Page 89 - SDIR5 Abstract book 21 12 2021.

POSTER PRESENTATIONS

P49

The role of PLAG1 oncogene and miR-26a/miR-26b in the pathogenesis of benign salivary
gland tumors

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Nadja Nikolic , Jelena Carkic , Boban Anicic , Zoran Jezdic , Branko Dozic , Jelena Milasin 1
1 University of Belgrade, School of Dental Medicine, Department of Human Genetics, Belgrade, Serbia

2 University of Belgrade, School of Dental Medicine, Clinic for Maxillofacial Surgery, Belgrade, Serbia
3 University of Belgrade, School of Dental Medicine, Department of Pathology, Belgrade, Serbia

Background: Pleomorphic adenoma (PA) and Warthin’s tumor (WT) are two common benign salivary gland
tumors (SGTs) that can undergo malignant transformation. Due to their histological diversity and
unpredictable behavior, they represent both diagnostic and therapeutic challenges and their pathogenesis
is still unclear. The aim of the present study was to assess in PA and WT the levels of PLAG1 oncogene
mRNA and two microRNAs (miR-26a and -26b) known to interact with PLAG1 and to exhibit either
oncogenic or tumor suppressive behavior, depending on the tumor type.
Material and Methods: Relative gene expression levels of PLAG1, miR-26a and miR-26b were determined
using quantitative real-time PCR analyses in 17 PAs and 24 WTs of the parotid glands and 7 normal salivary
glands (NSGs). Results: PLAG1 was significantly overexpressed in both PAs and WTs compared to NSGs
(P=0.028 and P=0.008, respectively). Levels of miR-26a were increased in both neoplasms, compared to
NSGs, suggesting a potential oncogenic role, but without statistical significance. On the other hand, miR-
26b was downregulated in both tumor types, suggesting its potential tumor suppressive role, but again
without reaching statistical significance (P>0.05). Additionally, no correlation was observed between PLAG1
expression and relative miR-26a/ miR-26b levels in neither of the examined patient groups. No association
was found between markers’ expression and clinical/epidemiological parameters of PA and WT patients.
Conclusion: PLAG1 role has been confirmed in both neoplasms, yet from the present study it does not
appear that the oncogene is a target of miR-26a/miR-26b.
Keywords: Salivary Gland Neoplasms; PLAG1; miR-26a; miR-26b; Pleomorphic Adenoma; Warthin Tumor

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