Tumoricidal efficacy of DZ-1 dye conjugated to dihydroartemisinin in patient-derived colorectal liver metastasis tumoroids

Hepatic colorectal metastases, also termed colorectal liver metastases (CRLM), remain a major clinical challenge, despite advances in surgery and chemotherapy. The complexity of CRLM pathology necessitates novel therapeutic approaches, yet current preclinical models often fail to accurately recapitulate the human tumor microenvironment. To overcome these limitations, we utilized patient-derived three-dimensional (3D) CRLM tumoroids to evaluate the efficacy of DZ-1-DHA, a novel conjugate consisting of the heptamethine carbocyanine dye DZ-1 linked to the anti-malarial derivative dihydroartemisinin (DHA). Data from TUNEL and immunoblotting assays revealed that treatment of CRLM tumoroids with DZ-1-DHA led to significant tumor cell death, accompanied by apoptotic signaling. Fluorescence imaging with MitoTracker, 2',7'-dichlorofluorescin diacetate, MitoSOX, and JC-1 showed that DZ-1-DHA accumulates in mitochondria, where it induces generation of cytotoxic Reactive Oxygen Species (ROS) and causes mitochondrial membrane depolarization. Furthermore, data from treatment with deferoxamine or MitoTEMPO indicated that DZ-1-DHA promotes mitochondrial ROS production through a Fenton-like mechanism. These findings demonstrate that DZ-1-DHA triggers Apoptosis through mitochondrial stress and apoptotic signaling pathways. Also, DZ-1-DHA represents a promising second-line therapeutic strategy for CRLM. By inducing selective tumor cell death through mitochondrial-targeted Apoptosis in a clinically relevant 3D model. This promising approach needs in vivo validation for safety and efficacy.