Phenotypic variation modulates the growth dynamics and response to radiotherapy of solid tumours under normoxia and hypoxia

Copyright © 2021 The Authors. Published by Elsevier Ltd.. All rights reserved..

In cancer, treatment failure and disease recurrence have been associated with small subpopulations of cancer cells with a stem-like phenotype. In this paper, we develop and investigate a phenotype-structured model of solid tumour growth in which cells are structured by a stemness level, which varies continuously between stem-like and terminally differentiated behaviours. Cell evolution is driven by proliferation and death, as well as advection and diffusion with respect to the stemness structure variable. Here, the magnitude and sign of the advective flux are allowed to vary with the oxygen level. We use the model to investigate how the environment, in particular oxygen levels, affects the tumour's population dynamics and composition, and its response to radiotherapy. We use a combination of numerical and analytical techniques to quantify how under physiological oxygen levels the cells evolve to a differentiated phenotype and under low oxygen level (i.e., hypoxia) they de-differentiate. Under normoxia, the proportion of cancer stem cells is typically negligible and the tumour may ultimately become extinct whereas under hypoxia cancer stem cells comprise a dominant proportion of the tumour volume, enhancing radio-resistance and favouring the tumour's long-term survival. We then investigate how such phenotypic heterogeneity impacts the tumour's response to treatment with radiotherapy under normoxia and hypoxia. Of particular interest is establishing how the presence of radio-resistant cancer stem cells can facilitate a tumour's regrowth following radiotherapy. We also use the model to show how radiation-induced changes in tumour oxygen levels can give rise to complex re-growth dynamics. For example, transient periods of hypoxia induced by damage to tumour blood vessels may rescue the cancer cell population from extinction and drive secondary regrowth.

Medienart:

E-Artikel

Erscheinungsjahr:

2021

Erschienen:

2021

Enthalten in:

Zur Gesamtaufnahme - volume:527

Enthalten in:

Journal of theoretical biology - 527(2021) vom: 21. Okt., Seite 110792

Sprache:

Englisch

Beteiligte Personen:

Celora, Giulia L [VerfasserIn]
Byrne, Helen M [VerfasserIn]
Zois, Christos E [VerfasserIn]
Kevrekidis, P G [VerfasserIn]

Links:

Volltext

Themen:

Cancer stem cells
Journal Article
Oxygen
Phenotypic variability
Radio-resistance
Research Support, Non-U.S. Gov't
S88TT14065

Anmerkungen:

Date Completed 09.08.2021

Date Revised 09.08.2021

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.jtbi.2021.110792

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM32635543X