737:chemistry / Q000494:pharmacology; D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D015153:Blotting, Western; D048429:Cell Size / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D053938:DNA Fragmentation / Q000187:drug effects; D005434:Flow Cytometry; D008856:Microscopy, Fluorescence; D008858:Microscopy, Phase-Contrast; D020932:Nerve Growth Factor / Q000494:pharmacology; D016716:PC12 Cells; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D000081082:Phosphoinositide-3 Kinase Inhibitors; D010766:Phosphorylation / Q000187:drug effects; D011161:Porifera; D011233:Precipitin Tests; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D011809:Quinones / Q000737:chemistry / Q000494:pharmacology*; D051381:Rats; D000077191:Wortmannin
D000111:Acetylcysteine; D000730:Androstadienes; D020932:Nerve Growth Factor; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins; D051057:Proto-Oncogene Proteins c-akt; D011809:Quinones; D000077191:Wortmannin; C430084:halenaquinone; C068501:xestoquinone