Tuncel Murat, Aydin Didem, Yaman Elif, Tazebay Uygar H, Güç Dicle, Doğan A Lale, Taşbasan Burçin, Uğur Omer
Department of Nuclear Medicine, Hacettepe University Faculty of Medicine, Ankara, Turkey.
Cancer Biother Radiopharm. 2007 Apr;22(2):281-8. doi: 10.1089/cbr.2006.319.
The aim of this study was to comparatively investigate the effects of 5-azacytidine-C (5-Aza), trichostatin-A (TSA), and all-trans retinoic acid (ATRA) on mRNA expressions of Na/I symporter (NIS), thyroglobulin (Tg), thyroid peroxidase (TPO), and thyroid stimulating hormone receptor (TSH-R), and radioiodine (RAI) uptake in cancer (B-CPAP) and normal (Nthy-ori 3-1) thyroid cell lines. Cell lines were treated with 10 ng/mL of TSA, 5 microM of 5-Aza, and 1 microM of ATRA, according to the MTT (methyl-thiazol-tetrazolium) test results. Additionally, recombinant thyroid stimulating hormone (rTSH) was also applied, with a selected dose of 100 ng/mL. Following the treatment, NIS, Tg, TPO, and TSH-R mRNA levels were detected by real-time-polymerase chain reaction (RT-PCR) and RAI uptakes were measured by using a well counter as the counts/cell number. 5-Aza increased TSH-R mRNA expression in both of the cell lines and decreased TPO, NIS, and Tg mRNA levels in the cancer cell line. In the normal thyroid cell line, 5-Aza increased TPO mRNA levels 2-fold and made no differences in NIS and Tg mRNA levels. TSA treatment repressed NIS and Tg mRNA levels, and made no differences on other thyroid specific genes investigated in the cancer cell line. In the normal thyroid cell line, TSA increased TSH-R mRNA levels in 72 hours and created no important differences in other genes. ATRA repressed the TSH-R mRNA levels in the normal thyroid cell line and increased the TPO and Tg mRNA levels slightly in both cell lines. Furthermore, in short-term treatment, ATRA repressed NIS gene expression slightly, but in the long term, this repression turned to basal levels. 5-Aza, TSA, and ATRA did not make any differences in RAI uptake in the cancer cell line, but rTSH increased RAI uptake significantly. In the normal thyroid cell line, TSA and ATRA decreased RAI uptake (to 1/10 and 1/2, respectively), but 5-Aza and rTSH increased RAI uptake significantly (2- and 4-fold, respectively). We have shown an increase in TSH-R gene expression and radioiodine uptake with 5-Aza. Further in vitro and in vivo studies are needed to support our findings and the potential clinical use of this agent.
本研究旨在比较研究5-氮杂胞苷-C（5-氮杂胞苷）、曲古抑菌素-A（TSA）和全反式维甲酸（ATRA）对钠/碘同向转运体（NIS）、甲状腺球蛋白（Tg）、甲状腺过氧化物酶（TPO）和促甲状腺激素受体（TSH-R）mRNA表达的影响，以及对癌症（B-CPAP）和正常（Nthy-ori 3-1）甲状腺细胞系中放射性碘（RAI）摄取的影响。根据MTT（甲基噻唑四氮唑）试验结果，用10 ng/mL的TSA、5 μM的5-氮杂胞苷和1 μM的ATRA处理细胞系。此外，还应用了重组促甲状腺激素（rTSH），选定剂量为100 ng/mL。处理后，通过实时聚合酶链反应（RT-PCR）检测NIS、Tg、TPO和TSH-R mRNA水平，并使用井型计数器测量RAI摄取量，以计数/细胞数表示。5-氮杂胞苷增加了两种细胞系中TSH-R mRNA的表达，并降低了癌细胞系中TPO、NIS和Tg mRNA水平。在正常甲状腺细胞系中，5-氮杂胞苷使TPO mRNA水平增加了2倍，而对NIS和Tg mRNA水平没有影响。TSA处理抑制了NIS和Tg mRNA水平，对癌细胞系中研究的其他甲状腺特异性基因没有影响。在正常甲状腺细胞系中，TSA在72小时内增加了TSH-R mRNA水平，对其他基因没有产生重要影响。ATRA抑制了正常甲状腺细胞系中TSH-R mRNA水平，并在两种细胞系中均轻微增加了TPO和Tg mRNA水平。此外，在短期处理中，ATRA轻微抑制了NIS基因表达，但在长期处理中，这种抑制恢复到基础水平。5-氮杂胞苷、TSA和ATRA对癌细胞系中的RAI摄取没有任何影响，但rTSH显著增加了RAI摄取。在正常甲状腺细胞系中，TSA和ATRA降低了RAI摄取（分别降至1/10和1/2），但5-氮杂胞苷和rTSH显著增加了RAI摄取（分别增加了2倍和4倍）。我们已经证明5-氮杂胞苷可增加TSH-R基因表达和放射性碘摄取。需要进一步的体外和体内研究来支持我们的发现以及该药物的潜在临床应用。
