Epistatic and Independent Effects on Schizophrenia-Related Phenotypes Following Co-disruption of the Risk Factors Neuregulin-1 x DISC1
SCHIZOPHRENIA BULLETIN
Authors: O'Tuathaigh, Colm M. P.; Fumagalli, Fabio; Desbonnet, Lieve; Perez-Branguli, Francesc; Moloney, Gerard; Loftus, Samim; O'Leary, Claire; Petit, Emilie; Cox, Rachel; Tighe, Orna; Clarke, Gerard; Lai, Donna; Harvey, Richard P.; Cryan, John F.; Mitchell, Kevin J.; Dinan, Timothy G.; Riva, Marco A.; Waddington, John L.
Abstract
Few studies have addressed likely gene x gene (ie, epistatic) interactions in mediating risk for schizophrenia. Using a preclinical genetic approach, we investigated whether simultaneous disruption of the risk factors Neuregulin-1 (NRG1) and Disrupted-in-schizophrenia 1 (DISC1) would produce a disease-relevant phenotypic profile different from that observed following disruption to either gene alone. NRG1 heterozygotes exhibited hyperactivity and disruption to prepulse inhibition, both reversed by antipsychotic treatment, and accompanied by reduced striatal dopamine D2 receptor protein expression, impaired social cognition, and altered glutamatergic synaptic protein expression in selected brain areas. Single gene DISC1 mutants demonstrated a disruption in social cognition and nest-building, altered brain 5-hydroxytryptamine levels and hippocampal ErbB4 expression, and decreased cortical expression of the schizophrenia-associated microRNA miR-29b. Co-disruption of DISC1 and NRG1, indicative of epistasis, evoked an impairment in sociability and enhanced self-grooming, accompanied by changes in hypothalamic oxytocin/ vasopressin gene expression. The findings indicate specific behavioral correlates and underlying cellular pathways downstream of main effects of DNA variation in the schizophrenia-associated genes NRG1 and DISC1.
Treatment with aromatase inhibitors stimulates the expression of epidermal growth factor receptor-1 and neuregulin 1 in ER positive/HER-2/neu non-amplified primary breast cancers
JOURNAL OF STEROID BIOCHEMISTRY AND MOLECULAR BIOLOGY
Authors: Flageng, Marianne Hauglid; Larionov, Alexey; Geisler, Jurgen; Knappskog, Stian; Prestvik, Wenche S.; Bjorkoy, Geir; Lilleng, Peer Kare; Dixon, J. Michael; Miller, William R.; Lonning, Per Eystein; Mellgren, Gunnar
Abstract
While estrogens have been shown to modulate EGFR/HER-1 and HER-2/neu expression in experimental systems, the effects of estrogen deprivation on expression levels of the HER-receptors and the neuregulin (NRG)1 ligand in breast cancers remain unknown. Here, we measured EGFR/HER-1-4 and NRG1 mRNA in ER positive tumors from 85 postmenopausal breast cancer patients before and after two weeks (n = 64) and three months (n = 85) of primary treatment with an aromatase inhibitor (AI). In tumors lacking HER-2/neu amplification, quantitative real-time PCR analyses revealed EGFR/HER-1 and NRG1 to vary significantly between the three time points (before therapy, after 2 weeks and after 3 months on treatment; P <= 0.001 for both). Pair-wise comparison revealed a significant increase in EGFR/HER-1 already during the first two weeks of treatment (P = 0.049) with a further increase for both EGFR/HER-1 and NRG1 after 3 months on treatment (P <= 0.001 and P=0.001 for both comparing values at 3 months to values at baseline and 2 weeks respectively). No difference between tumors responding versus non responders was recorded. Further, no significant change in any parameter was observed among HER-2/neu amplified tumors. Analyzing components of the HER-2/neu PI3K/Akt downstream pathway, the PlIC3CA H1047R mutation was associated with treatment response (P = 0.035); however no association between either Ala phosphorylation status or PIK3CA gene mutations and EGFR/HER-1 or NRG1 expression levels were observed. Our results indicate primary AI treatment to modulate expression of HER-family members and the growth factor NRG1 in HER-2/neu non-amplified breast cancers in vivo. Potential implications to long term sensitivity warrants further investigations. (C) 2016 Elsevier Ltd. All rights reserved.