Growth Hormone Signaling in Human T47D Breast Cancer Cells: Potential Role for a Growth Hormone Receptor-Prolactin Receptor Complex

摘要

John F. Langenheim, Wen Y. Chen, and Stuart J. FrankGH receptor (GHR) and prolactin (PRL) receptor (PRLR) are struc-turally similar cytokine receptor superfamily members that arehighlyconservedamongspecies.GHhasgrowth-promotingandmetabolic effects in various tissues in vertebrates, including hu-mans. PRL is essential for regulation of lactation in mammals.Recent studies indicate that breast tissue bears GHR and PRLRand that both GH and PRL may impact development or behaviorof breast cancer cells. An important facet of human GH (hGH)and human PRL (hPRL) biology is that although hPRL interactsonly with hPRLR, hGH binds well to both hGHR and hPRLR. Pres-ently, we investigated potential signaling effects of both hor-mones in the estrogen receptor- and progesterone receptor-positive human T47D breast cancer cell line. We found that thiscell type expresses ample GHR and PRLR and responds well toboth hGH and hPRL, as evidenced by activation of the Januskinase 2/signal transducer and activator of transcription 5 path-way.