A novel, transferable sialylation-mediated mechanism of chemoradioresistance in GI cancer

胃肠道癌症中一种新型的、可转移的唾液酸化介导的放化疗耐药机制

• 批准号: 10556396
• 负责人: Karin Marie Hardiman
• 金额: $ 37.88万
• 依托单位: UNIVERSITY OF ALABAMA AT BIRMINGHAM
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-02-01 至 2027-01-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10556396
• 关键词: Adenocarcinoma; Affect; Aftercare; Apoptosis; Apoptotic; Cancer Etiology; Cancer Model; Cancer cell line; Cell Separation; Cell Survival; Cell surface; Cells; Cessation of life; Charge; Data; Development; Enzymes; Future; Genetic Transcription; Glycoproteins; Golgi Apparatus; Human; Immunohistochemistry; Individual; Inhibition of Apoptosis; Malignant Neoplasms; Malignant neoplasm of gastrointestinal tract; Mediating; Mediator; Membrane Lipids; Messenger RNA; Modeling; Neoplasm Metastasis; Organoids; Patients; Persons; Primary Neoplasm; Proteins; Public Health; RNA; Rectal Cancer; Rectal Neoplasms; Recurrence; Regulation; Research; Resistance; Risk; Role; Sampling; Sialic Acids; Sorting; Structure; TNFRSF1A gene; Testing; Therapeutic; Tissues; Tumor Promotion; beta-site APP cleaving enzyme 1; cancer cell; cell type; chemoradiation; extracellular vesicles; functional gain; gastrointestinal; glycosylation; glycosyltransferase; inhibitor; inorganic phosphate; knock-down; novel; novel therapeutics; overexpression; particle; patient response; protein function; radiation resistance; receptor; resistance mechanism; response; sialylation; single cell sequencing; small hairpin RNA; standard of care; sugar; therapy resistant; trafficking; treatment response; tumor; vector

ABSTRACT — Combination chemoradiation is utilized to treat multiple gastrointestinal (GI) cancers including rectal cancer. Rectal cancer affects 40,000 people per year in the US. Approximately 85% of patients have an incomplete or poor response to treatment increasing their risk of recurrence. We have found that poor responders harbor sub-clones that are more resistant to treatment, and that the enzyme ST6Gal-1 is enriched in these sub- clones. ST6Gal-1 is a Golgi glycosyltransferase that adds the negatively-charged sugar, sialic acid (SA), to specific proteins destined for the cell surface. SA can have profound effects on the structure and function of proteins. ST6Gal-1 is one of the most pervasively upregulated glycosyltransferases in cancer cells. ST6Gal-1 has been shown to specifically promote tumor cell survival and resistance via sialylation. In addition, ST6Gal-1 has been found in extracellular vesicles (ECVs) made by cancer cells. ECVs are particles with a lipid membrane that contains RNA and protein cargo; thus, they are potential mediators of transferable resistance between cancer sub-clones. The role of ST6Gal-1 and ECVs in resistance to chemoradiation has not been investigated. The overall objective of this application is to ascertain the role of ST6Gal-1 in innate and transferable resistance to chemoradiotherapy in rectal cancer. Based on our preliminary data, we hypothesize that ST6Gal-1 mediates resistance to chemoradiation in individual sub-clones in rectal cancer, that this resistance is transferred to other sub-clones via ECVs spreading resistance, and that this resistance is regulated by ST6Gal-1 cleavage by BACE1. We have found that ST6Gal-1 is increased in rectal cancer models after treatment with chemoradiation. We will investigate our hypothesis with 3 aims: AIM 1 — Determine the role of ST6Gal-1 in chemoradiation resistance in human rectal cancer. We hypothesize that ST6Gal-1 causes treatment resistance after chemoradiation by inhibiting apoptosis. We will employ cell sorting, sequencing, and shRNA approaches. We will also conduct studies to investigate its function in patient samples. AIM 2 — Determine if ECVs carrying ST6Gal-1 transfer resistance to chemoradiation between sub-clones in rectal cancer. We hypothesize that ECVs act as vectors that impart resistance to chemoradiotherapy from sub-clone to sub-clone by trafficking ST6Gal-1, and thus, glycoprotein sialylation, in rectal cancer causing decreased apoptosis in the recipient sub-clones. AIM 3 — Determine if BACE1 promotes chemoradiosensitivity in rectal cancer due, in part, to ST6Gal-1 cleavage. We show that BACE1 mRNA is increased in tumors from patients who completely respond to chemoradiotherapy. BACE1 is known to cleave ST6Gal-1, and we found through inhibitor studies that BACE1 appear to regulate SA due to cleavage of ST6Gal-1 by BACE1. This research will evaluate a previously unknown mechanism of resistance to chemoradiotherapy in rectal cancer, with future potential for development of novel therapeutics that could target multiple resistant sub-clones across multiple GI adenocarcinomas, where the standard of care is pre-operative chemoradiation treatment.

摘要 — 联合放化疗用于治疗多种胃肠道 (GI) 癌症，包括 直肠癌。在美国，每年有 40,000 人患有直肠癌。大约 85% 的患者有 对治疗的不完全或反应不佳会增加复发的风险。我们发现反应不佳的人 含有对治疗更有抵抗力的亚克隆，并且酶 ST6Gal-1 在这些亚克隆中富集 克隆。 ST6Gal-1 是一种高尔基体糖基转移酶，它将带负电荷的糖、唾液酸 (SA) 添加到 运往细胞表面的特定蛋白质。 SA可以对结构和功能产生深远的影响 蛋白质。 ST6Gal-1 是癌细胞中最普遍上调的糖基转移酶之一。 ST6Gal-1 已被证明可以通过唾液酸化特异性促进肿瘤细胞存活和抵抗。另外，ST6Gal-1 已在癌细胞产生的细胞外囊泡（ECV）中发现。 ECV 是具有脂质膜的颗粒 含有 RNA 和蛋白质货物；因此，它们是可转移阻力的潜在调解者 癌症亚克隆。 ST6Gal-1 和 ECV 在化疗耐药中的作用尚未得到研究。 本申请的总体目标是确定 ST6Gal-1 在先天性和转移性耐药中的作用 用于直肠癌的放化疗。根据我们的初步数据，我们假设 ST6Gal-1 介导 直肠癌个体亚克隆对放化疗的耐药性，这种耐药性会转移 通过 ECV 传播耐药性到其他亚克隆，并且这种耐药性由 ST6Gal-1 调节 由 BACE1 切割。我们发现直肠癌模型中 ST6Gal-1 经治疗后增加 放化疗。我们将通过 3 个目标来研究我们的假设： AIM 1 — 确定 ST6Gal-1 在 人类直肠癌的放化疗耐药性。我们假设 ST6Gal-1 引起治疗 通过抑制细胞凋亡来抵抗放化疗后的耐药。我们将采用细胞分选、测序和 shRNA 接近。我们还将进行研究以调查其在患者样本中的功能。目标 2 — 确定是否 携带 ST6Gal-1 的 ECV 在直肠癌亚克隆之间转移对放化疗的耐药性。我们 假设 ECV 作为载体，使亚克隆对放化疗产生耐药性 通过运输 ST6Gal-1，从而在直肠癌中糖蛋白唾液酸化，导致细胞凋亡减少 受体亚克隆。目标 3 — 确定 BACE1 是否会促进直肠癌的放化疗敏感性， 部分地，ST6Gal-1 裂解。我们发现，以下患者的肿瘤中 BACE1 mRNA 增加： 对放化疗完全有反应。已知 BACE1 可以裂解 ST6Gal-1，我们通过抑制剂发现 研究表明，由于 BACE1 裂解 ST6Gal-1，BACE1 似乎可以调节 SA。这项研究将评估 直肠癌放化疗耐药的一种以前未知的机制，未来有潜力 开发可以针对多个胃肠道中的多个耐药亚克隆的新型疗法 腺癌，其护理标准是术前放化疗。