Influence of proteasome activator γ on iodine uptake capability of anaplastic thyroid carcinoma

Abstract

Objective To investigate the changes of iodine uptake capability (IUC) and mRNA expression of iodine uptake-related proteins in ARO and WRO thyroid carcinoma cell lines after silence of proteasome activator γ (REGγ), and observe the relation between REGγ and IUC of thyroid carcinoma. Methods The AROshN, AROshR, WROshN and WROshR (shN= blank plasmid, shR=plasmid with silence of REGγ) thyroid carcinoma cell lines were routinely cultured. Low dosage (3.7 kBq) of Na125I was added and then IUC was determined at different time points (5, 10, 15, 20, 40 and 70 min). The mRNA expressions of sodium/iodine symporter (NIS), thyroid stimulating hormone receptor (TSHR), thyroid peroxidase (TPO) and thyroglobulin (Tg) were examined by real-time PCR. Paired t test was used to analyze the data. Results After the silence of REGγ, the peak values of IUC in AROshR and WROshR cells were increased from (1 974±12) to (4 502±23) counts/min, and from (2 988±25) to (5 001±16) counts/min, respectively. The increase rates were 128.1% in AROshR cells and 67.4% in WROshR cells (t values: 17.30, 13.20, both P<0.05). The mRNA expressions of NIS, TSHR, TPO, Tg in AROshR cells were 2.82, 1.98, 2.65 and 2.31 times higher than those in AROshN cells, and the expressions in WROshR cells were 2.21, 1.78, 2.51 and 1.78 times higher than those in WROshN cells (t values: 13.80-21.93, all P<0.05). Conclusion Silence of REGγ can increase the gene expressions of the iodine uptake-related proteins and elevate the IUC of thyroid carcinoma cells. Key words: Thyroid neoplasms; Tumor cells, cultured; Proteasome endopeptidase complex; Gene silencing; Iodine radioisotopes