» Articles » PMID: 23376850

Design Optimization and Characterization of Her2/neu-targeted Immunotoxins: Comparative in Vitro and in Vivo Efficacy Studies

Overview
Journal Oncogene
Date 2013 Feb 5
PMID 23376850
Citations 23
Authors
Affiliations
Soon will be listed here.
Abstract

Targeted therapeutics are potential therapeutic agents because of their selectivity and efficacy against tumors resistant to conventional therapy. The goal of this study was to determine the comparative activity of monovalent, engineered anti-Her2/neu immunotoxins fused to recombinant gelonin (rGel) to the activity of bivalent IgG-containing immunoconjugates. Utilizing Herceptin and its derived humanized single-chain antibody (single-chain fragment variable, designated 4D5), we generated bivalent chemical Herceptin/rGel conjugate, and the corresponding monovalent recombinant immunotoxins in two orientations, 4D5/rGel and rGel/4D5. All the constructs showed similar affinity to Her2/neu-overexpressing cancer cells, but significantly different antitumor activities. The rGel/4D5 orientation construct and Herceptin/rGel conjugate were superior to 4D5/rGel construct in in vitro and in vivo efficacy. The enhanced activity was attributed to improved intracellular toxin uptake into target cells and efficient downregulation of Her2/neu-related signaling pathways. The Her2/neu-targeted immunotoxins effectively targeted cells with Her2/neu expression level >1.5 × 10(5) sites per cell. Cells resistant to Herceptin or chemotherapeutic agents were not cross-resistant to rGel-based immunotoxins. Against SK-OV-3 tumor xenografts, the rGel/4D5 construct with excellent tumor penetration showed impressive tumor inhibition. Although Herceptin/rGel conjugate demonstrated comparatively longer serum half-life, the in vivo efficacy of the conjugate was similar to the rGel/4D5 fusion. These comparative studies demonstrate that the monovalent, engineered rGel/4D5 construct displayed comparable in vitro and in vivo antitumor efficacy as bivalent Herceptin/rGel conjugate. Immunotoxin orientation can significantly impact the overall functionality and performance of these agents. The recombinant rGel/4D5 construct with excellent tumor penetration and rapid blood clearance may reduce the unwanted toxicity when administrating to patients, and warrants consideration for further clinical evaluation.

Citing Articles

The affinity of antigen-binding domain on the antitumor efficacy of CAR T cells: Moderate is better.

Mao R, Kong W, He Y Front Immunol. 2022; 13:1032403.

PMID: 36325345 PMC: 9618871. DOI: 10.3389/fimmu.2022.1032403.


Transient Inhibition of Trastuzumab-Tumor Binding to Overcome the "Binding-Site Barrier" and Improve the Efficacy of a Trastuzumab-Gelonin Immunotoxin.

Chen P, Bordeau B, Zhang Y, Balthasar J Mol Cancer Ther. 2022; 21(10):1573-1582.

PMID: 35930739 PMC: 9547943. DOI: 10.1158/1535-7163.MCT-22-0192.


Molecularly engineered tumor acidity-responsive plant toxin gelonin for safe and efficient cancer therapy.

Ding G, Zhu C, Wang Q, Cao H, Li B, Yang P Bioact Mater. 2022; 18:42-55.

PMID: 35387163 PMC: 8961304. DOI: 10.1016/j.bioactmat.2022.02.001.


Recombinant immunotoxins development for HER2-based targeted cancer therapies.

Mahmoudi R, Dianat-Moghadam H, Poorebrahim M, Siapoush S, Poortahmasebi V, Salahlou R Cancer Cell Int. 2021; 21(1):470.

PMID: 34488747 PMC: 8422749. DOI: 10.1186/s12935-021-02182-6.


Targeting Receptors on Cancer Cells with Protein Toxins.

Antignani A, Ho E, Bilotta M, Qiu R, Sarnvosky R, Fitzgerald D Biomolecules. 2020; 10(9).

PMID: 32957689 PMC: 7563326. DOI: 10.3390/biom10091331.


References
1.
Kreitman R . Recombinant toxins for the treatment of cancer. Curr Opin Mol Ther. 2003; 5(1):44-51. View

2.
Yokota T, Milenic D, Whitlow M, Schlom J . Rapid tumor penetration of a single-chain Fv and comparison with other immunoglobulin forms. Cancer Res. 1992; 52(12):3402-8. View

3.
Beckman R, Weiner L, Davis H . Antibody constructs in cancer therapy: protein engineering strategies to improve exposure in solid tumors. Cancer. 2006; 109(2):170-9. DOI: 10.1002/cncr.22402. View

4.
Rodriguez G, Boente M, Berchuck A, Whitaker R, OBriant K, Xu F . The effect of antibodies and immunotoxins reactive with HER-2/neu on growth of ovarian and breast cancer cell lines. Am J Obstet Gynecol. 1993; 168(1 Pt 1):228-32. DOI: 10.1016/s0002-9378(12)90918-7. View

5.
Villa J, Pearson D, Watson T, Liu E, Willingham M, Pastan I . Hepatotoxicity in cancer patients receiving erb-38, a recombinant immunotoxin that targets the erbB2 receptor. Clin Cancer Res. 1999; 5(9):2311-5. View