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HER2-specific pseudomonas exotoxin a pe25 based fusions : Influence of targeting domain on target binding, toxicity, and in vivo biodistribution

Ding, Haozhong ; Altai, Mohamed LU ; Yin, Wen ; Lindbo, Sarah ; Liu, Hao ; Garousi, Javad ; Xu, Tianqi ; Orlova, Anna ; Tolmachev, Vladimir and Hober, Sophia , et al. (2020) In Pharmaceutics 12(4).
Abstract

The human epidermal growth factor receptor 2 (HER2) is a clinically validated target for cancer therapy, and targeted therapies are often used in regimens for patients with a high HER2 expression level. Despite the success of current drugs, a number of patients succumb to their disease, which motivates development of novel drugs with other modes of action. We have previously shown that an albumin binding domain-derived affinity protein with specific affinity for HER2, ADAPT6, can be used to deliver the highly cytotoxic protein domain PE25, a derivative of Pseudomonas exotoxin A, to HER2 overexpressing malignant cells, leading to potent and specific cell killing. In this study we expanded the investigation for an optimal... (More)

The human epidermal growth factor receptor 2 (HER2) is a clinically validated target for cancer therapy, and targeted therapies are often used in regimens for patients with a high HER2 expression level. Despite the success of current drugs, a number of patients succumb to their disease, which motivates development of novel drugs with other modes of action. We have previously shown that an albumin binding domain-derived affinity protein with specific affinity for HER2, ADAPT6, can be used to deliver the highly cytotoxic protein domain PE25, a derivative of Pseudomonas exotoxin A, to HER2 overexpressing malignant cells, leading to potent and specific cell killing. In this study we expanded the investigation for an optimal targeting domain and constructed two fusion toxins where a HER2-binding affibody molecule, ZHER2:2891, or the dual- HER2-binding hybrid ZHER2:2891-ADAPT6 were used for cancer cell targeting. We found that both targeting domains conferred strong binding to HER2; both to the purified extracellular domain and to the HER2 overexpressing cell line SKOV3. This resulted in fusion toxins with high cytotoxic potency toward cell lines with high expression levels of HER2, with EC50 values between 10 and 100 pM. For extension of the plasma half-life, an albumin binding domain was also included. Intravenous injection of the fusion toxins into mice showed a profound influence of the targeting domain on biodistribution. Compared to previous results, with ADAPT6 as targeting domain, ZHER2:2891 gave rise to further extension of the plasma half-life and also shifted the clearance route of the fusion toxin from the liver to the kidneys. Collectively, the results show that the targeting domain has a major impact on uptake of PE25-based fusion toxins in different organs. The results also show that PE25-based fusion toxins with high affinity to HER2 do not necessarily increase the cytotoxicity beyond a certain point in affinity. In conclusion, ZHER2:2891 has the most favorable characteristics as targeting domain for PE25.

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organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Affibody molecule, Cancer, Half-life extension, HER2, Pseudomonas exotoxin A
in
Pharmaceutics
volume
12
issue
4
article number
391
publisher
MDPI AG
external identifiers
  • pmid:32344762
  • scopus:85083989782
ISSN
1999-4923
DOI
10.3390/pharmaceutics12040391
language
English
LU publication?
yes
id
27901384-07e7-4b87-8e20-97d0133ec44b
date added to LUP
2020-05-20 14:56:19
date last changed
2020-08-20 03:00:32
@article{27901384-07e7-4b87-8e20-97d0133ec44b,
  abstract     = {<p>The human epidermal growth factor receptor 2 (HER2) is a clinically validated target for cancer therapy, and targeted therapies are often used in regimens for patients with a high HER2 expression level. Despite the success of current drugs, a number of patients succumb to their disease, which motivates development of novel drugs with other modes of action. We have previously shown that an albumin binding domain-derived affinity protein with specific affinity for HER2, ADAPT<sub>6</sub>, can be used to deliver the highly cytotoxic protein domain PE25, a derivative of Pseudomonas exotoxin A, to HER2 overexpressing malignant cells, leading to potent and specific cell killing. In this study we expanded the investigation for an optimal targeting domain and constructed two fusion toxins where a HER2-binding affibody molecule, Z<sub>HER2:2891</sub>, or the dual- HER2-binding hybrid Z<sub>HER2:2891</sub>-ADAPT<sub>6</sub> were used for cancer cell targeting. We found that both targeting domains conferred strong binding to HER2; both to the purified extracellular domain and to the HER2 overexpressing cell line SKOV3. This resulted in fusion toxins with high cytotoxic potency toward cell lines with high expression levels of HER2, with EC<sub>50</sub> values between 10 and 100 pM. For extension of the plasma half-life, an albumin binding domain was also included. Intravenous injection of the fusion toxins into mice showed a profound influence of the targeting domain on biodistribution. Compared to previous results, with ADAPT<sub>6</sub> as targeting domain, Z<sub>HER2:2891</sub> gave rise to further extension of the plasma half-life and also shifted the clearance route of the fusion toxin from the liver to the kidneys. Collectively, the results show that the targeting domain has a major impact on uptake of PE25-based fusion toxins in different organs. The results also show that PE25-based fusion toxins with high affinity to HER2 do not necessarily increase the cytotoxicity beyond a certain point in affinity. In conclusion, Z<sub>HER2:2891</sub> has the most favorable characteristics as targeting domain for PE25.</p>},
  author       = {Ding, Haozhong and Altai, Mohamed and Yin, Wen and Lindbo, Sarah and Liu, Hao and Garousi, Javad and Xu, Tianqi and Orlova, Anna and Tolmachev, Vladimir and Hober, Sophia and Gräslund, Torbjörn},
  issn         = {1999-4923},
  language     = {eng},
  number       = {4},
  publisher    = {MDPI AG},
  series       = {Pharmaceutics},
  title        = {HER2-specific pseudomonas exotoxin a pe25 based fusions : Influence of targeting domain on target binding, toxicity, and in vivo biodistribution},
  url          = {http://dx.doi.org/10.3390/pharmaceutics12040391},
  doi          = {10.3390/pharmaceutics12040391},
  volume       = {12},
  year         = {2020},
}