AUTHOR=Rabinowits Guilherme , Bowden Michaela , Flores Ludmila M. , Verselis Sigitas , Vergara Victoria , Jo Vickie Y. , Chau Nicole , Lorch Jochen , Hammerman Peter S. , Thomas Tom , Goguen Laura A. , Annino Donald , Schoenfeld Jonathan D. , Margalit Danielle N. , Tishler Roy B. , Haddad Robert I. 

TITLE=Comparative Analysis of MicroRNA Expression among Benign and Malignant Tongue Tissue and Plasma of Patients with Tongue Cancer

JOURNAL=Frontiers in Oncology

VOLUME=Volume 7 - 2017

YEAR=2017

URL=https://www.frontiersin.org/journals/oncology/articles/10.3389/fonc.2017.00191

DOI=10.3389/fonc.2017.00191

ISSN=2234-943X

ABSTRACT=Background: Identification of a miRNA pattern to be used as a biomarker for HNSCC is challenging given the heterogeneity of the disease and different methodologies used.  To better define the field, we performed a prospective analysis of blood, tumor and paired benign tissues in tongue SCC patients.
Methods: Plasma samples were collected prior to surgery and paired tumor and benign tissue blocks were collected from tongue cancer resections.  Circulating free and exosomal-miRNA, and paired tumor and benign tissues-miRNA were analyzed.  TaqMan-based miRNA arrays were used to quantitate the expression of 747 human miRNAs.  The comparative Ct method assessed the miRNA profile results, and student t-test determined statistical significance between tumor and benign samples. 
Results: Sixteen of 359 miRNAs detected were differentially expressed between paired tumor and benign tissue.  Nine were upregulated and 7 downregulated in tumor tissue.  All 9 upregulated, and 6 of 7 downregulated tumor-miRNAs were expressed in circulating exosomes.  In contrast, 8 of 9 upregulated and 4 of 7 downregulated tumor-miRNAs were circulating free in the plasma.
Conclusions: An aberrantly expressed pattern of miRNA was identified in both tumor and plasma of patients with tongue SCC, suggesting this may be a biomarker for SCC of the oral tongue.  Circulating exosomes appear to be a more reliable method for evaluation of circulating tumor-miRNA expression.  Further studies with a larger cohort of patients and serial blood samples are needed to validate our findings.