Telomeres are affected by stress and can help predict cancer risk, according to recent studies presented at the AACR annual meeting. Researchers are exploring the role of stress in cancer development, and telomeres are a part of the puzzle. If stress affects telomeres, the protection they provide against chromosomal mutations can diminish and pave the way for the development of cancer.
“Maybe cancer will start to look more like cardiovascular disease, for which chronic psychological distress is 1 of the 6 major risk factors,” says Elizabeth Blackburn, PhD, immediate past president of the AACR, who spoke on the topic at a news conference. “The biology of cancer, diabetes, and cardiovascular disease, all diseases of aging, may have some underlying commonalities, but we don't have quantitative data in large cancer populations yet.” Dr. Blackburn, the Morris Herztein professor of biology and physiology at the University of California at San Francisco, won the Nobel Prize in 2009 in Physiology or Medicine for her role in the discovery of telomeres and the enzyme telomerase.
To make further progress against the disease, scientists must think about intercepting the biology of cancer as it unfolds on its deadly trajectory, she notes. “We understand what's happening over time and at earlier and earlier stages, but we need to start thinking more accurately about how to intervene, prevent, and also treat recurrence of cancers,” Dr. Blackburn says.
Several studies concerning the role of telomeres in the cancer process have provided some important information on how to do just that. Jian Gu, PhD, assistant professor of epidemiology at The University of Texas MD Anderson Cancer Center in Houston, presented research that found that the single nucleotide polymorphism (SNP) rs398652 on 14q21 was linked to both longer telomeres and a 19% reduction in the risk of bladder cancer. They 300,000 SNP5 in 459 healthy participants and found that 15,120 of them were associated with telomere length. Further validation in 890 SNP5 and 270 healthy individuals found 4 SNP5 that were significantly associated with telomere length. In addition, smoking particularly augmented the risk of bladder cancer in those with another genetic variant that was associated with shorter telomeres.
According to Dr. Blackburn, the effect of interventions to lengthen telomeres still needs to be tested in prospective studies. Nevertheless, she notes that the finding is a major research advance.
In another study, Edward Nelson, MD, division chief of hematology/oncology at the University of California at Irvine, j highlighted his multidisciplinary team's efforts to determine whether chronic stress was associated with accelerated telomere shortening in patients with cancer. “Cancer diagnosis and treatment results in psychological and physical stressors in patients that result in a chronic stress response,” he notes. “We hypothesized that interjecting a psychological/social intervention could improve quality of life and decrease stress response, decreasing cortisol and immune suppression.”
Maybe cancer will start to look more like cardiovascular disease, for which chronic psychological distress is 1 of the 6 major risk
—Elizabeth Blackburn, PhD
The group also wanted to discover whether the intervention could modulate telomere length. For the retrospective pilot study, they obtained archived biological samples from 31 women with cervical cancer who had been randomized into 2 groups: 1 that received 6 counseling sessions by telephone and another that received standard care without counseling. The sessions included managing stress and emotions, enhancing health and well- ness, addressing relational and sexual concerns, and integrating and summarizing the information. Researchers obtained biological samples from both groups at the time of enrollment and after 4 months and investigated changes over time. Both improved quality of life and reduced stress response were found to be associated with increases in telomere length.
“The study suggests that telomere length should be included in the stress-related biobehavioral paradigm and should be a stress-associated biomarker, but we need to confirm these results in an adequately powered longitudinal study,” Dr. Nelson adds.