title: Transcript and protein profiling identifies signaling, growth arrest, apoptosis, and NF-κB survival signatures following GNRH receptor activation.
abstract: GNRH significantly inhibits proliferation of a proportion of cancer cell lines by activating GNRH receptor (GNRHR)-G protein signaling. Therefore, manipulation of GNRHR signaling may have an under-utilized role in treating certain breast and ovarian cancers. However, the precise signaling pathways necessary for the effect and the features of cellular responses remain poorly defined. We used transcriptomic and proteomic profiling approaches to characterize the effects of GNRHR activation in sensitive cells (HEK293-GNRHR, SCL60) in vitro and in vivo, compared to unresponsive HEK293. Analyses of gene expression demonstrated a dynamic response to the GNRH superagonist Triptorelin. Early and mid-phase changes (0.5-1.0 h) comprised mainly transcription factors. Later changes (8-24 h) included a GNRH target gene, CGA, and up- or downregulation of transcripts encoding signaling and cell division machinery. Pathway analysis identified altered MAPK and cell cycle pathways, consistent with occurrence of G(2)/M arrest and apoptosis. Nuclear factor kappa B (NF-κB) pathway gene transcripts were differentially expressed between control and Triptorelin-treated SCL60 cultures. Reverse-phase protein and phospho-proteomic array analyses profiled responses in cultured cells and SCL60 xenografts in vivo during Triptorelin anti-proliferation. Increased phosphorylated NF-κB (p65) occurred in SCL60 in vitro, and p-NF-κB and IκBε were higher in treated xenografts than controls after 4 days Triptorelin. NF-κB inhibition enhanced the anti-proliferative effect of Triptorelin in SCL60 cultures. This study reveals details of pathways interacting with intense GNRHR signaling, identifies potential anti-proliferative target genes, and implicates the NF-κB survival pathway as a node for enhancing GNRH agonist-induced anti-proliferation.
authors.affiliation: Breakthrough Breast Cancer Research Unit and Division of Pathology, Institute of Genetics and Molecular Medicine, University of Edinburgh, Crewe Road South, Edinburgh, UK.
authors.forename: Colette
authors.initials: C
authors.lastname: Meyer
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Sims
authors.forename: Kevin
authors.initials: K
authors.lastname: Morgan
authors.forename: Beth
authors.initials: B
authors.lastname: Harrison
authors.forename: Morwenna
authors.initials: M
authors.lastname: Muir
authors.forename: Jianing
authors.initials: J
authors.lastname: Bai
authors.forename: Dana
authors.initials: D
authors.lastname: Faratian
authors.forename: Robert P
authors.initials: RP
authors.lastname: Millar
authors.forename: Simon P
authors.initials: SP
authors.lastname: Langdon
mesh_terms: D000818:Animals; D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology; D017209:Apoptosis; D015415:Biomarkers / Q000378:metabolism*; D015153:Blotting, Western; D002453:Cell Cycle; D002454:Cell Differentiation; D049109:Cell Proliferation; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005260:Female; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D006801:Humans; D007124:Immunoenzyme Techniques; D007668:Kidney / Q000166:cytology / Q000378:metabolism; D051379:Mice; D008819:Mice, Nude; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D020411:Oligonucleotide Array Sequence Analysis; D010750:Phosphoproteins / Q000276:immunology / Q000378:metabolism; D040081:Protein Array Analysis; D040901:Proteomics; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D011966:Receptors, LHRH / Q000235:genetics / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction / Q000187:drug effects; D017329:Triptorelin Pamoate / Q000031:analogs & derivatives / Q000494:pharmacology
chemical_list: D018931:Antineoplastic Agents, Hormonal; D015415:Biomarkers; D004791:Enzyme Inhibitors; D016328:NF-kappa B; D010750:Phosphoproteins; D012333:RNA, Messenger; D011966:Receptors, LHRH; D017329:Triptorelin Pamoate; C066438:deslorelin