Mimicking the tumour microenvironment: three different co-culture systems induce a similar phenotype but distinct proliferative signals in primary chronic lymphocytic leukaemia cells.
Interactions in the tumour microenvironment can promote chronic lymphocytic leukaemia (CLL) cell survival, proliferation and drug resistance. A detailed comparison of three co-culture systems designed to mimic the CLL lymph node and vascular microenvironments were performed; two were mouse fibroblast cell lines transfected with human CD40LG or CD31 and the third was a human microvascular endothelial cell line, HMEC-1. All three co-culture systems markedly enhanced CLL cell survival and induced a consistent change in CLL cell phenotype, characterized by increased expression of CD38, CD69, CD44 and ITGA4 (CD49d); this phenotype was absent following co-culture on untransfected mouse fibroblasts. In contrast to HMEC-1 cells, the CD40LG and CD31-expressing fibroblasts also induced ZAP70 expression and marked CLL cell proliferation as evidenced by carboxyfluorescein succinimidyl ester labelling and increased Ki-67 expression. Taken together, our data show that co-culture on different stroma induced a remarkably similar activation phenotype in CLL cells but only the CD40LG and CD31-expressing fibroblasts increased ZAP70 expression and CLL cell proliferation, indicating that ZAP70 may play a critical role in this process. This comparative study reveals a number of striking similarities between the co-culture systems tested but also highlights important differences that should be considered when selecting which system to use for in-vitro investigations.
Department of Haematology, King's College London, London, UK.
Emma
E
Hamilton
Laurence
L
Pearce
Liam
L
Morgan
Sophie
S
Robinson
Vicki
V
Ware
Paul
P
Brennan
N Shaun B
NS
Thomas
Deborah
D
Yallop
Stephen
S
Devereux
Chris
C
Fegan
Andrea G S
AG
Buggins
Chris
C
Pepper
D000818:Animals; D015703:Antigens, CD / Q000378:metabolism; D002450:Cell Communication / Q000502:physiology*; D018929:Cell Culture Techniques / Q000379:methods; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D002470:Cell Survival; D018920:Coculture Techniques / Q000379:methods; D042783:Endothelial Cells / Q000473:pathology; D005347:Fibroblasts / Q000473:pathology; D005434:Flow Cytometry; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000473:pathology*; D007963:Leukocytes, Mononuclear / Q000473:pathology; D051379:Mice; D055806:Microvessels / Q000473:pathology; D010641:Phenotype; D014162:Transfection; D059016:Tumor Microenvironment / Q000502:physiology*
D015703:Antigens, CD