Department of Otolaryngology-Head and Neck Surgery, Otolaryngology Institute of Shanghai JiaoTong University, Shanghai JiaoTong University Affiliated Sixth People's Hospital, 600 Yishan Road, Xuhui, 200233, Shanghai, China.
Shanghai Key Laboratory of Sleep Disordered Breathing, 600 Yishan Road, Xuhui, 200233, Shanghai, China.
Clin Transl Oncol. 2021 Sep;23(9):1942-1954. doi: 10.1007/s12094-021-02603-y. Epub 2021 Apr 7.
Glutamine plays an important role in tumor metabolism and progression. This research aimed to find out how Gln exert their effects on laryngeal squamous cell carcinoma (LSCC).
Cell proliferation was measured by CCK8 and EdU assay, mitochondrial bioenergetic activity was measured by mitochondrial stress tests. Gene expression profiling was revealed by RNA sequencing and validated by RT-qPCR. In LSCC patients, protein expression in tumor and adjacent tissues was examined and scored by IHC staining. RNAi was performed by stably expressed shRNA in TU177 cells. In vivo tumor growth analysis was performed using a nude mouse tumorigenicity model.
Gln deprivation suppressed TU177 cell proliferation, which was restored by αKG supplementation. By transcriptomic analysis, we identified CECR2, which encodes a histone acetyl-lysine reader, as the downstream target gene for Gln and αKG. In LSCC patients, the expression of CECR2 in tumors was lower than adjacent tissues. Furthermore, deficiency of CECR2 promoted tumor cell growth both in vitro and in vivo, suggesting it has tumor suppressor effects. Besides, cell proliferation inhibited by Gln withdrawal could be restored by CECR2 depletion, and the proliferation boosted by αKG supplementation could be magnified either, suggested that CECR2 feedback suppressed Gln and αKG's effect on tumor growth. Transcriptomic profiling revealed CECR2 regulated the expression of a series of genes involved in tumor progression.
We confirmed the Gln-αKG-CECR2 axis contributes to tumor growth in LSCC. This finding provided a potential therapeutic opportunity for the use of associated metabolites as a potential treatment for LSCC.
谷氨酰胺在肿瘤代谢和进展中发挥重要作用。本研究旨在探讨谷氨酰胺（Gln）如何发挥其对喉鳞状细胞癌（LSCC）的作用。
通过 CCK8 和 EdU 检测细胞增殖，通过线粒体应激试验检测线粒体生物能量活性。通过 RNA 测序揭示基因表达谱，并通过 RT-qPCR 进行验证。在 LSCC 患者中，通过免疫组化染色检测肿瘤和相邻组织中的蛋白表达并进行评分。通过 TU177 细胞中稳定表达的 shRNA 进行 RNAi。使用裸鼠肿瘤发生模型进行体内肿瘤生长分析。
Gln 剥夺抑制 TU177 细胞增殖，αKG 补充可恢复该增殖。通过转录组分析，我们确定了编码组蛋白乙酰-赖氨酸读取器的 CECR2 为 Gln 和 αKG 的下游靶基因。在 LSCC 患者中，肿瘤中 CECR2 的表达低于相邻组织。此外，CECR2 缺失促进了体外和体内肿瘤细胞的生长，表明其具有肿瘤抑制作用。此外，Gln 剥夺引起的细胞增殖抑制可通过 CECR2 耗竭恢复，而 αKG 补充引起的增殖增强也可放大，表明 CECR2 反馈抑制 Gln 和 αKG 对肿瘤生长的作用。转录组谱分析显示 CECR2 调节一系列参与肿瘤进展的基因的表达。
我们证实了 Gln-αKG-CECR2 轴在 LSCC 肿瘤生长中起作用。这一发现为将相关代谢物作为 LSCC 的潜在治疗方法提供了潜在的治疗机会。
