|Budget Amount *help
¥2,900,000 (Direct Cost : ¥2,900,000)
Fiscal Year 1998 : ¥1,100,000 (Direct Cost : ¥1,100,000)
Fiscal Year 1997 : ¥1,800,000 (Direct Cost : ¥1,800,000)
It is well recognized that tumor growth is dependent on the development of new blood vessels (angiogenesis). Many tumor cells produce growth factors of vascular endothelial cells. Such growth factors include basic fibroblast growth factor (FGF), acidic FGF, vascular endothelial growth factor (VEGF), and transforming growth factor-alpha (TGF-alpha). Acidic FGF, basic FGF and VEGF have affinity for heparin and bind to heparin sepharose affinity columns. We observed that the conditioned medium from a human lung cancer cell line T3M-11 was mitogenic for endothelial cells derived from porcine aorta. The activity did not bind to a heparin sepharose affinity column and was different from TGF-alpha immunologically. These findings led us to analyze the growth factor produced by T3M-11 cells.
A cDNA encoding the growth factor was isolated through functional expression cloning in COS-1 cells from a cDNA library prepared from T3M-11 cells. The nucleotide sequence encoded by the cDNA proved to be identical with insulin-like growth factor II (IGF-II). The result suggests the involvement of IGF-II in the angiogenesis induced by the malignant tumor cells.
肺扁平上皮癌の一例(T3M-11)以外の腫瘍が産生する血管内皮細胞増殖因子はfibroblast growth factor(FGF),vascular endiothelial growth factor(VEGF)などのheparinに親和性を持つ増殖因子であった