OXCT1 regulates NF-κB signaling pathway through β-hydroxybutyrate-mediated ketone body homeostasis in lung cancer.
OXCT1 regulates NF-κB signaling pathway through β-hydroxybutyrate-mediated ketone body homeostasis in lung cancer.
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OXCT1通过β-羟基丁酸介导的酮体稳态调节肺癌中NF-κB信号通路
DOI：
10.1016/j.gendis.2022.04.020
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发表时间：
2023-03
期刊：
影响因子：
6.8
通讯作者：
Wang, Jian-Bin
中科院分区：
文献类型：
--
作者：
Lu, Zhuo;Han, Tianyu;Wang, Tao;Gan, Mingxi;Xie, Caifeng;Yu, Bentong;Wang, Jian-Bin
代谢重编程是癌症的标志之一。1酮体作为癌细胞的替代燃料，以支持生存和增殖。2 3-含氧酸CoA转移酶1（OXCT 1）是催化酮解反应的第一步和限速步骤的关键酶。最近，一些研究已经揭示了OXCT 1在癌症发展中的重要性，尽管其潜在机制在很大程度上仍然未知。3本研究揭示了非小细胞肺癌（NSCLC）中OXCT 1通过酮体稳态调节SREBP 1-TRIM 21-p65轴的一种新的肿瘤发生调控机制。在机制上，我们发现OXCT 1可以通过抑制固醇调节元件结合蛋白1（SREBP 1）的转录活性来激活NF-κ B信号通路。SREBP 1作为转录因子，可与E3泛素连接酶TRIM 21的启动子结合，从而介导p65的泛素化。此外，我们证明OXCT 1可以维持b-羟基丁酸（b-HB）的稳态，其作为信号代谢物激活SREBP 1。因此，b-HB通过连接OXCT 1和SREBP 1，激活NF-kB信号通路，促进肿瘤的发生和发展。总之，这些发现强调了OXCT 1和酮体激活NF-kB信号传导的先前未被认识的机制，并证明靶向OXCT 1可以抑制NSCLC肿瘤发生。在血清饥饿的培养基中，NSCLC细胞的生长受到抑制。补充b-HB以剂量依赖性方式挽救NSCLC细胞的生长（图1A;图S1 B、C）。然而，补充b-HB不能挽救HBE细胞在血清饥饿培养基中的生长（图S1 A）。OXCT 1是酮体利用的限速酶，在酮解中起关键作用。与HBE细胞相比，NSCLC细胞中OXCT 1的mRNA和蛋白水平更高（图1 B;图S1 H）。OXCT 1敲低显著降低NSCLC细胞的生长，但仅轻微抑制HBE细胞的生长（图1C;图S11 eK）。我们还发现，在OXCT 1敲低后，NSCLC细胞中的细胞迁移被显著抑制（图S2 B、C）AXCT 1敲低降低了MMP 2、MMP 9、b1-整合蛋白和u-PA的表达（图S3 A），这些蛋白参与细胞增殖和迁移并由p65转录。接下来，我们研究了OXCT 1在调节p65表达中的作用。在OXCT 1敲低和TNFa处理指定时间后，p65和磷酸化p65的表达降低，这可以通过TRIM 21敲低来挽救（图1D、F）。TRIM 21是一种E3遍在蛋白连接酶，属于三方基序（TRIM）家族。当在H1299细胞中敲低0XCT 1时，TRIM 21的蛋白和mRNA水平增加（图1 E）。TRIM 21过表达增加了p65的泛素化（图S4 F）。以上结果表明OXCT 1可通过下调TRIM 21的表达，负性调节p65的泛素化，激活NF-kB信号通路。
Metabolic reprogramming is one of the hallmarks of cancer. 1 Ketone bodies behave as alternative fuel for cancer cells to support survival and proliferation. 2 3-Oxoacid CoA-transferase 1 (OXCT1) is a key enzyme that catalyzes the first and rate-limiting step of ketolysis. Recently, several studies have revealed the significance of OXCT1 in cancer development, though the underlying mechanisms remain largely unknown. 3 In this study, we revealed a novel regulatory mechanism for tumorigenesis that OXCT1 regulated SREBP1-TRIM21-p65 axis through ketone body homeostasis in non-small cell lung cancer (NSCLC). In terms of mechanism, we found that OXCT1 could activate NF-kB signaling pathway by suppressing transcriptional activity of the sterol regulatory element binding protein 1 (SREBP1). As a transcription factor, SREBP1 could bind to the promoter of E3 ubiquitin ligase TRIM21, which mediated the ubiquitination of p65. Furthermore, we demonstrated that OXCT1 could maintain the homeostasis of b-hydroxybutyrate (b-HB), which acted as a signaling metabolite to activate SREBP1. Thus, b-HB connected OXCT1 with SREBP1 to activate NF-kB signaling pathway and promoted tumor initiation and progression. Taken together, these findings highlight a previously unappreciated mechanism for activation of NF-kB signaling by OXCT1 and ketone body, and demonstrate that targeting OXCT1 can inhibit NSCLC tumorigenesis. The growth of NSCLC cells was inhibited in the serumstarved medium. Supplementation of b-HB rescued the growth of NSCLC cells in a dose-dependent manner (Fig. 1 A; Fig. S1B, C). However, supplementation of b-HB could not rescue the growth of HBE cells in serum-starved medium (Fig. S1A). OXCT1 is a rate-limiting enzyme in the utilization of ketone bodies and plays a critical role in ketolysis. Compared with HBE cells, the mRNA and protein levels of OXCT1 were higher in NSCLC cells (Fig. 1 B; Fig. S1H). OXCT1 knockdown dramatically decreased the growth of NSCLC cells, but only slightly inhibited the growth of HBE cells (Fig. 1 C; Fig. S1IeK). We also found that cell migration was significantly inhibited in NSCLC cells following OXCT1 knockdown (Fig. S2B, C).OXCT1 knockdown decreased the expression of MMP2, MMP9, b1-intgrin and u-PA (Fig. S3A), which were involved in cell proliferation and migration and were transcribed by p65. Next, we investigated the role of OXCT1 in the regulation of p65 expression. Following OXCT1 knockdown and TNFa treatment for indicted time, expression of p65 and phosphorylated p65 were decreased, which could be rescued by TRIM21 knockdown (Fig. 1 D, F). TRIM21 is an E3 ubiquitin ligase and belongs to the tripartite motif (TRIM) family. The protein and mRNA levels of TRIM21 increased when OXCT1 was knocked down in H1299 cells (Fig. 1 E). TRIM21 overexpression increased the ubiquitination of p65 (Fig. S4F). All these results indicated that OXCT1 could negatively regulate the ubiquitination of p65 and activate NF-kB signaling pathway by down-regulating TRIM21 in NSCLC cells.
影响因子：
16
作者：
Han YM;Bedarida T;Ding Y;Somba BK;Lu Q;Wang Q;Song P;Zou MH
通讯作者：
Zou MH
影响因子：
29
作者：
Puchalska P;Crawford PA
通讯作者：
Crawford PA
影响因子：
8.9
作者：
Newman JC;Verdin E
通讯作者：
Verdin E