Radiosensitizing Effect Of Bromodeoxyuridine On The Process Of Killing Thyroid Cancer Cell By ～(131)I

Objective To investigate the radiosensitizing effect of 5-bromo-2'-deoxyuridine (BrdUrd) on cells of thyroid carcinoma cultured in vitro as well as on the growth of cultred cells. Methods Primary in vitro was performed on cells obtained from patients with thyroid carcinoma and it was treated using different concentrations of BrdUrd with and without Na¹31I. The ratios of Na¹31I incorporation in cells were measured by Y -radioimmunoassay counter ;The growth-suppression andclonogenic formation of cells was analyzed; Induction of apoptosis and micronucleus formation has been studied . Results The cells of thyroid carcinoma cultured in vitro can take in Na¹31I easily ,with measurement of 4× 10^-3Bq per cell, the effect wasn't enhanced by BrdUrd; Na¹31I is demostrated to be radiobiological effection on cells in this study; BrdUrd has little effect on the growth-suppression and clonogenic formation of the cultured cells, as well as induction of apoptosis and micronucleus formation when it was cultred with cells alone; However it has significant effect on the growth-suppression and clonogenic formation of the cultured cells as well as induction of apoptosis and micronucleus formation when it was cultred with Na¹31I; BrdUrd can increase the number of cells in G₁/S phase. Conclusion BrdUrd is a promising radiosensitizing nucleoside analog , and it has little cytotoxicity , it can be used in clinical practice safely.