Short Report

Global gene expression profiling of oral cavity cancers suggests molecular heterogeneity within anatomic subsites

Patricia Severino¹, Adriana M Alvares², Pedro Michaluart³, Oswaldo K Okamoto⁴, Fabio D Nunes⁵, Carlos A Moreira-Filho⁶, Eloiza H Tajara^7,8* and Head and Neck Genome Project GENCAPO

• * Corresponding author: Eloiza H Tajara tajara@famerp.br

Author Affiliations

¹ Centro de Pesquisa Experimental, Instituto Israelita de Ensino e Pesquisa Albert Einstein, São Paulo, SP, Brazil

² Laboratório de Biologia Molecular, Hospital Heliópolis, São Paulo, SP, Brazil

³ Departamento de Cirurgia de Cabeça e Pescoço do Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil

⁴ Departamento de Neurologia e Neurocirurgia, Universidade Federal de São Paulo, São Paulo, SP, Brazil

⁵ Departamento de Estomatologia, Faculdade de Odontologia da Universidade de São Paulo, São Paulo, SP, Brazil

⁶ Departamento de Pediatria, Faculdade de Medicina da Universidade de São Paulo, São Paulo, SP, Brazil

⁷ Departamento de Biologia Molecular, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP, Brazil

⁸ Departamento de Genética e Biologia Evolutiva, Instituto de Biociências da Universidade de São Paulo, São Paulo, SP, Brazil

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BMC Research Notes 2008, 1:113 doi:10.1186/1756-0500-1-113

Published: 13 November 2008

Abstract

Background

Oral squamous cell carcinoma (OSCC) is a frequent neoplasm, which is usually aggressive and has unpredictable biological behavior and unfavorable prognosis. The comprehension of the molecular basis of this variability should lead to the development of targeted therapies as well as to improvements in specificity and sensitivity of diagnosis.

Results

Samples of primary OSCCs and their corresponding surgical margins were obtained from male patients during surgery and their gene expression profiles were screened using whole-genome microarray technology. Hierarchical clustering and Principal Components Analysis were used for data visualization and One-way Analysis of Variance was used to identify differentially expressed genes. Samples clustered mostly according to disease subsite, suggesting molecular heterogeneity within tumor stages. In order to corroborate our results, two publicly available datasets of microarray experiments were assessed. We found significant molecular differences between OSCC anatomic subsites concerning groups of genes presently or potentially important for drug development, including mRNA processing, cytoskeleton organization and biogenesis, metabolic process, cell cycle and apoptosis.

Conclusion

Our results corroborate literature data on molecular heterogeneity of OSCCs. Differences between disease subsites and among samples belonging to the same TNM class highlight the importance of gene expression-based classification and challenge the development of targeted therapies.