A BRD4‐Targeting Photothermal Agent for Controlled Protein Degradation

Abstract BRD4 protein plays a pivotal role in cell cycle regulation and differentiation. Disrupting the activity of BRD4 has emerged as a promising strategy for inhibiting the growth and proliferation of cancer cells. Herein, we introduced a BRD4‐targeting photothermal agent for controlled protein degradation, aiming to enhance low‐temperature photothermal therapy (PTT) for cancer treatment. By incorporating a BRD4 protein inhibitor into a cyanine dye scaffold, the photothermal agent specifically bond to the bromodomain of BRD4. Upon low power density laser irradiation, the agent induced protein degradation, directly destroying the BRD4 structure and inhibiting its transcriptional regulatory function. This strategy not only prolonged the retention time of the photothermal agent in cancer cells but also confined the targeted protein degradation process solely to the tumor tissue, minimizing side effects on normal tissues through the aid of exogenous signals. This work established a simple and feasible platform for future PTT agent design in clinical cancer treatment.