Correlative polymorphism of NAD(P)H: Quinone oxidoreductase (NQO1) with telomere shortening in colorectal cancer

Aim: The aim of this study was to examine whether any relationships could be found among polymorphism of the NQO1 gene, telomere length and telomerase activity in colorectal cancers. Materials and Methods: Fifty-one invasive colorectal cancers were studied. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis was undergone to detect mutation of the NQO1 gene. Telomere length was examined by Southern blot analysis. Telomerase activity was assayed by telomeric repeat amplification protocol with minor modifications. Results: Of the 51 tumors, 20 (39.2%) and 9 (17.6%) were heterozygous and homozygous for the mutation, respectively. Most of the cases homozygous for the mutation (88.9%) showed short telomeres and its frequency was significantly higher than in those heterozygous (p=0.0432). However no relationship was found between the telomerase activity and mutation in the NQO1 gene. Conclusion: Our data suggest that oxidative stress by the lack of NQO1 activity could result in telomere shortening through colorectal cancinogenesis.