Studies On Expression And Significance Of Fas And HSP70 In Beagle Spinal Cord After Spine Intensity Modulated Radiation Therapy And Conventional Radiation Therapy

Objective:By comparing the spine intensity modulated radiation therapy (IMRT) and the conventional radiation therapy of the beagle spinal cord neurons to demonstrate the biological safety of IMRT of the spinal cord. Methods:Select purebred beagles and sixteen were randomly divided into four groups. Mimic a beagle clinical model of tumor in the ninth and tenth thoracic vertebrae. Then four groups beagle were irradiated by two different models of IMRT and conventional radiation therapy, and the total irradiation doses were 50 Gy and 70 Gy in 20 days. The samples of spinal cord were taken out on the 3th month after radiation.2-DE technique was used to identify the differential protein in the spinal cord after spine IMRT and conventional radiation therapy. The samples were observed by the hematoxylin and eosin stain. The expression of Fas, HSP70 and Fas, HSP70mRNA were evaluated in spinal cord neurons by immunohistochemistry and RT-PCR. Terminal deoxynucleotidyl transferase mediated dUTP nick and labeling (TUNEL) technique was used to examine the apoptotic cells in the spinal cord. Results:①The differential proteins of Fas and HSP70 were identified by the 2-DE technique in the spinal cord after spine IMRT and conventional radiation therapy.②Compared with the IMRT group, the score of the ethology in the conventional radiation therapy group was higher following the same dose.③The late radiotherapy response of the spinal cord neurons was obviously observed on the 3th month. The neurons in the spinal cord of IMRT group were mainly reversible injury, but the conventional radiation therapy ones were mainly apoptosis.④Compared with the IMRT group, the apoptosis rate of the spinal cord neurons and the expression of Fas and FasmRNA in the conventional radiation therapy group increased obviously following the same dose.⑤The expression of HSP70 and HSP70mRNA descended. The numerus of Fas/HSP70 was positively correlated with the apoptosis rate of the spinal cord neurons. Conclusion:①The late radiotherapy response of the spinal cord neurons was existing on the 3th month.②Fas and HSP70 taken part in the apoptosis process of the spinal cord neurons after the radiation therapy. The numerus of Fas/HSP70 was a definitive factor to the apoptosis of the spinal cord neurons.③Biological safety of spinal cord in the IMRT group was much better than in the conventional radiation therapy group.