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.

摘要 口腔鳞状细胞癌(OSCC)是一种发病率高、存活率低、致命性差的恶性肿瘤。 而且几乎没有治疗选择。口腔鳞状细胞癌的特点是细胞状态不同，包括癌症干细胞。 (CSCs)，驱动转移和治疗耐药。尽管在以下方面取得了一些不大的成功 对于口腔鳞状细胞癌的靶向治疗，仍然需要更有效的治疗方案。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决定细胞的命运。内源性丝氨酸 合成产生副产物α-酮戊二酸(αKG)，它是核αKG-的共同底物- 依赖双加氧酶使组蛋白标记物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，转移的口腔鳞状细胞癌HSC3细胞的增殖速度减缓 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 5~6成熟。这与稳态信使核糖核酸和酶在统计学上显著增加有关。 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 生长所需的外源丝氨酸。观察到的从外源性丝氨酸摄取到内源性丝氨酸的转换 HSC3细胞的合成伴随着αKG浓度的增加。此外，丝氨酸饥饿 而αKG的增加与抑制性组蛋白标志物H3K27me3的减少有关，从而降低了抑制性组蛋白的表达 终末上皮分化基因。同时，开放的标志物H3K4me3也有所下降 染色质结构，与口腔鳞状细胞癌中的干性基因和侵袭性癌特征的促进有关。 利用肿瘤球体形成试验对干状身份可塑性的初步研究表明，丝氨酸 饥饿导致肿瘤球体缺乏稳定性。我们的发现表明，从外源性丝氨酸转变为 摄取内源性丝氨酸生物合成促进口腔鳞状细胞癌细胞分化伴随着 CSC身份。根据我的初步研究，我假设丝氨酸缺乏会促进表观遗传变化。 抑制CSCs和OSCC进展为晚期疾病。我将通过两个例子来研究我们的假设 目标。我的第一个目标是确定口腔鳞状细胞癌细胞表观遗传修饰的潜在机制 在体外对丝氨酸缺乏的反应。这将通过使用迁移和入侵进行调查 分析、深入的肿瘤球体分析和表观基因组图谱。我的第二个目标将是定义 体内肿瘤大小和肿瘤细胞数量对饮食丝氨酸限制的反应 4MOSC1同种异体口腔鳞状细胞癌小鼠模型的建立 带有生化验证的scRNAseq。这些研究将填补丝氨酸如何变化的知识空白 新陈代谢影响表观基因组环境，为口腔鳞癌提供新的治疗选择。