Glioblastoma multiforme (GBM) is a highly malignant and aggressive
primary brain tumor. In spite of an arsenal of therapeutic interventions, the prognosis of
glioblastoma remains very poor.
Cisplatin-based
therapy is one of the most important
chemotherapy treatments for GBM, although its efficacy is limited by drug resistance and undesirable side effects. In the present study, we designed a chimera molecule containing the
platinum binding moiety MBL-III-7 (1) attached N-terminal to the sequence of d-
maurocalcine (D-MCa), a
protease-resistant and highly efficient
cell-penetrating peptide (
CPP) derived from the Tunisian chactid
scorpion toxin, L-MCa. The concept behind this design is that MCa, through its cell retention properties, should reduce cell expulsion of the
platinum complex and increase its efficiency. The anti-
cancer properties of the synthesized
platinum analogue Pt-MBL-III_7-D_MCa (Pt-1-DMCa) were assessed in human
glioblastoma cells (U87) by assaying cell viability and apoptosis. The new molecule exhibited enhanced anti-
cancer efficacy compared to
cisplatin, especially at low doses. By inducing intracellular oxidative stress, Pt-1-DMCa potentiated
platinum-induced DNA damage and led to enhanced p53 phosphorylation, followed by increased activation of both mitochondrial and
death receptor pathways. Decreased phosphorylated AKT and ERK levels were associated with the apoptosis induced by the novel synthesized
cisplatin analogue. Our results suggested that a chimera between
platinum and a
maurocalcine-derived
CPP is a highly successful anti-
cancer compound that works by targeting the intracellular redox system. Pt-1-DMCa is an interesting candidate for a preclinical assessment of
platinum-based
therapy in GBM treatments and possibly other
cancer types.