To explore the relation between lung cancer and human aging.Telomeres are DNA binding proteins at the end of chromosomes. With age the telomeres undergo shortening or attrition in normal cells, represnting the biological clock of cell’s life cycle. Patients presenting with lung cancer at a younger age than others may be genetically predisposed to this aging-related disease.HYPOTHESIS: The biological age of patients who present with lung cancer at an early age is more advanced than their chronological age would indicate.
After IRB approval, informed consents were obtained from 11 Patients (male = 9, female = 2) undergoing lung cancer surgery. Patients were divided into two age groups, 50-60 years (n=5) and 72-76 years (n=6). Tissue samples were collected from normal lung (periphery of the removed lobe), skin and skeletal muscle during surgery. All samples were tested for telomere length. Muscle telomere length was used as a reference indicator representing telomere length at birth in each individual . Rate of telomere attrition was calculated by subtracting the telomeric length of each proliferating tissue (skin and lung) from non-proliferating tissue(muscle) and dividing by age of the individual . Student T-test (non-paired ) was used and regression and analysis of variance for the rate of telomeric attrition as a function of age, was calculated.RESULTS and DISCUSSION: 1- Telomere length was consistently longer in the muscle than in lung and skin samples (Figure 1); 2- There was no significant difference in telomere length in muscle tissue in two age groups. (p=0.2); 3- Rate of telomere attrition was higher in the younger subjects than in the older subjects (Figure 2, 3).CONCLUSIONS: Telomere attrition rate (that reflects biological aging) in cancer patients is higher in middle age patients than elderly cancer patients.
Results shed a new perspective on the relation between lung cancer and the biology of human aging. Large scale studies are needed to further explore the genetic risks to develop lung cancer.
J.F. Durrani, None.