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 glioblastomamultiforme (GBM) cells when combined with proton radiation in vitro.
Survivin (also known as baculoviral IAP repeat-containing protein 5 (BIRC5)) is a member of the inhibitor of apoptosis (IAP) family that interacts with and inhibits the apoptotic function of several proteins. LLP-3 is a cell-permeable ligand of Survivin that blocks its interaction with Ran, resulting in the induction of apoptosis (IAP) in glioma stem cells (IC50 = 31 μM). It abolishes the growth of glioblastomamultiforme cell in spheres and in tumor slice cultures.
K-TMZ is a DNA alkylating agent. It increases the concentration of O6-methylated deoxyguanosine in U87 glioblastomamultiforme (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, glioblastomamultiforme, 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.