PO.ET08.01 · 实验与分子治疗
LSD1抑制通过减弱SUMO化并激活NK细胞增强OSCC的放疗疗效
LSD1 inhibition enhances radiotherapy efficacy in OSCC by attenuating SUMOylation and activating NK cells
作者与单位 Authors & Affiliations
摘要 Abstract
中文摘要
背景：口腔鳞状细胞癌（OSCC）是一种常见且致命的癌症，单纯使用放射治疗（RT）的疗效有限。本研究探讨了赖氨酸特异性去甲基化酶1（LSD1）在促进OSCC致癌信号传导、RT耐受和免疫抑制中的作用。我们假设，靶向LSD1特异性机制并联合RT，可抑制OSCC生长和免疫逃逸。
方法：我们采用4NQO处理的进展性小鼠OSCC模型，以识别放疗以及LSD1抑制（使用SP2509）联合放射过程中的分子和细胞变化。为识别这些变化，我们使用RNA-seq检测通路相关变化，流式细胞术检测免疫调控，以及体外细胞培养技术进行ChIP、qRT-PCR和通路验证。最后，我们用SP2509与放射联合治疗猫自发性OSCC以检验其疗效。
结果：RT联合LSD1抑制剂SP2509促进了小鼠OSCC癌前病变中自然杀伤（NK）细胞的浸润和树突状细胞（DC）介导的抗肿瘤免疫。经LSD1抑制剂和RT治疗的猫OSCC显示肿瘤生长减少。体外研究表明联合治疗诱导IFNgamma+ CD8+ T细胞和NK细胞的激活。RNA测序显示联合治疗减弱了细胞周期和CDK相关通路。经RT治疗的临床OSCC样本表现出CD8+ T细胞受抑制，而LSD1抑制剂与RT联合则恢复了CD8+ T细胞增殖，并在小鼠OSCC以及与人OSCC细胞（HSC3）共培养的外周血单个核细胞中显著增加了NK细胞群。研究还观察到，LSD1抑制在OSCC中（体内和体外）减弱了SUMO化通路，下调了SUMO1基因，同时上调了NKG2DL相关基因，如人类的MICB及其小鼠类似物RAEgamma。通过ChIP-qPCR，我们观察到LSD1抑制增加了SUMO1基因位点的H3K9me2甲基化并降低了H3K4me2甲基化。LSD1抑制联合放疗可减弱猫OSCC的癌症生长。
结论：SP2509治疗通过抑制SUMO化通路增强放射治疗的疗效，从而通过NKG2DL-NKG2D轴激活增加NK细胞，进而诱导抗肿瘤免疫。
查看英文原文 English abstract
Background: Oral squamous cell carcinoma (OSCC) is a prevalent and deadly cancer, with limited treatment success using radiation therapy (RT) alone. This study investigated the role of lysine-specific demethylase 1 (LSD1) in promoting oncogenic signaling, resistance to RT, and immunosuppression in OSCC. We hypothesized that targeting LSD1-specific mechanisms, in combination with RT, could inhibit OSCC growth and immune evasion.
Methods: We employed a 4NQO-treated progressive mouse OSCC model to identify the molecular and cellular changes during radiotherapy and LSD1 inhibition (with SP2509) in combination with radiation. To identify these changes, we used RNA-seq for pathway-related changes, flow cytometry for immune regulation, and in vitro cell culture techniques for ChIP, qRT-PCR, and pathway validation. Finally, we treated feline spontaneous OSCC with a combination of SP2509 and radiation to test its efficacy.
Results: RT combined with the LSD1 inhibitor SP2509 promoted the infiltration of natural killer (NK) cells and dendritic cell (DC)-mediated antitumor immunity in mouse OSCC preneoplasia. Feline OSCC treated with an LSD1 inhibitor and RT showed reduced tumor growth. In vitro studies have demonstrated that combination therapy induces the activation of IFNgamma+ CD8+ T cells and NK cells. RNA sequencing showed that the combination therapy attenuated the cell cycle and CDK-related pathways. Clinical OSCC samples treated with RT exhibited inhibition of CD8+ T cells, while the combination of an LSD1 inhibitor and RT recovered CD8+ T cell proliferation with a significant increase in NK cell population in mouse OSCC and peripheral blood mononuclear cells co-cultured with human OSCC cells (HSC3). It was also observed that LSD1 inhibition in OSCC, both in vivo and in vitro, attenuated SUMOylation pathways and downregulated the SUMO1 gene while upregulating NKG2DL-related genes such as MICB in humans and their mouse analog RAEgamma. Using ChIP-qPCR, we observed that LSD1 inhibition increased H3K9me2 methylation at the SUMO1 gene locus and decreased H3K4me2 methylation. LSD1 inhibition in combination with radiotherapy in feline OSCC attenuates cancer growth.
Conclusion: SP2509 treatment enhances the efficacy of radiation therapy by inhibiting SUMOylation pathways, which increases NK cells by NKG2DL-NKG2D axis activation, thereby inducing anti-tumor immunity.
利益披露 Disclosure
C. Choudhury, None..
A. K. Chakraborty, None..
R. Raut, None..
M. Takada, None..
B. Sahay, None..
M. Truong, None..
J. Burton, None..
M. V. Bais, None.