Optimal intercellular competition in senescence and cancer

TL;DR

This paper models the balance of cooperation and competition among cells in multicellular organisms, proposing an optimal competition level that maximizes vitality and delays aging and cancer.

Contribution

It introduces a statistical mechanical framework to quantify the optimal intercellular competition balancing aging and cancer risks.

Findings

Identifies an optimal competition level that maximizes organismal vitality.

Demonstrates that excessive cooperation or competition accelerates aging or cancer.

Provides a generalized replicator dynamics model for cell populations.

Abstract

Effective multicellularity requires both cooperation and competition between constituent cells. Cooperation involves sacrificing individual fitness in favor of that of the community, but excessive cooperation makes the community susceptible to senescence and aging. Competition eliminates unfit senescent cells via natural selection and thus slows down aging, but excessive competition makes the community susceptible to cheaters, as exemplified by cancer and cancer-like phenomena. These observations suggest that an optimal level of intercellular competition in a multicellular organism maximizes organismal vitality by delaying the inevitability of aging. We quantify this idea using a statistical mechanical framework that leads to a generalized replicator dynamical system for the population of cells that change their vitality and cooperation due to somatic mutations that make them susceptible to aging and/or cancer. By accounting for the cost of cooperation and strength of competition in a minimal setting, we show that our model predicts an optimal value of competition that maximizes vitality and delays the inevitability of senescence or cancer.