Comparison of basic fibroblast growth factor levels in clone A human colon cancer cells in vitro with levels in xenografted tumours.
We measured levels of basic fibroblast growth factor (FGF-2) in human colon cancer cells (clone A) in vitro and in xenografted solid tumours using a commercial enzyme-linked immunoassay. In Vitro, levels in unfed plateau phase or exponentially growing cells were low, averaging respectively about 2 and 8 pg 10(-6) cells. However, when solid tumours (average volumes 787 mm3) were cut into halves and either enzymatically disaggregated to obtain a cellular fraction or extracted in toto, levels were much higher. In the cellular fraction, values averaged 110 pg 10(-6) cells, while in whole tumour extracts, average values were 24 pg mg-1 tumour tissue. These results indicate that growth factor levels in solid neoplasms may differ markedly from those predicted from in vitro measurements. We hypothesise that the apparent increase in FGF-2 levels in vivo results primarily from the presence of a significant fraction of host cells (in particular, macrophages, which may contain high levels of FGF-2) within xenografted clone A neoplasms.
McCarty
L P
LP
Department of Radiation Medicine, Brown University School of Medicine, Providence, Rhode Island 02912, USA.
Karr
S M
SM
Harris
B Z
BZ
Michelson
S G
SG
Leith
J T
JT
D000818:Animals; D001483:Base Sequence; D003110:Colonic Neoplasms / Q000737:chemistry* / Q000473:pathology; D016222:Fibroblast Growth Factor 2 / Q000032:analysis* / Q000235:genetics; D006801:Humans; D008297:Male; D051379:Mice; D008819:Mice, Nude; D008969:Molecular Sequence Data; D009368:Neoplasm Transplantation; D012333:RNA, Messenger / Q000032:analysis; D014183:Transplantation, Heterologous
D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2