The spontaneous immortalization probability of mammalian cell culture strains, as their proliferative capacity, correlates with species body mass, not longevity

Primary Cell Culture as a Model System for Evolutionary Molecular Physiology

Primary cell culture is a powerful model system to address fundamental questions about organismal physiology at the cellular level, especially for species that are difficult, or impossible, to study under natural or semi-natural conditions. Due to their ease of use, primary fibroblast cultures are the dominant model system, but studies using both somatic and germ cells are also common. Using these models, genome evolution and phylogenetic relationships, the molecular and biochemical basis of differential longevities among species, and the physiological consequences of life history evolution have been studied in depth. With the advent of new technologies such as gene editing and the generation of induced pluripotent stem cells (iPSC), the field of molecular evolutionary physiology will continue to expand using both descriptive and experimental approaches.

[Evolution of cancer resistance in the animal kingdom]

Cancer is an inevitable collateral problem inherent in the evolution of multicellular organisms, which appeared at the end of the Precambrian. Faced to this constraint, a range of diverse anticancer defenses has evolved across the animal kingdom. Today, investigating how animal organisms, especially those of large size and long lifespan, manage cancer-related issues has both fundamental and applied outcomes, as it could inspire strategies for preventing or treating human cancers. In this article, we begin by presenting the conceptual framework for understanding evolutionary theories regarding the development of anti-cancer defenses. We then present a number of examples that have been extensively studied in recent years, including naked mole rats, elephants, whales, placozoa, xenarthras (such as sloths, armadillos and anteaters) and bats. The contributions of comparative genomics to understanding evolutionary convergences are also discussed. Finally, we emphasize that natural selection has also favored anti-cancer adaptations aimed at avoiding mutagenic environments, for example by maximizing immediate reproductive efforts in the event of cancer. Exploring these adaptive solutions holds promise for identifying novel approaches to improve human health.

Peto's paradox: Nature has used multiple strategies to keep cancer at bay while evolving long lifespans and large body masses. A systematic review

Comparative oncology is an understudied field of science. We are far from understanding the key mechanisms behind Peto's paradox, i.e., understanding how long-lived and large animals are not subject to a higher cancer burden despite the longer exposure time to mutations and the larger number of cells exposed. In this work, we investigated the scientific evidence on such mechanisms through a systematic mini-review of the literature about the relation of longevity and/or large body mass with physiological, genetic, or environmental traits among mammalian species. More than forty thousand articles were retrieved from three repositories, and 383 of them were screened using an active-learning-based tool. Of those, 36 articles on longevity and 37 on body mass were selected for the review. Such articles were examined focusing on: number and type of species considered, statistical methods used, traits investigated, and observed relationship with longevity and/or body mass. Where applicable, the traits investigated were matched with one or more hallmarks of cancer. We obtained a list of potential candidate traits to explain Peto's paradox related to replicative immortality, cell senescence, genome instability and mutations, proliferative signaling, growth suppression evasion, and cell resistance to death. Our investigation suggests that different strategies have been followed to prevent cancer in large and long-lived species. The large number of papers retrieved emphasizes that more studies can be launched in the future, using more efficient analytical approaches to comprehensively evaluate the convergent biological mechanisms essential for acquiring longevity and large body mass without increasing cancer risk.

Aging like fine wine: Mischievous microbes and other factors influencing senescence

In this issue, a special section is dedicated to the factors affecting senescence. It examines the interplay between immunosenescence and chronic kidney disease, probes into Peto's paradox, and explores how epigenetic switches can potentially mitigate senescence and inflammation. Additionally, insights are offered on understanding a specific Ras mechanism in yeast for potential therapeutic interventions against cancer and for longevity. Furthermore, the remarkable endurance of last year's Nobel Prize winner in Physiology or Medicine is also highlighted. Moreover, the discovery of potential biomarkers for hepatocellular carcinoma, the link between osteoarthritis and the circadian clock, and the multifaceted role of DNAJA3 in B cell lifecycle are discussed. Further, study findings shed light on the influence of extracellular matrix molecules on cleft palate formation, the renal protective effects of combination therapy in diabetic kidney disease, and novel approaches to detect developmental dysplasia of the hip. Finally, a correspondence delves into the role of autonomic regulation in cognitive decline.

"How sad it is! I shall grow old, and horrible, and dreadful" - The ups and downs of cell senescence

This issue of the Biomedical Journal contains a special section about cell senescence. The reader gets an insight into the crosstalk between immune system and senescent cells, into an approach to fight aging by tweaking macronutrient intake, and also learns about the connection that does (not) exist between body mass and cancer risk. Further articles in the current issue give details about the effect of Damask rose on PCOS, illustrate the issues gender bias may exert in research studies, go into a joint drug approach in ischemia-reperfusion injury, and a promising tool to diagnose Parkinsonian disorders. Two articles dive into challenges related to obstructive sleep apnea, another article explores the benefits a composite mixture may have for improving bone cement material, with lastly a research team presenting a modified procedure to managing involutional lower eyelid entropion in individuals of Asian descent. Finally, BMJ issue 46-3 is complemented with a correspondence about mpox spreading from endemic areas to other parts of the world.