Mitochondrial DNA 4977 BP deletion mutations in lung carcinoma

BACKGROUND: The most common and also the most often assayed mtDNA deletion mutation, ΔmtDNA⁴⁹⁷⁷sub has been demonstrated in various types of human cancer. However, knowledge about ΔmtDNA⁴⁹⁷⁷ in lung carcinoma is poor.
AIM: To study the 4977 bp deletions of mitochondrial DNA (ΔmtDNA⁴⁹⁷⁷) in lung cancer, adjacent histologically normal and normal lung tissue and its potential roles in the development of cancer.
MATERIALS AND METHODS: Thirty-seven matched lung cancer/adjacent histologically normal and 20 histologically normal lung tissue samples in subjects without lung cancer were analyzed by PCR technique.
RESULTS: ΔmtDNA⁴⁹⁷⁷ deletions were detected in 54.1% (20/37) of lung cancers, 59.5% (22/37) of adjacent normal and 30.0% (6/20) of normal lung tissue samples. No significant difference was found in the frequency of ΔmtDNA⁴⁹⁷⁷ deletions between the tumor and adjacent normal lung tissues ( P value = 0.815). Moreover, no significant difference was found in the frequency of ΔmtDNA⁴⁹⁷⁷ deletions between the tumor and histologically normal lung tissues in subjects without lung cancer ( P value = 0.101). However, the correlation between ΔmtDNA⁴⁹⁷⁷ deletion and age and smoking factors was present in our data.
STATISTICAL ANALYSIS: Fisher's exact test was used to assess the difference in different groups by the Scientific Package for Social Sciences (SPSS), version 10.0, Statistical analysis software.
CONCLUSIONS: Mitochondrial DNA 4977 bp deletion, which is not specific to lung cancer, may reflect the environmental and aging process influences operative during tumor progression.