TOOLBOX: Strep‑Tagged nano‑assemblies of antibody‑drug‑conjugates (ADC) for modular and conditional cancer drugging

Herein, we describe TOOLBOX, a 3‑step modular nano‑assembly targeting system that permits the combinatorial exchange of antibody specificities and toxic payloads, introducing modularity in antibody‑drug conjugate (ADC) manufacturing. TOOLBOX integrates 3 building blocks: i) a recombinant antibody fragment (that in the selected setting targets the proto‑oncogene ERBB2) genetically fused to an 8 amino acid Strep‑Tag^®; ii) a multivalent protein adapter, called Strep‑Tactin^®; iii) two anticancer agents, e.g. DNA nanobinders and the maytansinoid DM1, both carrying a chemically attached Strep‑Tag that reversibly turns them into inactive prodrugs. Stoichiometrically optimized complexes of Strep‑Tagged antibody fragments and drugs, bridged by Strep‑Tactin, were specifically uptaken by breast cancer cells expressing ERBB2, and this unexpectedly resulted in conditional prodrug reactivation. A promoter‑reporter system showed that TOOLBOX inhibited downstream ERBB2 signaling not only in ERBB2‑overexpressing/‑amplified SK‑BR‑3 cells grown in vitro, but also in ERBB2‑low/non‑amplified BRC230 triple‑negative breast carcinoma cells xenotransplanted in nude mice. Thus, TOOLBOX is a modular ADC‑like nano‑assembly platform for precision oncology.

The AOM/DSS murine model for the study of colon carcinogenesis: From pathways to diagnosis and therapy studies

Colorectal cancer (CRC) is a major health problem in industrialized countries. Although inflammation-linked carcinogenesis is a well accepted concept and is often observed within the gastrointestinal tract, the underlying mechanisms remain to be elucidated. Inflammation can indeed provide initiating and promoting stimuli and mediators, generating a tumour-prone microenvironment. Many murine models of sporadic and inflammation-related colon carcinogenesis have been developed in the last decade, including chemically induced CRC models, genetically engineered mouse models, and xenoplants. Among the chemically induced CRC models, the combination of a single hit of azoxymethane (AOM) with 1 week exposure to the inflammatory agent dextran sodium sulphate (DSS) in rodents has proven to dramatically shorten the latency time for induction of CRC and to rapidly recapitulate the aberrant crypt foci–adenoma–carcinoma sequence that occurs in human CRC. Because of its high reproducibility and potency, as well as the simple and affordable mode of application, the AOM/DSS has become an outstanding model for studying colon carcinogenesis and a powerful platform for chemopreventive intervention studies. In this article we highlight the histopathological and molecular features and describe the principal genetic and epigenetic alterations and inflammatory pathways involved in carcinogenesis in AOM/DSS–treated mice; we also present a general overview of recent experimental applications and preclinical testing of novel therapeutics in the AOM/DSS model.

Synthesis and pharmacological evaluation of 2,3-dialkylindoles, "in vitro" inhibitors of thrombin-induced platelet aggregation

A series of 2,3-dialkylindoles (1-5) have been prepared and tested as antithrombotic agents. The whole class showed in vitro interesting activity in the inhibition of thrombin-induced aggregation. Among these compounds some ones showed activity comparable to standards also in the inhibition of collagen-induced aggregation. Owing to a very fast metabolic degradation through a beta-oxidative mechanism, a drastic decrease of activity in several tests ex vivo or in vivo was observed.