Doxorubicin attached to HPMA copolymer via amide bond modifies the glycosylation pattern of EL4 cells

Abstract

To avoid the side effects of the anti-cancer drug doxorubicin (Dox), we conjugated this drug to a N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer backbone. Dox was conjugated via an amide bond (Dox-HPMA(AM), PK1) or a hydrazone pH-sensitive bond (Dox-HPMA(HYD)). In contrast to Dox and Dox-HPMA(HYD), Dox-HPMA(AM) accumulates within the cell's intracellular membranes, including those of the Golgi complex and endoplasmic reticulum, both involved in protein glycosylation. Flow cytometry was used to determine lectin binding and cell death, immunoblot to characterize the presence of CD7, CD43, CD44, and CD45, and high-performance anion exchange chromatography with pulsed amperometric detector analysis for characterization of plasma membrane saccharide composition. Incubation of EL4 cells with Dox-HPMA(AM) conjugate, in contrast to Dox or Dox-HPMA(HYD), increased the amounts of membrane surface-associated glycoproteins, as well as saccharide moieties recognized by peanut agglutinin, Erythrina cristagalli, or galectin-1 lectins. Only Dox-HPMA(AM) increased expression of the highly glycosylated membrane glycoprotein CD43, while expression of others (CD7, CD44, and CD45) was unaffected. The binding sites for galectin-1 are present on CD43 molecule. Furthermore, we present that EL4 treated with Dox-HPMA(AM) possesses increased sensitivity to galectin-1-induced apoptosis. In this study, we demonstrate that Dox-HPMA(AM) treatment changes glycosylation of the EL4 T cell lymphoma surface and sensitizes the cells to galectin-1-induced apoptosis.

Chain‐Shattering Polymeric Therapeutics with On‐Demand Drug‐Release Capability

“…[5] As such, batch-to-batch variations of drug loading and release profiles are often observed with polymer–drug conjugates, and these variations may present a key bottleneck to the clinical translation of PTs. [6] …”

Gemcitabine‐(5′‐phosphoramidate)‐[anti‐IGF‐1R]: molecular design, synthetic organic chemistry reactions, and antineoplastic cytotoxic potency in populations of pulmonary adenocarcinoma (A549)

“…In contrast to the anthracycline class of chemotherapeutics, a comparatively limited body of investigation has been devoted to the molecular design and optimization of organic chemistry reactions that can be utilized in synthesis regimens for covalently bonding non‐anthracycline small‐molecular‐weight chemotherapeutics to biologically relevant molecular platforms. Classical small molecular weight chemotherapeutics that have been synthesized and become available commercially as covalent immunochemotherapeutics include (i) irinotecan metabolite SN38 that inhibits topoisomerase‐I for CD74(+) multiple myeloma and chronic lymphocytic leukemia/CLL (SN38‐milatuzumab); or CEA(+) lung, breast, and colorectal adenocarcinomas/carcinomas (SN38‐labetuzumab); or EPG‐1(+) or TROP‐2(+) adenocarcinoma and carcinoma classified as triple‐negative breast cancer, small‐cell lung cancer, and colorectal cancer (SN38‐hRS7 or IMMU132); and (ii) anthracyclines that inhibit topoisomerase‐II and nucleotide strand formation while promoting ‘free’ oxygen radical formation and chromatin histone eviction with efficacy against CD74(+) chronic lymphocytic leukemia and multiple myeloma (doxorubicin‐milatuzumab).…”

“…Covalent immunochemotherapeutics that possess properties of selective ‘targeted’ delivery have traditionally been synthesized utilizing the anthracyclines where doxorubicin has been most commonly been utilized in this capacity while daunorubicin and epirubicin have also be employed but less frequently. Organic chemistry reactions for covalently bonding gemcitabine chemotherapeutic to a biologically relevant peptide sequences or large molecular weight proteins have rarely been described .…”

Drug Delivery Systems for Phthalocyanines for Photodynamic Therapy

“…After successful delivery of PNP to tumor cells, the entrapped PS can be released (typical mechanism for biodegradable particles) or the porous structure of PNP may allow permeation of ROS and interaction with the captured PS and thus maintaining their PDT performance in cells (158,164). In case of drugs conjugated to polymer backbone, they can be cleaved enzymatically, hydrolytically or as a response of pH-sensitive bonds on change of pH (165). If targeting moieties such as oligopeptides are bound to the polymer, selective tumor uptake can be achieved (166).…”