Delta 7/11 on prolactin action

Prolactin is essential for normal mammary gland development and differentiation, and has been shown to promote tumour cell proliferation and chemotherapeutic resistance. The direct interactions of prolactin with delta 7/11 (a product of alternate splicing of the prolactin receptor primary transcript), and the resulting effect on cell behaviour, have not been investigated.

Fleming et al. are the first to demonstrate a direct effect of the prolactin binding protein, delta 7/11, on prolactin-stimulated cell behaviours including inhibition of prolactin-induced cell proliferation as well as alteration of prolactin-induced rescue of cell cycle arrest/early senescence events in breast epithelial cells. Biochemical analyses demonstrated that delta 7/11 was heavily glycosylated, and that glycosylation regulated the cellular localization and secretion of delta 7/11. Further, low levels of delta 7/11 were detected in serum samples of healthy volunteers, but were undetectable in human milk samples. Collectively, these data demonstrate that delta 7/11 is a novel regulatory mechanism of prolactin bioavailability and signalling. Fleming et al. (2013) Journal of Molecular Endocrinology 50, 79-90.

Read the full article at DOI: 10.1530/JME-12-0201.