Anti-apoptotic effects of curcumin on photosensitized human epidermal carcinoma A431 cells

2004 ◽  
Vol 92 (1) ◽  
pp. 200-212 ◽  
Author(s):  
Wen-Hsiung Chan ◽  
Hsin-Jung Wu
Keyword(s):  
A431 Cells ◽  
Apoptotic Effects ◽  
Epidermal Carcinoma

Apoptotic signalling cascade in photosensitized human epidermal carcinoma A431 cells: involvement of singlet oxygen, c-Jun N-terminal kinase, caspase-3 and p21-activated kinase 2

2000 ◽  
Vol 351 (1) ◽  
pp. 221-232 ◽  
Author(s):  
Wen-Hsiung CHAN ◽  
Jau-Song YU ◽  
Shiaw-Der YANG
Keyword(s):  
Singlet Oxygen ◽  
Caspase 3 ◽  
Early Stage ◽  
A431 Cells ◽  
Caspase Family ◽  
P21 Activated Kinase ◽  
Induced Apoptosis ◽  
Jnk Activation ◽  
Epidermal Carcinoma ◽  
Signalling Cascade

Photodynamic treatment (PDT) elicits diverse cellular responses and can also cause apoptosis. In the present study the cascade of signalling events involved in PDT-induced apoptosis was investigated using Rose Bengal (RB) as the photosensitizer, and human epidermal carcinoma A431 cells as the cell model. We show that a 36-kDa kinase detected by an in-gel kinase assay is markedly activated during PDT-triggered apoptosis. Immunoblot analysis revealed that this 36-kDa kinase represents the C-terminal catalytic fragment of p21-activated kinase (PAK)2. Generation of this active fragment of PAK2 is mediated by the caspase family of proteases, which are activated by PDT. The specific caspase inhibitors (acetyl-Asp-Glu-Val-Asp-aldehyde and acetyl-Tyr-Val-Ala-Asp-chloromethylketone) block the PDT-induced caspase-3 activation and subsequent PAK2 cleavage/activation, indicating a major role for the caspase family proteases in PDT-induced apoptosis. Both PDT-induced caspase-3 activation and PAK2 cleavage/activation can be inhibited by the singlet oxygen scavengers, L-histidine and α-tocopherol, but not the hydroxyl radical scavenger, mannitol, demonstrating that singlet oxygen is an immediate early-apoptotic signal generated by PDT. In addition, PDT can induce a two-stage activation of the c-Jun N-terminal kinase/stress-activated protein kinase (JNK/SAPK) in A431 cells; the early-stage JNK activation is singlet oxygen-dependent, whereas the late-stage JNK activation is mediated by the singlet oxygen-triggered caspase activation. Experiments using anti-sense oligonucleotides against JNK1 and PAK2 further show that during PDT-induced apoptosis the early-stage JNK activation is required for caspase activation, and that the late-stage JNK activation is regulated by the caspase-mediated cleavage/activation of PAK2. Collectively, a model for the PDT-triggered apoptotic signalling cascade with RB is proposed, which involves singlet oxygen, JNK, caspase-3 and PAK2, sequentially.

Regulation of the calcium-channelI min/I crac activity in human epidermal carcinoma A431 cells

2000 ◽  
Vol 32 (3) ◽  
pp. 149-149
Author(s):  
K. O. Gusev ◽  
E. V. Kaznacheyeva ◽  
A. N. Zubov ◽  
G. N. Mozhayeva
Keyword(s):  
A431 Cells ◽  
Epidermal Carcinoma

Hypericin is an encouraging new photosensitizer for photodynamic therapy of esophageal dysplasia/cancer: Antiproliferative and apoptotic effects

2001 ◽  
Vol 120 (5) ◽  
pp. A443-A443
Author(s):  
M LENZ ◽  
M HOEPFNER ◽  
A THEISS ◽  
B LAMPE ◽  
H KASHTAN ◽  
...  
Keyword(s):  
Photodynamic Therapy ◽  
Esophageal Dysplasia ◽  
Apoptotic Effects
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