A mGluR1-targeted radiotheranostic strategy visualizes lesions and potentiates antitumor efficacy in melanoma and pancreatic cancer.

Abstract

Targeting metabotropic glutamate receptor 1 (mGluR1), an oncoprotein involved in glutamine metabolism that is frequently overexpressed in most cancers, is a promising strategy for cancer treatment and management. Here, we engineered a radiotheranostic strategy to target mGluR1 by integrating positron emission tomography (PET)-guided targeted α-particle therapy (TAT) with a small-molecule pair, β-emittingC-IMTM and α-emittingAt-AMTM, to identify and eradicate refractory cancers, including melanoma and pancreatic cancer.C-IMTM PET clearly visualized the primary and metastatic melanoma burden; α-particles fromAt-AMTM anchored to mGluR1 downregulated this oncoprotein, which was subsequently internalized to trigger cancer cell senescence via the p21/caveolin-1 pathway. In mice with localized and metastatic melanoma, a single dose ofAt-AMTM induced a >86% reduction in tumor volume and a 2-fold increase in survival. Moreover, 46.67% (7/15) of the tumor-bearing mice exhibited complete elimination of pancreatic cancer without significant toxicity. This mGluR1-targeted radiotheranostic strategy,C-IMTM PET-guidedAt-AMTM TAT, represents an effective approach for the diagnosis and treatment of melanoma and pancreatic cancer and provides unique insights into the clinical development and application of approaches targeting cancer-specific metabolic vulnerabilities.