Targeted delivery of a designed sTRAIL mutant results in superior apoptotic activity towards EGFR-positive tumor cells.
J Mol Med (Berl)
; 86(8): 909-24, 2008 Aug.
Article
em En
| MEDLINE
| ID: mdl-18504532
ABSTRACT
Previously, we have shown that epidermal growth factor receptor (EGFR)-selective delivery of soluble tumor necrosis factor-related apoptosis-inducing ligand (sTRAIL), by genetic fusion to antibody fragment scFv425, enhances the tumor-selective pro-apoptotic activity of sTRAIL. Insight into the respective contribution of the agonistic receptors TRAIL-R1 and TRAIL-R2 to TRAIL-induced apoptosis may provide a rational approach to further optimize TRAIL-based therapy. Recently, this issue has been investigated using sTRAIL mutants designed to selectively bind to either receptor. However, the relative contribution of the respective TRAIL receptors, in particular TRAIL-R1, in TRAIL signaling is still unresolved. Here, we fused scFv425 to designed sTRAIL mutant sTRAILmR1-5, reported to selectively activate TRAIL-R1, and investigated the therapeutic apoptotic activity of this novel fusion protein. EGFR-specific binding of scFv425sTRAILmR1-5 potently induced apoptosis, which was superior to the apoptotic activity of scFv425sTRAIL-wt and a nontargeted MOCK-scFvsTRAILmR1-5. During cotreatment with cisplatin or the histone deacetylase inhibitor valproic acid, scFv425sTRAILmR1-5 retained its superior pro-apoptotic activity compared to scFv425sTRAIL-wt. However, in catching-type Enzyme-Linked ImmunoSorbent Assays with TRAIL-R1Fc and TRAIL-R2Fc, scFv425sTRAILmR1-5 was found to not only bind to TRAIL-R1 but also to TRAIL-R2. Binding to TRAIL-R2 also had functional consequences because the apoptotic activity of scFv425sTRAILmR1-5 was strongly inhibited by a TRAIL-R2 blocking monoclonal antibody. Moreover, scFv425sTRAILmR1-5 retained apoptotic activity upon selective knockdown of TRAIL-R1 using small inhibitory RNA. Collectively, these data indicate that both agonistic TRAIL receptors are functionally involved in TRAIL signaling by scFv425sTRAILmR1-5 in solid tumor cells. Moreover, the superior target cell-restricted apoptotic activity of scFv425sTRAILmR1-5 indicates its therapeutic potential for EGFR-positive solid tumors.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Apoptose
/
Ligante Indutor de Apoptose Relacionado a TNF
/
Receptores ErbB
/
Antineoplásicos
Limite:
Humans
Idioma:
En
Revista:
J Mol Med (Berl)
Assunto da revista:
BIOLOGIA MOLECULAR
/
GENETICA MEDICA
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Holanda