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ORIGINAL RESEARCH article

Front. Oncol.

Sec. Radiation Oncology

Volume 15 - 2025 | doi: 10.3389/fonc.2025.1616943

Fractionated radiation alters the extracellular matrix produced by muscle-invasive bladder cancer cells

Provisionally accepted
Conrado  Guerrero QuilesConrado Guerrero Quiles1*Siobhan  FahySiobhan Fahy1Matej  BartakMatej Bartak1Julia  Gonzalez AbalosJulia Gonzalez Abalos2Emilia  PowelEmilia Powel1Rachel  ReedRachel Reed1Kim  ReevesKim Reeves1Alex  BakerAlex Baker3PETER  HOSKINPETER HOSKIN1Nicholas  JamesNicholas James4Emma  HallEmma Hall4Robert  Anthony HuddartRobert Anthony Huddart4Nuria  PortaNuria Porta4Catharine  WestCatharine West1Luisa  V. BiolattiLuisa V. Biolatti1Ananya  ChoudhuryAnanya Choudhury1
  • 1The University of Manchester, Manchester, United Kingdom
  • 2Institute Curie, Immunity and Cancer Unit (U932), Paris 73005, France, Paris, France
  • 3Cancer Research UK Manchester Institute, The University of Manchester, Manchester, England, United Kingdom
  • 4Institute of Cancer Research (ICR), London, England, United Kingdom

The final, formatted version of the article will be published soon.

Muscle-invasive bladder cancer (MIBC) is a prevalent disease that can be treated with radiotherapy, but has a poor prognosis. Radiation-induced extracellular matrix (ECM) remodelling and fibrosis can induce tumour resistance and recurrence, but have not been studied in MIBC. Here, we aimed to characterise the impact of radiation on the ECM composition of MIBC. Materials and Methods. Three MIBC cell lines (T24, UMUC3, J82) were treated with fractionated radiation. We used proteomics to analyse the ECM composition produced by surviving cancer cells and immunofluorescence to investigate changes in the morphology and number of ECM fibres. We evaluated the RNA expression of identified ECM proteins (FN1, COL5A1, COL1A1, TNF6AIP6, FLG) in one cystectomy (TCGA-BLCA, n=397) and two radiotherapy (BC2001, n=313; BCON, n=151) cohorts. Results. There were 613 proteins affected by radiation (padj<0.05, fold change >2 or <-2), 68 of which were ECMassociated proteins. There was a general increase in proteases and protease regulators but heterogeneity across cell lines. Enrichment analysis showed ECM organisation was the primary pathway affected. Immunofluorescence confirmed radiation affected ECM structure, generally, reducing the number, length and width of fibres. Five ECM genes of interest were identified (COL1A1, COL5A2, FN1, FLG, TNFAIP6), constituting an ECM signature. High FN1, COL1A1, TNF6AIP6 mRNA levels and ECM signature scores were independent poor prognostic markers, while FLG mRNA expression independently predicted radiotherapy benefit in a meta-analysis (n=861). We found high COL1A1 expression levels predicted hypoxia-modifying treatment benefit. Prognostic significance of COL5A2, FN1 and the ECM signature was dependent on patients harbouring TP53-mutations. Conclusion. Radiation alters the composition and structure of the ECM produced by MIBC. As a proof-of-concept, we showed that radiation-affected ECM genes are independent prognostic and predictive markers of radiotherapy benefit in MIBC. Future studies should validate these radiationinduced ECM changes in clinical samples, and explore the role of FLG in radioresistance.

Keywords: Radiotherapy, ECM - extracellular matrix, Bladder cancer (BCa), radioresistance mechanisms, biomarker

Received: 23 Apr 2025; Accepted: 04 Jul 2025.

Copyright: © 2025 Guerrero Quiles, Fahy, Bartak, Gonzalez Abalos, Powel, Reed, Reeves, Baker, HOSKIN, James, Hall, Huddart, Porta, West, Biolatti and Choudhury. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

* Correspondence: Conrado Guerrero Quiles, The University of Manchester, Manchester, United Kingdom

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