The role of serine metabolism on the evolution of oral squamous cell carcinoma

丝氨酸代谢在口腔鳞状细胞癌演变中的作用

• 批准号: 10825875
• 负责人: Stacy Jankowski
• 金额: $ 4.85万
• 依托单位: BOSTON UNIVERSITY MEDICAL CAMPUS
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-09-12 至 2025-08-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10825875
• 关键词: Alcohol consumption; Algorithms; Anabolism; Anatomy; Biochemical; Biological; Biological Assay; Carcinoma; Cell Communication; Cell Differentiation process; Cell Line; Cell Lineage; Cells; Chromatin; Chromatin Structure; Clinical; Cluster Analysis; Complex; Coupled; Development; Dietary Intervention; Differentiated Gene; Differentiation Antigens; Dioxygenases; Environment; Enzymes; Epigenetic Process; Epithelium; Evolution; Genes; Genomics; Global Change; Growth; Head and Neck Cancer; Heterogeneity; Histones; Human; Human Papillomavirus; Immunofluorescence Immunologic; Immunohistochemistry; In Vitro; Invaded; Isogenic transplantation; Knowledge; Lead; Lysine; Malignant Epithelial Cell; Malignant Neoplasms; Mesenchymal; Messenger RNA; Metabolism; Modeling; Modification; Morbidity - disease rate; Morphology; Neoplasm Metastasis; Nuclear; Nutrient; Operative Surgical Procedures; Outcome; Pathway interactions; Patients; Pharmaceutical Preparations; Phenotype; Play; Population; Proliferating; Proliferation Marker; Proteins; Radiation therapy; Repression; Research; Resistance; Role; Science; Serine; Signal Pathway; Starvation; Therapeutic; Tobacco use; Transcription Initiation Site; Validation; Western Blotting; Withdrawal; advanced disease; alpha ketoglutarate; cancer stem cell; cancer therapy; cell motility; chemotherapy; cost effective; demethylation; deprivation; derepression; dietary; dietary restriction; enzyme pathway; epigenomic profiling; epigenomics; histone modification; in vivo; insight; malignant mouth neoplasm; migration; mortality; mouse model; mouth squamous cell carcinoma; neoplastic cell; novel; novel therapeutic intervention; novel therapeutics; precision nutrition; programs; response; side effect; stem; stem cell genes; stem cell population; stemness; success; targeted treatment; therapeutically effective; trait; treatment response; tumor; tumor growth; tumor heterogeneity; tumor progression; tumorigenic; uptake

ABSTRACT Oral squamous cell carcinoma (OSCC) is a devastating malignancy associated with high morbidity, poor survival, and few therapeutic options. OSCC is characterized by heterogeneous cell states, including cancer stem cells (CSCs), which drive metastasis and therapy resistance. Although there has been some modest success with targeted therapies, there remains a need for more effective therapeutic options for OSCC. Increasing evidence has shown that changes in serine metabolism can direct cell fate via epigenomic changes. Endogenous serine synthesis generates a by-product, alpha-ketoglutarate (αKG), which is a co-substrate for nuclear αKG- dependent dioxygenases to demethylate histone marker H3K27me3 and de-repress differentiation genes. We have shown that under serine starvation conditions, metastatic OSCC HSC3 cells slowed proliferation concomitant with a change in morphology from mesenchymal to epithelial, compared to cells grown in complete medium. This was associated with a statistically significant increase in the steady-state mRNA and enzyme levels in the serine synthesis pathway under serine starvation conditions, indicating that HSC3 cells rely on exogenous serine for growth. The observed switch from exogenous serine uptake to endogenous serine synthesis in HSC3 cells was accompanied by an increase in αKG concentration. Furthermore, serine starvation and increased αKG were associated with decrease of repressive histone marker H3K27me3, thus de-repressing terminal epithelial differentiation genes. Simultaneously, there is a decrease in H3K4me3, a marker of open chromatin structure, associated with the promotion of stemness genes and aggressive cancer traits in OSCC. Initial studies into the plasticity of the stem-like identity using the tumorsphere formation assay shows that serine starvation leads to a lack of tumorspheres stability. Our findings suggest that a switch from exogenous serine uptake to the endogenous serine biosynthesis promotes OSCC cell differentiation concomitant with the loss of CSC identity. Given my preliminary studies, I hypothesize that serine deprivation promotes epigenetic changes that inhibit CSCs and OSCC progression to advanced disease. I will investigate our hypotheses through two aims. My first aim will be to determine mechanisms underlying epigenetic modifications in a panel of OSCC cell lines in response to serine deprivation in vitro. This will be investigated through use of migration and invasion assays, in depth tumorsphere analysis, and epigenomic profiling. My second aim will be to define changes in tumor size and tumor cell populations in response to dietary serine restriction in vivo, utilizing a syngeneic 4MOSC1 isograft mouse model of OSCC to interrogate the heterogeneity of tumor cell populations through scRNAseq with biochemical validation. These studies will fill the gap in knowledge how changes in serine metabolism impact the epigenomic environment and provide insight into novel therapeutic options for OSCC.

抽象的 口腔鳞状细胞癌（OSCC）是一种毁灭性的恶性肿瘤，发病率高、生存率低、 和很少的治疗选择。 OSCC 的特点是异质细胞状态，包括癌症干细胞 （CSC），它会导致转移和治疗耐药。尽管取得了一些小小的成功 靶向治疗，仍然需要更有效的 OSCC 治疗选择。越来越多的证据 研究表明，丝氨酸代谢的变化可以通过表观基因组的变化来指导细胞的命运。内源丝氨酸 合成会产生副产物 α-酮戊二酸 (αKG)，它是核 αKG- 的共底物 依赖双加氧酶使组蛋白标记 H3K27me3 去甲基化并去抑制分化基因。我们 研究表明，在丝氨酸饥饿条件下，转移性 OSCC HSC3 细胞的增殖速度减慢 与完全生长的细胞相比，伴随着从间充质到上皮的形态变化 中等的。这与稳态 mRNA 和酶的统计显着增加相关。 丝氨酸饥饿条件下丝氨酸合成途径的水平，表明HSC3细胞依赖于 外源丝氨酸促进生长。观察到从外源丝氨酸摄取到内源丝氨酸的转变 HSC3 细胞中的合成伴随着 αKG 浓度的增加。此外，丝氨酸饥饿 αKG 的增加与抑制性组蛋白标记物 H3K27me3 的减少相关，从而解除抑制 终末上皮分化基因。同时，开放标记物 H3K4me3 也有所减少。 染色质结构，与 OSCC 中干性基因和侵袭性癌症特征的促进相关。 使用肿瘤球形成测定对茎样身份的可塑性进行的初步研究表明，丝氨酸 饥饿导致肿瘤球缺乏稳定性。我们的研究结果表明，外源丝氨酸的转变 摄取内源丝氨酸生物合成促进 OSCC 细胞分化，同时丧失丝氨酸 CSC 身份。根据我的初步研究，我假设丝氨酸剥夺会促进表观遗传变化 抑制 CSC 和 OSCC 进展为晚期疾病。我将通过两个方面来研究我们的假设 目标。我的首要目标是确定一组 OSCC 细胞表观遗传修饰的机制 体外对丝氨酸剥夺的反应。这将通过使用迁移和入侵来调查 分析、深入的肿瘤球分析和表观基因组分析。我的第二个目标是定义变化 利用同源方法研究体内饮食丝氨酸限制对肿瘤大小和肿瘤细胞群的响应 4MOSC1同种移植OSCC小鼠模型通过以下方式探究肿瘤细胞群的异质性 scRNAseq 进行生化验证。这些研究将填补丝氨酸如何变化的知识空白 代谢影响表观基因组环境，并为口腔鳞癌的新治疗选择提供见解。