Gallium(III) Complex Induces Immunogenic Cell Death Hallmarks for Chemoimmunotherapy

Tumor metastases account for nearly 90% of cancer-related fatalities. To tackle this issue, chemotherapeutic agents that induce immunogenic cell death (ICD) are being investigated as promising candidates for metastatic cancer treatment. Herein, the chemical synthesis and biological evaluation of a novel Ga(III) complex with Schiff bases, [Ga((E)-1-((quinolin-8-ylimino)methyl)naphthalen-2-olato)₂][Cl], for potential use in combined chemotherapy and immunotherapy are reported. This compound exhibited broad cytotoxicity against human breast cancer, pancreatic cancer, cervical cancer cell lines, and the noncancerous human fibroblast cell line. Mechanistic investigations revealed that the compound triggers apoptosis and ICD hallmarks, such as translocation of calreticulin, phosphorylation of eIF2α, migration of high mobility group protein 1, and release of adenosine triphosphate. Deeper biological assessment using multicellular tumor spheroids of cervical cancer cell lines, a solid tumor model, demonstrated successful eradication at micromolar concentrations. This study presents one of the few reported Ga(III) complexes capable of inducing immunogenic cell death.