Myofibroblasts enable invasion of endothelial cells into three-dimensional tumor cell clusters: a novel in vitro tumor model.
OBJECTIVE
In an effort to study the importance of stromal involvement in angiogenesis, we developed a novel, multicellular model that utilizes three of the primary cell types involved in tumor angiogenesis.


METHODS
Fluorescently labeled human microvascular endothelial cells (HMVECs), 10T1/2 cells and myofibroblasts were incubated in the presence of a three-dimensional tumor cell cluster resuspended in collagen and embedded in Matrigel.


RESULTS
HMVECs cultured in the presence of a human SKOV-3 ovarian carcinoma tumor cell cluster, surrounded the tumor cell cluster, while myofibroblasts invaded the cluster, localizing within the tumor cell mass. In contrast, 10T1/2 cells, a pluripotent mouse mesenchymal cell line with pericyte-like properties, did not demonstrate the same invasive phenotype. HMVECs cultured in the presence of myofibroblasts invaded the tumor cell cluster and colocalized with the myofibroblasts as demonstrated by fluorescent microscopy and immunohistochemistry. The angiogenesis inhibitors SU6668 and paclitaxel inhibited stromal invasion, while a broad-spectrum matrix metalloproteinase inhibitor did not.


CONCLUSIONS
This model emphasizes the critical interaction between endothelial cells and myofibroblasts and provides a more complete in vitro model for studying angiogenesis and tumor progression.
Walter-Yohrling
Jennifer
J
Department of Tumor Biology, Genzyme Molecular Oncology, Genzyme Corporation, Five Mountain Road, Framingham, MA 01701, USA. jyohrlin@cntus.jnj.com
Pratt
Bruce M
BM
Ledbetter
Steve
S
Teicher
Beverly A
BA
D000328:Adult; D020533:Angiogenesis Inhibitors / Q000494:pharmacology; D000972:Antineoplastic Agents, Phytogenic / Q000494:pharmacology; D045744:Cell Line, Tumor; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000473:pathology*; D005347:Fibroblasts / Q000473:pathology*; D006801:Humans; D007150:Immunohistochemistry; D007211:Indoles / Q000494:pharmacology; D045726:Metalloproteases / Q000037:antagonists & inhibitors; D009361:Neoplasm Invasiveness / Q000473:pathology* / Q000517:prevention & control; D009369:Neoplasms / Q000473:pathology*; D000078183:Oxindoles; D017239:Paclitaxel / Q000494:pharmacology; D011422:Propionates; D011480:Protease Inhibitors / Q000494:pharmacology; D011758:Pyrroles / Q000494:pharmacology; D017154:Stromal Cells / Q000187:drug effects / Q000473:pathology
D020533:Angiogenesis Inhibitors; D000972:Antineoplastic Agents, Phytogenic; D007211:Indoles; D000078183:Oxindoles; D011422:Propionates; D011480:Protease Inhibitors; D011758:Pyrroles; C412603:orantinib; D045726:Metalloproteases; D017239:Paclitaxel