Targeting inflammatory pathways for tumor radiosensitization

Biochem Pharmacol. 2010 Dec 15;80(12):1904-14. doi: 10.1016/j.bcp.2010.06.039. Epub 2010 Jun 30.


Although radiation therapy (RT) is an integral component of treatment of patients with many types of cancer, inherent and/or acquired resistance to the cytotoxic effects of RT is increasingly recognized as a significant impediment to effective cancer treatment. Inherent resistance is mediated by constitutively activated oncogenic, proliferative and anti-apoptotic proteins/pathways whereas acquired resistance refers to transient induction of proteins/pathways following radiation exposure. To realize the full potential of RT, it is essential to understand the signaling pathways that mediate inducible radiation resistance, a poorly characterized phenomenon, and identify druggable targets for radiosensitization. Ionizing radiation induces a multilayered signaling response in mammalian cells by activating many pro-survival pathways that converge to transiently activate a few important transcription factors (TFs), including nuclear factor kappa B (NF-κB) and signal transducers and activators of transcription (STATs), the central mediators of inflammatory and carcinogenic signaling. Together, these TFs activate a wide spectrum of pro-survival genes regulating inflammation, anti-apoptosis, invasion and angiogenesis pathways, which confer tumor cell radioresistance. Equally, radiation-induced activation of pro-inflammatory cytokine network (including interleukin (IL)-1β, IL-6 and tumor necrosis factor-α) has been shown to mediate symptom burden (pain, fatigue, local inflammation) in cancer patients. Thus, targeting radiation-induced inflammatory pathways may exert a dual effect of accentuating the tumor radioresponse and reducing normal tissue side-effects, thereby increasing the therapeutic window of cancer treatment. We review recent data demonstrating the pivotal role played by inflammatory pathways in cancer progression and modulation of radiation response.

Publication types

  • Review

MeSH terms

  • Animals
  • Cyclooxygenase 2 / physiology
  • Cytokines / metabolism
  • Disease Progression
  • Humans
  • Inflammation / metabolism
  • Inflammation / prevention & control
  • Molecular Targeted Therapy
  • NF-kappa B / physiology
  • Neoplasms / immunology
  • Neoplasms / pathology
  • Neoplasms / radiotherapy*
  • Radiation Injuries / prevention & control
  • Radiation Tolerance* / drug effects
  • STAT Transcription Factors / physiology


  • Cytokines
  • NF-kappa B
  • STAT Transcription Factors
  • Cyclooxygenase 2