TY - JOUR
T1 - Down-regulation of procaspase-8 expression by focal adhesion kinase protects HL-60 cells from TRAIL-induced apoptosis
AU - Tamagiku, Yuji
AU - Sonoda, Yoshiko
AU - Kunisawa, Mari
AU - Ichikawa, Daiju
AU - Murakami, Yayoi
AU - Aizu-Yokota, Eriko
AU - Kasahara, Tadashi
N1 - Funding Information:
We thank Keiko Suzuki and Shinya Motonaga for their technical assistance. This study was supported by grants (13672398 and 14572066) from the MEXT, Japan.
PY - 2004/10/15
Y1 - 2004/10/15
N2 - We have demonstrated that focal adhesion kinase (FAK)-overexpressed (HL-60/FAK) cells have marked resistance against various apoptotic stimuli such as hydrogen peroxide, etoposide, and ionizing radiation compared with the vector-transfected (HL-60/Vect) cells. HL-60/FAK cells are highly resistant to TRAIL-induced apoptosis, while original HL-60 or HL-60/Vect cells were sensitive. TRAIL at 500 ng/ml induced significant DNA fragmentation, activation of caspase-8 and 3, the processing of a proapoptotic BID, and mitochondrial release of cytochrome c in HL-60/Vect cells, whereas no such events were observed in the HL-60/FAK cells. In particular, the expression of procaspase-8 gene and subsequent cleavage of caspase-8 were markedly reduced in HL-60/FAK cells, while expression of TRAIL-receptor 2 and 3, TRADD, and FADD was equivalent in both types of cells. In HL-60/FAK cells, the phosphoinositide 3 (PI3)-kinase/Akt survival pathway was constitutively activated, accompanied by significant induction of inhibitor-of-apoptosis proteins, XIAP, RIP, and Bcl-Xl. The introduction of FAK siRNA in HL-60/FAK cells sensitized them against TRAIL-induced apoptosis, confirming that overexpressed FAK downregulates procaspase-8 expression, which subsequently inhibits downstream apoptosis pathway in the HL-60/FAK cells.
AB - We have demonstrated that focal adhesion kinase (FAK)-overexpressed (HL-60/FAK) cells have marked resistance against various apoptotic stimuli such as hydrogen peroxide, etoposide, and ionizing radiation compared with the vector-transfected (HL-60/Vect) cells. HL-60/FAK cells are highly resistant to TRAIL-induced apoptosis, while original HL-60 or HL-60/Vect cells were sensitive. TRAIL at 500 ng/ml induced significant DNA fragmentation, activation of caspase-8 and 3, the processing of a proapoptotic BID, and mitochondrial release of cytochrome c in HL-60/Vect cells, whereas no such events were observed in the HL-60/FAK cells. In particular, the expression of procaspase-8 gene and subsequent cleavage of caspase-8 were markedly reduced in HL-60/FAK cells, while expression of TRAIL-receptor 2 and 3, TRADD, and FADD was equivalent in both types of cells. In HL-60/FAK cells, the phosphoinositide 3 (PI3)-kinase/Akt survival pathway was constitutively activated, accompanied by significant induction of inhibitor-of-apoptosis proteins, XIAP, RIP, and Bcl-Xl. The introduction of FAK siRNA in HL-60/FAK cells sensitized them against TRAIL-induced apoptosis, confirming that overexpressed FAK downregulates procaspase-8 expression, which subsequently inhibits downstream apoptosis pathway in the HL-60/FAK cells.
KW - Caspase-8
KW - Focal adhesion kinase
KW - Phosphoinositide-3-kinase
KW - TNF-related apoptosis-inducing ligand
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U2 - 10.1016/j.bbrc.2004.08.115
DO - 10.1016/j.bbrc.2004.08.115
M3 - Article
C2 - 15369772
AN - SCOPUS:4544224151
SN - 0006-291X
VL - 323
SP - 445
EP - 452
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 2
ER -