Proteomic Analysis of FFPE Tissue Samples Identifies Potential Molecular Mechanisms Mediating Resistance to Radiotherapy in Rectal Cancer

Author(s)
Tobias Zott, Michael Wolf, Günter Plessl-Walder, Heinz Regele, Michael Bergmann, Samuel M. Meier-Menches, Christopher Gerner, Gerd R. Silberhumer, Andrea Bileck
Abstract

Chemoradiation prior to surgery in locally advanced rectal cancer is the current standard therapy but is not effective in all rectal cancer patients. Prognostic markers supporting patient stratification with respect to clinical response would therefore be desirable. The aim of this study was to investigate pathophysiological mechanisms underlying radioresistance and to identify potential prognostic markers by comparative proteome profiling. Therefore, formalin fixed paraffin-embedded tissue (FFPE) samples from rectal tumors (n = 50) and normal control tissue (n = 39) of nonresponders and responders to neoadjuvant chemoradiation were analyzed. As a result, 1685 robustly identified proteins were further evaluated. Comparing tumor with corresponding control samples revealed 221 differentially expressed proteins (FDR < 0.05) with FTL, PCOLCE, and RCN3 being most striking in tumor tissue. CEACAM 1, 5, and 6, as well as MCM protein complex components, were significantly up-regulated in tumor tissue of nonresponders. The autophagic activity-related and DNA damage repair proteins TOM1, CAPNS1, TP53BP1, HS1BP3, as well as COTL1 and DCPS, discriminated non- and nearly complete from complete responders. In the tumor-surrounding tissue of nonresponders, the innate immune response-suppressing protein CD55 was found specifically up-regulated. These proteins may serve as prognostic markers and potential therapeutic targets, requiring further validation in prospective studies.

Organisation(s)
Department of Analytical Chemistry, Joint Metabolome Facility, Department of Inorganic Chemistry
External organisation(s)
Medizinische Universität Wien, Vienna Doctoral School in Chemistry (DoSChem)
Journal
Journal of Proteome Research
ISSN
1535-3893
DOI
https://doi.org/10.1021/acs.jproteome.5c00114
Publication date
2025
Peer reviewed
Yes
Austrian Fields of Science 2012
104002 Analytical chemistry, 106037 Proteomics, 301904 Cancer research
Keywords
ASJC Scopus subject areas
General Chemistry, Biochemistry
Sustainable Development Goals
SDG 3 - Good Health and Well-being
Portal url
https://ucrisportal.univie.ac.at/en/publications/a03b001a-67a1-445d-9732-88fc3c37f841