Relationship between mutations of the hyper-variable region of mitochondrial DNA D-loop and clinical characteristics in laryngeal cancer / 中国耳鼻咽喉头颈外科

ABSTRACT

OBJECTIVE To investigate the features of somatic mutations of the hypervariable region (HV) of mitochondrial DNA (mtDNA) D-loop in laryngeal squamous cell carcinoma (LSCC) and the relationship with clinicopathological characteristics. METHODS Microdissected cancerous tissues, paracancerous tissues and peripheral vein blood were obtained from 40 patients with LSCC and total DNA was extracted. HVⅠ and HVⅡ fragments were amplified by PCR and purified. Mutations were determined by DNA sequencing. The mutations of HVⅠand HVⅡ and their relationship with clinicopathological characteristics were analyzed. RESULTS ①In 40 LSCC samples, 86 polymorphisms were found, 21 (52.5 %) tumors presented somatic mtDNA mutations with a total of 34 mutations. Among them, 28 (82.4 %) and 6 (17.6 %) were located in HVⅠ and HVⅡ respectively. ②Tumor D-loop mutation showed significant correlation with tumor differentiation(P=0.028) and p53 mutation (P=0.041), respectively. CONCLUSION Mitochondrial DNA D-loop in LSCC is an unstable region with high frequency of somatic mutation and high polymorphism and might play a potential role in the carcinogenesis of the larynx.