[en] Objective: To study the changes of iodine uptake of the follicular thyroid carcinoma cell line (FTC-133) and nude mice bearing human follicular thyroid carcinoma after the induction with all-trans retinoic acid (ATRA), trichostatin A (TSA) or ATRA combined with TSA. Methods: After the induction with ATRA, TSA, or ATRA combined with TSA in different concentrations for 96 h, the iodine uptake of FTC-133 cells was observed. The concentrations for different groups were as follows: ATRA 1.0 ×10^-6 mol/L(A_low group), ATRA 1.0 × 10^-4 mol/L (A_high group), TSA 1.65 ×10^-7 mol/L (T group), A_low + T group, A_high + T group and ethanol (control group). Cell quantities and morphology were observed by HE staining. FTC-133 cells were subcutaneously injected into nude mice. Twelve nude mice were randomly divided into 4 groups after tumor formation: ATRA group (2 mg/kg, intragastric administration), TSA group (10 mg/kg, intraperitoneal injection), combined therapy group (ATRA + TSA, the same doses as above) and saline control group (10 ml/kg, intragastric and intraperitoneal administration, respectively). Drugs were administered to the tumor-bearing mice according to the mouse body mass daily. At the 22nd day, the tumor-bearing mice were injected with 37 MBq ¹³¹I intraperitoneally. The biodistribution of ¹³¹I and gamma imaging were performed at 4, 6, 12 and 24 h after the injection respectively. Histopathological examinations of the tumor samples were taken after imaging completion. The results were analyzed by analysis of variance (ANOVA) with SPSS 13.0. Results: The cellular iodine uptake were (23 885 ± 616.0) and (13 849 ±728.2) counts · min^-1 · 10^-6 cells in the A_low + T group and A_high + T group respectively, and the data were (985 ± 84.2) - (17 600 ± 782.7) counts · min^-1 · 10^-6 in the other groups (F=600.879, P<0.001). The % ID/g of tumor at 6 h was 6.17 ±0.46 in the combined group and it increased to 9.34 ±0.61 at 12 h and 11.19 ± 0.98 at 24 h. The % ID/g of tumor in the other groups were from (1.97 ± 0.34) to (5.14 ± 0.65). The tumor qualities of the 4 groups were significantly different (F=3.723, P<0.05). Conclusion: The iodine uptake of the tumor could be enhanced in the tumor-bearing mice administered with ATRA combined with TSA, a potential way for treating follicular thyroid carcinoma. (authors)