Discovery of ERα-targeting PROTACs with intrinsic fluorescence for precision theranostics of breast cancer.

Real-time monitoring of protein degradation is challenging. Herein, novel ERα-targeted dual-function PROTACs with intrinsic fluorescence were designed and synthesized for precision theranostics of breast cancer. Among them, W2 showed good antiproliferative activity, selective ERα degradation and imaging capabilities in MCF-7 breast cancer cell lines. The safety assay indicated that W2 was well-tolerated up to a dose of 500 mg kg with no acute toxicity. This work demonstrates the great potential of ERα-targeted PROTACs as theranostic agents in breast cancer treatment.