Type I collagen promotes the malignant phenotype of pancreatic ductal adenocarcinoma.
OBJECTIVE
The purpose of this study was to determine the role of functional interactions between pancreatic cancer cells and pancreatic stellate cells (PSCs) in the formation of the desmoplastic reaction (DR) in pancreatic cancer and to characterize the effect of type I collagen (the predominant component of the DR) on pancreatic cancer cell phenotype.


METHODS
PSCs and type I collagen were identified in sections of pancreatic cancer using immunohistochemistry, and their anatomic relationship was studied. Interactions among pancreatic cancer cell lines (MIA PaCa-2, Panc-1, and AsPC-1), primary cultures of human PSCs, and type I collagen were investigated in a series of tissue culture models.


RESULTS
In vivo, the DR causes gross distortion of normal pancreas, bringing cancer cells into close contact with numerous PSCs and abundant type I collagen. In tissue culture models of pancreatic cancer, conditioned media from each cell line increased PSC [3H]thymidine incorporation up to 6.3-fold that of controls, and AsPC-1 cells also increased PSC collagen synthesis 1.3-fold. Type I collagen was observed to increase long-term survival of pancreatic cancer cells treated with 5-fluorouracil, by up to 62% in clonogenic assays. This was because type I collagen increased the proliferation of cancer cells ([3H]thymidine incorporation was up to 2.8-fold that of cells cultured on tissue culture plastic) and reduced apoptosis of AsPC-1 cells in response to 5-fluorouracil (by regulating mcl-1).


CONCLUSIONS
These experiments elucidate a mechanism by which the DR in pancreatic cancer may form and, via the collagen within it, promote the malignant phenotype of pancreatic cancer cells, suggesting significant detriment to the host.
Armstrong
Thomas
T
Divisions of Tissue Remodelling and Repair, University of Southampton, Southampton General Hospital, Southampton, United Kingdom. armstrongthomas@talk21.com
Packham
Graham
G
Murphy
Lindsay B
LB
Bateman
Adrian C
AC
Conti
John A
JA
Fine
David R
DR
Johnson
Colin D
CD
Benyon
R Christopher
RC
Iredale
John P
JP
D000230:Adenocarcinoma / Q000378:metabolism / Q000473:pathology*; D017209:Apoptosis; D015153:Blotting, Western; D021441:Carcinoma, Pancreatic Ductal / Q000378:metabolism / Q000473:pathology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002469:Cell Separation; D003094:Collagen / Q000737:chemistry / Q000378:metabolism; D024042:Collagen Type I / Q000378:metabolism / Q000502:physiology*; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004247:DNA / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D005434:Flow Cytometry; D006801:Humans; D007150:Immunohistochemistry; D010179:Pancreas / Q000166:cytology; D010190:Pancreatic Neoplasms / Q000378:metabolism / Q000473:pathology*; D010641:Phenotype; D012313:RNA / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000378:metabolism
D024042:Collagen Type I; D017077:Culture Media, Conditioned; D019715:Tissue Inhibitor of Metalloproteinase-1; D012313:RNA; D003094:Collagen; D004247:DNA