Discovering metabolic vulnerability using spatially resolved metabolomics for antitumor small molecule-drug conjugates development as a precise cancer therapy strategy

Against tumor-dependent metabolic vulnerability is an attractive strategy for tumor-targeted therapy. However, metabolic inhibitors are limited by the drug resistance of cancerous cells due to their metabolic plasticity and heterogeneity. Herein, choline metabolism was discovered by spatially resolved metabolomics analysis as metabolic vulnerability which is highly active in different cancer types, and a choline-modified strategy for small molecule-drug conjugates (SMDCs) design was developed to fool tumor cells into indiscriminately taking in choline-modified chemotherapy drugs for targeted cancer therapy, instead of directly inhibiting choline metabolism. As a proof-of-concept, choline-modified SMDCs were designed, screened, and investigated for their druggability in vitro and in vivo. This strategy improved tumor targeting, preserved tumor inhibition and reduced toxicity of paclitaxel, through targeted drug delivery to tumor by highly expressed choline transporters, and site-specific release by carboxylesterase. This study expands the strategy of targeting metabolic vulnerability and provides new ideas of developing SMDCs for precise cancer therapy.

A branched small molecule-drug conjugate nanomedicine strategy for the targeted HCC chemotherapy

Off-target toxicity is one of the main challenges faced by anticancer chemotherapeutics. For tumor targeted and precision chemotherapy, we take the advantages of the ligand directed tumor active targeting of small molecule drug conjugates (SMDCs) and the passive tumor targeting of nanoparticles via the enhanced penetration and retention (EPR) effects, put forward a branched small molecule drug conjugate (BSMDC) nanomedicine design concept. In a proof of concept, we used pentaerythritol as the branched moiety, galactosamine (GalN) as the hepatocellular carcinoma (HCC) directing ligands, PTX as a payload, and a stearoyl moiety as the amphiphilic property adjusting group, designed and synthesized BSMDC 1 and prepared its NPs. In cellular level, the BSMDC 1 NPs targeted asialoglycoprotein receptor (ASGPR)-overexpressing HepG2 cells, were effectively taken up in the cells and released in tumor microenvironments, inhibited the HepG2 cell proliferation, arrested HepG2 cell in G2/M phase and induced tumor cell apoptosis. In HepG2 xenograft nude mice, the BSMDC 1 NPs were high specific to target the tumor and demonstrated a higher antitumor efficiency than BSMDC 1, having no apparent influences on mice body weights and major organs, supporting our BSMDC nanomedicine design concept. Therefore, this new strategy may find applications for cancer targeted and precision chemotherapy.