title: Epithelial-Specific SHP1-P2 Methylation - a Novel Universal Tumor Marker for Detection of Colorectal Cancer Lymph Node Metastasis.
abstract: BACKGROUND
  Methylation of promoter 2 of the SHP1 gene is epithelial cell specific, with reported potential as a lymph node metastatic marker.
  
  
  OBJECTIVE
  To demonstrate SHP1-P2 methylation-specific quantitative PCR effectiveness in detecting colorectal cancer (CRC) DNA in lymph nodes.
  
  
  METHODS
  SHP1-P2 methylation levels were measured in lymph nodes of CRC patients and compared with pathological findings and patient prognosis.
  
  
  RESULTS
  Lymph nodes of CRC metastatic patients without microscopically detectable cancer cells had higher SHP1-P2 methylation levels than lymph nodes of controls (<0.001). In addition, a higher SHP1-P2 methylation level was associated with a shorter duration until adverse disease events, metastasis, recurrence and death (r2 = 0.236 and p value = 0.048). Studying two cohorts of 74 CRC patients without microscopic lymph node metastases showed that only the cohort containing samples with high SHP1-P2 methylation levels had a significant hazard ratio of 3.8 (95%CI = 1.02 to 14.2).
  
  
  CONCLUSIONS
  SHP1-P2 methylation PCR can detect CRC cancer DNA in lymph nodes even if cancer cells are not visible under a microscope, confirming applicability as a potential universal lymph node metastatic marker.
authors.affiliation: Center of Excellence in Molecular Genetics of Cancer and Human Disease, Department of Anatomy, Faculty of Medicine, Chulalongkorn University, King Chulalongkorn Memorial Hospital, Bangkok, Thailand E-mail : mapiwat@chula.ac.th.
authors.forename: Prakasit
authors.initials: P
authors.lastname: Rattanatanyong
authors.forename: Somboon
authors.initials: S
authors.lastname: Keelawat
authors.forename: Nakarin
authors.initials: N
authors.lastname: Kitkumthorn
authors.forename: Apiwat
authors.initials: A
authors.lastname: Mutirangura
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001483:Base Sequence; D014408:Biomarkers, Tumor / Q000378:metabolism*; D015179:Colorectal Neoplasms / Q000378:metabolism* / Q000473:pathology*; D019175:DNA Methylation / Q000502:physiology*; D005260:Female; D006801:Humans; D008198:Lymph Nodes / Q000378:metabolism / Q000473:pathology; D008207:Lymphatic Metastasis / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000378:metabolism / Q000473:pathology; D011379:Prognosis; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6 / Q000378:metabolism*
chemical_list: D014408:Biomarkers, Tumor; C509249:PTPN6 protein, human; D053824:Protein Tyrosine Phosphatase, Non-Receptor Type 6