Frequency of the mitochondrial DNA 4977bp deletion in oesophageal mucosa during the progression of Barrett's oesophagus.

ABSTRACT

PURPOSE: The mechanisms of the progression of Barrett's oesophagus (BO) to oesophageal adenocarcinoma (OA) are poorly understood. The frequency of the 4977bp deletion in mitochondrial DNA (mtDNA) was investigated in specimens ranging from normal oesophageal tissue to OA in order to investigate whether this deletion represents a useful biomarker of disease progression. METHODS: The presence of the 4977bp deletion was screened by PCR amplification from 70 specimens in total. RESULTS: The frequency of specimens with the 4977bp deletion increased in relation to the degree of dysplasia (8.3% in normal squamous epithelium; 15.4% in BO; 40% in low grade dysplasia (LGD); 69.2% in high-grade dysplasia and 90% in para-tumoural tissue). However, the frequency of the deletion reduced sharply in OA specimens (16.7%; p<0.001). CONCLUSION: The mtDNA 4977bp deletion may be useful as a biomarker to detect the severity of dysplasia but not the presence of OA.