Autocrine growth mechanism by transforming growth factor (TGF)-beta 1 and TGF-beta 1-receptor regulation by epidermal growth factor in a human endometrial cancer cell line IK-90.
Transforming growth factor-beta 1 (TGF-beta 1) enhanced cell proliferation in a concentration-dependent manner in a human endometrial cancer cell line, IK-90. Scatchard analysis of TGF-beta 1 receptor in IK-90 cells, using 125I-TGF-beta 1 as a ligand, revealed the presence of a class of high-affinity TGF-beta 1 receptors (2,000 sites per cell, KD = 74pM). Moreover, IK-90 cells produced and secreted TGF-beta 1: TGF-beta 1 messenger RNA was detected at 2.5 and 4.0 kb by Northern-blot analysis using 32P-labeled TGF-beta 1 cDNA as a probe, and TGF-beta 1 activity in conditioned medium by the inhibition of 3H-thymidine uptake into CCl 64 mink lung epithelial cells. We investigated the regulation of TGF-beta 1 receptor by 4 kinds of growth factor: epidermal growth factor (EGF) but not TGF-beta 1, insulin or insulin-like growth factor-1 increased the level of TGF-beta 1 binding sites in a concentration- and time-dependent manner. These findings suggest that TGF-beta 1 may be a potential autocrine growth factor in a human endometrial cancer cell line IK-90 and that this autocrine mechanism may be affected by EGF.
Department of Obstetrics and Gynecology, Osaka University Medical School, Japan.
M
M
Sakata
H
H
Kurachi
H
H
Ikegami
H
H
Jikihara
K
K
Morishige
A
A
Miyake
N
N
Terakawa
O
O
Tanizawa
D000328:Adult; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D016895:Culture Media, Serum-Free; D004273:DNA, Neoplasm / Q000187:drug effects / Q000378:metabolism; D016889:Endometrial Neoplasms / Q000473:pathology*; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005260:Female; D006801:Humans; D011956:Receptors, Cell Surface / Q000187:drug effects* / Q000378:metabolism; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta / Q000096:biosynthesis* / Q000378:metabolism / Q000494:pharmacology; D014407:Tumor Cells, Cultured
D016895:Culture Media, Serum-Free; D004273:DNA, Neoplasm; D011956:Receptors, Cell Surface; D018125:Receptors, Transforming Growth Factor beta; D016212:Transforming Growth Factor beta; D004815:Epidermal Growth Factor