Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden.
Department of Pathology and Cancer Diagnostics, Karolinska University Hospital, Stockholm, Sweden.
J Histochem Cytochem. 2023 Aug;71(8):451-458. doi: 10.1369/00221554231190437. Epub 2023 Jul 24.
Telomerase reverse transcriptase () gene aberrancies correlate to adverse prognosis in follicular thyroid carcinoma (FTC). As loss of 5-hydroxymethylcytosine (5hmC) has been associated with promoter mutations in papillary thyroid carcinoma, this study sought to analyze the levels of 5hmC in a cohort of follicular thyroid tumors with available data. A total of 29 tumors (26 FTCs, 2 follicular thyroid tumors of uncertain malignant potential, and 1 oncocytic thyroid carcinoma) with known promoter mutational status and gene expression were assessed for 5hmC immunoreactivity using two antibodies (clones RM236 and 4D9.) Slides were analyzed using a semiquantitative scoring system. Of the 10 tumor cases with aberrant , only 1 scored negative with both antibodies (1/10; 10%), whereas the remaining 9 cases (9/10; 90%) exhibited some positivity for at least one antibody. Of the 19 wild-type tumors, no case was scored negative using RM236, and 2 cases (2/19; 11%) using 4D9. The differences between promoter mutated and wild-type groups were non-significant. The sensitivity and specificity for 5hmC immunohistochemistry (IHC) to detect mutated cases were 10% and 100% (RM236) and 20% and 89% (4D9). Therefore, 5hmC IHC is not a sensitive marker for detecting promoter mutations in follicular thyroid tumors.
端粒酶逆转录酶 () 基因异常与滤泡状甲状腺癌 (FTC) 的不良预后相关。由于 5-羟甲基胞嘧啶 (5hmC) 的缺失与甲状腺乳头状癌的 启动子突变有关，本研究旨在分析一组具有可获得 数据的滤泡状甲状腺肿瘤中的 5hmC 水平。共评估了 29 个肿瘤（26 个 FTC、2 个滤泡状甲状腺肿瘤恶性潜能不确定和 1 个嗜酸细胞性甲状腺癌）的 5hmC 免疫反应性，使用两种抗体（克隆 RM236 和 4D9）。使用半定量评分系统分析幻灯片。在 10 个存在异常 的肿瘤病例中，只有 1 个病例在两种抗体上均呈阴性（1/10；10%），而其余 9 个病例（9/10；90%）至少有一种抗体呈阳性。在 19 个 野生型肿瘤中，没有病例在使用 RM236 时评分阴性，而在使用 4D9 时则有 2 个病例（2/19；11%）评分阴性。 启动子突变和野生型组之间的差异无统计学意义。5hmC 免疫组化 (IHC) 检测突变病例的敏感性和特异性分别为 10%和 100%（RM236）和 20%和 89%（4D9）。因此，5hmC IHC 不是检测滤泡状甲状腺肿瘤 启动子突变的敏感标志物。
