Browsing by Author "Chen, Yuda"

Now showing 1 - 4 of 4
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    Bone-Specific Enhancement of Antibody Therapy for Breast Cancer Metastasis to Bone
    (American Chemical Society, 2022) Tian, Zeru; Yu, Chenfei; Zhang, Weijie; Wu, Kuan-Lin; Wang, Chenhang; Gupta, Ruchi; Xu, Zhan; Wu, Ling; Chen, Yuda; Zhang, Xiang H.-F.; Xiao, Han
    Despite the rapid evolution of therapeutic antibodies, their clinical efficacy in the treatment of bone tumors is hampered due to the inadequate pharmacokinetics and poor bone tissue accessibility of these large macromolecules. Here, we show that engineering therapeutic antibodies with bone-homing peptide sequences dramatically enhances their concentrations in the bone metastatic niche, resulting in significantly reduced survival and progression of breast cancer bone metastases. To enhance the bone tumor-targeting ability of engineered antibodies, we introduced varying numbers of bone-homing peptides into permissive sites of the anti-HER2 antibody, trastuzumab. Compared to the unmodified antibody, the engineered antibodies have similar pharmacokinetics and in vitro cytotoxic activity, but exhibit improved bone tumor distribution in vivo. Accordingly, in xenograft models of breast cancer metastasis to bone sites, engineered antibodies with enhanced bone specificity exhibit increased inhibition of both initial bone metastases and secondary multiorgan metastases. Furthermore, this engineering strategy is also applied to prepare bone-targeting antibody–drug conjugates with enhanced therapeutic efficacy. These results demonstrate that adding bone-specific targeting to antibody therapy results in robust bone tumor delivery efficacy. This provides a powerful strategy to overcome the poor accessibility of antibodies to the bone tumors and the consequential resistance to the therapy.
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    Creation of Cells with Endogenous Noncanonical Amino Acids for Genetic Incorporation
    (2022-04-14) Chen, Yuda; Xiao, Han
    While most organisms utilize 20 canonical amino acid building blocks for protein synthesis, adding additional noncanonical amino acids (ncAAs) to the amino acid repertoire can greatly facilitate the investigation of protein structures and functions. Genetic incorporation of ncAAs requires 3 key components: a “blank” (normally non-coding) codon, a biorthogonal translational system and sufficient amount of intracellular ncAAs. Despite significant efforts focused on biorthogonal machinery and available codon for encoding ncAAs, current methodologies to reach sufficient amount of cellular ncAAs have largely relied on the exogenous feeding of chemically-synthesized ncAAs and successful uptake of these ncAAs by cells. The requirement of external addition of ncAAs limits the development of genetic code expansion in its efficiency as well as applicability in both academic and industrial settings. To solve this limitation, creation of completely autonomous cells with both biosynthetic pathway and genetic incorproation mechinery for ncAAs has been accomplished in this thesis. Before engineering cells with novel ncAA as its 21st amino acid, the reported bacterial cells with p-aminophenylalanine (pAF) as its 21st amino acid was optimized and its application to produce proteins with site-specific modifications was explored. Two bacterial cells with novel ncAAs (5-hydroxyltryptophan and 3,4-dihydroxylphenylalanine) as its 21st amino acid have been created by introducing external biosynthetic pathways reported in the literature and their corresponding genetic incorporation machineries. Comparing with classical genetic expansion technology, cells with those ncAAs as their 21st amino acid have been demonstrated with superior ability to detect oxidative stress and prepare site-specific conjugate of therapeutic proteins. Beyond the usage of reported biosynthetic way, a novel sulfotransferase was discovered from bioinformatics for biosynthesizing sulfotysoine (sTyr), which is inefficient to penetrate cell membrane. As an important protein post-translational modification, sTyr produced in situ could be genetically incorporated into proteins in both prokaryotic and eukaryotic cells with higher efficiency than classical genetic code expansion based on exogenous addition of sTyr. The cells with sTyr as its 21st amino acid was applied to produce thrombin inhibitors with enhanced affinity. As another component towards creation of cells with a 21st amino acid, the genetic incorporation machineries for two isocyanide-containing ncAAs were discovered and the genetic incorporation of this novel functional group was used for protein activation and site-specific conjugation.
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    Harnessing the power of antibodies to fight bone metastasis
    (AAAS, 2021) Tian, Zeru; Wu, Ling; Yu, Chenfei; Chen, Yuda; Xu, Zhan; Bado, Igor; Loredo, Axel; Wang, Lushun; Wang, Hai; Wu, Kuan-Lin; Zhang, Weijie; Zhang, Xiang H.-F.; Xiao, Han
    Antibody-based therapies have proved to be of great value in cancer treatment. Despite the clinical success of these biopharmaceuticals, reaching targets in the bone microenvironment has proved to be difficult due to the relatively low vascularization of bone tissue and the presence of physical barriers. Here, we have used an innovative bone-targeting (BonTarg) technology to generate a first-in-class bone-targeting antibody. Our strategy involves the use of pClick antibody conjugation technology to chemically couple the bone-targeting moiety bisphosphonate to therapeutic antibodies. Bisphosphonate modification of these antibodies results in the delivery of higher conjugate concentrations to the bone metastatic niche, relative to other tissues. In xenograft mice models, this strategy provides enhanced inhibition of bone metastases and multiorgan secondary metastases that arise from bone lesions. Specific delivery of therapeutic antibodies to the bone, therefore, represents a promising strategy for the treatment of bone metastatic cancers and other bone diseases. Precision modification of antibodies with bone-targeting moieties unleashes their potential for the treatment of bone metastases. Precision modification of antibodies with bone-targeting moieties unleashes their potential for the treatment of bone metastases.
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    Unleashing the potential of noncanonical amino acid biosynthesis to create cells with precision tyrosine sulfation
    (Springer Nature, 2022) Chen, Yuda; Jin, Shikai; Zhang, Mengxi; Hu, Yu; Wu, Kuan-Lin; Chung, Anna; Wang, Shichao; Tian, Zeru; Wang, Yixian; Wolynes, Peter G.; Xiao, Han; Center for Theoretical Biological Physics
    Despite the great promise of genetic code expansion technology to modulate structures and functions of proteins, external addition of ncAAs is required in most cases and it often limits the utility of genetic code expansion technology, especially to noncanonical amino acids (ncAAs) with poor membrane internalization. Here, we report the creation of autonomous cells, both prokaryotic and eukaryotic, with the ability to biosynthesize and genetically encode sulfotyrosine (sTyr), an important protein post-translational modification with low membrane permeability. These engineered cells can produce site-specifically sulfated proteins at a higher yield than cells fed exogenously with the highest level of sTyr reported in the literature. We use these autonomous cells to prepare highly potent thrombin inhibitors with site-specific sulfation. By enhancing ncAA incorporation efficiency, this added ability of cells to biosynthesize ncAAs and genetically incorporate them into proteins greatly extends the utility of genetic code expansion methods.