title: Calcium-regulatory proteins as modulators of chemotherapy in human neuroblastoma.
abstract: Neuroblastoma (NB) is a pediatric cancer treated with poly-chemotherapy including platinum complexes (e.g. cisplatin (CDDP), carboplatin), DNA alkylating agents, and topoisomerase I inhibitors (e.g. topotecan (TOPO)). Despite aggressive treatment, NB may become resistant to chemotherapy. We investigated whether CDDP and TOPO treatment of NB cells interacts with the expression and function of proteins involved in regulating calcium signaling. Human neuroblastoma cell lines SH-SY5Y, IMR-32 and NLF were used to investigate the effects of CDDP and TOPO on cell viability, apoptosis, calcium homeostasis, and expression of selected proteins regulating intracellular calcium concentration ([Ca2+]i). In addition, the impact of pharmacological inhibition of [Ca2+]i-regulating proteins on neuroblastoma cell survival was studied. Treatment of neuroblastoma cells with increasing concentrations of CDDP (0.1-10 μM) or TOPO (0.1 nM-1 μM) induced cytotoxicity and increased apoptosis in a concentration- and time-dependent manner. Both drugs increased [Ca2+]i over time. Treatment with CDDP or TOPO also modified mRNA expression of selected genes encoding [Ca2+]i-regulating proteins. Differentially regulated genes included S100A6, ITPR1, ITPR3, RYR1 and RYR3. With FACS and confocal laser scanning microscopy experiments we validated their differential expression at the protein level. Importantly, treatment of neuroblastoma cells with pharmacological modulators of [Ca2+]i-regulating proteins in combination with CDDP or TOPO increased cytotoxicity. Thus, our results confirm an important role of calcium signaling in the response of neuroblastoma cells to chemotherapy and suggest [Ca2+]i modulation as a promising strategy for adjunctive treatment.
authors.affiliation: Institute of Neuropathology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: Ana-Maria
authors.initials: AM
authors.lastname: Florea
authors.affiliation: Weill Cornell Medicine in Qatar, Qatar Foundation-Education City, Doha, Qatar.
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Varghese
authors.affiliation: Weill Cornell Medicine in Qatar, Qatar Foundation-Education City, Doha, Qatar.
authors.forename: Jennifer E
authors.initials: JE
authors.lastname: McCallum
authors.affiliation: Weill Cornell Medicine in Qatar, Qatar Foundation-Education City, Doha, Qatar.
authors.forename: Safa
authors.initials: S
authors.lastname: Mahgoub
authors.affiliation: Weill Cornell Medicine in Qatar, Qatar Foundation-Education City, Doha, Qatar.
authors.forename: Irfan
authors.initials: I
authors.lastname: Helmy
authors.affiliation: Weill Cornell Medicine in Qatar, Qatar Foundation-Education City, Doha, Qatar.
authors.forename: Sharon
authors.initials: S
authors.lastname: Varghese
authors.affiliation: Weill Cornell Medicine in Qatar, Qatar Foundation-Education City, Doha, Qatar.
authors.forename: Neha
authors.initials: N
authors.lastname: Gopinath
authors.affiliation: Institute of Computational Biology, Helmholtz Zentrum München, Neuherberg, Germany.
authors.forename: Steffen
authors.initials: S
authors.lastname: Sass
authors.affiliation: Institute of Computational Biology, Helmholtz Zentrum München, Neuherberg, Germany.
authors.forename: Fabian J
authors.initials: FJ
authors.lastname: Theis
authors.affiliation: Institute of Neuropathology, Heinrich Heine University Düsseldorf, Düsseldorf, Germany.
authors.forename: Guido
authors.initials: G
authors.lastname: Reifenberger
authors.affiliation: Weill Cornell Medicine in Qatar, Qatar Foundation-Education City, Doha, Qatar.
authors.forename: Dietrich
authors.initials: D
authors.lastname: Büsselberg
mesh_terms: D017209:Apoptosis; D002118:Calcium / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D002135:Calcium-Binding Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D006801:Humans; D009447:Neuroblastoma / Q000188:drug therapy* / Q000378:metabolism*; D011379:Prognosis
chemical_list: D002135:Calcium-Binding Proteins; D002118:Calcium
keywords: calcium signaling; chemotherapy; cisplatin; neuroblastoma; topotecan