title: Notch activation augments nitric oxide/soluble guanylyl cyclase signaling in immortalized ovarian surface epithelial cells and ovarian cancer cells.
abstract: Nitric oxide (NO) is generated by tumor, stromal and endothelial cells and plays a multifaceted role in tumor biology. Many physiological functions of NO are mediated by soluble guanylyl cyclase (sGC) and NO/sGC signaling has been shown to promote proliferation and survival of ovarian cancer cells. However, how NO/sGC signaling is modulated in ovarian cancer cells has not been studied. The evolutionarily conserved Notch signaling pathway plays an oncogenic role in ovarian cancer. Here, we report that all three ovarian cancer cell lines we examined express a higher level of GUCY1B3 (the β subunit of sGC) compared to non-cancerous immortalized ovarian surface epithelial (IOSE) cell lines. Interestingly, the highest expression of GUCY1B3 in ovarian cancer OVCAR3 cells is concurrent with the expression of Notch3. In IOSE cells, forced activation of Notch3 increases the expression of GUCY1B3, NO-induced cGMP production, and the expression of cGMP-dependent protein kinase (PKG), thereby enhancing NO- and cGMP-induced phosphorylation of vasodilator-stimulated phosphoprotein (VASP, a direct PKG substrate protein). In contrast, inhibition of Notch by DAPT reduces GUCY1B3 expression and NO-induced cGMP production and VASP phosphorylation in OVCAR3 cells. Finally, we confirmed that inhibition of sGC by ODQ decreases growth of ovarian cancer cells. Together, our work demonstrates that Notch is a positive regulator of NO/sGC signaling in IOSE and ovarian cancer cells, providing the first evidence that Notch and NO signaling pathways interact in IOSE and ovarian cancer cells.
authors.affiliation: Department of Oncology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AB, Canada.
authors.forename: Ahmed
authors.initials: A
authors.lastname: El-Sehemy
authors.forename: Alex C
authors.initials: AC
authors.lastname: Chang
authors.forename: Abul Kalam
authors.initials: AK
authors.lastname: Azad
authors.forename: Nidhi
authors.initials: N
authors.lastname: Gupta
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Xu
authors.forename: Helen
authors.initials: H
authors.lastname: Steed
authors.forename: Aly
authors.initials: A
authors.lastname: Karsan
authors.forename: YangXin
authors.initials: Y
authors.lastname: Fu
mesh_terms: D002460:Cell Line; D045744:Cell Line, Tumor; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D006162:Guanylate Cyclase / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D009569:Nitric Oxide / Q000378:metabolism*; D010051:Ovarian Neoplasms / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D010053:Ovary / Q000166:cytology* / Q000378:metabolism / Q000473:pathology; D000071656:Receptor, Notch3; D018160:Receptors, Cytoplasmic and Nuclear / Q000235:genetics / Q000378:metabolism*; D051880:Receptors, Notch / Q000378:metabolism*; D015398:Signal Transduction; D000071756:Soluble Guanylyl Cyclase
chemical_list: C000605664:GUCY1B1 protein, human; C499374:NOTCH3 protein, human; D000071656:Receptor, Notch3; D018160:Receptors, Cytoplasmic and Nuclear; D051880:Receptors, Notch; D009569:Nitric Oxide; D006162:Guanylate Cyclase; D000071756:Soluble Guanylyl Cyclase
keywords: 1H-[1,2,4]Oxadiazolo[4,3-a]quinoxalin-1-one; 8-Br-cGMP; 8-Bromoguanosine 3′,5′-cyclic monophosphate; DAPT; EIA; GSNO; GUCY1B3; IOSE; N-[N-(3,5-Difluorophenacetyl-L-alanyl)]-S-phenylglycine t-Butyl Ester; NICD; NO; Nitric oxide; Notch; Notch intracellular domain; ODQ; Ovarian cancer; PKG; Quantitative Reverse Transcription-Polymerase Chain Reaction; S-Nitrosoglutathione; Soluble guanylyl cyclase; VASP; cGMP; cGMP-dependent protein kinases; enzyme immunoassay; guanosine 3′,5′-cyclic monophosphate; immortalized ovarian surface epithelial; nitric oxide; qRT-PCR; sGC; soluble guanylyl cyclase; vasodilator-stimulated phosphoprotein