ST6GalNAc-I/MUC5AC promoting angiogenesis in lung adenocarcinoma

摘要 非小细胞肺癌（NSCLC）是一种侵袭性疾病，约占所有肺癌的85 癌的尽管最近取得了进展，但NSCLC患者的总体5年生存率仍然令人沮丧。肺 腺癌（LUAD）是NSCLC最常见的亚型。LUAD的高发病率显示出 侵袭性疾病、频繁转移并且与不良预后相关。因此，理解 LUAD血管生成、肿瘤发展和转移背后的机制将显著改善LUAD 成果。St 6 galnac-I在侵袭型（KrasG 12 D/+; Trp 53 R172 H/+; Ad-1）中的独特表达被鉴定。 Cre（KPA））原位肿瘤。ST 6 GalNAc-1是一种O-糖基转移酶，其催化 唾液酸与第一种糖GalNAc（Tn）结合，形成Neu 5Ac α2，6 GalNAc（STn）碳水化合物 抗原的ST 6 GalNAc-1 KO细胞显示LUAD细胞中唾液酸化MUC 5AC水平降低，而ST 6 GalNAc-1 KO细胞显示LUAD细胞中唾液酸化MUC 5AC水平降低。 I KO或MUC 5AC敲低（KD）细胞具有较少的血管生成和迁移潜力。特别地，MUC 5AC KD LC显示两肺器官特异性内皮结合和管形成能力显著降低 （HUVEC）和脑（HBEC-5i）。基于这些研究，我们假设“ST 6 GalNAc-1改变MUC 5AC LUAD肿瘤微环境中的糖基化，并促进原发性肿瘤和 通过整合素β4的转移位点。”为了检验这一假设，提出了两个具体目标。目标1将 全面定义ST 6 GalNAc-I对MUC 5AC糖基化的影响及其对肿瘤生长的影响 和血管生成。目的2系统阐明ST 6 GalNAc-I介导的细胞凋亡的分子机制， MUC 5AC糖基化及其在原发性和转移性位点的肿瘤微环境中的作用， 尤其是脑转移瘤。为了证明这一概念，我们将使用ST 6 GalNAc-1 KO 或MUC 5AC KO细胞系、经胸和心内转移模型和Muc 5ac敲除小鼠 模型我们还将使用3D类器官模型来研究表达MUC 5AC的肿瘤细胞与表达MUC 5AC的肿瘤细胞之间的相互作用。 原发和转移部位的非肿瘤细胞。它将突出的机制和功能的意义， ST 6 GalNAc-I/MUC 5AC轴在细胞粘附和转移中的作用。拟议研究的主要影响是 将提供ST 6 GalNAc-1对MUC 5AC唾液酸化的影响以及该途径在肿瘤生长中的作用 和血管生成。这项研究的结果将有助于设计新的治疗策略， LUAD患者。

Abstract Non-small cell lung cancer (NSCLC) is an aggressive disease accounting for approximately 85% of all lung cancers. Despite recent advances, the overall 5-year survival rate remains dismal for NSCLC patients. Lung adenocarcinoma (LUAD) is the most common subtype of NSCLC. A high incidence of LUAD displays an aggressive disease, frequent metastasis and is associated with poor prognosis. Hence, understanding the mechanisms behind LUAD angiogenesis, tumor development, and metastasis would significantly improve LUAD outcomes. The unique expression of St6galnac-I was identified in aggressive type (KrasG12D/+; Trp53R172H/+; Ad- Cre (KPA)) autochthonous tumors. ST6GalNAc-I is an O-glycosyltransferase, which catalyzes the addition of sialic acid onto first sugar GalNAc (Tn) and results in the formation of Neu5Acα2, 6GalNAc (STn) carbohydrate antigen. ST6GalNAc-I KO cells showed a reduced level of sialylated MUC5AC in LUAD cells, and ST6GalNAc- I KO or MUC5AC knockdown (KD) cells had less angiogenesis and migratory potential. In particular, MUC5AC KD LC showed significantly reduced organ-specific endothelial binding and tube formation ability in both lung (HUVEC) and brain (HBEC-5i). Based on these studies, we hypothesize that “ST6GalNAc-I alters MUC5AC glycosylation in the LUAD tumor microenvironment and promotes angiogenesis in both the primary tumor and metastatic sites through integrin β4.” To test this hypothesis, two specific aims are proposed. Aim 1 will comprehensively define the impact of ST6GalNAc-I on MUC5AC glycosylation and its impact on tumor growth and angiogenesis. Aim 2 will systemically delineate the molecular mechanism of ST6GalNAc-I mediated MUC5AC glycosylation and their role in the tumor microenvironment in both primary and metastatic sites, especially brain metastasis, using available mouse models. To prove this concept, we will use ST6GalNAc-I KO or MUC5AC KO cell lines, transthoracic and intracardiac metastatic models, and Muc5ac knockout mouse models. We will also use 3D organoid models to study the interaction of MUC5AC expressing tumor cells and non-tumor cells in primary and metastatic sites. It will highlight the mechanistic and functional significance of the ST6GalNAc-I/MUC5AC axis in cellular adhesion and metastasis. The major impact of the proposed study would be to provide the impact of ST6GalNAc-I on MUC5AC sialylation and the role of this pathway in tumor growth and angiogenesis. The outcomes from the study will help to design novel therapeutic strategies for metastatic LUAD patients.