Mitochondrial DNA variations in tongue squamous cell carcinoma

Area of Science:

• Genomics
• Molecular Biology
• Oncology

Background:

• Tongue squamous cell carcinoma (TSCC) is the most prevalent oral cancer.
• Mitochondrial DNA (mtDNA) is increasingly recognized as a mutation hotspot in various cancers.
• mtDNA alterations in TSCC have not been previously investigated.

Purpose of the Study:

• To investigate mitochondrial genome alterations in TSCC.
• To identify mutations, polymorphisms, and microsatellite instability in the mtDNA of TSCC patients.
• To explore the potential role of mtDNA alterations in TSCC pathogenesis.

Main Methods:

• Sequencing and alignment of mitochondrial genomes from tongue carcinoma, adjacent non-cancerous tissue, and peripheral blood samples of 8 TSCC patients.
• Comparison with the revised Cambridge Reference Sequence.
• Analysis of mutations, polymorphisms, and mitochondrial microsatellite instability (mtMSI).

Main Results:

• One synonymous mutation was identified in the NADH:ubiquinone oxidoreductase core subunit 5 gene in one patient.
• Twenty-one polymorphisms were detected across various mtDNA regions, including the D-loop, respiratory chain complexes, and rRNA genes.
• Mitochondrial microsatellite instability (mtMSI) was observed in 2 out of 8 TSCC samples, localized in the D310 region.

Conclusions:

• The study identified significant mtDNA variations, including polymorphisms and mtMSI, in TSCC.
• These findings suggest the mitochondrial genome could be a hotspot for genomic alterations in tongue cancer.
• Further research is needed to elucidate the role of mtDNA alterations in TSCC development and their clinical significance.