Antitumor effects of an engineered and energized fusion protein consisting of an anti-CD20 scFv fragment and lidamycin.

Abstract

Antibody-based fusion proteins are the next generation of antibody therapies for cancer and other diseases. CD20 antigen, which is overexpressed on cell membranes in nearly 95% of cases of B-cell Non-Hodgkin's Lymphoma, is an attractive target for the therapy of B-lymphoid malignancies. Lidamycin (LDM) is a potent enediyne-containing antitumor antibiotic that now has entered phase II clinical trials. In this study, we prepared an engineered fusion protein, scFv-LDP, consisting of an anti-CD20 scFv fragment and the apoprotein LDP of LDM using DNA recombination. After purification and refolding, scFv-LDP was found to bind specifically to CD20-positive lymphoma cells using ELISA and indirect immunofluorescent cytochemical staining assays. The energized fusion protein scFv-LDP-AE was obtained using molecular reconstitution of the active chromophore AE of LDM and scFv-LDP. MTT assay revealed potent cytotoxicity of scFv-LDP-AE to CD20-positive Raji and Daudi cells, with IC(50) values of 1.21×10(-11) and 6.24×10(-11) mol L(-1), respectively. An in vivo subcutaneous xenograft model of CD20-positive B cell lymphoma in BALB/c (nu/nu) mice was also utilized. Drugs were given intravenously on day 14 and 21 after tumor transplantation. In terms of maximal tolerated doses, scFv-LDP-AE at 0.3 mg kg(-1) suppressed tumor growth by 79.3%, and LDM at 0.05 mg kg(-1) by 68.6% (P<0.05). Results suggested scFv-LDP-AE could be a potential candidate for tumor-targeting therapy.

• Authors: Hong Fang, Qingfang Miao, Shenghua Zhang, Xin Cheng, Dongsheng Xiong, Yongsu Zhen
• Journal: Science China. Life sciences (Sci China Life Sci) Vol. 54 Issue 3 Pg. 255-62 (Mar 2011) ISSN: 1869-1889 [Electronic] China
• PMID: 21416325 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Aminoglycosides
• Antibiotics, Antineoplastic
• Antigens, CD20
• Enediynes
• Recombinant Fusion Proteins
• Single-Chain Antibodies
• C 1027

Topics

• Aminoglycosides (genetics, pharmacology)
• Animals
• Antibiotics, Antineoplastic (chemistry, pharmacology, therapeutic use)
• Antigens, CD20 (immunology)
• Cell Line, Tumor (drug effects)
• Enediynes (pharmacology)
• Female
• Lymphoma, B-Cell (drug therapy, pathology)
• Mice
• Mice, Inbred BALB C
• Mice, Nude
• Protein Engineering
• Recombinant Fusion Proteins (genetics, pharmacology, therapeutic use)
• Single-Chain Antibodies (genetics, immunology, pharmacology, therapeutic use)
• Xenograft Model Antitumor Assays