Abstract 5050: MicroRNAs profiling in salivary rinse from patients with head and neck squamous cells carcinoma
Authors: Horst Maria Aderuza , Carvalho Ana Carolina de , Maia Danielle , Carlin Viviane , Carvalho André Lopes , Kowalski Luiz Paulo , Vettore André Luiz 
Published: August 2012

Abstract
Head and neck squamous cell carcinomas (HNSCC) constitute the fifth most common malignancy worldwide. Over the last years, diagnosis and management have improved through combined efforts in surgery, radiotherapy and chemotherapy, but long-term survival rates have improved only marginally, and the overall 5-year survival rate for HNSCC patients is around 50%. Late diagnosis and frequent locoregional relapse after definitive therapy are the major causes of morbidly and mortality in HNSCC cases. Hence, there is a need to acquire deeper understanding of HNSCC biology and to identify effective molecular biomarkers useful for a precocious recognition of the relapses. MicroRNAs (miRNAs) are evolutionarily conserved, endogenous, small, noncoding RNA molecules of about 19-24 nucleotides in length that function as posttranscriptional gene regulators, might also function as tumor suppressors and oncogenes. These small regulatory RNAs have been recently recognized to play important roles in human cancers and increasing data support the value of miRNA expression profiling to distinguish different types of human malignancies and to categorize various cancer subtypes. The aim of this study is to evaluate the miRNA expression profile in salivary rinse samples from HNSCC patients and to investigate the significance of miRNA as molecular marker for tumor recurrence detection. Comprehensive miRNA profile was done in 4 salivary rinse samples from HNSCC patients and 3 samples from healthy donors using a Megaplex TaqMan Low Density miRNA Arrays (TLDA - Life Technologies) to assess the expression status of 670 miRNAs. Expression values were calculated using the ΔΔCt method, where mean Ct of the 3 normal samples was used as reference. All target miRNAs with undetermined Ct values in all samples were removed, leaving 198 miRNAs in the analysis. Using a cut-off of 2X to identify the differentially expressed miRNAs, 101 candidates were selected. From that, 21 were upregulated in the HNSCC samples while 80 were downregulated in these samples. After a deep revision of the information available from the 101 differentially expressed miRNA, we selected 10 candidates to be validated in an independent group of 100200 salivary rinses collected from HNSCC patient at diagnoses. A preliminary result indicated that one of the selected miRNA is overexpressed 95% (19/20) of tumor samples evaluated. In the future, the validated candidates will be evaluated in salivary rinses that are being collected each six months during the fallow-up of 300 patients included in the study. So we could evaluate their uselfulness as markers for HNSCC relapses. Supported by Fapesp (Grant 2011/01919-2).
Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 5050. doi:1538-7445.AM2012-5050