Bortezomib-enhanced radiosensitization through the suppression of radiation-induced nuclear factor-κB activity in

Tetsuya Tamatani1, Natsumi Takamaru, Kanae Hara

  • 1Department of Oral Surgery, Subdivision of Molecular Oral Medicine, Division of Integrated Sciences of Translational Research, Institute of Health Biosciences, the University of Tokushima Graduate School, Tokushima 770-8504, Japan. ttama@dent.tokushima-u.ac.jp

Insights

Bortezomib effectively inhibits oral cancer growth by targeting nuclear factor-κB (NF-κB). Combined with radiation, it suppresses tumor proliferation, angiogenesis, and induces apoptosis, offering a novel treatment strategy.

Area of Science:

  • Oncology
  • Molecular Biology
  • Cancer Therapeutics

Background:

  • Oral cancer exhibits elevated nuclear factor-κB (NF-κB) activity, a key driver of tumor growth.
  • NF-κB inhibition is a validated strategy for suppressing oral cancer progression.
  • Bortezomib, a proteasome inhibitor, targets NF-κB and is used in molecular-targeted therapy.

Purpose of the Study:

  • To investigate bortezomib's efficacy as a proliferation inhibitor and radiosensitizer in oral cancer treatment.
  • To evaluate the combined effects of bortezomib and radiation (RT) on oral cancer growth.
  • To elucidate the molecular mechanisms underlying bortezomib's anti-tumor effects.

Main Methods:

  • Assessed NF-κB activity and cell proliferation inhibition by bortezomib in vitro and in vivo.
  • Evaluated the combined effects of bortezomib and RT on oral cancer cell growth.
  • Utilized ELISA to examine downstream signaling molecules, including angiogenic factors and anti-apoptotic proteins.
  • Measured cleaved poly(ADP-ribose) polymerase expression to assess apoptosis induction.

Main Results:

  • Bortezomib significantly inhibited NF-κB activity and oral cancer cell proliferation.
  • Combined bortezomib and RT treatment demonstrated superior suppression of NF-κB activity and tumor growth compared to RT alone.
  • The combination therapy markedly reduced radiation-induced pro-angiogenic factors and tumor vascularization.
  • Bortezomib counteracted RT-induced upregulation of anti-apoptotic proteins and enhanced apoptosis induction.

Conclusions:

  • Bortezomib is a potent inhibitor of oral cancer growth, both alone and in combination with radiation.
  • The combined treatment strategy effectively suppresses tumor proliferation, angiogenesis, and promotes apoptosis.
  • Targeting NF-κB with bortezomib represents a promising novel molecular therapy for oral cancer.

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