A novel immunotoxin - rCCK8PE38 targeting of CCK-R overexpressed colon cancers.
J Drug Target
; 23(5): 462-8, 2015 Jun.
Article
en En
| MEDLINE
| ID: mdl-25673265
BACKGROUND: Cholecystokinin (CCK) receptors are overexpressed in numerous human cancers, such as pancreatic, colon and gastric cancers. Previous studies have shown that the specific receptor-binding property of CCK for CCK receptors (CCKRs) can be exploited to produce immunotoxins (ITs) that target cancer cells overexpressing CCK receptors. PURPOSE: Construct a new IT-targeting CCKR-overexpressing colon cancers. METHODS: To construct the CCKR-targeted IT, a reverse CCK8 peptide was fused with a modified 38-kDa truncated form of the Pseudomonas exotoxin (PE38KDEL). An efficient immunoaffinity purification procedure was used to produce a PE38-based IT. Several analyses, including CCK8 competition and indirect immunofluorescence assays, were performed to confirm the interaction between rCCK8 and CCKR. After cytotoxic assays on several cell lines, the anti-tumor activity of the new IT was detected in nude mice. RESULTS: The rCCK8PE38 IT showed specific cytotoxicity for two colon cancer cell lines and one gastric cancer cell line. After purification, 18-26 mg of pure rCCK8PE38 per 1 L of culture was obtained. Purified rCCK8PE38 showed high cytotoxicity in colon cancer cell lines with IC50 values of 0.8-3.5 ng/mL. The results of the CCK8 competition and indirect immunofluorescence assays showed that rCCK8 had a specific interaction with CCKR. Nude mice inoculated with HCT-8 tumor xenografts were treated with rCCK8PE38, which efficiently decreased the tumor size in those mice. CONCLUSIONS AND DISCUSSION: All of these data suggest that rCCK8PE38 has potential as a new immunotherapy agent. Furthermore, the results of this study further support the high value of the immunoaffinity method for IT purification procedures.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fragmentos de Péptidos
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Colecistoquinina
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Inmunotoxinas
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Receptores de Colecistoquinina
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Neoplasias del Colon
Límite:
Animals
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Female
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Humans
Idioma:
En
Revista:
J Drug Target
Asunto de la revista:
FARMACOLOGIA
Año:
2015
Tipo del documento:
Article
Pais de publicación:
Reino Unido