title: Prolactin Pro-Differentiation Pathway in Triple Negative Breast Cancer: Impact on Prognosis and Potential Therapy.
abstract: Triple negative breast cancer (TNBC) is a heterogeneous disease associated with poor clinical outcome and lack of targeted therapy. Here we show that prolactin (PRL) and its signaling pathway serve as a sub-classifier and predictor of pro-differentiation therapy in TNBC. Using immunohistochemistry and various gene expression in silica analyses we observed that prolactin receptor (PRLR) protein and mRNA levels are down regulated in TNBC cases. In addition, examining correlation of PRLR gene expression with metagenes of TNBC subtypes (580 cases), we found that PRLR gene expression sub-classifies TNBC patients into a new subgroup (TNBC-PRLR) characterized by epithelial-luminal differentiation. Importantly, gene expression of PRL signaling pathway components individually (PRL, PRLR, Jak2 and Stat5a), or as a gene signature is able to predict TNBC patients with significantly better survival outcomes. As PRL hormone is a druggable target we determined the biological role of PRL in TNBC biology. Significantly, restoration/activation of PRL pathway in TNBC cells representative of mesenchymal or TNBC-PRLR subgroups led to induction of epithelial phenotype and suppression of tumorigenesis. Altogether, these results offer potential new modalities for TNBC stratification and development of personalized therapy based on PRL pathway activation.
authors.affiliation: Department of Medicine, Cancer Research Program, McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
authors.forename: Vanessa M
authors.initials: VM
authors.lastname: López-Ozuna
authors.affiliation: Department of Medicine, Cancer Research Program, McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
authors.forename: Ibrahim Y
authors.initials: IY
authors.lastname: Hachim
authors.affiliation: Medical Microbiology Department, RAK Medical and Health Sciences University, UAE.
authors.forename: Mahmood Y
authors.initials: MY
authors.lastname: Hachim
authors.affiliation: Department of Medicine, Cancer Research Program, McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
authors.forename: Jean-Jacques
authors.initials: JJ
authors.lastname: Lebrun
authors.affiliation: Department of Medicine, Cancer Research Program, McGill University Health Centre, McGill University, Montreal, Quebec, Canada.
authors.forename: Suhad
authors.initials: S
authors.lastname: Ali
mesh_terms: D000818:Animals; D017209:Apoptosis; D014408:Biomarkers, Tumor / Q000378:metabolism*; D002454:Cell Differentiation; D049109:Cell Proliferation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D011379:Prognosis; D011388:Prolactin / Q000378:metabolism*; D011981:Receptors, Prolactin / Q000378:metabolism*; D015398:Signal Transduction; D015996:Survival Rate; D064726:Triple Negative Breast Neoplasms / Q000378:metabolism / Q000473:pathology*; D014407:Tumor Cells, Cultured; D023041:Xenograft Model Antitumor Assays
chemical_list: D014408:Biomarkers, Tumor; D011981:Receptors, Prolactin; D011388:Prolactin