School of Pharmacy, Fudan University, Shanghai 200032, China.
Lab of Reproductive Pharmacology, NHC Key Lab of Reproduction Regulation, Shanghai Institute for Biomedical and Pharmaceutical Technologies, Fudan University, Shanghai 200032, China.
Int J Mol Sci. 2022 Oct 19;23(20):12517. doi: 10.3390/ijms232012517.
Progestin resistance is a major obstacle to conservative therapy in patients with endometrial cancer (EC) and endometrial atypical hyperplasia (EAH). However, the related inducing factor is yet unclear. In this study, thyroid hormone and its receptor α (TRα) and β (TRβ) of patients were assayed. THRB-silenced RL95-2 and KLE EC cells were cultured to investigate the response of progestins. Transcriptomics and Western blotting were performed to investigate the changes in signaling pathways. We found that THRB, rather than THRA, knockdown promoted the viability and motilities of RL95-2 cells but not KLE cells. The suppressive effect of progestins on cell growth and motility significantly decreased in THRB-silenced RL95-2 cells. Multiple proliferation-related signaling pathways were enriched, and the activities of mammalian targets of rapamycin (mTOR)/4e-binding protein 1 (4EBP1)/eukaryotic translation initiation factor 4G (eIF4G) rather than phosphorylated protein kinase B (Akt) were remarkably boosted. Progestin treatment enhanced the effects, and the augmentation was partially abated on supplementation with T3. In THRB-knockdown KLE cells, the progestins-activated partial signaling pathway expression (either mTOR or eIF4G), and supplementation with T3 did not induce noticeable alterations. The serum levels of triiodothyronine (T3) were significantly lower in patients with EC compared with healthy women. A strong expression of TRβ was observed in most patients with EC and EAH sensitive to progestin treatment. In contrast, TRα positive expression was detected in less than half of the patients sensitive to progestin therapy. In conclusion, THRB knockdown enhanced the viability and motility of type I EC cells and attenuated the suppressive effects of progestins by activating the mTOR-4EBP1/eIF4G pathway. Lower expression of THRB is likely correlated with progesterone resistance.
孕激素抵抗是子宫内膜癌（EC）和子宫内膜非典型增生（EAH）患者保守治疗的主要障碍。然而，相关的诱导因素尚不清楚。在这项研究中，检测了患者的甲状腺激素及其受体α（TRα）和β（TRβ）。培养沉默 THRB 的 RL95-2 和 KLE EC 细胞，以研究孕激素的反应。进行转录组学和 Western blot 分析，以研究信号通路的变化。我们发现，与 THRA 相比，THRB 的敲低促进了 RL95-2 细胞而非 KLE 细胞的活力和迁移。THRB 沉默的 RL95-2 细胞中孕激素对细胞生长和迁移的抑制作用显著降低。多个增殖相关信号通路被富集，哺乳动物雷帕霉素靶蛋白（mTOR）/4e 结合蛋白 1（4EBP1）/真核翻译起始因子 4G（eIF4G）的活性而非磷酸化蛋白激酶 B（Akt）明显增强。孕激素处理增强了这些作用，而 T3 的补充部分减弱了这种增强作用。在 THRB 敲低的 KLE 细胞中，孕激素激活的部分信号通路表达（mTOR 或 eIF4G），而 T3 的补充并没有引起明显的变化。与健康女性相比，EC 患者的血清三碘甲状腺原氨酸（T3）水平显著降低。大多数对孕激素治疗敏感的 EC 和 EAH 患者中观察到强烈的 TRβ 表达。相比之下，对孕激素治疗敏感的患者中不到一半检测到 TRα 阳性表达。总之，THRB 的敲低通过激活 mTOR-4EBP1/eIF4G 通路增强了 I 型 EC 细胞的活力和迁移，并减弱了孕激素的抑制作用。THRB 表达水平较低可能与孕激素抵抗有关。
