Radiation-induced non-targeted effect in vivo: Evaluation of cyclooygenase-2 and endothelin-1 gene expression in rat heart tissues

J Cancer Res Ther. 2017 Jan-Mar;13(1):51-55. doi: 10.4103/0973-1482.203601.


Aim: In this study, we investigated expression levels of cyclooxygenase-2 (COX-2) and endothelin-1 (ET-1) genes after pelvis and heart irradiation in a rat model. These factors are involved in heart diseases (HDs).

Materials and methods: We used seven groups, including two groups of pelvic irradiation, two groups of whole body irradiation, two groups of heart irradiation, and one control nonirradiated group. Pelvis irradiations were conducted at a 2 cm × 2 cm in the pelvis area. Irradiation condition conducted using 1.25 MeV cobalt-60 gamma-rays (30 cGy/min). The changes at ET-1 and COX-2 gene expressions in heart tissue after pelvis and heart irradiation were measured and compared to the control and whole body irradiation groups at 24 h and 72 h after the exposure.

Results: In heart irradiation groups, 3-fold up-regulation of both ET-1 and COX-2 was observed. In pelvis irradiation groups, 3-fold up-regulation of ET-1 was seen, but not significant changes in COX-2 gene expression have observed at distant heart tissues after pelvis irradiation.

Conclusion: This study reveals that nontargeted effect induced by radiation may be considered as an important phenomenon for induction of HD after radiotherapy.

MeSH terms

  • Abnormalities, Radiation-Induced / genetics*
  • Animals
  • Cyclooxygenase 2 / genetics*
  • Endothelin-1 / genetics*
  • Gene Expression Regulation, Neoplastic
  • Heart / radiation effects
  • Humans
  • Myocardium / metabolism
  • Neoplasms / genetics
  • Neoplasms / pathology
  • Neoplasms / radiotherapy*
  • Pelvis / pathology
  • Pelvis / radiation effects
  • Rats


  • Endothelin-1
  • Cyclooxygenase 2