Targeted Degradation of SETDB1 by an Aptamer-CRBNL PROTAC as a Novel Therapeutic Strategy for Breast Cancer

Aptamers, with their high specificity and binding affinity, have recently been explored as alternative recognition elements in PROTAC design. Here, we developed an aptamer-based PROTAC targeting SET domain bifurcated histone lysine methyltransferase 1 (SETDB1), an epigenetic regulator implicated in breast cancer progression.

The SETDB1-specific aptamer identified in our previous work was conjugated to a CRBN E3 ligase ligand via click chemistry, generating a serum-stable PROTAC, designated as P-SETDB1-4. P-SETDB1-4 effectively recruits CRBN to SETDB1, inducing proteasome-dependent degradation of SETDB1 in breast cancer cells. Consequently, P-SETDB1-4 significantly inhibits the proliferation and migration of breast cancer cells.