Fibrosis and cytokine mechanisms: relevant in hadron therapy?
BACKGROUND
Cytokines are important for signalling between cells and tissues and constitute a humoral component of the response of cells and tissues to radiotherapy. Although several cytokines have been implicated in mediating radiation-induced reactions of normal tissues to both conventional photon and heavy ion irradiation, the mechanisms are only beginning to be elucidated.


METHODS
Published and own data on radiation-induced cytokine expression from cell culture and clinical studies are reviewed. Current models of cytokine-mediated multicellular interactions in radiation-induced reactions are presented.


CONCLUSIONS
The major cytokines in the radiation response of non-hemopoietic tissues include IL-6, IL-1, TNF-alpha and TGF-beta. Different cell types interact via cytokines in a complex network of effector and receptor cells, including inflammatory cells, tissue-specific functional cells and fibroblasts. TGF-beta appears to be of particular importance in the development of late reactions to radiation therapy, such as fibrosis, in response to both conventional therapy as well as hadron therapy.
Haase
Oliver
O
Section of Radiobiology & Molecular Environmental Research, Dept. of Radiation Oncology, University of Tuebingen, Roentgenweg 11, 72076 Tuebingen, Germany.
Rodemann
H Peter
HP
D002244:Carbon; D016207:Cytokines / Q000235:genetics*; D005355:Fibrosis; D015870:Gene Expression / Q000528:radiation effects; D020450:Heavy Ions / Q000009:adverse effects*; D006801:Humans; D007375:Interleukin-1 / Q000235:genetics; D011832:Radiation Injuries / Q000378:metabolism*; D016212:Transforming Growth Factor beta / Q000235:genetics; D014409:Tumor Necrosis Factor-alpha / Q000235:genetics
D016207:Cytokines; D007375:Interleukin-1; D016212:Transforming Growth Factor beta; D014409:Tumor Necrosis Factor-alpha; D002244:Carbon