Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCB217

Poster Communications

I-131 ablation/metastasis treatment may lead protective effects on lymphocyte DNA by activating repair mechanisms in patients with differentiated thyroid cancer

E. Kilic-Toprak1, T. Sengoz2, O. Yaylali2, O. Kilic-Erkek1, Y. Ozdemir1, B. Oymak1, H. Senol3, D. Yuksel2, V. Kucukatay1, M. Bor-Kucukatay1

1. Department of Physiology, Pamukkale University,Faculty of Medicine, Denizli, Turkey. 2. Department of Nuclear Medicine, Pamukkale University,Faculty of Medicine, Denizli, Turkey. 3. Department of Biostatistics, Pamukkale University,Faculty of Medicine, Denizli, Turkey.


Thyroidectomy followed by administration of large activities of 131-iodine (I-131) is the treatment of choice for differentiated thyroid carcinoma (DTC) (1). Although I-131 was suggested to form chain fractures in DNA of thyroid cells, the effect of RAIT on peripheral blood cell DNA remains controversial. The aim of this study was to determine the effect of RAIT on DNA damage in lymphocytes in patients with DTC. Totally 21 DTC patients were included in our study (mean age 45.09±10.02 years). Of the 21 patients; 6 (%28.6) were treated with a low (30 mCi) RAIT dose, 11 (%52.4) with ablation (100 mCi) dose and 4 (%19) with higher dose (>100 mCi). Venous blood samples were taken from each patient before treatment, 7 days and 6 months after the treatment. DNA damage was assessed using COMET assay following lymphocyte isolation from venous whole blood. Seventy-five cells per slide per sample were scored to evaluate DNA damage. Head length, tail length, head intensity, tail intensity, tail moment were evaluated for quantitative analysis of DNA damage. Data were analyzed with the SPSS 24.0 program. Repeated Measures Analysis of Variance was used when parametric test assumptions were provided; and the Friedman test was used when parametric test assumptions were not provided. p<0.05 was considered statistically significant. Tail intensity values were significantly lower after treatment (1st week and 6 months) (18.30±6.48 and 18.06±5.58) compared to before treatment (23.83±9.82) (p=0.002). The head intensity values were statistically significantly higher after treatment (1st week and 6 months) (81.69±6.48 and 81.93±5.58) than before treatment (76.16±9.82) (p=0.002). The tail moment was lower at 6 months following treatment compared to before treatment (5.24±2.51 vs. 8.04±3.86) (p=0.005) (Table 1). The increase in head intensity and decrease in tail intensity and moment followed by treatment have shown that RAIT does not cause significant DNA damage in peripheral blood cells. RAIT may have activated protective effects on lymphocyte DNA by activating repair mechanisms.

Where applicable, experiments conform with Society ethical requirements