RESUMEN
Asialoglycoprotein receptor (ASGP-R) belongs to a wide family of C-type lectins and it is currently regarded as an attractive protein in the field of targeted drug delivery (TDD). It is abundantly expressed in hepatocytes and can be found predominantly on the sinusoidal surface especially of HepG2 cells. Therefore, ASGP-R can be used for the TDD of anticancer therapeutics against HCC and molecular diagnostic tools. To date, a variety of mono- and multivalent selective ASGP-R ligands have been discovered. Although many of these compounds have demonstrated a relatively high binding affinity towards the target, the reported synthetic schemes are not handled, complicated and include many non-trivial steps. In the current study, we describe a convenient and versatile synthetic approach to novel monovalent drug-conjugates containing N-acetyl-2-deoxy-2-aminogalactopyranose fragment as an ASGP-R-recognition "core-head" and well-known nonselective cytostatic - Doxorubicin (Dox). This is the first example of the direct conjugation of a drug molecule to the ASGP-targeted warhead by a really convenient manner via a simple linker sequence. The performed MTS-based biological evaluation in HepG2 cells revealed the novel conjugates as having anticancer activity. Confocal microscopy showed that the molecules readily penetrated HepG2 membrane and were mainly localized within the cytoplasm instead of the nucleus. Per contra, Dox under the same conditions demonstrated good anticancer activity and was predominantly concentrated in the nucleus. Therefore, we speculate that the amide "trigger" that we have used in this study for linker attachment is a sufficiently stable inside the cells to be enzymatically or spontaneously degraded. As a consequence, we did not observe the release of the drug. Ligands containing triggers that are more liable towards endogenous hydrolysis within the tissue of targeting are strongly required.
Asunto(s)
Antibióticos Antineoplásicos/farmacología , Receptor de Asialoglicoproteína/antagonistas & inhibidores , Doxorrubicina/farmacología , Galactosa/farmacología , Antibióticos Antineoplásicos/síntesis química , Antibióticos Antineoplásicos/química , Receptor de Asialoglicoproteína/metabolismo , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Doxorrubicina/química , Sistemas de Liberación de Medicamentos , Ensayos de Selección de Medicamentos Antitumorales , Galactosa/análogos & derivados , Galactosa/química , Células Hep G2 , Humanos , Estructura Molecular , Relación Estructura-ActividadRESUMEN
Asialoglycoprotein receptor (ASGP-R) is a promising biological target for drug delivery into hepatoma cells. Nevertheless, there are only few examples of small-molecule conjugates of ASGP-R selective ligand equipped by a therapeutic agent for the treatment of hepatocellular carcinoma (HCC). In the present work, we describe a convenient and versatile synthetic approach to novel mono- and multivalent drug-conjugates containing N-acetyl-2-deoxy-2-aminogalactopyranose and anticancer drug - paclitaxel (PTX). Several molecules have demonstrated high affinity towards ASGP-R and good stability under physiological conditions, significant in vitro anticancer activity comparable to PTX, as well as good internalization via ASGP-R-mediated endocytosis. Therefore, the conjugates with the highest potency can be regarded as a promising therapeutic option against HCC.