Inhibiting Cancer Metastasis through Combination Therapy

Strategic Insights -

Combination therapy targeting vascular endothelial growth factor-C (VEGF-C) and VEGF-A has shown promising results in inhibiting cancer metastasis in a murine metastatic mammary cancer model. Scientists from Osaka Medical College observed that direct intratumoral injection of plasmid siRNA vectors targeting VEGF-C and/or VEGF-A resulted in significantly reduced tumor volume, lymph node metastasis, and multiplicity of lung metastases. The combination therapy targeting both VEGF-C and VEGF-A showed the most significant reduction in metastasis, suggesting its potential as a high-impact treatment for metastatic breast cancer.

Key Takeaways:

  • Combination therapy with siRNA vectors targeting VEGF-C and VEGF-A inhibited both lymph node and lung metastasis in a mouse immunocompetent mammary cancer model.
  • Direct intratumoral injection of plasmid siRNA vectors targeting VEGF-C and/or VEGF-A resulted in significantly reduced tumor volume, lymph node metastasis, and multiplicity of lung metastases.
  • Specific silencing of the VEGF-C or VEGF-A gene alone can inhibit lymph node metastasis, but combination therapy targeting both genes appears to be more effective.
  • The anti-metastatic activity of siRNA-expressing vectors targeting VEGF-C or VEGF-A may have high clinical significance in the treatment of metastatic breast cancer.
  • Gene electrotransfer was performed on the tumors after each injection to enhance the expression of siRNA.
  • The researchers used a synergistic approach by combining siRNA vectors targeting VEGF-C and VEGF-A to inhibit both lymph node and lung metastasis.

Statistics:

  • 8 weeks: duration of the study
  • 4 times a week: intratumoral injection of siRNA vectors
  • 76% inhibition of lymph node metastasis in the psiRNA-VEGF-C group
  • 92% inhibition of lung metastasis in the psiRNA-VEGF-C+A group
  • 25% reduction in the number of dilated lymphatic vessels containing intraluminal cancer cells
  • 30% reduction in microvessel density

Sources:

  • Shibata, M.A., et al. "Combination therapy with short interfering RNA vectors against VEGF-C and VEGF-A suppresses lymph node and lung metastasis in a mouse immunocompetent mammary cancer model." Cancer Gene Therapy 15(12): 776-786, 2008.