Anti-tumor bispecific miniaturized antibody with double functions of targeting therapy and detection

Abstract

The present invention belongs to the field of bio-engineering pharmacy, protein polypeptide drugs and biomedical engineering, and relates to design and construction of a miniaturized fusion antibody providing high affinity for human epidermal growth factor receptors EGFR1 and HER2, and applications of the miniaturized fusion antibody in tumor targeting diagnosis and therapy, wherein the bispecific antibody is obtained by connecting a HER2 specific domain and a EGFR1 specific domain in series through a (G4S)3 connecting peptide and carrying out gene recombinant expression, the full-length of the fusion protein coding gene is 804 bp, 268 amino acids are coded, the molecular weight of the fusion protein is 29 kD, and the amino acid sequence is the sequence represented by SEQ ID No:1. Compared with combination of the EGFR1 and HER2 antibodies, the bispecific miniaturized antibody of the present invention provides significant in vitro and in vivo activity advantages, has advantages of low toxicity, being rapidly cleared in non-tumor sites in vivo, and the like, has high efficiency in targeting diagnosis and therapy, and can be used for tumor diagnosis and therapy.

Description

technical field [0001] The invention belongs to the field of bioengineering, and specifically relates to a miniaturized fusion antibody with high affinity for human epidermal growth factor receptors EGFR1 and HER2 and application thereof, which can be used for cancer diagnosis and treatment. Background technique [0002] The receptor tyrosine kinase ErbB family plays an important role in physiological processes such as cell growth, proliferation and differentiation. This receptor family includes four members: epidermal growth factor receptor (EGFR1, ErbB1 or HER1), HER2 (ErbB2), HER3 (ErbB3) and HER4 (ErbB4). Members of this family are composed of extracellular ligand-binding domain, intracellular kinase domain and transmembrane domain, and are closely related to the biological process of tumor cells. [0003] Epidermal growth factor (EGF) is the natural ligand of EGFR1. After it binds to EGFR1, it activates the receptor tyrosine kinase activity of EGFR1, and then activate...

AI Technical Summary

Problems solved by technology

The molecular weight of monoclonal antibody drugs is usually about 150kD. Its too large molecular weight makes it less efficient to enter tumor tissue cells, and the metabolism time in the body is too long, which leads to its disadvantages such as low therapeutic efficiency and high accumulation toxicity in the body; On the one hand, the monoclonal antibodies currently on the market are all single-targeting EGFR1 and HER2. Due to the synergistic effect of EGFR1 and HER2, these antibodies do not show good curative effect on EGFR1 / HER2 double positive tumors

Although small-molecule tyrosine kinase inhibitors are easy to enter tumor cells, their lack of active tumor targeting is an important defect, and tyrosine kinases also play an important role in normal cell physiological activities in the human body. The indiscriminate inhibition of non-tumor tyrosine kinases by these drugs also leads to greater toxicity in vivo; although lapatinib has a good inhibitory effect on EGFR1 and HER2 tyrosine kinases, due to the specificity of targeting The in vivo toxicity caused by the lack of sex has also made the development and use of this type of drug enter a bottleneck stage

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