title: MALDI-TOF Mass Array Analysis of Nell-1 Promoter Methylation Patterns in Human Gastric Cancer.
abstract: Mass spectrometry (MS) enables rapid and sensitive qualitative and quantitative analyses of biomolecules (proteins, peptides, oligosaccharides, lipids, DNA, and RNA), drugs, and metabolites. MS has become an essential tool in modern biomedical research, including the analysis of DNA methylation. DNA methylation has been reported in many cancers, suggesting that it can be utilized as an early biomarker to improve the early diagnosis rate. Using matrix-assisted laser desorption/ionization time-of-flight MS and MassCLEAVE reagent, we compared Nell-1 hypermethylation levels among tumor tissues, paracarcinoma tissues, and normal tissues from gastric cancer patients. Almost 80% of the CpG sites in the amplicons produced were covered by the analysis. Our results indicate a significant difference in methylation status between gastric cancer tissue (a higher level) and normal tissue. The same trend was identified in gastric cancer tissue versus paracarcinoma tissue. We also detected lower relative expression of Nell-1 by real-time PCR. Furthermore, immunohistochemical analyses revealed that Nell-1 staining was less intense in cancer tissue relative to normal tissue and that the tumor cells had spread to the muscle layer. These findings may serve as a guide for the early diagnosis of gastric cancer.
authors.affiliation: Department of Surgical Oncology, The Fourth Hospital of Harbin Medical University, Harbin 150010, China.
authors.forename: Changlu
authors.initials: C
authors.lastname: Gao
authors.affiliation: Central Laboratory, School of Stomatology, Peking University, Beijing 100081, China.
authors.forename: Qian
authors.initials: Q
authors.lastname: Zhang
authors.affiliation: Department of Nephrology, First Affiliated Hospital of Harbin Medical University, Harbin 150010, China.
authors.forename: Deyang
authors.initials: D
authors.lastname: Kong
authors.affiliation: Department of Surgical Oncology, The Fourth Hospital of Harbin Medical University, Harbin 150010, China.
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.affiliation: Department of Surgical Oncology, The Fourth Hospital of Harbin Medical University, Harbin 150010, China.
authors.forename: Changlei
authors.initials: C
authors.lastname: Su
authors.affiliation: Department of Surgical Oncology, The Fourth Hospital of Harbin Medical University, Harbin 150010, China.
authors.forename: Jinxue
authors.initials: J
authors.lastname: Tong
authors.affiliation: Central Laboratory, School of Stomatology, Peking University, Beijing 100081, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Chen
authors.affiliation: Department of Surgical Oncology, The Fourth Hospital of Harbin Medical University, Harbin 150010, China.
authors.forename: Qifan
authors.initials: Q
authors.lastname: Zhang
mesh_terms: D000368:Aged; D002135:Calcium-Binding Proteins; D019175:DNA Methylation / Q000235:genetics*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009419:Nerve Tissue Proteins / Q000235:genetics*; D011401:Promoter Regions, Genetic; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013274:Stomach Neoplasms / Q000235:genetics* / Q000473:pathology
chemical_list: D002135:Calcium-Binding Proteins; C104144:NELL1 protein, human; D009419:Nerve Tissue Proteins