EGF stimulates Pit-1 independent transcription of the human prolactin pituitary promoter in human breast cancer SK-BR-3 cells through its proximal AP-1 response element.

摘要: Normal and neoplastic human mammary gland cells are targets for the proliferative action of prolactin. These also synthesize prolactin, thereby inducing an autocrine/paracrine loop. We present first extensive analysis transcriptional regulation prolactin gene (hPRL) in tumor cells, SK-BR-3. show that pituitary promoter is functional these absence pituitary-specific factor Pit-1. Expression exogenous Pit-1 or epidermal growth (EGF) treatment stimulates transfected hPRL endogenous expression. EGF stimulation mediated by increased synthesis c-fos c-jun, resulting AP-1 binding to proximal promoter. This involves receptor, possibly ErbB2 highly expressed SK-BR-3 a PI3K/JNK pathway. The transcription may include complex regulatory network controlling cells.