Production of immunoreactive insulin-like growth factor I and response to exogenous IGF-I in small cell lung cancer cell lines.
Small cell lung cancer (SCLC) cell lines were examined for the presence of insulin-like growth factor I-related protein (IGF-I) in cell pellets and culture media. IGF-I immunoreactivity was detected in 11/14 pellets, ranging from 12 to 76 mIU/mg soluble protein. The IGF-I levels in the cell pellets showed a correlation to the corresponding culture media. IGF-I binding sites were found in all tested cell lines. The maximum binding (Bmax) ranged from 131 to 1230 fmol/mg protein and the dissociation constant (KD) from 0.89 to 5.21 nM. The incorporation of [3H]thymidine in the presence of recombinant human IGF-I resulted in a clearly increased DNA synthesis in two of seven cell lines. Thus, IGF-I may be an important growth factor in SCLC.
Jaques
G
G
Philipps University Medical Center, Division of Hematology/Oncology, Marburg, West Germany.
Rotsch
M
M
Wegmann
C
C
Worsch
U
U
Maasberg
M
M
Havemann
K
K
D000818:Animals; D018288:Carcinoma, Small Cell / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D007334:Insulin-Like Growth Factor I / Q000096:biosynthesis* / Q000494:pharmacology; D008175:Lung Neoplasms / Q000378:metabolism*; D011863:Radioimmunoassay; D011972:Receptor, Insulin / Q000032:analysis; D017451:Receptors, Somatomedin; D013002:Somatomedins / Q000096:biosynthesis*; D014407:Tumor Cells, Cultured
D017451:Receptors, Somatomedin; D013002:Somatomedins; D007334:Insulin-Like Growth Factor I; D011972:Receptor, Insulin