Peripheral leukocyte response to oncological radiotherapy: expression of heat shock proteins.
OBJECTIVE
To study Heat Shock Proteins (HSP) expression in patients subjected to radiotherapy and their potential use as biomarkers for radiation tolerance. An evaluation is also made of whether irradiated volume is critical to the outcome of normal tissue injury using polymorphonuclear neutrophils as biosensors, and whether HSP antibodies (Ab) may be involved in post-radiotherapy disease.


METHODS
Twelve patients receiving the same total dose of radiotherapy, but in three different volumes, and four healthy volunteers used as controls were analysed. hsp27 and 70i mRNA were determined by Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and Southern-blot, HSP by flow cytometry, and HSP-Ab by Enzyme-linked Immnoadsorbent Assay (ELISA). The clinical protocol included radiation related toxicity based on clinical and analytical scales.


RESULTS
Radiotherapy caused hsp downregulation, maximum in patients with the largest irradiated volumes, and a decrease in intracellular HSP content. Patients with greatest intraleukocyte HSP levels before treatment suffered more severe radiation morbidity. Patients with endocrine neoplasms presented the highest HSP-Ab titers.


CONCLUSIONS
Radiotherapy downregulates hsp27 and 70i, which would enhance radiosensitivity. HSP content prior to treatment is suggested as a prognostic biomarker for radiation tolerance, with circulating leukocytes as biosensors. HSP-Ab may be biomarkers of tumor disease, but do not seem to be involved in the morbidity of acute post-radiotherapy disease, which is closely related to the volumes irradiated.
Guisasola
M C
MC
Cellular Biology Laboratory, Experimental Medical and Surgery Unit, and Oncology Department Hospital General Universitario Gregorio Marañón, Madrid, Spain. hsp@mce.hggm.es
Calvo
F
F
Marcos
P
P
Simón
I
I
Villanueva
F J
FJ
Andrés
E
E
Suárez
A
A
García-Barreno
P
P
D000368:Aged; D001323:Autoantibodies / Q000097:blood; D005260:Female; D005434:Flow Cytometry; D006360:Heat-Shock Proteins / Q000032:analysis / Q000235:genetics* / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000532:radiotherapy*; D009504:Neutrophils / Q000378:metabolism / Q000528:radiation effects*; D012333:RNA, Messenger / Q000032:analysis
D001323:Autoantibodies; D006360:Heat-Shock Proteins; D012333:RNA, Messenger