Pyrazolo[3,4-d]pyrimidine Tyrosine Kinase Inhibitors Induce Oxidative Stress in Patient-Derived Glioblastoma Cells

Area of Science:

• Oncology
• Molecular Biology
• Biochemistry

Background:

• Glioblastoma (GBM) exhibits high Src tyrosine kinase expression, promoting tumor cell survival, proliferation, angiogenesis, and invasiveness.
• Src activation is linked to reduced reactive oxygen species (ROS) generation, while Src inhibitors increase cellular ROS levels.

Purpose of the Study:

• To investigate the pro-oxidative effects of pyrazolo[3,4-d]pyrimidine derivatives, Si306 and its prodrug pro-Si306, as Src tyrosine kinase inhibitors in human glioblastoma cells.
• To evaluate the impact of these inhibitors on ROS production, mitochondrial membrane potential, antioxidant enzyme expression, DNA damage, cell death, and senescence.

Main Methods:

• Utilized human GBM cell lines (U87 and patient-derived GBM-6) for experiments.
• Assessed ROS production and mitochondrial membrane potential via flow cytometry.
• Examined superoxide dismutase 1 (SOD1) and 2 (SOD2) expression using Western blot.
• Investigated DNA damage, cell death induction, and senescence in GBM-6 cells.

Main Results:

• Si306 and pro-Si306 significantly induced ROS production and antioxidant enzyme expression in primary GBM cells.
• Observed disruption of mitochondrial membrane potential, double-strand DNA breaks, and induction of senescence.
• These pro-oxidative effects ultimately led to necrosis in GBM cells.

Conclusions:

• Src kinase inhibitors Si306 and pro-Si306 demonstrate significant pro-oxidative potential in patient-derived GBM cells.
• This pro-oxidative activity complements their known anti-glioblastoma properties.
• The findings encourage further clinical investigation of Si306 and pro-Si306 for glioblastoma treatment.