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Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:26:26Z No. of bitstreams: 0 Made available in DSpace on 2014-05-27T11:26:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-04-01 The search for molecular markers to improve diagnosis, individualize treatment and predict behavior of tumors has been the focus of several studies. This study aimed to analyze homeobox gene expression profile in oral squamous cell carcinoma (OSCC) as well as to investigate whether some of these genes are relevant molecular markers of prognosis and/or tumor aggressiveness. Homeobox gene expression levels were assessed by microarrays and qRT-PCR in OSCC tissues and adjacent non-cancerous matched tissues (margin), as well as in OSCC cell lines. Analysis of microarray data revealed the expression of 147 homeobox genes, including one set of six at least 2-fold up-regulated, and another set of 34 at least 2-fold down-regulated homeobox genes in OSCC. After qRT-PCR assays, the three most up-regulated homeobox genes (HOXA5, HOXD10 and HOXD11) revealed higher and statistically significant expression levels in OSCC samples when compared to margins. Patients presenting lower expression of HOXA5 had poorer prognosis compared to those with higher expression (P=0.03). Additionally, the status of HOXA5, HOXD10 and HOXD11 expression levels in OSCC cell lines also showed a significant up-regulation when compared to normal oral keratinocytes. Results confirm the presence of three significantly upregulated (>4-fold) homeobox genes (HOXA5, HOXD10 and HOXD11) in OSCC that may play a significant role in the pathogenesis of these tumors. Moreover, since lower levels of HOXA5 predict poor prognosis, this gene may be a novel candidate for development of therapeutic strategies in OSCC. Department of Oral Pathology School of Dentistry University of São Paulo, Av. Prof. Lineu Prestes 2227, Cidade Universitária, 05508-000 São Paulo Department of Head and Neck Surgery School of Medicine University of São Paulo, Av. Dr. Arnaldo 455, Cerqueira César, 01246903 São Paulo Head and Neck Surgery Division Heliópolis Hospital Complex, Rua Cônego Xavier 276, Sacomã, 04231-030 São Paulo Department of Head and Neck Surgery Arnaldo Vieira de Carvalho Cancer Institute, Rua Dr Cesário Motta Junior 112, Vila Buarque, 01221020 São Paulo Department of Molecular Biology São José do Rio Preto School of Medicine, Av. Brigadeiro Faria Lima 5416-Vila São Pedro, 15090-000 São José do Rio Preto Department of Genetics and Evolutionary Biology Institute of Biosciences University of São Paulo, R. do Matão, travessa 14 321, Cidade Universitária, 05508-090 São Paulo Department of Genetics Biosciences Institute University of São Paulo, Rua do Matão, trav. 14 321, Cidade Universitária, 05508-090 São Paulo School of Medicine USP, São Paulo Albert Einstein Jewish Teaching and Research Institute (IIEP), São Paulo School of Medicine of São José do Rio Preto São José Dos Campos Dental School UNESP Cancer Institute Arnaldo Vieira de Carvalho, São Paulo School of Dentistry USP, São Paulo Heliópolis Hospital, São Paulo School of Medicine of Ribeirão Preto USP School of Public Health USP, São Paulo University of Vale do Paraíba, São José dos Campos School of Medicine UNIFESP, São Paulo Faculty of Pharmaceutical Sciences of Ribeirão Preto USP, SP São José Dos Campos Dental School UNESP

Hypermethylation in the promoter region has been associated with a loss of gene function that may give a selective advantage to neoplastic cells. In this study, the methylation pattern of genes CDKN2A (alias p14 , p14 ARF , p16 , p16 INK4a ), DAPK1 , CDH1 , and ADAM23 was analyzed in 43 samples of head and neck tumors using methylation-specific polymerase chain reaction. In the oropharynx, there was a statistically significant association between hypermethylation of the DAPK1 gene and the occurrence of lymph node metastases, and in the larynx there was statistically significant evidence of an association between hypermethylation of the ADAM23 gene and advanced stages of the tumors. Thus, a correlation was observed between hypermethylation of the promoter region of genes DAPK1 and ADAM23 and the progression of head and neck cancer.

Univ Estadual Paulista, Inst Biociencias Letras & Ciencias Exatas, Dept Biol, BR-15054 Sao Jose do Rio Preto, Brazil

Head and neck squamous cell carcinoma is a disease associated with tobacco and alcohol abuse. There is evidence that the oncogenic human papillomavirus (HPV) may also be a risk for upper aerodigestive tract cancers. High-risk HPVs encode two early proteins, E6 and E7, that can bind to p53 and pRb, respectively, and induce its degradation or inactivation. The TP53 gene has a single polymorphism at codon 72 of exon 4 that encodes either arginine (Arg) or proline (Pro). The purpose of this study was to evaluate the role of HPV infection and TP53 polymorphism in head and neck cancer. We analyzed 50 tumors, as well swabs of oral mucosa from 142 control individuals, with a polymerase chain reaction technique. The prevalence of HPV in controls was 10.6% and in cancer specimens 16%. The frequency distribution of genotypes in controls was 50% Arg/Arg, 43% Arg/Pro and 7% Pro/Pro; in tumors, it was 52% Arg/Arg, 32% Arg/Pro, and 16% Pro/Pro. Contrary to the results of some studies on cervical cancer, no association between any TP53 genotype or allele and the development of head and neck cancer was observed, regardless of HPV status, except for the Pro/Pro genotype, which is associated with the absence of HPV. The arginine allele appears to protect against head and neck cancers. Also, the data showed that HPV infection results in no increased risk of developing head and neck tumors.