title: [Relationship between methylation status of promoter and expression of XAF1 gene in papillary thyroid carcinoma].
abstract: OBJECTIVE
  To explore the relationship between methylation status of XAF1 (X-linked inhibitor of apoptosis protein associated factor-1) gene promoter and its protein expression in papillary thyroid carcinoma (PTC).
  
  
  METHODS
  Methylation-specific polymerase chain reaction (MSP) and immunohistochemical substance P (SP) technique were used to detect the methylation status of XAF1 gene promoter and its protein expression in 70 PTC cases and their matched adjacent non-cancerous epithelium (NCE).
  
  
  RESULTS
  In NCE, there was no promoter methylation of XAF1 gene while the rate was 35.7% (25/70) in PTC (χ(2) = 27.206, P < 0.01). And it was correlated with tumor TNM stage, pathological grade and lymph node metastasis (P < 0.05). The positive rates of XAF1 protein expression in NCE and PTC were 100% (70/70) and 55.7% (39/70) respectively. And there was significant difference (χ(2) = 36.458, P < 0.01). In PTC, the positive rates of XAF1 protein expression in Grades I and II were 67.5% (27/40) and 40.0% (12/30) respectively. And they were 35.7% (10/28) and 69.0% (29/42) in the lymph node metastasis and non-metastasis groups respectively. And there were significant differences between two groups (P < 0.05). Futhermore, there was distinct correlation between methylation of XAF1 gene promoter and its protein expression (χ(2) = 8.864, P < 0.01).
  
  
  CONCLUSIONS
  Methylation of promoter may be one of the important inactivating factors of XAF1 gene. And it plays an important role in the carcinogenesis and progression of PTC.
authors.affiliation: Department of Thyroid Surgery, First Affiliated Hospital of Zhengzhou University, Zhengzhou, China. detaoyin@zzu.edu.cn
authors.forename: De-tao
authors.initials: DT
authors.lastname: Yin
authors.forename: Guo
authors.initials: G
authors.lastname: Chen
authors.forename: Hong-qiang
authors.initials: HQ
authors.lastname: Li
authors.forename: Xiang-yu
authors.initials: XY
authors.lastname: Zheng
authors.forename: Yong-fei
authors.initials: YF
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Jin-hua
authors.initials: JH
authors.lastname: Jiang
authors.forename: Qing-duan
authors.initials: QD
authors.lastname: Wang
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000293:Adolescent; D000328:Adult; D000368:Aged; D051017:Apoptosis Regulatory Proteins; D002277:Carcinoma / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D002291:Carcinoma, Papillary; D019175:DNA Methylation; D005260:Female; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics* / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009363:Neoplasm Proteins / Q000235:genetics* / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D000077273:Thyroid Cancer, Papillary; D013964:Thyroid Neoplasms / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D055815:Young Adult
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009363:Neoplasm Proteins; C417551:XAF1 protein, human