Visualization of early events in tumor formation of eGFP-transfected rat colon cancer cells in liver.
Colon cancer preferentially metastasizes to the liver. To determine cellular backgrounds of this preference, we generated an enhanced green fluorescent protein (eGFP)-expressing rat adenocarcinoma cell line (CC531s) that forms metastases in rat liver after administration to the portal vein. Intravital videomicroscopy (IVVM) was used to visualize early events in the development of tumors in livers of live animals from the time of injection of the cancer cells up to 4 days afterward. Based on information obtained with IVVM, tissue areas were selected for further analysis using confocal laser scanning microscopy (CLSM), electron microscopy (EM), and electron tomography. It was shown that initial arrest of colon cancer cells in sinusoids of the liver was due to size restriction. Adhesion of cancer cells to endothelial cells was never found. Instead, endothelial cells retracted rapidly and interactions were observed only between cancer cells and hepatocytes. Tumors developed exclusively intravascularly during the first 4 days. In conclusion, initial steps in the classic metastatic cascade such as adhesion to endothelium and extravasation are not essential for colon cancer metastasis in liver.
Mook
Olaf R F
OR
Department of Cell Biology and Histology, Academic Medical Centre, Amsterdam, The Netherlands.
Van Marle
Jan
J
Vreeling-Sindelárová
Heleen
H
Jonges
Remmet
R
Frederiks
Wilma M
WM
Van Noorden
Cornelis J F
CJ
D000818:Animals; D002277:Carcinoma / Q000556:secondary*; D003110:Colonic Neoplasms / Q000473:pathology*; D049452:Green Fluorescent Proteins; D066298:In Vitro Techniques; D007202:Indicators and Reagents / Q000378:metabolism; D008113:Liver Neoplasms / Q000556:secondary*; D008164:Luminescent Proteins / Q000235:genetics; D008297:Male; D008854:Microscopy, Electron; D009368:Neoplasm Transplantation; D011169:Portal Vein; D051381:Rats; D011919:Rats, Inbred Strains; D014162:Transfection; D014407:Tumor Cells, Cultured / Q000637:transplantation / Q000648:ultrastructure
D007202:Indicators and Reagents; D008164:Luminescent Proteins; D049452:Green Fluorescent Proteins