Piplartine induces caspase-mediated apoptosis in PC-3 human prostate cancer cells.
The present study examined the anti-proliferative effects of piplartine on the human prostate cancer cell line PC-3. This is the first report demonstrating the piplartine anti-cancer activity toward prostate cancer cell lines, although its precise mechanism of action is still not completely defined. In MTT assays, it preferentially inhibited growth of androgen-independent PC-3 cells in a dose-dependent (3-30 microM) and time-dependent (12-48 h) manner. In PC-3 cells, it showed an IC50 of 15 microM after 24 h of treatment. After a 24-30 microM treatment for 24 h, there were some reduction of cell volume, cell vacuolization, chromatin condensation and increased number of apoptotic cells visible by light and fluorescence microscopy. Agarose gel electrophoresis revealed that cells treated with piplartine exhibited DNA fragmentation. In addition, growth inhibition of PC-3 cells was associated with G2/M arrest and sub-G1 accumulation. Higher concentrations (24-30 microM) of piplartine modulated apoptosis-related protein expression by down-regulating cdc-2 expression and up-regulating PARP/procaspase-3 cleavage. Also, PC-3 cells treated with piplartine demonstrated caspase-3 activation, as observed with an in vitro caspase-3 colorimetric assay kit. Taken together, these results demonstrated that high concentrations of piplartine exhibited anti-proliferative and anti-cancer effects on PC-3 cells and that caspase-3-mediated PARP cleavage and cell cycle arrest at G2/M phase are involved in the underlying cellular mechanism of the apoptosis process.
Kong
Eun-Hee
EH
Department of Family Medicine, Kosin University Gospel Hospital, Busan, Korea.
Kim
Yun-Jin
YJ
Kim
Young-Jin
YJ
Cho
Hyo-Jin
HJ
Yu
Sun-Nyoung
SN
Kim
Kwang-Youn
KY
Chang
Jeong-Hyun
JH
Ahn
Soon-Cheol
SC
D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D016203:CDC2 Protein Kinase; D053148:Caspase 3 / Q000502:physiology*; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D019926:Cyclin B / Q000032:analysis; D056744:Cyclin B1; D018844:Cyclin-Dependent Kinases; D053938:DNA Fragmentation / Q000187:drug effects; D016195:G2 Phase / Q000187:drug effects; D006801:Humans; D008297:Male; D010881:Piperidones / Q000494:pharmacology*; D011065:Poly(ADP-ribose) Polymerases / Q000502:physiology; D011471:Prostatic Neoplasms / Q000188:drug therapy* / Q000473:pathology; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000032:analysis
D000972:Antineoplastic Agents, Phytogenic; C534699:CCNB1 protein, human; D019926:Cyclin B; D056744:Cyclin B1; D010881:Piperidones; D019253:Proto-Oncogene Proteins c-bcl-2; C498077:piperlongumine; D011065:Poly(ADP-ribose) Polymerases; D016203:CDC2 Protein Kinase; C528899:CDK1 protein, human; D018844:Cyclin-Dependent Kinases; D053148:Caspase 3