title: DNA methylation in the CTCF-binding site I and the expression pattern of the H19 gene: does positive expression predict poor prognosis in early stage head and neck carcinomas?
abstract: Loss of allele-specific expression by the imprinted genes IGF2 and H19 has been correlated with a differentially methylated region (DMR) upstream to the H19 gene. The H19-DMR contains seven potential CCCTC-binding factor (CTCF) binding sites. CTCF is a chromatin insulator and a multifunctional transcription factor whose binding to the H19-DMR is suppressed by DNA methylation. Our study included a group of 41 head and neck squamous cell carcinoma (HNSCC) samples. The imprinting status of the H19 gene was analyzed in 11 out of 35 positive cases for H19 gene expression, and only 1 of them showed loss of imprinting. We detected a significant correlation (P = 0.041, Fisher's exact test) between H19 expression and tumor recurrence. Among H19 positive cases, six were T2, in which five developed recurrence and/or metastasis. Inversely, in the group of tumors that showed no H19 gene expression, 5 out of 24 were T2 and only 1 presented regional recurrence. These data support the hypothesis that H19 expression could be used as a prognostic marker to indicate recurrence in early stage tumors. We also examined the methylation of the CTCF binding site 1 in a subgroup of these samples. The H19 gene silencing and loss of imprinting were not correlated with the methylation pattern of the CTCF binding site 1. However, the significant correlation between H19 expression and tumor recurrence suggest that this transcript could be a marker for the progression of HNSCC.
authors: Department of Genetics, Institute of Biosciences, UNESP, Sao Paulo State University, Botucatu, Sao Paulo, Brazil.
authors: Leda I C V
authors: LI
authors: Esteves
authors: Afonso C
authors: AC
authors: Javaroni
authors: Inês N
authors: IN
authors: Nishimoto
authors: José
authors: J
authors: Magrin
authors: Jeremy A
authors: JA
authors: Squire
authors: Luiz P
authors: LP
authors: Kowalski
authors: Cláudia A
authors: CA
authors: Rainho
authors: Silvia R
authors: SR
authors: Rogatto
mesh_terms: D000328:Adult; D000368:Aged; D001665:Binding Sites; D000076246:CCCTC-Binding Factor; D002277:Carcinoma / Q000235:genetics / Q000378:metabolism; D019175:DNA Methylation; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D016147:Genes, Tumor Suppressor; D018392:Genomic Imprinting; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated / Q000378:metabolism*; D012097:Repressor Proteins / Q000378:metabolism*
chemical_list: D000076246:CCCTC-Binding Factor; C000619697:CTCF protein, human; D004268:DNA-Binding Proteins; C094335:H19 long non-coding RNA; D062085:RNA, Long Noncoding; D022661:RNA, Untranslated; D012097:Repressor Proteins