Fluorogenic Real-Time Reporters of DNA Repair by MGMT, a Clinical Predictor of Antitumor Drug Response

摘要: Common alkylating antitumor drugs, such as temozolomide, trigger their cytotoxicity by methylating the O6-position of guanosine in DNA. However, therapeutic effect these drugs is dampened elevated levels DNA repair enzyme, O6-methylguanine methyltransferase (MGMT), which directly reverses this alkylation. As a result, assessing MGMT patient samples provides an important predictor response; however, current methods available to measure protein are indirect, complex and slow. Here we describe design synthesis fluorescent chemosensors that report on activity single step within minutes. The incorporate fluorophore quencher pair, become separated dealkylation reaction, yielding light-up responses up 55-fold, reflecting activity. Experiments show best-performing probe retains near-native at mid-nanomolar concentrations. A nuclease-protected probe, NR-1, was prepared tested tumor cell lysates, demonstrating ability evaluate relative twenty In addition, employed inhibitors MGMT, suggesting utility for discovering new high-throughput manner. Probe designs NR-1 may prove valuable clinicians selection patients drug therapies resistance arises during treatment.