Chronic DNA damage response may contribute to biological aging

A new review was published in Volume 18 of Aging on August 31, 2026, titled "The guardian paradox: DNA damage response overactivation as an integrative driver of aging – a tumor suppressor–negative regulator framework."

The review presents a new framework proposing that chronic overactivation of the DNA damage response (DDR) may serve as a major integrating driver of biological aging. Rather than framing aging in the same mutation-centered terms often applied to cancer, the framework suggests that many tumor-suppressor pathways remain structurally intact but become persistently overactivated or otherwise dysregulated as tissues age.

The review was authored by Patrick E. Sewell from Triple Helix Science in Santa Ana, California. The paper organizes 16 candidate tumor suppressor–negative regulator axes into three evidence tiers and proposes experiments designed to determine whether chronic DDR signaling plays a causal role in aging.

The DNA damage response is the cellular surveillance system that detects genomic damage and coordinates repair. In young, healthy tissues, DDR signaling normally activates temporarily following stresses such as DNA double-strand breaks, replication stress or oxidative lesions and subsides after repair. With aging, however, persistent signals associated with telomere attrition, epigenetic erosion, mitochondrial dysfunction and transposable-element activity may maintain DDR activation even without new driver mutations.

According to the proposed model, chronic DDR signaling can stabilize p53 and increase p21 and p16INK4a, promoting cell-cycle arrest and cellular senescence. Senescent cells can then produce the senescence-associated secretory phenotype (SASP), releasing inflammatory mediators that may spread senescence to neighboring cells, reduce stem-cell function, disrupt tissue homeostasis and contribute to systemic inflammaging. Importantly, these effects can occur while the underlying tumor-suppressor genes remain intact.

This forms the basis of what Sewell calls the "guardian paradox." Tumor-suppressor mechanisms protect younger tissues from damaged or potentially cancerous cells, but the review proposes that persistent engagement of some of these same protective programs may become detrimental later in life. In this framework, cancer and aging represent contrasting forms of dysregulation: cancer frequently removes proliferative restraints through mutation or deletion, whereas aging may involve persistent activation or altered regulation of otherwise intact pathways.

The framework does not claim that DDR overactivation is the sole or necessarily earliest cause of aging. Instead, it positions DDR signaling as a possible integrating node connecting several established aging mechanisms. The review compares this hypothesis with mitochondria-first, proteostasis-first and epigenetic-drift or reprogramming-centered models, acknowledging that mitochondrial dysfunction, impaired protein quality control or loss of epigenetic information could instead lie upstream of DDR activation.

Somatic mutations are also incorporated into the model. The review discusses clonal hematopoiesis of indeterminate potential (CHIP), in which age-acquired mutations in genes such as DNMT3A, TET2 and ASXL1 promote clonal expansion. Rather than dismissing these processes, the framework treats them as potentially important accelerating cofactors alongside largely mutation-independent DDR dysregulation.

To organize these mechanisms, the review identifies 16 candidate tumor suppressor–negative regulator axes across three evidence tiers. Among the best-supported candidates are p53/MDM2, p16INK4a/BMI-1, SIRT1/DBC1, telomerase/TRF1, PTEN/PI3K-AKT-mTOR and NRF2/KEAP1. Other candidate axes involve FOXO3, AMPK, Klotho, PGC-1α, TFEB and additional regulators. The evidence varies substantially across these pathways, and many proposed restoration strategies remain preclinical or conceptual.

The review also introduces a conceptual Aging Axis Profile (AAP) that would combine proteomic, transcriptomic, epigenomic, senescence and telomere measurements to characterize individual pathways as functional, declining or dysfunctional. Rather than primarily searching for mutations, this proposed system would assess the functional state of aging-related regulatory networks. The author emphasizes that the AAP has not been analytically or clinically validated, and its proposed biomarker thresholds are illustrative rather than clinical cutoffs.

The framework further considers whether dysfunctional pathways could eventually be restored toward physiological states. Proposed approaches include modulating endogenous negative regulators and, in some cases, AAV-based gene delivery. For chronically overactivated tumor-suppressor pathways such as p53 or p16, the theoretical objective would be to reduce persistent signaling without eliminating their cancer-protective functions. For protective pathways that decline with age, such as SIRT1, FOXO3, NRF2 or Klotho, restoring physiological activity is proposed for future investigation.

These strategies remain theoretical or preclinical and carry important safety concerns. Excessive modulation of regulators such as MDM2, BMI-1 or NRF2 could increase oncogenic risk. The paper therefore emphasizes controlled expression, appropriate participant selection, CHIP screening, long-term cancer surveillance and extensive preclinical validation before any consideration of human intervention.

Importantly, the review proposes ways to test-and potentially refute-the DDR-centered hypothesis. Longitudinal studies could determine whether persistent DDR activation precedes other aging changes, while head-to-head experiments could compare DDR-directed interventions with mitochondrial, proteostatic or other approaches. This makes the framework a testable research hypothesis rather than an assumption that DDR is the dominant cause of aging.

"We therefore suggest that the framework's primary value, at present, lies in research design: it provides tractable, testable hypotheses and points to the biomarker panels, experimental comparators, and safety questions that should be prioritized before any consideration of human intervention."

Important limitations remain. There are no integrated human interventional data validating the framework, many individual axes are supported primarily by animal or in vitro evidence, and the Aging Axis Profile remains conceptual. Aging is also multi-causal and heterogeneous across tissues and individuals, and mitochondrial, proteostatic, metabolic or epigenetic mechanisms could ultimately prove more causally important than DDR overactivation. The paper therefore presents the framework as a falsifiable research agenda, not a therapeutic protocol.

Overall, the "guardian paradox" reframes an important biological tradeoff: cellular programs that protect against cancer and genomic instability may become harmful when chronically engaged. By organizing these mechanisms into testable molecular axes, the review provides a framework for investigating how persistent DNA damage signaling may connect cellular senescence, inflammation and other hallmarks of aging-and whether restoring selected regulatory pathways could eventually improve aging-related phenotypes without compromising tumor suppression.

Source:

Aging-US

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