Department of Microbiology and Oncology, Graduate School of Medicine, University of the Ryukyus, Nishihara, Japan.
Division of Health Sciences, Transdisciplinary Research Organization for Subtropics and Island Studies, University of the Ryukyus, Nishihara, Japan.
Eur J Haematol. 2024 Jul;113(1):99-109. doi: 10.1111/ejh.14209. Epub 2024 Apr 1.
We aimed to determine the role of dihydroorotate dehydrogenase (DHODH) in pathogenesis of adult T-cell leukemia (ATL) caused by human T-cell leukemia virus type 1 (HTLV-1) and the effects of its inhibition on the de novo pyrimidine biosynthesis pathway.
Cell proliferation, viability, cycle, and apoptosis were analyzed using WST-8 assays, flow cytometry, and Hoechst 33342 staining. To elucidate the molecular mechanisms involved in the anti-ATL effects of DHODH knockdown and inhibition, RT-PCR and immunoblotting were conducted.
HTLV-1-infected T-cell lines aberrantly expressed DHODH. Viral infection and the oncoprotein, Tax, enhanced DHODH expression, while knockdown of DHODH decreased HTLV-1-infected T-cell growth. In addition, BAY2402234, a DHODH inhibitor, exerted an anti-proliferative effect, which was reversed by uridine supplementation. BAY2402234 induced DNA damage and S phase arrest by downregulating c-Myc, CDK2, and cyclin A and upregulating p53 and cyclin E. It also induced caspase-mediated apoptosis by the upregulation of pro-apoptotic and downregulation of anti-apoptotic proteins. Furthermore, BAY2402234 induced caspase-independent ferroptosis and necroptosis. It decreased phosphorylation of IKK, IκBα, PTEN, Akt, and its downstream targets, suggesting that inhibition of NF-κB and Akt signaling is involved in its anti-ATL action.
These findings highlight DHODH as a potential therapeutic target for treating ATL.
我们旨在确定二氢乳清酸脱氢酶（DHODH）在人类 T 细胞白血病病毒 1（HTLV-1）引起的成人 T 细胞白血病（ATL）发病机制中的作用，以及其对从头嘧啶生物合成途径的抑制作用。
使用 WST-8 测定法、流式细胞术和 Hoechst 33342 染色分析细胞增殖、活力、周期和凋亡。为了阐明 DHODH 敲低和抑制对 ATL 抑制作用的分子机制，进行了 RT-PCR 和免疫印迹。
HTLV-1 感染的 T 细胞系异常表达 DHODH。病毒感染和癌蛋白 Tax 增强了 DHODH 的表达，而 DHODH 的敲低则降低了 HTLV-1 感染的 T 细胞生长。此外，DHODH 抑制剂 BAY2402234 发挥了抗增殖作用，而尿嘧啶补充则逆转了该作用。BAY2402234 通过下调 c-Myc、CDK2 和细胞周期蛋白 A 以及上调 p53 和细胞周期蛋白 E 来诱导 DNA 损伤和 S 期阻滞。它还通过上调促凋亡蛋白和下调抗凋亡蛋白来诱导 caspase 介导的细胞凋亡。此外，BAY2402234 诱导 caspase 非依赖性铁死亡和坏死性凋亡。它降低了 IKK、IκBα、PTEN、Akt 及其下游靶标的磷酸化，表明 NF-κB 和 Akt 信号通路的抑制参与了其抗 ATL 作用。
这些发现强调了 DHODH 作为治疗 ATL 的潜在治疗靶点。
