Alteration of Telomere Length in Lung Cancer

There are characteristic G-rich repeats, i.e. telomeric repeats, at every chromosome end in eukaryotes. Telomeres are thought to protect chromosomes from end-to-end fusion or exonucleolytic degradation. Stabilization of telomeres is considered to be concomitant with the attainment of immortality in tumor cells. Using the Southern blotting method, we examined telomere length in 71 surgically resected primary lung cancer tissues and adjacent noncancerous tissues. Among 71 primary lung cancer tissues, alterations in telomere length were observed in 19 tumors (26.8%) including 13 with short and 6 with elongated telomeres. Alterations of telomere length were frequently observed in small cell carcinomas and tumors with high levels of telomerase activity. The present results indicate that the proliferative potential of lung cancer cells is likely to be more affected by histology and genetic alterations than clinical stage.