Cancer adaptations: Atavism, de novo selection, or something in between?

Authors: Frédéric Thomas, Beata Ujvari, François Renaud, Mark Vincent

Source: BioEssays Volume 39, Issue 8, August 2017

Brief summary of the paper: From an evolutionary perspective, both atavism and somatic evolution/convergent evolution theories can account for the consistent occurrence, and astounding attributes of cancers: being able to evolve from a single cell to a complex organized system, and malignant transformations showing significant similarities across organs, individuals, and species.

Here, we first provide an overview of these two hypotheses, including the possibility of them not being mutually exclusive, but rather potentially representing the two extremes of a continuum in which the diversity of cancers can emerge.

In reviewing the current literature, we also discuss the criteria that should be applied to discriminate between the two competing theories and to determine their relevant contributions to oncogenesis and cancer progression.

Finally, we deliberate on the potential applications of this conceptual framework in developing novel treatment strategies.

Changes in diet associated with cancer: An evolutionary perspective

Beata U.

Authors: Frédéric Thomas, Sophie Rome, Frédéric Mery, Erika Dawson, Jacques Montagne, Peter A. Biro, Christa Beckmann, François Renaud, Robert Poulin, Michel Raymond, Beata Ujvari

SourceEvolutionary Applications, Volume 10, Issue 7, Pages 651–657, August 2017

Brief summary of the paper: Changes in diet are frequently correlated with the occurrence and progression of malignant tumors (i.e., cancer) in both humans and other animals, but an integrated conceptual framework to interpret these changes still needs to be developed.

Our aim is to provide a new perspective on dietary changes in tumor-bearing individuals by adapting concepts from parasitology. Dietary changes may occur alongside tumor progression for several reasons: (i) as a pathological side effect with no adaptive value, (ii) as the result of self-medication by the host to eradicate the tumor and/or to slow down its progression, (iii) as a result of host manipulation by the tumor that benefits its progression, and finally (iv) as a host tolerance strategy, to alleviate and repair damages caused by tumor progression.

Surprisingly, this tolerance strategy can be beneficial for the host even if diet changes are beneficial to tumor progression, provided that cancer-induced death occurs sufficiently late (i.e., when natural selection is weak).

We argue that more data and a unifying evolutionary framework, especially during the early stages of tumorigenesis, are needed to understand the links between changes in diet and tumor progression. We argue that a focus on dietary changes accompanying tumor progression can offer novel preventive and therapeutic strategies against cancer.

What can Tasmanian devils teach us about cancer?

Something extraordinary is evolving among the feisty inhabitants of the remote north-west coast of Tasmania. Something that’s both astounding and delighting the researchers monitoring them.

For more than 20 years, these apple-isle locals have been suffering an ugly cancer that’s caused population numbers to rapidly decline. The problem has raised many complex questions and stirred urgent conservation efforts among research institutions around the world. But now, in an unprecedented and ground-breaking discovery, an isolated colony of Tasmanian devils appear to be saving themselves from extinction.

Having immersed herself and her research in the devil’s world for a number of years, Dr Beata Ujvari, an evolutionary ecologist and Senior Lecturer in Bioinformatics and Genetics at Deakin University, is excited by the new findings. ‘Encouragingly, the results suggest the devils may be able to overcome the extinction threat of the disease that has devastated the population for over two decades.’

Read more on this new and exciting research by Dr Beata Ujvari via Deakin (this.)

 

PhD Position @ UTAS: Learning to Live with Cancer – Local adaptations to transmissible tumours in Tasmanian devils

Tasmanian Devil Facial Tumour Disease

University of Tasmania is urgently looking for a PhD student to work on the diseases ecology and epidemiology of Tasmanian devil facial tumour disease.

The student will be based in Tasmania at the University of Tasmania, and will be supervised by Dr Rodrigo Hamede. The student will receive a 3 year PhD stipend, and if it’s an international student, then the offer comes with a tuition fee waiver, so no costs for the candidate.

They are looking for an outstanding candidate who is keen on doing fieldwork and ready to work with this iconic species.

Start date: As soon as possible.

For full details on this position CLICK HERE.

If you are or know a potential candidate, please pass on the details to her/him and ask the student to get in touch directly with Dr Rodrigo Hamede.

Purifying selection and concerted evolution of RNA-sensing toll-like receptors in migratory waders

Nynke R., Thomas M. and Beata U.

Authors: Nynke Raven, Simeon Lisovski, Marcel Klaassen, Nathan Lo, Thomas Madsen, Simon Y.W. Ho, Beata Ujvari

Source: Infection, Genetics and Evolution (Available online 18 May 2017)

Brief summary of the paper: Migratory birds encounter a broad range of pathogens during their journeys, making them ideal models for studying immune gene evolution. Despite the potential value of these species to immunoecology and disease epidemiology, previous studies have typically focused on their adaptive immune gene repertoires.

In this study, we examined the evolution of innate immune genes in three long-distance migratory waders (order Charadriiformes). We analysed two parts of the extracellular domains of two Toll-like receptors (TLR3 and TLR7) involved in virus recognition in the Sanderling (Calidris alba), Red-necked Stint (Calidris ruficollis), and Ruddy Turnstone (Arenaria interpres). Our analysis was extended to 50 avian species for which whole-genome sequences were available, including two additional waders.

We found that the inferred relationships among avian TLR3 and TLR7 do not match the whole-genome phylogeny of birds. Further analyses showed that although both loci are predominantly under purifying selection, the evolution of the extracellular domain of avian TLR3 has also been driven by episodic diversifying selection. TLR7 was found to be duplicated in all five wader species and in two other orders of birds, Cuculiformes and Passeriformes.

The duplication is likely to have occurred in the ancestor of each order, and the duplicated copies appear to be undergoing concerted evolution. The phylogenetic relationships of wader TLR7 matched those of the five wader species, but that of TLR3 did not. Instead, the tree inferred from TLR3 showed potential associations with the species’ ecology, including migratory behaviour and exposure to pathogens.

Our study demonstrates the importance of combining immunological and ecological knowledge to understand the impact of immune gene polymorphism on the evolutionary ecology of infectious diseases.

Infections and cancer: the “fifty shades of immunity” hypothesis

Beata U.

Authors: Jacqueline, Camille; Tasiemski, Aurelie; Sorci, Gabriele; Ujvari, Beata; Maachi, Fatima; Misse, Dorothee; Renaud, Francois; Ewald, Paul; Thomas, Frederic; Roche, Benjamin

Source: BMC CANCER, 17, APR 12 2017

Brief summary of the paper:

Background: Since the beginning of the twentieth century, infection has emerged as a fundamental aspect of cancer causation with a growing number of pathogens recognized as oncogenic. Meanwhile, oncolytic viruses have also attracted considerable interest as possible agents of tumor destruction.

Discussion: Lost in the dichotomy between oncogenic and oncolytic agents, the indirect influence of infectious organisms on carcinogenesis has been largely unexplored. We describe the various ways – from functional aspects to evolutionary considerations such as modernity mismatches – by which infectious organisms could interfere with oncogenic processes through immunity. Finally, we discuss how acknowledging these interactions might impact public health approaches and suggest new guidelines for therapeutic and preventive strategies both at individual and population levels.

Summary: Infectious organisms, that are not oncogenic neither oncolytic, may play a significant role in carcinogenesis, suggesting the need to increase our knowledge about immune interactions between infections and cancer.

Cancer: A disease at the crossroads of trade-offs

Beata U.

Authors: Jacqueline, Camille; Biro, Peter A.; Beckmann, Christa; Moller, Anders Pape; Renaud, Francois; Sorci, Gabriele; Tasiemski, Aurelie; Ujvari, Beata; Thomas, Frederic

Source: EVOLUTIONARY APPLICATIONS, 10 (3):215-225, MAR 2017

Brief summary of the paper: Central to evolutionary theory is the idea that living organisms face phenotypic and/or genetic trade‐offs when allocating resources to competing life‐history demands, such as growth, survival, and reproduction. These trade‐offs are increasingly considered to be crucial to further our understanding of cancer.

First, evidences suggest that neoplastic cells, as any living entities subject to natural selection, are governed by trade‐offs such as between survival and proliferation. Second, selection might also have shaped trade‐offs at the organismal level, especially regarding protective mechanisms against cancer. Cancer can also emerge as a consequence of additional trade‐offs in organisms (e.g., eco‐immunological trade‐offs).

Here, we review the wide range of trade‐offs that occur at different scales and their relevance for understanding cancer dynamics. We also discuss how acknowledging these phenomena, in light of human evolutionary history, may suggest new guidelines for preventive and therapeutic strategies.

Ecology and Evolution of Cancer – book launch

Ecology and Evolution of CancerA world-first book combining evolutionary ecology with oncology was launched last Friday by French scientific and technology attaché Anne Rouault.

The book Ecology and Evolution of Cancer (edited by Beata Ujvari, Benjamin Roche and Frederic Thomas; cover by artist Eric Pelatan) outlining an exceptional new approach of this terrible disease as an evolutionary and ecological process.

According to Dr Ujvari the book was the first to look at using an evolutionary ecology approach with the aim of improving cancer prevention and therapies.

The book provides both an introduction to cancer evolution and a review of the current research on this burgeoning, exciting field, presented by an international group of leading editors and contributors. This project is a collaboration between the French research institute, the National Centre for Scientific Research (CNRS), and Deakin University.

French scientific and technology attaché, Anne Rouault from the French embassy; Frederic Thomas from the French National Centre for Scientific Research; Beata Ujvari and Marcel Klaassen from the Centre for Integrative Ecology

Want to hear more? Listen to Beata’s interview about the book by Red Symons from ABC Radio Melbourne – Breakfast (scroll to 45min,10s).

 

Cancer brings forward oviposition in the fly Drosophila melanogaster

Beata U.

Beata U.

Authors: Audrey Arnal, Camille Jacqueline, Beata Ujvari, Lucas Léger, Céline Moreno, Dominique Faugere, Aurélie Tasiemski, Céline Boidin-Wichlacz, Dorothée Missé, Francois Renaud, Jacques Montagne, Andreu Casali, Benjamin Roche, Frédéric Mery, Frederic Thomas

SourceEcology and Evolution, 7(1), November 2016

Brief summary of the paper: Hosts often accelerate their reproductive effort in response to a parasitic infection, especially when their chances of future reproduction decrease with time from the onset of the infection.

Because malignancies usually reduce survival, and hence potentially the fitness, it is expected that hosts with early cancer could have evolved to adjust their life‐history traits to maximize their immediate reproductive effort. Despite the potential importance of these plastic responses, little attention has been devoted to explore how cancers influence animal reproduction.

Here, we use an experimental setup, a colony of genetically modified flies Drosophila melanogaster which develop colorectal cancer in the anterior gut, to show the role of cancer in altering life‐history traits. Specifically, we tested whether females adapt their reproductive strategy in response to harboring cancer.

We found that flies with cancer reached the peak period of oviposition significantly earlier (i.e., 2 days) than healthy ones, while no difference in the length and extent of the fecundity peak was observed between the two groups of flies. Such compensatory responses to overcome the fitness‐limiting effect of cancer could explain the persistence of inherited cancer‐causing mutant alleles in the wild.