A recent study has uncovered a significant link between changes in gut stem cells and an increased risk of colorectal cancer as individuals age. This research, conducted by a team at the University of Turin in Italy, highlights how a process known as Aging and Colon Cancer-Associated (ACCA) drift, driven by inflammation and disrupted cell signaling, may contribute to cancer susceptibility.
The researchers found that as people age, chemical modifications on their DNA gradually shift, leading to epigenetic changes that can deactivate tumor-suppressing genes. This drift in DNA methylation allows cancer risk to accumulate in gut cells long before any tumors form. The findings emphasize that the risk of colorectal cancer rises notably with age, but the underlying mechanisms were not fully understood until now.
According to Francesco Neri, a molecular biologist involved in the study, “We observe an epigenetic pattern that becomes increasingly apparent with age.” The research team analyzed tissue samples from both healthy colons and colon cancer tumors, identifying common patterns of gene silencing in older individuals. This suggests a shared pathway between aging and cancerous tissue.
To further explore these findings, the team conducted experiments using mouse models and organoids—miniature versions of human guts developed in the laboratory. These experiments revealed that the ACCA drift originates in intestinal stem cells located in small structures known as crypts, which are responsible for renewing the intestinal lining.
The study found that several factors contribute to this drift, including increased inflammation, reduced growth signaling, and decreased iron levels in stem cells. These conditions disrupt the natural processes that maintain healthy DNA methylation, allowing genes to be improperly silenced. As Anna Krepelova, another key researcher, explained, “Over time, more and more areas with an older epigenetic profile develop in the tissue.”
The implications of this research are significant. As stem cell-driven crypts divide, patches of tissue with older, cancer-prone epigenetic profiles expand, leading to a greater risk of colorectal cancer. The study suggests that these changes can occur earlier in the aging process than previously thought, creating “danger zones” in the gut that vary among individuals.
Encouragingly, the research team discovered that they could slow or partially reverse the epigenetic drift in organoids by enhancing iron uptake or restoring specific growth signals. “This means that epigenetic aging does not have to be a fixed, final state,” Krepelova noted. “For the first time, we are seeing that it is possible to tweak the parameters of aging that lie deep within the molecular core of the cell.”
Published in the journal Nature Aging, these findings not only enhance the understanding of the relationship between aging and cancer but also open new avenues for potential interventions. The research underscores the importance of maintaining healthy gut environments as a strategy to mitigate cancer risk associated with aging.
As the scientific community continues to unravel the complexities of cancer biology, this study marks a step forward in developing targeted approaches to combat colorectal cancer through early intervention and lifestyle modifications.
