logo logo
Mucin expression pattern in pancreatic diseases: findings from EUS-guided fine-needle aspiration biopsies. Carrara Silvia,Cangi Maria Giulia,Arcidiacono Paolo Giorgio,Perri Francesco,Petrone Maria Chiara,Mezzi Gianni,Boemo Cinzia,Talarico Anna,Cin Elena Dal,Grassini Greta,Doglioni Claudio,Testoni Pier Alberto The American journal of gastroenterology OBJECTIVES:Alterations in mucin (MUC) glycosylation and expression have been described in cancer. Endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) can provide material for molecular biology analysis. This study assessed the feasibility of evaluating MUC expression from material obtained by EUS-FNA and studied the profile of MUC expression in benign and malignant pancreatic lesions. METHODS:A total of 90 patients with solid or cystic pancreatic lesions underwent FNA. The aspirated material was used for cytological analysis and RNA extraction to assess the expression pattern of MUCs by reverse transcription-PCR with primers specific for the MUC1, MUC2, MUC3, MUC4, MUC5A, MUC5B, MUC6, and MUC7 genes. RESULTS:RNA extraction was successful in 81% of the biopsies. The prevalences of MUC1, MUC2, MUC4, and MUC7 in ductal adenocarcinoma were 57.7, 51.4, 18.9, and 73.0%, respectively. Fifty percent of benign lesions and neuroendocrine tumors (NETs), and 63% of intraductal papillary mucinous neoplasms (IPMNs) were positive for MUC1. Twenty-five percent of benign lesions, 86% of NETs, and 47% of IPMNs were positive for MUC2. Of NETs, 50% were positive for MUC1, and 14% were positive for MUC7. None of the benign lesions or NETs expressed MUC4. MUC7 expression was highly significant for adenocarcinoma (P=0.007) and borderline for IPMN (P=0.05). MUC7 was expressed in 37.5% of chronic pancreatitis cases. CONCLUSIONS:RNA can be extracted from samples obtained under EUS-FNA. MUC7 could serve as a potential biological marker to identify malignant lesions, especially pancreatic adenocarcinoma. 10.1038/ajg.2011.22
Discrimination between adenocarcinoma and normal pancreatic ductal fluid by proteomic and glycomic analysis. Journal of proteome research Sensitive and specific biomarkers for pancreatic cancer are currently unavailable. The high mortality associated with adenocarcinoma of the pancreatic epithelium justifies the broadest possible search for new biomarkers that can facilitate early detection or monitor treatment efficacy. Protein glycosylation is altered in many cancers, leading many to propose that glycoproteomic changes may provide suitable biomarkers. In order to assess this possibility for pancreatic cancer, we have performed an in-depth LC-MS/MS analysis of the proteome and MS(n)-based characterization of the N-linked glycome of a small set of pancreatic ductal fluid obtained from normal, pancreatitis, intraductal papillary mucinous neoplasm (IPMN), and pancreatic adenocarcinoma patients. Our results identify a set of seven proteins that were consistently increased in cancer ductal fluid compared to normal (AMYP, PRSS1, GP2-1, CCDC132, REG1A, REG1B, and REG3A) and one protein that was consistently decreased (LIPR2). These proteins are all directly or indirectly associated with the secretory pathway in normal pancreatic cells. Validation of these changes in abundance by Western blotting revealed increased REG protein glycoform diversity in cancer. Characterization of the total N-linked glycome of normal, IPMN, and adenocarcinoma ductal fluid clustered samples into three discrete groups based on the prevalence of six dominant glycans. Within each group, the profiles of less prevalent glycans were able to distinguish normal from cancer on this small set of samples. Our results emphasize that individual variation in protein glycosylation must be considered when assessing the value of a glycoproteomic marker, but also indicate that glycosylation diversity across human subjects can be reduced to simpler clusters of individuals whose N-linked glycans share structural features. 10.1021/pr400422g
Gastric gland mucin-specific O-glycan expression decreases with tumor progression from precursor lesions to pancreatic cancer. Ohya Ayumi,Yamanoi Kazuhiro,Shimojo Hisashi,Fujii Chifumi,Nakayama Jun Cancer science Pancreatic cancer is lethal, as it is often detected late. Thus, novel biomarkers of precursor lesions are needed to devise timely therapies. Pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN) are major precursors of pancreatic cancer. In normal gastric mucosa, gastric gland mucin-specific O-glycans are unique in having α1,4-linked N-acetylglucosamine (αGlcNAc) residues attached to MUC6. Recently we reported that αGlcNAc functions as a tumor suppressor for differentiated-type gastric adenocarcinoma (Karasawa et al., J Clin Invest 122, 923, 2012). MUC6 is also expressed in pancreatic neoplasms, including PanIN and IPMN, but the role of αGlcNAc expression in pancreatic neoplasms remains unknown. Here, we analyze expression patterns of αGlcNAc, MUC6 and MUC5AC in pancreatic neoplasms and compare them with progression from PanIN to invasive ductal adenocarcinoma (IDAC) (the PanIN-IDAC sequence; 20 cases) and from IPMN to IPMN with associated invasive carcinoma (IPMNAIC) (the IPMN-IPMNAIC sequence; 20 cases). At both sequences, the frequency of MUC6-positive and αGlcNAc-positive lesions decreased with tumor progression. We then compared expression levels of αGlcNAc and MUC6 at each step of the progression. At the PanIN-IDAC sequence, αGlcNAc expression significantly decreased relative to MUC6 in low-grade PanIN (P = 0.021), high-grade PanIN/intraductal spread of IDAC (P = 0.031) and IDAC (P = 0.013). At the IPMN-IPMNAIC sequence, decreased αGlcNAc expression was also observed in low-grade IPMN exhibiting gastric-type morphology (P = 0.020). These results suggest that decreased expression of αGlcNAc relative to MUC6 occurs early and marks the initiation of tumor progression to pancreatic cancer. 10.1111/cas.13317
Reduced αGlcNAc glycosylation on gastric gland mucin is a biomarker of malignant potential for gastric cancer, Barrett's adenocarcinoma, and pancreatic cancer. Yamanoi Kazuhiro,Nakayama Jun Histochemistry and cell biology Gastric gland mucin secreted from pyloric gland cells, mucous neck cells, and cardiac gland cells of the gastric mucosa harbors unique O-glycans carrying terminal α1,4-linked N-acetylglucosamine residues (αGlcNAc), which are primarily attached to the scaffold mucin core protein MUC6. αGlcNAc acts as an antibiotic against Helicobacter pylori (H. pylori), a microbe causing gastric cancer. In addition, mice deficient in A4gnt, which encodes the enzyme α1,4-N-acetylglucosaminyltransferase (α4GnT) that catalyzes αGlcNAc biosynthesis, spontaneously develop gastric differentiated-type adenocarcinoma, even if not infected by H. pylori. Thus, αGlcNAc prevents gastric cancer as both an antibiotic and a tumor suppressor (Nakayama in Acta Histochem Cytochem 47:1-9, 2014b). Indeed, in humans αGlcNAc loss on MUC6 in differentiated-type adenocarcinoma is closely associated with poor patient prognosis (Shiratsu et al. in Cancer Sci 105:126-133, 2014). Recently, we reported reduced αGlcNAc expression on MUC6 in both pyloric gland adenoma of the stomach and chronic atrophic gastritis, in Barrett's esophagus, and in pancreatic intraductal papillary-mucinous neoplasm (IPMN)/pancreatic intraepithelial neoplasia (PanIN), all potentially premalignant conditions. This review discusses whether relatively reduced levels of αGlcNAc in these lesions could serve as a biomarker to predict malignant potential and cancer progression. 10.1007/s00418-018-1667-8
High-density and targeted glycoproteomic profiling of serum proteins in pancreatic cancer and intraductal papillary mucinous neoplasm. Aronsson Linus,Andersson Roland,Bauden Monika,Andersson Bodil,Bygott Thomas,Ansari Daniel Scandinavian journal of gastroenterology OBJECTIVE:Glycoproteomics is an emerging subfield of proteomics. Tumor-specific variations in protein glycosylation might be potential targets for the development of new cancer diagnostics. Here, we performed high-throughput screening and targeted verification of glycome alterations in serum samples from patients with pancreatic cancer and the precancerous lesion intraductal papillary mucinous neoplasm (IPMN). MATERIAL AND METHODS:The glycosylation profile of 1000 proteins was mapped in a discovery cohort comprising serum samples from 16 individuals, including 8 patients with pancreatic cancer and 8 healthy controls. The top 10 glycoprotein biomarker candidates with the highest signal intensity difference in glycosylation levels were evaluated in a cohort consisting of 109 serum samples, including 49 patients with resectable pancreatic cancer, 13 patients with resectable noninvasive IPMN and 47 healthy controls, using a targeted assay. RESULTS:Multivariable analysis defined sets of panels comprising CA19-9 and distinctively glycosylated proteins for discrimination between pancreatic cancer, IPMN and healthy controls. A panel including CA 19-9, IL.17E, B7.1 and DR6 gave an AUC of 0.988 at 100% sensitivity at 90% specificity for the discrimination of stage 1 pancreatic cancer and healthy controls. B7.1 was found to be a valuable biomarker for differentiating between IPMN and healthy controls, with better performance alone than CA 19-9. CONCLUSIONS:Measurement of protein glycosylation profiles in serum may aid in the early detection of pancreatic cancer and precursor lesions. 10.1080/00365521.2018.1532020