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 - 化学放疗的组合用于治疗多种胃肠道（GI）癌症 直肠癌。在美国，直肠癌每年影响40,000人。大约85％的患者有 对治疗的反应不完整或不良的反应增加了他们的复发风险。我们发现响应者很差 对治疗更具耐药性的港口亚克隆 克隆。 ST6GAL-1是一种高尔基糖基转移酶，将负含量的糖，唾液酸（SA）添加到 特定的蛋白质注定针对细胞表面。 SA可以对 蛋白质。 ST6GAL-1是癌细胞中最普遍更新的糖基转移酶之一。 ST6GAL-1 已证明可以通过囊酰化特异性促进肿瘤细胞的存活和抗性。另外，ST6GAL-1 在癌细胞制造的细胞外蔬菜（ECV）中发现。 ECV是具有脂质膜的颗粒 其中包含RNA和蛋白质货物；因此，它们是在 癌症子卡隆。尚未研究ST6GAL-1和ECV在对化学放疗的抗性中的作用。 该应用的总体目的是确定ST6GAL-1在先天和可转移阻力中的作用 进行直肠癌的化学放射治疗。根据我们的初步数据，我们假设ST6GAL-1媒体 直肠癌中各个子锁的化学放疗的抗性，该抗药性被转移 通过ECV传播电阻到其他子卡隆 BACE1乳沟。我们发现，治疗后直肠癌模型中的ST6GAL-1增加了 化学放疗。我们将以3个目标研究我们的假设：目标1-确定st6gal-1在 人直肠癌的化学放疗耐药性。我们假设ST6GAL-1会导致治疗 化学放疗后通过抑制细胞凋亡。我们将采用细胞分类，测序和shRNA 方法。我们还将进行研究以研究其在患者样品中的功能。目标2 - 确定是否 在直肠癌中携带ST6GAL-1转移对化疗的ECV抗性。我们 假设ECV充当载体，从而对化学放射疗法抗拒从亚行为到亚欺骗 通过运输ST6GAL-1，因此，在直肠癌中糖脂蛋白溶解度，导致凋亡降低 接受者子唱片。 AIM 3 - 确定BACE1是否促进到期的直肠癌的化学放射效率， 在某种程度上进行ST6GAL-1裂解。我们表明，来自患者的肿瘤中的Bace1 mRNA增加 已知Bace1可以清除ST6GAL-1，我们通过抑制剂发现 BACE1的研究似乎通过BACE1裂解ST6GAL-1。这项研究将评估 以前未知的直肠癌化学放疗的抗性机制，未来的潜力 开发新的疗法，该疗法可以针对多个gi的多种耐药子锁定 腺癌，其中护理标准是术前化学放疗治疗。