Aurora Nedelcu (Univ. New Brunswick, Canada) (virtual), Cancer and the evolution of multicellularity: limitations of current views and paradigms

Abstract

The evolution of multicellularity requires the integration of single cells into new functionally, reproductively and evolutionary stable multicellular individuals. As part of this process, a change in levels of selection occurs, with selection at the multicellular level overriding selection at the cell level. The stability of multicellular individuals is dependent on a combination of mechanisms that control within-group evolution, by both reducing the occurrence of somatic mutations as well as supressing somatic selection. Nevertheless, mutations that, in a particular microenvironment, confer mutant cell lineages a fitness advantage relative to normal somatic cells do occur, and can (but not always) result in cancer. This talk will highlight several views and paradigms that relate the evolution of multicellularity to cancer. Cancer is generally understood as a disease of multicellularity, and is interpreted in different frameworks: (i) a breakdown of cooperative behaviors (i.e., cheating) underlying the evolution of multicellularity, (ii) a disruption of molecular networks established during the emergence of multicellularity to impose constraints on single-celled units, or (iii) an atavistic state resulting from reactivating primitive programs that originated in the earliest unicellular species. Several assumptions are common in all the views relating cancer as a disease to the evolution of multicellularity. For instance, cancer is considered a reversal to selfish unicellularity, and cancer cells are thought to resemble unicellular organisms and benefit from ancestral-like traits. I will discuss potential limitations of current views and paradigms and show how different perspectives can provide novel insights with potential therapeutic implications.

Video of the talk

Academic interests

• Evolutionary Biology
• Genome/Molecular Evolution
• Cancer Biology

Brief biography

Dr. Aurora Nedelcu is a Professor of Biology at the University of New Brunswick (Canada). She received her BSc (Biology) from Babes-Bolyai University (Cluj-Napoca, Romania) in 1988. Prior to coming to Canada to start her PhD, Dr. Nedelcu has worked for several years as a Biology teacher in a Secondary School, as a Research Scientist in an Electron Microscopy Lab, and as an Assistant Professor of Biochemistry.

She completed her PhD (Biology) at Dalhousie University (1993-1997) and then continued her training as a postdoctoral fellow in the Organelle Genome Megasequencing Lab at the Universite de Montreal (1998) and as an NSERC Postdoctoral Fellow and Research Associate in the Ecology and Evolutionary Biology Department at the University of Arizona (1998 – 2002).

Dr. Nedelcu has joined the Biolgy Department at UNB in 2002, where she is currently a Professor. She also holds an Adjunct position in the Departament of Ecology and Evolutionary Biology at the University of Arizona.

Dr. Nedelcu’s general research interests center around understanding how and why biological systems evolve, especially in terms of major innovations and the emergence of new levels of complexity. Most of her current research is rooted in the framework of transitions in individuality and complexity (at a conceptual level) and of cellular responses to stress, gene co-option and trade-offs (at a mechanistic level). She is using a combination of approaches (experimental and theoretical), spanning various levels of biological organization (genes, genomes, cells, individuals) and fields(genetics/genomics, molecular/cell/developmental biology, experimental evolution).

Specific areas include:

• Molecular, gene and genome (both nuclear and organelle) evolution
• The genetic basis of key transitions and major innovations in evolution – such as the evolution of multicellularity, development, cell differentiation, programmed cell death, sex
• Evolution of cooperation and altruism
• Evolution and cancer

The model-systems currently used are the volvocine green algae and human cancer cell lines.