Department of Pathology, University of Washington, Seattle, WA, USA.
Institute of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
Lab Invest. 2014 Jul;94(7):788-95. doi: 10.1038/labinvest.2014.68. Epub 2014 May 19.
Owing to the loss of heterochromatin integrity that occurs during thyroid tumorigenesis, the expression of Heterochromatin Protein 1 isoforms HP1α and HP1β was assessed by immunohistochemistry in 189 thyroid tumors and non-neoplastic tissues. Expression of HP1β was significantly decreased in all thyroid lesions, except in follicular adenomas, when compared with matched adjacent normal tissue. This loss of HP1β expression may in part be caused by microRNA dysregulation. An example is miR-205, a microRNA that is abundantly upregulated in thyroid carcinomas and shown to reduce the expression of HP1β. In contrast to HP1β, HP1α expression was only reduced in metastatic carcinomas and poorly differentiated lesions. These results suggest the reduction of HP1β followed by a decrease in HP1α contributes to the pathogenesis of thyroid carcinomas, and their loss is a potential marker of thyroid malignancy and metastatic potential, respectively.
由于甲状腺肿瘤发生过程中异染色质完整性的丧失，通过免疫组织化学方法在 189 个甲状腺肿瘤和非肿瘤组织中评估了异染色质蛋白 1 同种型 HP1α 和 HP1β 的表达。与匹配的相邻正常组织相比，除滤泡性腺瘤外，所有甲状腺病变中 HP1β 的表达均显著降低。这种 HP1β 表达的丧失部分可能是由于 microRNA 失调引起的。例如，miR-205 是一种在甲状腺癌中大量上调的 microRNA，被证明可以降低 HP1β 的表达。与 HP1β 相反，HP1α 的表达仅在转移性癌和低分化病变中降低。这些结果表明，HP1β 的减少随后 HP1α 的减少导致甲状腺癌的发病机制，其丢失分别是甲状腺恶性肿瘤和转移潜能的潜在标志物。
