Apoptosis of HL-60 leukemia cells induced by the bisindole alkaloids sungucine and isosungucine from Strychnos icaja.
Sungucine and isosungucine are two bisindole alkaloids isolated from the roots of the African plant Strychnos icaja Baillon. They both exhibit antiplasmodial activities but also show cytotoxic effects against human cancer cell lines. In order to elucidate their mechanism of action, we have investigated the interaction of the alkaloids with DNA and their capacity to inhibit nucleic acids and protein synthesis in the human HL-60 promyelocytic leukemia cell line. Cell treatment with both sungucine and isosungucine leads to the appearance of a hypo-diploid DNA content peak. Western blotting analysis reveals that the two alkaloids induce cleavage of the poly(ADP-ribose) polymerase (PARP) and promote the cleavage of a caspase-3 DEVD peptide substrate. The activation of the caspase cascade is accompanied with a fragmentation of DNA in cells, as revealed by the TUNEL assay. Altogether, the results shed light on the mechanism of action of these two plant alkaloids and identify signaling factors involved in (iso)sungucine-induced apoptosis in HL-60 cells.
Lansiaux
Amélie
A
INSERM U-524 et Centre Oscar Lambret, Lille, France.
Bailly
Christian
C
Houssier
Claude
C
Colson
Pierre
P
De Pauw-Gillet
Marie-Claire
MC
Frédérich
Michel
M
Tits
Monique
M
Angenot
Luc
L
D000972:Antineoplastic Agents, Phytogenic / Q000302:isolation & purification / Q000494:pharmacology*; D017209:Apoptosis; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects; D002843:Chromatin / Q000187:drug effects; D004247:DNA / Q000187:drug effects / Q000378:metabolism; D053938:DNA Fragmentation / Q000187:drug effects; D004354:Drug Screening Assays, Antitumor; D004789:Enzyme Activation / Q000187:drug effects; D018922:HL-60 Cells; D006801:Humans; D026121:Indole Alkaloids / Q000302:isolation & purification / Q000494:pharmacology*; D007938:Leukemia / Q000473:pathology; D029541:Loganiaceae / Q000737:chemistry*; D019384:Nucleic Acid Synthesis Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000302:isolation & purification / Q000494:pharmacology; D013331:Strychnine
D000972:Antineoplastic Agents, Phytogenic; D002843:Chromatin; D026121:Indole Alkaloids; D019384:Nucleic Acid Synthesis Inhibitors; D011500:Protein Synthesis Inhibitors; C464957:isosungucine; C464946:sungucine; D004247:DNA; C505407:CASP3 protein, human; D053148:Caspase 3; D020169:Caspases; D013331:Strychnine