Tong Mengying, Gao Shuhang, Qi Wenjing, Shi Chang, Qiu Meng, Yang Fang, Bai Shanshan, Li Husha, Wang Zhizhou, Sun Zhigang, Wang Lina, Che Ying
Department of Ultrasound, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116044, P.R. China.
Clinical Laboratory of Integrative Medicine, The First Affiliated Hospital of Dalian Medical University, Dalian, Liaoning 116044, P.R. China.
Oncol Lett. 2019 Sep;18(3):2304-2309. doi: 10.3892/ol.2019.10531. Epub 2019 Jun 27.
DNA methylation at the 5 position of cytosine (5-mC) is an epigenetic hallmark that is critical in various biological and pathological processes such as DNA methylation regulation, and initiation and development of cancers. 5-mC can be oxidized to 5-hydroxymethylcytosine (5-hmC) by the ten-eleven translocation family of DNA hydroxylases. Accumulating evidence has reported that loss of 5-hmC is associated with cancer development. However, its level in papillary thyroid carcinoma (PTC) remains unclear. The present study reports that the loss of 5-hmC is an epigenetic mark of PTCs, associated with their malignant biological behavior, providing diagnostic and predictive advantages over DNA hypomethylation (5-mC), an acknowledged epigenetic alteration in cancer. In addition, the 5-hmC staining levels were decreased in cases of micro-carcinoma with lymph node metastasis, which suggests that 5-hmC expression levels could be used as valuable biomarkers for predicting malignant potential and assist in the selection of therapeutic strategies in PTC; therefore, 5-hmC has the potential to provide a more precise direction for PTC therapy.
胞嘧啶第5位的DNA甲基化（5-甲基胞嘧啶，5-mC）是一种表观遗传标志，在诸如DNA甲基化调控以及癌症的发生和发展等各种生物学和病理过程中至关重要。5-甲基胞嘧啶可被DNA羟化酶的十一-易位家族氧化为5-羟甲基胞嘧啶（5-hmC）。越来越多的证据表明，5-羟甲基胞嘧啶的缺失与癌症发展有关。然而，其在甲状腺乳头状癌（PTC）中的水平仍不清楚。本研究报告称，5-羟甲基胞嘧啶的缺失是甲状腺乳头状癌的一种表观遗传标志，与其恶性生物学行为相关，与DNA低甲基化（5-甲基胞嘧啶）相比具有诊断和预测优势，DNA低甲基化是癌症中公认的表观遗传改变。此外，在伴有淋巴结转移的微癌病例中，5-羟甲基胞嘧啶染色水平降低，这表明5-羟甲基胞嘧啶表达水平可作为预测恶性潜能的有价值生物标志物，并有助于选择甲状腺乳头状癌的治疗策略；因此，5-羟甲基胞嘧啶有可能为甲状腺乳头状癌的治疗提供更精确的指导。
