第一部分 唾液酸化IgG与喉鳞癌进展的相关性研究
【背景与目的】 喉鳞状细胞癌（Laryngeal squamous cell carcinoma，LSCC），简称喉鳞癌，是喉恶性肿瘤中最常见的病理类型，约60%的患者在确诊时已为晚期，传统综合治疗局部复发率高，预后不佳。而肿瘤来源的唾液酸化免疫球蛋白G（Sialylated-immunoglobulin G，SIA-IgG）近年来被发现可在多种上皮来源的肿瘤中产生，其并不发挥抗体的活性，而通过多种机制促进肿瘤的发生发展。目前SIA-IgG在喉鳞癌中的研究尚为空白，本研究旨在探索SIA-IgG作为一个新型分子标志物在喉鳞癌发生发展及预后判断中的临床作用。
【材料与方法】 回顾性分析于2010-2016年期间，在中国医学科学院肿瘤医院头颈外科完成首次根治性手术的75例声门上型喉鳞癌患者的临床病理资料并进行随访，同时调阅患者术后福尔林固定石蜡包埋的组织标本。利用免疫组化染色方法探索SIA-IgG在喉鳞癌患者标本中的表达水平并对染色结果进行评分，分析SIA-IgG的表达情况与患者的临床病理特征及预后之间的关系。基础实验部分，利用两种siRNA对喉鳞癌细胞LCC中的SIA-IgG进行敲减，并应用Western Blot及免疫荧光染色方法验证敲减效果，进一步通过细胞克隆形成实验、CCK-8增殖实验、转板迁移实验（Transwell）等表型实验，研究 SIA- IgG的表达对喉鳞癌发生、发展及转移的影响。
【结果】 利用SIA-IgG的特异性单克隆抗体RP215进行免疫组化染色结果显示，所有喉鳞癌患者的肿瘤组织均表达 SIA-IgG，其中44例 （58.67%）患者呈低表达，31例 （41.33%） 患者呈高表达，且SIA-IgG的高表达与肿瘤的T分期（p=0.045），N分期 （p<0.001），TNM分期（p<0.001）及随访期间的复发（p=0.002）相关；此外，Kaplan-Meier分析显示SIA-IgG低表达组患者的总生存期（Overall survival，OS）及无病生存期（Disease-free survival，DFS）显著优于 SIA-IgG 高表达组患者（p=0.005）。基础实验中，体外实验结果显示喉鳞癌LCC细胞可以表达SIA-IgG，且定位于细胞膜上；利用两种siRNA对LCC细胞系中的SIA-IgG进行敲减，与对照组相比，敲减SIA-IgG后的LCC细胞增殖能力、克隆形成能力及迁移能力均明显减弱。
【结论】 喉鳞癌患者的肿瘤组织中存在SIA-IgG的普遍表达，且其高表达与肿瘤较差的分期以及不良预后密切相关。此外，SIA-IgG具有促进喉鳞癌细胞增殖、迁移的作用，其有望成为喉鳞癌的一个新型生物标志物。
 

第二部分 头颈鳞癌的蛋白质及磷酸化蛋白质组学研究
【背景与目的】 头颈鳞状细胞癌（Head and neck squamous cell carcinoma, HNSCC）是全球第六大常见癌症，也是预后不良的恶性肿瘤之一。为了深入了解 HNSCC，本研究使用定量质谱分析了癌和癌旁正常组织样本之间的蛋白质组和磷酸化蛋白质组。
【材料与方法】 从五对HNSCC肿瘤及癌旁正常样本中提取蛋白质并消化，进行数据独立的采集质谱分析。随后，使用TiO2来富集磷酸肽以用于磷酸蛋白质组的检测。最后，对所获取的数据进行生物信息学分析，从而确定 HNSCC 的潜在生物标志物。
【结果】 经过分析，共筛选出发生差异表达的1239个蛋白组和2025个磷酸化位点。其中，KRT16、MUC21、SH3BGRL2和METTL7A被选为 HNSCC的生物标志物。
【结论】 本研究利用质谱对五对 HNSCC 样本（包括癌及癌旁正常组织）进行了全面的定量分析，揭示了HNSCC的五种潜在蛋白质生物标志物。
 

Part 1 Mechanistic studies of cancer-derived sialylated IgG in the development of laryngeal squamous cell carcinoma
【Background and Objective】 Laryngeal squamous cell carcinoma (LSCC) is the most prevalent histological subtype among laryngeal malignant tumors. Approximately 60% of patients are diagnosed at an advanced stage, and conventional comprehensive treatment exhibits a high local recurrence rate and unfavorable prognosis. In recent years, cancer-derived Sialylated immunoglobulin G (SIA-IgG) has been identified in various epithelial tumors. Although it lacks antibody activity, it promotes tumorigenesis and progression through diverse mechanisms. Currently, there is a dearth of research on SIA-IgG in LSCC. The aim of this study is to investigate the clinical significance of SIA-IgG as a novel biomarker in the development and prognosis of LSCC.
【Materials and Methods】 We retrospectively analyzed clinical data from 75 patients with supraglottic laryngeal squamous cell carcinoma who underwent primary radical surgery at Cancer Hospital, Chinese Academy of Medical Sciences between 2010 and 2016. Follow-up was conducted for these patients, and postoperative formalin fixed paraffin-embedded (FFPE) tumor tissue specimens were retrieved. Immunohistochemical (IHC) staining was performed to detect the expression level of SIA-IgG in LSCC specimens, followed by scoring the staining results. The relationship between SIA-IgG expression and clinicopathological characteristics as well as prognosis of LSCC patients was analyzed accordingly. In basic experiments, two types of siRNA were employed to knock down SIA-IgG in LCC cells; Western Blotting and immunofluorescence (IF) staining were utilized to validate the knockdown effect. Subsequent phenotypic experiments such as cell clone formation assay, CCK-8 proliferation assay, and Transwell migration assay were conducted to explore the impact of SIA-IgG expression on occurrence, development, and metastasis of LSCC.
【Results】 IHC using the specific monoclonal antibody RP215 revealed universal expression of SIA-IgG in all tumor tissues obtained from patients with LSCC. Among these cases, 44 (58.67%) exhibited low expression while 31 (41.33%) showed high expression levels of SIA-IgG. High expression of SIA-IgG was significantly associated with advanced tumor T stage (p=0.045), N stage (p<0.001), TNM staging (p<0.001), and recurrence during follow-up (p=0.002). Furthermore, Kaplan-Meier analysis demonstrated that patients with low SIA-IgG expression had significantly improved overall survival (OS) and disease-free survival (DFS) compared to those with high SIA-IgG expression (p=0.005). In vitro experiments confirmed the presence of SIA-IgG on the cell membrane of LCC cells and its knockdown resulted in a significant decrease in proliferation, colony formation, and migration abilities when compared to control groups.
【Conclusion】The findings indicate that SIA-IgG is universally expressed in tumor tissues from patients with LSCC and its high expression is closely associated with poor tumor stage and prognosis outcomes. Additionally, the results suggest that SIA-IgG promotes proliferation and migration of LSCC cells, highlighting its potential as a novel biomarker for LSCC.
 

Part 2 Proteomics and phosphorylation proteomics of head and neck squamous carcinoma
【Background and Objective】 Head and neck squamous cell carcinoma (HNSCC) is the sixth most common cancer worldwide and one of the malignant tumors with poor prognosis. To gain insights into HNSCC, we analyzed the proteome and phosphoproteome between cancerous and paracancerous normal tissue samples using quantitative mass spectrometry.
【Materials and Methods】 Proteins were extracted from five pairs of tumor-normal samples and digested for data-independent acquisition mass spectrometry. Subsequently, phosphopeptides were enriched using TiO2 and prepared for phosphoproteome detection. A bioinformatics analysis was then conducted to identify potential biomarkers for HNSCC.
【Results】 A total of 1239 protein groups and 2025 phosphorylation sites were differentially expressed. Among these, KRT16, MUC21, SH3BGRL2 and METTL7A were selected as biomarkers for HNSCC.
【Conclusion】This study presents a comprehensive and quantitative analysis using mass spectrometry of five pairs of HNSCC samples, including five adjacent non-cancerous tissues, unveiling five potential protein biomarkers for HNSCC.