title: Methylation of p16 CpG islands correlated with metastasis and aggressiveness in papillary thyroid carcinoma.
abstract: BACKGROUND
  Inactivation of p16 by methylation of CpG islands is a frequent early event in human cancers, including papillary thyroid carcinoma (PTC). This study was to observe the methylation status of the p16 gene in papillary thyroid carcinoma (PTC) and its correlation with clinical parameters.
  
  
  METHODS
  Methylation-specific PCR (MSP) was used to analyze the methylation status of the p16 gene in 74 PTCs and 21 adjacent normal thyroid tissues.
  
  
  RESULTS
  Hypermethylation of p16 gene was observed in 27.0% (20/74) of PTC. None of the normal thyroid tissues was methylated, when compared to the PTCs (p < 0.05). There was no marked relationship between the methylation of p16 gene and the patients' age, gender, size of cancer, histological subtypes and occurrence of recurrent disease (p > 0.05). The methylation of p16 gene was positively associated with metastasis, a high AMES (age, metastasis to distant sites, extrathyroidal invasion, size) risk group (p < 0.05) and advanced pathological tumor-lymph node-metastasis stages.
  
  
  CONCLUSIONS
  The methylation of the p16 gene, one event of significance in molecular biology, was common and correlated with biological metastasis and histological features in PTC, and may be involved in thyroid tumorigenesis and aggressiveness.
authors.affiliation: Department of Head and Neck Surgery, Zhejiang Cancer Hospital, Hangzhou, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wang
authors.forename: Renguang
authors.initials: R
authors.lastname: Pei
authors.forename: Zheming
authors.initials: Z
authors.lastname: Lu
authors.forename: Xiaosong
authors.initials: X
authors.lastname: Rao
authors.forename: Baoguo
authors.initials: B
authors.lastname: Liu
mesh_terms: D000328:Adult; D000368:Aged; D002277:Carcinoma / Q000235:genetics* / Q000473:pathology; D002291:Carcinoma, Papillary; D018899:CpG Islands; D019175:DNA Methylation; D005260:Female; D019942:Genes, p16; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000473:pathology