EZH2 Expression in B Cell Lymphocyte Subsets of Hashimoto's Thyroiditis and the Therapeutic Mechanism and Effect of Its Inhibitors

Background Thyroid autoantibody is a marker for the diagnosis of Hashimoto's thyroiditis (HT), and B cells are essential in the pathogenesis of HT. Enhancer of Zeste homolog 2 (EZH2), which is an important epigenetic regulator, plays an important role in the regulation of lymphocytes development and function. Objective To investigate EZH2 expression in plasmoblasts and plasma cells in HT, and further explore the therapeutic effect of EZH2 inhibitors in experimental autoimmune thyroiditis (EAT) model. Methods The thyroid tissues from 6 patients who underwent thyroidectomy (3 HT patients with PTC, 3 patients with PTC alone) in Peking University First Hospital between 2010 and 2020 were obtained from the contralateral lobe with thyroid cancer, and screened for the expression of B-lymphocyte-related genes by RNA-seq; thyroid tissues from 16 HT patients and 8 normal thyroid tissues were collected and verified for the the expression of EZH2 in B cells in HT thyroid tissues by immunohistochemistry or immunofluoresce