To elucidate the role of hst in pituitary tumorigenesis we treated primary rat pituitary and pituitary tumor cell cultures with recombinant FGF-4 and also stably transfected pituitary cell lines with full-length human hst cDNA.
Although hst-1 and int-2 are usually not expressed despite amplification, elevated transcription of the cyclin D gene is accompanied by its amplification, suggesting a role of a G1 cyclin in oesophageal carcinogenesis.
These results suggest that amplification of chromosomal locus of the hst-1 and int-2 genes might participate in carcinogenesis, in progression, and particularly in metastasis of esophageal carcinomas.
These observations indicate that OCT3 protein is selectively expressed in human breast cancer cells, and its expression may be implicated in mammary gland tumorigenesis via up-regulating FGF-4 expression.