Activation of fibroblast growth factor 8 gene expression in human embryonal carcinoma cells

To study the role of fibroblast growth factor 8 (FGF-8) in human development and malignancies, we have isolated and characterized its gene. The gene spans 6.0 kbp and is comprised of five exons. Using reverse transcription-polymerase chain reaction, we were able to show that FGF-8 is expressed in two of the seven human mammary carcinoma cell lines tested and in only one of nine breast tumors. In contrast, both of the two normal breast tissues tested express FGF-8. FGF-8 was previously shown to be present in adult testis and ovary. Surprisingly, only one of the seven testis carcinomas and one of 12 ovary carcinomas express FGF-8, whereas all three kidney carcinomas tested express FGF-8. We further showed that fetal brain and lung express FGF-8, whereas fetal intestine and liver do not. Finally, we showed that a teratocarcinoma cell line, Tera-2, can be induced to express FGF-8 mRNA by fetal bovine serum.