Basement membrane matrix modifies cytokine interactions between lung cancer cells and fibroblasts.
OBJECTIVE
Proliferation of fibroblasts (desmoplastic reaction) in the lung adenocarcinomas is an important phenomenon that correlates with metastases and poor prognosis. Because basement membranes are often involved in the desmoplastic areas and many cytokines have binding capacity to basement membrane molecules, we hypothesized that basement membrane modify the paracrine effects between cancer cells and fibroblasts via the fibrogenic cytokines and this hypothesis was experimentally investigated.


METHODS
The effects of conditioned media derived from ten lung carcinoma cell lines and normal airway epithelial cells on DNA synthesis of fetal lung fibroblasts were determined. We focused on fibroblast growth factor 2 (FGF-2) as the candidate paracrine cytokines and examined their diffusion through an experimental basement membrane matrix model, Matrigel.


RESULTS
All the conditioned media promoted DNA synthesis of fetal lung fibroblasts. Detection by ELISA methods and the neutralizing antibodies suggested that FGF-2 was one of the responsible factors for the growth promotion. Diffusion of FGF-2 across the polycarbonate membrane was suppressed by coating with Matrigel. When FGF-2-secreting A549 cells were covered with Matrigel, FGF-2 was stored in Matrigel and its diffusion into the culture media was significantly reduced. Binding of FGF-2 to Matrigel was completely blocked by a basic protein, protamine sulfate. In the presence of protamine sulfate in Matrigel overlaid on A549 cells, diffusion of FGF-2 increased 7-fold as much as that without overlaid Matrigel.


CONCLUSIONS
These results suggest that the basement membrane acts as a barrier to the diffusion and a reservoir of cytokines secreted by cancer cells, and that the subsequent degradation of the basement membrane by cancer cells could release the stored cytokines and promote growth of fibroblasts.
Akashi
Takumi
T
Department of Pathology, Tokyo Medical and Dental University, Yushima, Bunkyou-ku, Tokyo, Japan. akashi.path@med.tmd.ac.jp
Minami
Junko
J
Ishige
Yuki
Y
Eishi
Yoshinobu
Y
Takizawa
Touichiro
T
Koike
Morio
M
Yanagishita
Masaki
M
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D019138:Antibodies, Blocking / Q000494:pharmacology; D001485:Basement Membrane / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D045744:Cell Line, Tumor / Q000187:drug effects; D003094:Collagen / Q000378:metabolism; D017077:Culture Media, Conditioned / Q000494:pharmacology; D004247:DNA / Q000096:biosynthesis; D004261:DNA Replication / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D016222:Fibroblast Growth Factor 2 / Q000276:immunology / Q000378:metabolism* / Q000494:pharmacology; D005347:Fibroblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D006497:Heparan Sulfate / Q000378:metabolism; D006801:Humans; D007375:Interleukin-1 / Q000378:metabolism* / Q000494:pharmacology; D007797:Laminin / Q000378:metabolism; D008168:Lung / Q000166:cytology; D008175:Lung Neoplasms / Q000378:metabolism* / Q000473:pathology; D019899:Paracrine Communication / Q000187:drug effects / Q000502:physiology*; D011479:Protamines / Q000494:pharmacology; D011509:Proteoglycans / Q000378:metabolism; D011994:Recombinant Proteins
D019138:Antibodies, Blocking; D003094:Collagen; D017077:Culture Media, Conditioned; D004247:DNA; D004338:Drug Combinations; D016222:Fibroblast Growth Factor 2; D006497:Heparan Sulfate; D007375:Interleukin-1; D007797:Laminin; D011479:Protamines; D011509:Proteoglycans; D011994:Recombinant Proteins; C059485:matrigel