Prolactin hormone (PRL) is well characterized as a terminal differentiation factor for mammary epithelial cells and as an autocrine growth/survival factor in breast cancer cells. However, this function of PRL may not fully signify its role in breast tumorigenesis. Cancer is a complex multistep progressive disease resulting not only from defects in cell growth but also in cell differentiation. I...

PRL receptor (PRLR) signal transduction supports PRL-induced growth/differentiation processes. While PRL is known to activate Jak2-Stat5 (signal transducer and activator of transcription 5) signaling pathway, the mechanism by which cell proliferation is stimulated is less known. We show that PRL induces proliferation of bovine mammary gland epithelial cells and AP-1 site activation. Using PRLR ...

PURPOSE The PRL-3 phosphatase has been found expressed at higher levels in metastasis than in primary tumors of patients with colorectal cancer. In the present study, we evaluated the expression of PRL-3 in ovarian cancer tissue and its role in ovarian cancer cell growth. EXPERIMENTAL DESIGN PRL-3 phosphatase expression was evaluated in 84 ovarian tumor samples. PRL-3 expression has been knoc...

In vivo and in vitro studies have indicated that the anterior pituitary hormone prolactin (PRL) is an immunoregulator and functions in the development of the neonatal immune system. In this study, prolactin receptor (PRL-R) expression from birth to adulthood as well as the effect of milk ingestion on the PRL-R expression were examined in splenocytes and thymocytes of neonatal rats. Three approa...

THE HORMONES PROLACTIN (PRL) and oxytocin (OT) are functionally linked to regulate processes in and beyond reproduction. Both hormones are released into the circulation in response to orgasm, mating, nursing, stress, and osmotic stimulation to regulate reproductive behavior, pregnancy, lactation, stress-related responses, and fluid and electrolyte homeostasis (3, 4, 7, 9, 10, 13). Notably, PRL ...

Phosphatases of regenerating liver (PRL) constitute a subfamily of the protein tyrosine phosphatases that are implicated in oncogenic and metastatic phenotypes. In this study, we evaluated the role of PRL-1 in cell proliferation and metastatic processes in human lung cancer cells. We stably transfected human A549 lung cancer cells with several short hairpin RNAs for PRL-1 and found decreased in...

In the mouse, there is a large family of paralogous genes closely related to PRL. The objective of this report was to investigate the organization of the mouse PRL gene family locus. PRL family genes reside on chromosome 13 of the mouse genome. The PRL gene family members were localized to a series of overlapping bacterial artificial chromosome clones and arranged based on structural relationsh...

In the present study we investigated how the suprachiasmatic nucleus (SCN) controls the E(2)-induced PRL surge in female rats. First, the role of vasopressin (VP), a SCN transmitter present in medial preoptic area (MPO) projections and rhythmically released by SCN neurons, as a circadian signal for the E(2)-induced PRL surge was investigated. Using a reverse microdialysis technique, VP was admi...

Metastasis-associated phosphatase of regenerating liver-3 (PRL-3) has pleiotropic effects in driving cancer progression, yet the signaling mechanisms of PRL-3 are still not fully understood. Here, we provide evidence for PRL-3-induced hyperactivation of EGFR and its downstream signaling cascades in multiple human cancer cell lines. Mechanistically, PRL-3-induced activation of EGFR was attribute...

Studies were carried out to assess the role of insulin (I), cortisol (H), and prolactin (P or PRL) in regulating myoinositol (inositol) uptake in the mammary gland. Using cultured mammary gland explants from pregnant mice (12-14 days into gestation), insulin and prolactin were found to stimulate inositol uptake, while cortisol impaired inositol uptake. Optimal inositol uptake was observed when ...