The control by estradiol of pituitary tumor and cell growth is not correlated with that of kallikrein gene expression.

From an MtTF4 pituitary tumor we established new cell lines and tumors whose growth is sensitive (stimulation or inhibition) or insensitive to estradiol (Cancer Res., 1991, 50, 3786-3794). The main objective of the present work was to determine whether such a diversity of responses is correlated with the estradiol control of kallikrein gene expression. From kallikrein mRNA analyses and from kallikrein activity assays in conditioned medium it appears highly probable that the diversity of responses to estradiol of pituitary tumors and cell growth is not due to a differential regulation of kallikrein gene expression. In addition, prolactin gene expression and estrogen receptor mRNA have been studied to further characterize this experimental model.