Prostate-Specific Membrane Antigen-Specific Antitumor Activity of a Self-Immolative Tubulysin Conjugate.
Bioconjug Chem
; 30(6): 1805-1813, 2019 06 19.
Article
em En
| MEDLINE
| ID: mdl-31075200
ABSTRACT
Prostate-specific membrane antigen (PSMA) is a biomarker that is overexpressed on prostate cancer, and it is also present on the neovasculature within many non-prostate solid tumors. Herein, we report on the construction and biological testing of novel tubulysin B-containing therapeutic agents for the treatment of PSMA-expressing cancer. One of these compounds, EC1169, emerged as a lead candidate for preclinical development and phase 1 clinical testing. This water-soluble conjugate was shown to have high affinity for PSMA-positive cells. When tested in vitro, EC1169 was found to inhibit the growth of PSMA-positive cells, but it displayed no activity against PSMA-negative cells. Brief treatment of nude mice bearing PSMA-positive LNCaP human xenografts with EC1169 led to complete remissions and cures. Furthermore, this activity occurred in the absence of weight loss. In contrast, the nontargeted tubulysin B drug proved to be inactive against the LNCaP tumor model when administered at doses near to or greater than the maximum tolerated level. PSMA-negative KB tumors did not appreciably respond to EC1169 therapy, thereby confirming this compound's targeted specificity for PSMA-positive cells. Finally, treatment of LNCaP-bearing mice with docetaxel (the most active chemotherapeutic agent approved for late stage prostate cancer therapy) was found to produce only modest anti-tumor activity, and this outcome was also associated with severe weight loss. Taken together, these results strongly indicate that PSMA-positive tumors may be effectively treated using highly potent, PSMA-targeted small-molecule drug conjugates using regimens that do not cause undesirable side effects.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Oligopeptídeos
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Ácidos Pipecólicos
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Neoplasias da Próstata
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Glutamato Carboxipeptidase II
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Antígenos de Superfície
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Antineoplásicos
Limite:
Animals
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Humans
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Male
Idioma:
En
Revista:
Bioconjug Chem
Assunto da revista:
BIOQUIMICA
Ano de publicação:
2019
Tipo de documento:
Article
País de afiliação:
Estados Unidos