黏液性/浆液性胰腺囊性肿瘤囊液蛋白质糖基化差异表达研究

Difference in Glycosylation Between MCN and SCN in Pancreatic Cystic Neoplasm

随着影像学技术的进步,胰腺囊性病变(恶性胰腺囊性病变包括黏液性囊腺瘤(mucinous cystic neoplasm,MCN)和导管内乳头状黏液瘤(intraductal papillary mucinous neoplasm,IPMN)以及黏液性囊腺癌(mucinous cystic adenocarcinoma,MCA)的检出率有所提高,但是区分囊性病变的良恶性仍然是一个难题.本研究根据外科手术病理结果及囊液液基细胞结果,从120例经CT或MRI方法诊断为胰腺囊性肿瘤患者中选取35例样本,其中胰腺黏液性囊腺瘤(MCN)组17例与浆液性囊腺瘤(serous cystic neoplasm,SCN)组18例,通过超声内镜下细针穿刺(endoscopic ultrasonography-guided fine needle aspiration,EUS-FNA)方法吸取囊液,采用凝集素芯片分析蛋白质糖链谱差异.经t检验结果表明,MCN组与SCN组相比,6种凝集素,STL、WGA、BPL、DBA、PTL-Ⅰ及MAL-Ⅰ,识别的糖链结构二者之间存在明显差异(P<0.05),其中凝集素BPL、DBA、WGA、STL识别的糖链结构在MCN囊液中呈高表达(R>2.0),例如DBA特异识别的Tn抗原表达的增多,可能与肿瘤上皮细胞分泌的黏蛋白增多密切相关.而凝集素PTL-Ⅰ、MAL-Ⅰ特异识别Galβ-1、4Glc NAc结构以及Gal NAcα-1、3Gal结构在MCN囊液中表达降低(R<0.5).通过凝集素印记法检测了STL和BPL分别于MCN、SCN囊液中蛋白的结合情况,结果表明STL和BPL与囊液中的糖蛋白结合明显强于SCN组.本文通过比较MCN和SCN糖蛋白糖谱表达差异,寻找胰腺囊性肿瘤诊断和肿瘤良恶性评估的新方法,同时为探索胰腺囊性肿瘤发生发展机制和治疗的潜在靶点奠定基础.

With the progress of imaging technology, the detection rate of malignant pancreatic cystic including mucinous cystic neoplasm（MCN）, intraductal papillary mucinous neoplasm（IPMN）, mucinous cystic adenocarcinoma（MCA） have increased, but the distinction between benign and malignant lesions remains a problem. This study is based on the results of surgical pathology and cystic fluid cytology in 35 cases from 120 cases diagnosed by CT or MRI in patients with pancreatic cystic tumor samples. Of the 35 cases, 17 are from the MCN group and 18 are from the serous cystic adenoma（SCN） group. The liquid samples are gained through fine needle biopsy under endoscopic ultrasonography（endoscopic ultrasonography-guided fine needle aspiration, EUSFNA）. A lectin microarray was used to character the altered glycosylation between MCN and SCN. The t test results show that 6 lectins（STL, WGA, BPL, DBA, PTL-Ⅰ and MAL-Ⅰ） showed different binding signals between two groups（P〈 0. 05）. Among these, STL, WGA, BPL and DBA exhibited increased binding signals in the MCN cyst（the ratio value 〉2.0）, which indicated the abundance of Tn antigen in MCN group was higher than that in SCN group. It may correlated with a significant increase in the mucin secretion of cancer epithelial cells.Conversely, the glycopatterns of Gal NAcα-1, 3Gal and Galβ-1, 4GlcNAc identified by PTL-Ⅰ and MAL-Ⅰ were decreased in MCN group when compared with SCN group（ratio values 〈0.5）. In order to investigate precisely alterations of glycopatterns associated with MCN and SCN, SDS-PAGE and lectin blotting analysis was performed with STL and BPL staining. The binding signals of this glycoprotein were significantly higher in MCN than that in SCN groups.