Modification of daunorubicin-GnRH-III bioconjugates with oligoethylene glycol derivatives to improve solubility and bioavailability for targeted cancer chemotherapy.
Daunorubicin-GnRH-III bioconjugates have recently been developed as drug delivery systems with potential applications in targeted cancer chemotherapy. In order to improve their biochemical properties, several strategies have been pursued: (1) incorporation of an enzymatic cleavable spacer between the anticancer drug and the peptide-based targeting moiety, (2) peptide modification by short chain fatty acids, or (3) attachment of two anticancer drugs to the same GnRH-III derivative. Although these modifications led to more potent bioconjugates, a decrease in their solubility was observed. Here we report on the design, synthesis and biochemical characterization of daunorubicin-GnRH-III bioconjugates with increased solubility, which could be achieved by incorporating oligoethylene glycol-based spacers in their structure. First, we have evaluated the effect of an oligoethylene glycol-based spacer on the solubility, enzymatic stability/degradation, cellular uptake, and in vitro cytostatic effect of a bioconjugate containing only one daunorubicin attached through a GFLG tetrapeptide spacer to the GnRH-III targeting moiety. Thereafter, more complex compounds containing two copies of daunorubicin, GFLG spacers as well as Lys(nBu) in position 4 of GnRH-III were synthesized and biochemically characterized. Our results indicated that all synthesized oligoethylene glycol-containing bioconjugates had higher solubility in cell culture medium than the unmodified analogs. They were degraded in the presence of rat liver lysosomal homogenate leading to the formation of small drug containing metabolites. In the case of bioconjugates containing two copies of daunorubicin, the incorporation of oligoethylene glycol-based spacers led to increased in vitro cytostatic effect on MCF-7 human breast cancer cells.
MTA-ELTE Research Group of Peptide Chemistry, Eötvös L. University, 1117, Budapest, Hungary.
Rózsa
R
Hegedüs
Department of Chemistry, University of Konstanz, 78457, Konstanz, Germany.
Aline
A
Pauschert
MTA-ELTE Research Group of Peptide Chemistry, Eötvös L. University, 1117, Budapest, Hungary.
Erika
E
Orbán
MTA-ELTE Research Group of Peptide Chemistry, Eötvös L. University, 1117, Budapest, Hungary.
Ildikó
I
Szabó
Department of Experimental and Health Sciences, Pompeu Fabra University, 08003, Barcelona, Spain.
David
D
Andreu
Proteomics Facility, Department of Biology, University of Konstanz, 78457, Konstanz, Germany.
Andreas
A
Marquardt
MTA-ELTE Research Group of Peptide Chemistry, Eötvös L. University, 1117, Budapest, Hungary.
Gábor
G
Mező
Department of Chemistry, University of Konstanz, 78457, Konstanz, Germany.|Zukunftskolleg, University of Konstanz, 78457, Konstanz, Germany.
Marilena
M
Manea
D000818:Animals; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003630:Daunorubicin / Q000737:chemistry / Q000494:pharmacology; D016503:Drug Delivery Systems / Q000379:methods*; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000737:chemistry / Q000494:pharmacology; D006801:Humans; D061986:MCF-7 Cells; D011092:Polyethylene Glycols / Q000737:chemistry / Q000494:pharmacology; D051381:Rats; D012995:Solubility
D007987:Gonadotropin-Releasing Hormone; D011092:Polyethylene Glycols; D003630:Daunorubicin
cytostatic effect; daunorubicin; drug delivery systems; enhanced solubility; gonadotropin-releasing hormone; oligoethylene glycol