Ageing is associated with an increased onset of cancer. Understanding the molecular mechanisms that underlie the age dependency of cancer will have important implications for preventing and treating this pathology. The signalling pathway connecting insulin and FOXO transcription factors provides the most compelling example for a conserved genetic pathway at the interface between ageing and cancer. FOXO transcription factors (FOXO) promote longevity and tumour suppression.
When we discuss advances in longevity research during lectures and seminars, the question of the deciding factor for longevity often comes up. Even without looking at examples of research in molecular biology research, it is obvious to most that genetics play a major factor in longevity. The longest-lived human recorded was a French woman named Jeanne Calment, who died at age 122. All her family was long-lived. The quest for the identification of longevity genes by studying centenarian families has been explored for a decade, but no bona-fide longevity gene was identified.
Genetic studies in model organisms such as yeast, worms, flies, and mice leading to lifespan extension suggest that longevity is subject to regulation. In addition, various system-wide interventions in old animals can reverse features of aging. To better understand these processes, much effort has been put into the study of aging on a molecular level. In particular, genome-wide microarray analysis of differently aged individual organisms or tissues has been used to track the global expression changes that occur during normal aging.
Mutations in single genes and environmental interventions can extend healthy lifespan in laboratory model organisms. Some of the mechanisms involved show evolutionary conservation, opening the way to using simpler invertebrates to understand human ageing. Forkhead transcription factors have been found to play a key role in lifespan extension by alterations in the insulin/IGF pathway and by dietary restriction. Interventions that extend lifespan have also been found to delay or ameliorate the impact of ageing-related pathology and disease, including cancer.
Autophagy is a highly regulated intracellular process involved in the turnover of most cellular constituents and in the maintenance of cellular homeostasis. It is well-established that the basal autophagic activity of living cells decreases with age, thus contributing to the accumulation of damaged macromolecules during aging. Conversely, the activity of this catabolic pathway is required for lifespan extension in animal models such as Caenorhabditis elegans and Drosophila melanogaster.
Proceedings of the National Academy of Sciences of the United States of America
The burden of protein misfolding is believed to contribute to aging. However, the links between adaptations to conditions associated with protein misfolding and resistance to the time-dependent attrition of cellular function remain poorly understood. We report that worms lacking aip-1, a homologue of mammalian AIRAP (arsenic-inducible proteasomal 19S regulatory particle-associated protein), are not only impaired in their ability to resist exposure to arsenite but also exhibit shortened lifespan and hypersensitivity to misfolding-prone proteins under normal laboratory conditions.
An association between aging/longevity and cancer has long been suggested, yet the evolutionary and molecular links between these complicated traits remain elusive. Here, we analyze the relationship between longevity- and cancer-associated genes/proteins (LAGs/LAPs and CAGs/CAPs, respectively). Specifically, we address the following questions: (1) to what extent the CAGs and LAGs are evolutionary conserved and how they (or their orthologs) are related to each other in diverse species?
The complex, highly integrative endocrine system regulates all aspects of somatic maintenance and reproduction and has been widely implicated as an important determinant of longevity in short-lived traditional model organisms of aging research. Genetic or experimental manipulation of hormone profiles in mice has been proven to definitively alter longevity. These hormonally induced lifespan extension mechanisms may not necessarily be relevant to humans and other long-lived organisms that naturally show successful slow aging.
Trans-resveratrol or (E)-resveratrol [3,4',5 trihydroxy-trans-stilbene, t-RESV or (E)-RESV] is a natural component of Vitis vinifera L. (Vitaceae), abundant in the skin of grapes (but not in the flesh) and in the leaf epidermis and present in wines (especially red wines). In in vitro, ex vivo and in vivo experiments, t-RESV exhibits a number of biological activities, including anti inflammatory, antioxidant, platelet antiaggregatory and anticarcinogenic properties, and modulation of lipoprotein metabolism.
Mutant dwarf and calorie-restricted mice benefit from healthy aging and unusually long lifespan. In contrast, mouse models for DNA repair-deficient progeroid syndromes age and die prematurely. To identify mechanisms that regulate mammalian longevity, we quantified the parallels between the genome-wide liver expression profiles of mice with those two extremes of lifespan. Contrary to expectation, we find significant, genome-wide expression associations between the progeroid and long-lived mice.