A novel recombinant immuno-tBid with a furin site effectively suppresses the growth of HER2-positive osteosarcoma cells in vitro.

Abstract

Immunotherapy is a promising strategy for the treatment of human epidermal growth factor receptor 2 (HER2)-positive tumors. Previously, we constructed an immuno-carboxy terminal fragment of Bid (immuno-tBid) and reported its specific and effective destruction of HER2-positive tumor cells. In this study, in order to further reduce the immunogenicity of the previous immuno-proapoptotic protein, we constructed a novel immuno-tBid by replacing domain II of Pseudomonas exotoxin A with a short furin cleavage sequence from the diphtheria toxin. In order to explore the possible application of this novel immuno-tBid in the treatment of osteosarcoma, we first examined the expression of the HER2 protein in a subclone of a human osteosarcoma cell line with relatively high metastatic potential (SOSP-9607-E10), as well as in clinical specimens of osteosarcoma. Quantitative real-time PCR and Western blot analysis revealed that the expression of HER2 was up-regulated in the SOSP-9607-E10 cells, while immunohistochemical analysis revealed that HER2 was overexpressed in 37% of the tissue specimens examined. Both HER2-positive SOSP-9607-E10 and SKBR-3 cells, as well as HER2-negative HeLa cells were transiently transfected with the novel immuno-tBid in order to study its specific pro-apoptotic effect. We demonstrate here that this novel immuno-tBid induces the specific destruction of HER2-overexpressing SOSP-9607-E10 cells through the release of cytochrome C. These results suggest that the novel immuno-tBid with a minimized exogenous fragment could represent a competitive approach for the treatment of HER2-positive osteosarcoma.

• Authors: Le-Qun Shan, Sai Ma, Xiu-Chun Qiu, Tao Wang, Shi-Bin Yu, Bao-An Ma, Yong Zhou, Qing-Yu Fan, An-Gang Yang
• Journal: Oncology reports (Oncol Rep) Vol. 25 Issue 2 Pg. 325-31 (Feb 2011) ISSN: 1791-2431 [Electronic] Greece
• PMID: 21152867 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• BH3 Interacting Domain Death Agonist Protein
• Immunoconjugates
• Peptide Fragments
• Recombinant Fusion Proteins
• ERBB2 protein, human
• Receptor, ErbB-2
• Furin

Topics

• BH3 Interacting Domain Death Agonist Protein (chemistry, pharmacology)
• Binding Sites
• Bone Neoplasms (genetics, metabolism, pathology)
• Cell Proliferation (drug effects)
• Down-Regulation (drug effects)
• Drug Evaluation, Preclinical
• Furin (metabolism)
• HeLa Cells
• Humans
• Immunoconjugates (chemistry, pharmacology)
• Osteosarcoma (genetics, metabolism, pathology)
• Peptide Fragments (chemistry, pharmacology)
• Protein Structure, Tertiary (physiology)
• Receptor, ErbB-2 (genetics, metabolism)
• Recombinant Fusion Proteins (chemistry, pharmacology)
• Transfection
• Tumor Cells, Cultured