Apoptosis initiation and angiogenesis inhibition: melanoma targets for nanosecond pulsed electric fields

Area of Science:

• Biophysics
• Cancer Biology
• Oncology

Background:

• Anti-cancer strategies often target apoptosis and angiogenesis.
• Nanosecond pulsed electric fields (nsPEFs) show promise for cancer treatment by inducing apoptosis in vitro and eliminating tumors in vivo.
• Further investigation into the in vivo mechanisms of nsPEF action is needed.

Purpose of the Study:

• To investigate the mechanisms of nsPEF-induced apoptosis and anti-angiogenesis in vivo.
• To analyze the cellular and molecular responses to nsPEF treatment in a tumor model.
• To evaluate the therapeutic potential of nsPEFs for cancer treatment.

Main Methods:

• Treatment of tumors with one hundred 300 ns pulses at 40 kV/cm.
• Analysis of apoptosis markers (caspase activation, Histone 2AX phosphorylation, DNA fragmentation) using fluorescent microscopy and immunoblots.
• Assessment of anti-angiogenic effects by quantifying vessel numbers and specific growth factors (VEGF, PD-ECGF) and markers (CD31, CD35, CD105).
• Tumor morphology and growth (weight, volume) evaluation.

Main Results:

• nsPEFs induced transient caspase activation, suggesting caspase-mediated apoptosis.
• Peaks in Histone 2AX phosphorylation and DNA damage markers indicated caspase-independent nuclear/DNA effects.
• Incomplete apoptosis was observed, with large DNA fragments but no 180 bp ladders.
• Significant reduction in tumor weight and volume, with complete tumor disappearance in some cases.
• Decreased vessel formation and reduced levels of VEGF, PD-ECGF, CD31, CD35, and CD105 one week post-treatment, confirming anti-angiogenesis.

Conclusions:

• nsPEFs activate multiple therapeutic targets in melanoma, including pathways for apoptosis and angiogenesis.
• The findings support the efficacy of nsPEFs in reducing tumor burden and inhibiting tumor growth in vivo.
• nsPEF application represents a promising new therapeutic modality for cancer treatment.