title: Store-operated Ca(2+) entry in proliferating and retinoic acid-differentiated N- and S-type neuroblastoma cells.
abstract: Neuroblastoma cell lines are heterogeneous, comprised of at least three distinct cell phenotypes; neuroblastic N-type cells, non-neuronal substrate-adherent S-type cells and intermediate I-type cells. N- and S-type cell populations were enriched from the parental SH-SY5Y neuroblastoma cell line and induced to differentiate by the addition of retinoic acid (RA), a drug used in the treatment of neuroblastoma. N- and S-type cells were identified based on their differential expression of β-tubulin III, vimentin and Bcl-2. Store-operated Ca(2+) entry (SOCE) was then measured in proliferating and differentiated N- and S-type cell populations and the expression of STIM1, Orai1 and TRPC1, three proteins reported to play a key role in SOCE, was determined. In N-type cells the RA-induced switch from proliferation to differentiation was accompanied by a down-regulation in SOCE. STIM1 and Orai1 expression became down-regulated in differentiated cells, consistent with their respective roles as ER Ca(2+) sensor and store-operated Ca(2+) channel (SOC). TRPC1 became up-regulated suggesting that TRPC1 is not involved in SOCE, at least in differentiated N-type cells. In S-type cells SOCE remained active following the RA-induced switch from proliferation to differentiation and the expression of STIM1 and Orai1 remained unchanged. TRPC1 was not expressed in S-type cells. Our results indicate that differentiation of neuronal cells is associated with a remodelling of SOCE. Therapeutic targeting of SOCE proteins could potentially be a means of promoting neuronal differentiation in the treatment of neuroblastoma.
authors.affiliation: Institute for Cell and Molecular Biosciences, The Medical School, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
authors.forename: Natalie
authors.initials: N
authors.lastname: Bell
authors.forename: Victoria
authors.initials: V
authors.lastname: Hann
authors.forename: Christopher P F
authors.initials: CP
authors.lastname: Redfern
authors.forename: Timothy R
authors.initials: TR
authors.lastname: Cheek
mesh_terms: D000970:Antineoplastic Agents / Q000494:pharmacology; D015153:Blotting, Western; D002118:Calcium / Q000378:metabolism*; D015220:Calcium Channels / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects; D002454:Cell Differentiation / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects*; D005455:Fluorescent Antibody Technique; D006801:Humans; D017136:Ion Transport / Q000187:drug effects; D008565:Membrane Proteins / Q000378:metabolism*; D009363:Neoplasm Proteins / Q000378:metabolism*; D009447:Neuroblastoma / Q000188:drug therapy / Q000378:metabolism* / Q000473:pathology; D000071740:ORAI1 Protein; D000071737:Stromal Interaction Molecule 1; D050052:TRPC Cation Channels / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D000970:Antineoplastic Agents; D015220:Calcium Channels; D008565:Membrane Proteins; D009363:Neoplasm Proteins; D000071740:ORAI1 Protein; C510746:ORAI1 protein, human; C103530:STIM1 protein, human; D000071737:Stromal Interaction Molecule 1; D050052:TRPC Cation Channels; C096351:transient receptor potential cation channel, subfamily C, member 1; D014212:Tretinoin; D002118:Calcium