Evidence map›Paper›PMID 41174677›Full record

ArticleBMC oral health2025

Methylation-Driven downregulation of GABRB2 in oral carcinoma's subtype: implications for early diagnosis and differentiation.

Sena Sen, Can Doruk, Murat Ulusan, Vakur Olgaç, Gülsüm Ak, Semra Demokan

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Article in BMC oral health, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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5 · Who and what money

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6 authors.

Sena SenDepartment of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Capa, 34093, Türkiye. sena.sen@istanbul.edu.tr.ORCID http://orcid.org/0000-0003-3967-8903
Can DorukDepartment of Otorhinolaryngology-Head and Neck Surgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.ORCID http://orcid.org/0000-0002-4983-3666
Murat UlusanDepartment of Otorhinolaryngology-Head and Neck Surgery, Istanbul Faculty of Medicine, Istanbul University, Istanbul, Türkiye.ORCID http://orcid.org/0000-0003-3885-1620
Vakur OlgaçDepartment of Tumor Pathology and Oncology Cytology, Oncology Institute, Istanbul University, Istanbul, Türkiye.ORCID http://orcid.org/0000-0003-0497-0314
Gülsüm AkDepartment of Oral and Maxillofacial Surgery, Department of Clinical Sciences, Faculty of Dentistry, Istanbul University, Istanbul, Türkiye.ORCID http://orcid.org/0000-0002-3339-1568
Semra DemokanDepartment of Basic Oncology, Oncology Institute, Istanbul University, Istanbul, Capa, 34093, Türkiye. demokan@istanbul.edu.tr.ORCID http://orcid.org/0000-0002-8066-8419

Funding

Bilimsel Araştirma Projeleri Birimi, Istanbul Üniversitesi 27208
6 · The paper itself

Abstract

backgroundOral squamous cell carcinoma (OSCC) remains a major global health burden, often diagnosed at advanced stages, with limited survival improvement. Epigenetic dysregulation, particularly promoter hypermethylation, plays a significant role in OSCC pathogenesis. Previous study by Demokan et al. identified Gamma-Aminobutyric Acid Receptor Beta-2 (GABRB2) as a candidate gene subject to methylation-dependent transcriptional silencing. This study aimed to evaluate the methylation and expression profiles of GABRB2 in OSCC and to explore its potential as a diagnostic biomarker.

methodsTissue and serum samples from 48 OSCC patients and 15 healthy controls were analyzed for GABRB2 promoter methylation via quantitative methylation-specific PCR and for gene expression levels via quantitative real-time PCR. Relationships between methylation, expression levels, clinicopathological parameters, and patient outcomes were statistically assessed.

resultsGABRB2 promoter hypermethylation was detected in 14.6% of tumor samples, predominantly in floor of the mouth and buccal tumors. Decreased GABRB2 expression was observed in 52.1% of tumor tissues compared to matched-normal tissues, while 22.9% of tumors exhibited increased expression. Methylation-dependent expression loss was confirmed in 71.4% of methylated tumors. Notably, decreased expression and hypermethylation of GABRB2 were correlated with poor prognosis parameters (p < 0.05). ROC analysis showed moderate discrimination for GABRB2 expression in distinguishing tumor from normal tissues (AUC = 0.635, p = 0.022), while serum-based analysis demonstrated poor diagnostic performance. Survival analysis revealed no statistically significant prognostic impact of GABRB2 expression levels (p > 0.05). However, alcohol consumption (p = 0.006) and recurrence developed (p = 0.030) as independent predictors of poor prognosis in multivariate analysis.

conclusionOur study suggests that there was association between methylation-based expression loss of GABRB2 with OSCC' subgroups. To our knowledge, this is the first study to investigate GABRB2 gene methylation and expression profiling in both invasive/non-invasive samples from OSCC patients. Hypermethylation in the newly identified candidate GABRB2 gene may play a role in the development of tumors originating from the mouth floor and buccal anatomical regions of the oral cavity. However, since the loss of expression seen in the majority of our patients, we thought that only methylation may not the inhibition mechanism for GABRB2 gene decreased expression. The new identified candidate gene may be specific for the OSCC's subgroups.

Indexed as

Carcinoma, Squamous CellDNA MethylationMouth NeoplasmsReceptors, GABA-AAdultAgedBiomarkers, TumorCase-Control StudiesDown-RegulationEarly Detection of CancerFemaleGene Expression Regulation, NeoplasticHumansMaleMiddle AgedPromoter Regions, GeneticBiomarkers, TumorGABRB2 protein, humanReceptors, GABA-ABiomarkerExpressionMethylationNew target geneOral cancer

Identifiers

PMID41174677
PMCPMC12579410

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.