Basic Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Nov 7, 2018; 24(41): 4663-4678
Published online Nov 7, 2018. doi: 10.3748/wjg.v24.i41.4663
Typing of pancreatic cancer-associated fibroblasts identifies different subpopulations
Michael Friberg Bruun Nielsen, Michael Bau Mortensen, Sönke Detlefsen
Michael Friberg Bruun Nielsen, Sönke Detlefsen, Department of Pathology, Odense University Hospital, Department of Clinical Research, University of Southern Denmark, Odense Pancreas Center (OPAC), Odense C 5000, Denmark
Michael Bau Mortensen, Department of Surgery, HPB Section, Odense University Hospital, Department of Clinical Research, University of Southern Denmark, Odense Pancreas Center (OPAC), Odense C 5000, Denmark
Author contributions: Mortensen MB and Detlefsen S initiated the study; Detlefsen S conceptualized the study; Nielsen MFB and Detlefsen S designed and coordinated the experiments; Nielsen MFB and Detlefsen S performed a majority of the experiments; Nielsen MFB and Detlefsen S evaluated the results; Nielsen MFB, Mortensen MB and Detlefsen S discussed and interpreted the data; Nielsen MFB and Detlefsen S wrote the manuscript; Nielsen MFB, Mortensen MB and Detlefsen S critically revised the manuscript.
Supported by Aase-and-Ejnar Danielsen’s Foundation, No. 10-001452; Brødrene Hartmann’s Foundation, No. A28308; the Foundation of 17.12.1981, No. 19024005; Karen S. Jensens Grant, No. 27-A1433; University of Southern Denmark Faculty Scholarship; Odense University Hospital Free Research Fund, No. 29-A1500, 22-A1133 and 49-A2379; Odense University Hospital Ph.D. stipend, No. 1032; and Odense Pancreas Center (OPAC).
Institutional review board statement: The study was approved by the Ethical Committee of the Region of Southern Denmark (project ID: S-20140168 and project ID: S-20150130).
Conflict-of-interest statement: The authors declare no conflict of interest.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Sönke Detlefsen, MD, PhD, Associate Professor, Department of Pathology, Odense University Hospital, University of Southern Denmark, J.B. Winsløws Vej 15, Odense C 5000, Denmark. sonke.detlefsen@rsyd.dk
Telephone: +45-65414806 Fax: +45-65912943
Received: July 23, 2018
Peer-review started: July 23, 2018
First decision: August 25, 2018
Revised: October 12, 2018
Accepted: October 21, 2018
Article in press: October 21, 2018
Published online: November 7, 2018
Abstract
AIM

To determine whether it is possible to identify different immune phenotypic subpopulations of cancer-associated fibroblasts (CAFs) in pancreatic cancer (PC).

METHODS

We defined four different stromal compartments in surgical specimens with PC: The juxtatumoural, peripheral, lobular and septal stroma. Tissue microarrays were produced containing all pre-defined PC compartments, and the expression of 37 fibroblast (FB) and 8 extracellular matrix (ECM) markers was evaluated by immunohistochemistry, immunofluorescence (IF), double-IF, and/or in situ hybridization. The compartment-specific mean labelling score was determined for each marker using a four-tiered scoring system. DOG1 gene expression was examined by quantitative reverse transcription PCR (qPCR).

RESULTS

CD10, CD271, cytoglobin, DOG1, miR-21, nestin, and tenascin C exhibited significant differences in expression profiles between the juxtatumoural and peripheral compartments. The expression of CD10, cytoglobin, DOG1, nestin, and miR-21 was moderate/strong in juxtatumoural CAFs (j-CAFs) and barely perceptible/weak in peripheral CAFs (p-CAFs). The upregulation of DOG1 gene expression in PC compared to normal pancreas was verified by qPCR. Tenascin C expression was strong in the juxtatumoural ECM and barely perceptible/weak in the peripheral ECM. CD271 expression was barely perceptible in j-CAFs but moderate in the other compartments. Galectin-1 was stronger expressed in j-CAFs vs septal fibroblasts, PDGF-Rβ, tissue transglutaminase 2, and hyaluronic acid were stronger expressed in lobular fibroblasts vs p-CAFs, and plectin-1 was stronger expressed in j-CAFs vs l-FBs. The expression of the remaining 33 markers did not differ significantly when related to the quantity of CAFs/FBs or the amount of ECM in the respective compartments.

CONCLUSION

Different immune phenotypic CAF subpopulations can be identified in PC, using markers such as cytoglobin, CD271, and miR-21. Future studies should determine whether CAF subpopulations have different functional properties.

Keywords: Pancreatic cancer, Tumour stroma, Cancer-associated fibroblasts, Extracellular matrix, Subtyping, Immunohistochemistry

Core tip: Pancreatic cancer (PC) has a poor prognosis, which may partially be attributed to the abundant desmoplastic stroma, produced by cancer-associated fibroblasts (CAFs). The exact role of CAFs in PC is currently unclear, as these cells exhibited stimulation of cancer cell proliferation in vitro, but depletion of these cells promoted cancer progression in animal models. In this study, using immunohistochemistry, immunofluorescence (IF), double-IF, and/or in situ hybridization, we identified different immune phenotypic subpopulations of CAFs in PC, which may, at least in part, explain the previously published, partly contradictory data on the role of CAFs in PC. Further studies are needed to elucidate whether certain CAF subpopulations in PC have different functional properties.