Aspartate‐modified doxorubicin on its N‐terminal increases drug accumulation in LAT1‐overexpressing tumors

Abstract

L-type amino acid transporter 1 (LAT1), overexpressed on the membrane of various tumor cells, is a potential target for tumor-targeting therapy. This study aimed to develop a LAT1-mediated chemotherapeutic agent. We screened doxorubicin modified by seven different large neutral amino acids. The aspartate-modified doxorubicin (Asp-DOX) showed the highest affinity (Km = 41.423 μmol/L) to LAT1. Aspartate was attached to the N-terminal of DOX by the amide bond with a free carboxyl and a free amino group on the α-carbon atom of the Asp residue. The product Asp-DOX was characterized by HPLC/MS. In vitro, Asp-DOX exerted stronger inhibition on the cancer cells overexpressing LAT1 and the uptake of Asp-DOX was approximately 3.5-fold higher than that of DOX in HepG2 cells. Pharmacokinetic data also showed that Asp-DOX was expressed over a longer circulation time (t1/2 = 49.14 min) in the blood compared to DOX alone (t1/2 = 15.12 min). In HepG2 and HCT116 tumor-bearing mice, Asp-DOX achieved 3.1-fold and 6.4-fold accumulation of drugs in tumor tissue, respectively, than those of the unmodified DOX. More importantly, treatment of tumor-bearing mice with Asp-DOX showed a significantly stronger inhibition of tumor growth than mice treated with free DOX in HepG2 tumor models. Furthermore, after Asp modification, Asp-DOX avoided MDR mediated by P-glycoprotein. These results suggested that the Asp-DOX modified drug may provide a new treatment strategy for tumors that overexpress LAT1 and MDR1.

Targeted tumour theranostics in mice via carbon quantum dots structurally mimicking large amino acids

“…38). Tumour-targeting ligands have previously been tested for LAT1-mediated drug delivery to tumours through conjugation of aspartate 16 . It was found that LAT1 targeting improved the accumulation of DOX in tumours by threefold to sixfold.…”

“…In contrast to LAAM CQDs, aspartate has only one pair of α-carboxyl and amino groups and, as a result, the interaction between aspartate-conjugated DOX and LAT1 could be weak owing to a lack of multivalency. As a consequence, aspartate-conjugated DOX has a low affinity for tumour cells and can non-specifically penetrate normal cells, leading to high accumulation in normal organs 16 .…”

“…It was shown that conjugation of aspartate enabled LAT1-mediated delivery, improving the accumulation of doxorubicin (DOX) in tumours by threefold to sixfold (ref. 16 ).…”

New 1H-Benzo[f]indazole-4,9-diones Conjugated with C-Protected Amino Acids and Other Derivatives: Synthesis and in Vitro Antiproliferative Evaluation

“…We have recently reported the synthesis of unsubstituted and N-substituted 3-methyl-7-(4-methylpent-3-enyl)-1H-benzo[f]indazole-4,9-diones 2 from the reaction of 2-acetyl-6-(4-methylpent-3-enyl)-1,4-naphthoquinone 1 with hydrazine or substituted hydrazines [23]. The objective of this work was to continue previous research on the design and synthesis of new potentially cytotoxic 1,4-naphthoquinone compounds [24,25] while taking into account the enhanced cytotoxic effect that has been observed in drugs or compounds conjugated with amino acids [26,27]. Therefore, we prepared twenty one new 1H-benzo[f]indazole-4,9-dione compounds conjugated with glycine and the L-type amino acids alanine, phenylalanine, and glutamic acid 6a-l, as well as the epoxides 3a-c, aldehydes 4a-c and carboxylic acids 5a-c, by chemically modifying the prenyl 7-(4-methylpent-3-enyl) substituent of 2.…”

Studies on antitumor activity spectrum of doxycycline

“…For instance, antibiotics can be used as anticancer drugs. [1][2][3][4] Four to five classes of drugs, such as tetracyclines, can also be used to eradicate 12 cancer cell lines. [5] Tetracyclines are cytotoxic to tumor cells.…”