Abstract
We have established a squamous cell carcinoma cell line (SCCNI) in a protein-free medium consisting of 1:9 mixture of Dulbecco's modified Eagle's medium (DMEM) and MCDB 153, and purified an autocrine growth factor from the conditioned medium. One protein was isolated from the protein-free conditioned medium by using heparin affinity, strong anion exchange, gel filtration, and reversed phase chromatography. Analysis of SDS-page electrophorosis revealed that molecular weight of the protein was approximately 25kDa under the non-reduced condition, and 15kDa under the reduced condition. In Westernblotting analysis, the 25kDa protein was reacted by the anti-inhibin β A antibody. These results indicated that the 25kDa protein is Activin A. We also detected expression of inhibin β A mRNA in this squamous cell carcinoma line by RT-PCR. These results suggested that this squamous cell carcinoma cell line produces Activin, which may act as an autocrine growth factor for the proliferation of squamous carcinoma cells.
