title: Methylation of the hTERT promoter: a novel cancer biomarker for leptomeningeal metastasis detection in cerebrospinal fluids.
abstract: OBJECTIVE
  The diagnosis of leptomeningeal metastases is usually confirmed by the finding of malignant cells by cytologic examination in the cerebrospinal fluid (CSF). More sensitive and specific cancer biomarkers may improve the detection of tumor cells in the CSF. Promoter methylation of the human telomerase reverse transcriptase (hTERT) gene characterizes most cancer cells. The aim of this study was to develop a sensitive method to detect hTERT methylation and to explore its use as a cancer biomarker in CSF.
  
  
  METHODS
  In 77 CSF specimens from 67 patients, hTERT promoter methylation was evaluated using real-time methylation-sensitive high-resolution melting (MS-HRM) and real-time TaqMan PCR and MS-HRM in a single-tube assay.
  
  
  RESULTS
  Real-time MS-HRM assay was able to detect down to 1% hTERT-methylated DNA in a background of unmethylated DNA. PCR products were obtained from 90% (69/77) of CSF samples. No false positive hTERT was detected in the 21 non-neoplastic control cases, given to the method a specificity of 100%. The sensitivity of the real-time MS-HRM compared with the cytologic gold standard analysis was of 92% (11/12). Twenty-six CSFs from 22 patients with an hTERT-methylated primary tumor showed cytologic results suspicious for malignancy; in 17 (65%) of them, a diagnosis of leptomeningeal metastases could be confirmed by the hTERT methylation test.
  
  
  CONCLUSIONS
  The hTERT real-time MS-HRM approach is fast, specific, sensitive, and could therefore become a valuable tool for diagnosis of leptomeningeal metastases as an adjunct to the traditional examination of CSF.
authors: Authors' Affiliation: Institute of Pathology, Lausanne University Hospital, Lausanne, Switzerland.
authors: Stéphanie
authors: S
authors: Bougel
authors: Benoit
authors: B
authors: Lhermitte
authors: Gabrielle
authors: G
authors: Gallagher
authors: Jeanne-Chantal
authors: JC
authors: de Flaugergues
authors: Robert C
authors: RC
authors: Janzer
authors: Jean
authors: J
authors: Benhattar
mesh_terms: D014408:Biomarkers, Tumor / Q000134:cerebrospinal fluid / Q000235:genetics; D019175:DNA Methylation; D004273:DNA, Neoplasm / Q000134:cerebrospinal fluid / Q000235:genetics; D005260:Female; D006801:Humans; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis / Q000235:genetics / Q000556:secondary; D009369:Neoplasms / Q000201:enzymology / Q000235:genetics* / Q000473:pathology; D011401:Promoter Regions, Genetic / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D019098:Telomerase / Q000235:genetics*
chemical_list: D014408:Biomarkers, Tumor; D004273:DNA, Neoplasm; C509186:TERT protein, human; D019098:Telomerase