Clinical Significance of the D-Loop Gene Mutation in Mitochondrial DNA in Laryngeal Cancer.

Objective: The aim of the present study was to investigate the D-loop gene mutation and microsatellite instability in the mitochondrial DNA (mtDNA) and the correlation with the clinical and pathological parameters in laryngeal cancer.

Methods: The tumor tissues and paratumor tissues in 60 cases of laryngeal cancer were selected, and DNA was extracted from these tissues. The D-loop region in mtDNA was amplified by PCR with the gene sequence of the amplified product being detected. The gene sequence of the detected region was compared with the revised Cambridge Reference Sequence (rCRS) and the related database by using the Mitomaster software. The correlation between the D-loop gene mutation and the clinical and pathological parameters was investigated.

Results: A total of 174 mutations across 38 sites were detected in 51 (85%) of samples. Most of the mutations were concentrated in the high various (HV) I region, and the main types of mutations were the substitution of a single base or insertion and deletion of a single base. There was also microsatellite instability in the D310 region. The statistical results showed that there was no correlation between the age, gender, tumor diameter, and TNM stage, and the number of the D-loop mutations in mtDNA (P > 0.05).

Conclusion: There existed high-frequency mutation of the D-loop gene in mtDNA in laryngeal cancer, which might play an important role in the pathogenesis of laryngeal cancer.