Browsing by Author "Lu, Yun-Chi"

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Bispecific antibody (HER2 x mPEG) enhances anti-cancer effects by precise targeting and accumulation of mPEGylated liposomes
(2020-07-15)
Chen, I-Ju
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Cheng, Yi-An
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Ho, Kai-Wen
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Lin, Wen-Wei
;
Cheng, Kai-Wen
Targeted antibodies and methoxy-PEGylated nanocarriers have gradually become a mainstream of cancer therapy. To increase the anti-cancer effects of targeted antibodies combined with mPEGylated liposomes (mPEG-liposomes), we describe a bispecific antibody in which an anti-methoxy-polyethylene glycol scFv (alpha mPEG scFv) was fused to the C-terminus of an anti-HER2 (alpha HER2) antibody to generate a HER2 x mPEG BsAb that retained the original efficacy of a targeted antibody while actively attracting mPEG-liposomes to accumulate at tumor sites. HER2 xmPEG BsAb can simultaneously bind to HER2high expressing MCF7/HER2 tumor cells and mPEG molecules on mPEG-liposomal doxorubicin (Lipo-Dox). Pre-incubation of HER2 x mPEG BsAb with cells increased the endocytosis of Lipo-DiD and enhanced the cytotoxicity of Lipo-Dox to MCF7/HER2 tumor cells. Furthermore, pre-treatment of HER2 x mPEG BsAb enhanced the tumor accumulation and retention of Lipo-DiR 2.2-fold in HER2-high expressing MCF7/HER2 tumors as compared to HER2-low expressing MCF7/neol tumors. Importantly, HER2 x mPEG BsAb plus Lipo-Dox significantly suppressed tumor growth as compared to control BsAb plus Lipo-Dox in MCF7/HER2 tumor-bearing mice. These results indicate that HER2 x mPEG BsAb can enhance tumor accumulation of mPEG-liposomes to improve the therapeutic efficacy of combination treatment. Anti-mPEG scFv can be fused to any kind of targeted antibody to generate BsAbs to actively attract mPEG-drugs and improve anti-cancer efficacy. Statement of Significance Antibody targeted therapy and PEGylated drugs have gradually become the mainstream of cancer therapy. To enhance the anti-cancer effects of targeted antibodies combined with PEGylated drugs is very important. To this aim, we fused an anti-PEG scFv to the C-terminal of HER2 targeted antibodies to generate a HER2xmPEG bispecific antibody (BsAb) to retain the original efficacy of targeted antibody whilst actively attract mPEG-liposomal drugs to accumulate at tumor sites. The present study demonstrates pretreatment of HER2xmPEG BsAb can enhance tumor accumulation of mPEG-liposomal drugs to improve the therapeutic efficacy of combination treatment. Anti-mPEG scFv can be fused to any kind of targeted antibody to generate BsAbs to actively attract mPEG-drugs and improve anti-cancer efficacy. (C) 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Enhanced drug internalization and therapeutic efficacy of PEGylated nanoparticles by one-step formulation with anti-mPEG bispecific antibody in intrinsic drug-resistant breast cancer
(2019-08-01)
Cheng, Yi-An
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Chen, I-Ju
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Su, Yu-Cheng
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Cheng, Kai-Wen
;
Lu, Yun-Chi
For those patients with HER2-overexpressing breast cancer, treatment with PEGylated liposomal doxorubicin (PLD) is inefficacious due to the intrinsic low sensitivity to doxorubicin. A very large increase in drug accumulation by active targeting may enhance the therapeutic efficacy of PLD. We established a humanized bispecific antibody (BsAb; mPEG x HER2) which has dual specificity for methoxy-polyethylene glycol (mPEG) and human epidermal growth factor receptor 2 (HER2) to enhance the specificity, internalization and anticancer activity of PLD for cancer cells that overexpress HER2. One-step formulation of PLD with mPEG x HER2 converted the PLD into HER2 targeted liposomes that were stable at 4 degrees C in PBS as well as at 37 degrees C in the presence of serum. alpha HER2/PLD induced receptor-mediated endocytosis and enhanced doxorubicin accumulation in MCF7/HER2 (HER2-amplified) breast cancer cells. alpha HER2/PLD also displayed more than 200-fold increased cytotoxicity to MCF7/HER2 cells and 28-fold increased cytotoxicity to drug-resistant MDA-MB-361 cells with a physical deletion of the TOP2A gene. alpha HER2/PLD specifically accumulated doxorubicin in the nucleus of cancer cells in tumor-bearing mice and produced significantly greater antitumor activity against MCF7/HER2 (P < 0.0001) and MDA-MB-361 (P < 0.05) tumors as compared to untargeted PLD. Furthermore, the cardiotoxicity of alpha HER2/PLD was similar to that of PLD in human cardiomyocytes and in mice. Our results indicate that the one-step formulation of PLD by mPEG x HER2 is a simple method to confer tumor specificity, increase drug internalization and enhance the anticancer activity of PLD against HER2-overexpressing and doxorubicin-resistant breast cancer.
Humanized bispecific antibody (mPEG x HER2) rapidly confers PEGylated nanoparticles tumor specificity for multimodality imaging in breast cancer
(2020-08-27)
Cheng, Yi-An
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Wu, Tung-Ho
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Wang, Yun-Ming
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Cheng, Tian-Lu
;
Chen, I-Ju
Background: Developing a universal strategy to improve the specificity and sensitivity of PEGylated nanoaparticles (PEG-NPs) for assisting in the diagnosis of tumors is important in multimodality imaging. Here, we developed the anti-methoxypolyethylene glycol (mPEG) bispecific antibody (BsAb; mPEG x HER2), which has dual specificity for mPEG and human epidermal growth factor receptor 2 (HER2), with a diverse array of PEG-NPs to confer nanoparticles with HER2 specificity and stronger intensity. Result: We used a one-step formulation to rapidly modify the nanoprobes with mPEG x HER2 and optimized the modified ratio of BsAbs on several PEG-NPs (Lipo-DiR, SPIO, Qdot and AuNP). The alpha HER2/PEG-NPs could specifically target MCF7/HER2 cells (HER2(++)) but not MCF7/neo1 cells (HER2(+/-)). The alpha HER2/Lipo-DiR and alpha HER2/SPIO could enhance the sensitivity of untargeted PEG-NPs on MCF7/HER2 (HER2(++)). In in vivo imaging, alpha HER2/Lipo-DiR and alpha HER2/SPIO increased the specific targeting and enhanced PEG-NPs accumulation at 175% and 187% on 24 h, respectively, in HER2-overexpressing tumors. Conclusion: mPEG x HER2, therefore, provided a simple one-step formulation to confer HER2-specific targeting and enhanced sensitivity and contrast intensity on HER2 positive tumors for multimodality imaging.
Selective antibody activation through protease-activated pro-antibodies that mask binding sites with inhibitory domains
(2017-09-14)
Chen, I-Ju
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Chuang, Chih-Hung
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Hsieh, Yuan-Chin
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Lu, Yun-Chi
;
Lin, Wen-Wei
Systemic injection of therapeutic antibodies may cause serious adverse effects due to on-target toxicity to the antigens expressed in normal tissues. To improve the targeting selectivity to the region of disease sites, we developed protease-activated pro-antibodies by masking the binding sites of antibodies with inhibitory domains that can be removed by proteases that are highly expressed at the disease sites. The latency-associated peptide (LAP), C2b or CBa of complement factor 2/B were linked, through a substrate peptide of matrix metalloproteinase-2 (MMP-2), to an anti-epidermal growth factor receptor (EGFR) antibody and an anti-tumor necrosis factor-alpha (TNF-alpha) antibody. Results showed that all the inhibitory domains could be removed by MMP-2 to restore the binding activities of the antibodies. LAP substantially reduced (53.8%) the binding activity of the anti-EGFR antibody on EGFR-expressing cells, whereas C2b and CBa were ineffective (21% and 9.3% reduction, respectively). Similarly, LAP also blocked 53.9% of the binding activity of the anti-TNF-alpha antibody. Finally, molecular dynamic simulation showed that the masking efficiency of LAP, C2b and CBa was 33.7%, 10.3% and -5.4%, respectively, over the binding sites of the antibodies. This strategy may aid in designing new protease-activated pro-antibodies that attain high therapeutic potency yet reduced systemic on-target toxicity.