The inhibin-βC subunit is down-regulated, while inhibin-βE is up-regulated by interferon-β1a in Ishikawa carcinoma cell line.

Introduction: Inhibins are important regulators of the female reproductive system. Recently, two new inhibin-subunits βC and βE have been described, although, their function is still quite unclear. Interestingly, there is an association between interferon and TGF-β expression. Therefore, the aim of this study was to determine expression changes of inhibin-βC and -βE subunits in endometrial Ishikawa carcinoma cell line after stimulation with interferon-β1a.
Materials and Methods: The Ishikawa cell line was cultured until confluence was observed (after 2 days). After adding interferon-β1a (1,000 IE/ml), Ishikawa cells were analyzed for inhibin-βC and -βE subunits by RT-PCR. The fibroblast cell line BJ6 served as negative control. Experiments were performed in triplicates.
Results: The endometrial adenocarcinoma cell line Ishikawa synthesized the inhibin- βC and -βE subunits. The fibroblast cells BJ6 did not demonstrate an inhibin -βC and -βE mRNA expression, while inhibin-βC subunit is down-regulated and inhibin-βE is up-regulated in Ishikawa carcinoma cell line after stimulation with interferon-β1a in Ishikawa.
Discussion: We demonstrated for the first time a functional relationship between interferon and the novel inhibin-βC and -βE subunits. It might be possible that interferon exerts a possible apoptotic function through the βE-subunit, while, by down-regulating the βC isoform, cell proliferation is inhibited. However, the precise function of the novel βC- and βE-subunits are still not known in human endometrial tissue and a possible association with interferon is still unclear and warrants further research.