Activin A inhibits growth-inhibitory signals by TGF-beta1 in differentiated human endometrial adenocarcinoma cells.
Although human endometrial adenocarcinoma tissues express high levels of activin A, the pathophysiological functions of endometrial activin A remain unclear. Human endometrial cancer cells express both activin receptor and TGF-beta receptor, and TGF-beta1 utilizes the same intracellular signaling molecules as activin A. Using three differentiated human endometrial adenocarcinoma cell lines, we investigated whether there are interactions between TGF-beta1- and activin A-mediated signaling. Flow cytometric analysis revealed cell surface expression of two types of TGF-beta receptor subunits and four types of activin receptor subunits. TGF-beta1 inhibited cell proliferation in three endometrial adenocarcinoma cell lines. Activin A did not affect the growth of the three endometrial cell lines, and pre-incubation with activin A dose-dependently reduced TGF-beta1-mediated inhibition of cell growth. These results suggest that in endometrial adenocarcinoma cells, the intracellular signals underlying TGF-beta1-mediated inhibition of growth can themselves be inhibited by activin A. Therefore, the increased expression of activin A may be involved in carcinogenesis by reducing TGF-beta-mediated signals inhibiting cell growth in human endometrial adenocarcinoma tissues.
Tanaka
Tetsuji
T
Department of Obstetrics and Gynecology, Wakayama Medical University, Wakayama 641-0012, Japan. tetanaka@wakayama-med.ac.jp
Toujima
Saori
S
Umesaki
Naohiko
N
D028341:Activins / Q000494:pharmacology*; D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D002454:Cell Differentiation; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor; D016889:Endometrial Neoplasms / Q000378:metabolism* / Q000473:pathology; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D028322:Inhibin-beta Subunits / Q000494:pharmacology*; D015398:Signal Transduction / Q000187:drug effects*; D016212:Transforming Growth Factor beta / Q000037:antagonists & inhibitors* / Q000378:metabolism; D053773:Transforming Growth Factor beta1
C508960:TGFB1 protein, human; D016212:Transforming Growth Factor beta; D053773:Transforming Growth Factor beta1; C422405:activin A; D028341:Activins; D028322:Inhibin-beta Subunits