Duocarmycin SA is an extremely potent cytotoxic agent and antitumor antibiotic that induces sequence-selective alkylation of duplex DNA, with an IC50 of 10 pM. It demonstrates synergistic cytotoxicity against glioblastoma multiforme (GBM) cells when combined with proton radiation in vitro.
K-TMZ is a DNA alkylating agent. It increases the concentration of O6-methylated deoxyguanosine in U87 glioblastoma multiforme (GBM) cells in a concentration-dependent manner. K-TMZ reduces cell viability of GBM cell lines lacking (IC50s = 18-44 μM) or expressing O6-methylguanine DNA methyltransferase (MGMT; IC50s = 115-240 μM). K-TMZ can cross the blood-brain barrier and increases survival in a Br23c mouse xenograft model of GBM when administered at a dose of 14.9 mg/kg.
GPI-15427 is a potent PARP-1 inhibitor capable of crossing the blood-brain barrier, which can significantly increased the antitumor activity of the methylating agent TMZ against malignant melanoma, glioblastoma multiforme, or lymphoma growing at the CNS site. GPI-15427 acts as a potent inhibitor of the enzyme, being capable of inhibiting the activity of purified PARP-1 at nanomolar concentrations. GPI-15427 induced significant sensitization to radiotherapy, representing a promising new treatment in the management of HNSCC.