Elevated p16INK4a Expression Hints at Accelerated Aging After Chemotherapy

Cancer treatment may cause premature aging in patients, a new study says. A team of researchers at the University of North Carolina at Chapel Hill's Lineberger Comprehensive Cancer Center found higher expression of a gene associated with aging in young patients that had received treatment with chemotherapy and in frail survivors. The findings were published in Cancer. 

By measuring the expression of the gene that codes for p16INK4a as a marker of age, the team examined immune cells circulating in the blood of young adult survivors and adolescents newly diagnosed with cancer.

Researchers took a closer look at the cells of 60 survivors and compared them with cells from age-matched individuals without a history of cancer. They observed that expression of the gene that codes for p16INK4a was higher in survivors than the control group, representing an estimated 25-year age acceleration. From the nine survivors who were frail, the levels expressed were also higher than survivors who were not frail, having an estimated 35-year age acceleration in their aging. 

Their analysis also showed that in the nine children and adolescents in the study who had a new diagnosis of cancer, expression was significantly higher after treatment with chemotherapy than before treatment. "Higher expression of p16INK4a in peripheral blood lymphocytes has been described in older adults following chemotherapy, but prior to this study, not in young adult survivors," says first author Andrew Smitherman. "This study is important as we try to understand the biological mechanisms underlying the manifestations of early aging in this population."