VIP potentiates retinoic-acid effect on tissue transglutaminase activity in human neuroblastoma, the SK-N-SH cells (original) (raw)
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FEBS Letters, 1989
Retinoic acid (RA) induces partial differentiation of neuroblastoma (NB) cells in vitro. In the human NB line, SH-SY5Y (a neuroblastic subelone of SK-N-SH), RA was previously shown to enhance the stimulatory (PGE1) and inhibitory (opioid) regulation of adenylyl cyclas¢. Since these cells are also sensitive to cAMP stimulation by vasoactive intestinal peptide (VIP), we have tested the effects of RA on VIP receptor expression and function. Pretreatment of SH-SY5Y cells with 10/~M RA over 6 days dramatically increased VIP receptor number from ~ 3 000 to ~ 70 000 sites per cell and enhanced threefold the cAMP accumulation after external VIP addition, while VIP immunoreactive content in the cells increased 2-3-fold. In the light of the recently proposed autocrine function of VIP in this cell lineage, the strong enhancement of the VIP system may contribute to the differentiation effects of RA. Vasoactive intestinal peptide; Vasoactive intestinal peptide receptor; cyclic AMP stimulation; Retinoic acid; Neuroblastoma differentiation; (SH-SY5Y human neuroblastoma cell)
Peptides, 1997
acid regulation of the VIP and PACAP autocrine ligand and receptor system in human neuroblastoma cell lines. PEPTIDES 18(6) [835][836][837][838][839][840][841] 1997.-Neuroendocrine tumors, neuroblastoma in particular, commonly express the neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP) and their receptors. Retinoic acid (RA) has been shown to induce differentiation of neuroblastoma cell lines, possibly by augmenting or interfering with neuropeptide autocrine loops. We sought to determine which receptor gene subtypes are expressed in selected human neuroblastoma cell lines (SH-SY5Y, IMR-32, and LA-N-5), and the effect of RA on the VIP/PACAP ligand/receptor system. Expression of both PACAP 1 and VIP 1 /PACAP 2 receptor genes was detected by Northern analysis, which characteristically encode Type I (PACAP-preferring), and Type II (bivalent VIP/PACAP) receptors, respectively. Binding experiments carried out on IMR-32 cells, using 125 I VIP and 125 I PACAP-27 as tracers, corroborated that both receptor subtypes were expressed. In contrast to RA upregulation of VIP binding (confirmed here in IMR-32 cells), levels of both receptor mRNAs were reduced after RA treatment. VIP mRNA in each cell line was increased by RA, whereas PACAP mRNA, detected in IMR-32 cells only, was reduced. The studies indicate that several components of the VIP/PACAP autocrine system are regulated in neuroblastoma cell lines during RA differentiation. ᭧ 1997 Elsevier Science Inc.
Peptides, 1997
docrine tumors, neuroblastoma in particular, commonly express the neuropeptides vasoactive intestinal peptide (VIP) and pituitary adenylate cyclase activating peptide (PACAP) and their receptors. Retinoic acid (RA) has been shown to induce differentiation of neuroblastoma cell lines, possibly by augmenting or interfering with neuropeptide autocrine loops. We sought to determine which receptor gene subtypes are expressed in selected human neuroblastoma cell lines (SH-SY5Y, IMR-32, and LA-N-5), and the effect of RA on the VIP/PACAP ligand/receptor system. Expression of both PACAP 1 and VIP 1 /PACAP 2 receptor genes was detected by Northern analysis, which characteristically encode Type I (PACAP-preferring), and Type II (bivalent VIP/PACAP) receptors, respectively. Binding experiments carried out on IMR-32 cells, using 125 I VIP and 125 I PACAP-27 as tracers, corroborated that both receptor subtypes were expressed. In contrast to RA upregulation of VIP binding (confirmed here in IMR-32 cells), levels of both receptor mRNAs were reduced after RA treatment. VIP mRNA in each cell line was increased by RA, whereas PACAP mRNA, detected in IMR-32 cells only, was reduced. The studies indicate that several components of the VIP/PACAP autocrine system are regulated in neuroblastoma cell lines during RA differentiation.
Neuroscience Letters, 1992
Neuronal differentiation was induced in cultures of the human neuroblastoma cell line subclone SH-SY5Y by' 14-day treatment with dibutyryl cAMP (dBcAMPI, retmmc amd, and phorbol 12-myristate 13-acetate (PMA) An appro'~lmate 4-lk~ld increase m vasoactlve intestinal peptlde (VIP) mRNA concentrauon was observed after dffferentmtlon with retmolc acid, whereas no change in V1P mRNA concentratmn was observed after differentiation with dBcAMP or PMA A short-term treatment of cells with PMA did however result m a 5-fold transient increase m VIP mRNA: prior dffferentmtmn with retinmc acid or dBcAMP &tarnished this effect. Observed increases m VIP mRNA were m all cases accompamed by increases in VIP lmmunoreactwlty. Remarkably, however, long-term treatment of cells with dBcAMR whmh caused no change in mRNA levels, resulted m a s~x-fold increase in VIP immunoreactivlty. Acute 136-h) treatment with carbachol also caused an increase m VIP lmmunoreactwlty (about 2-tMd, and blocked by atropine) ~lthout an increase an VIP mRNA level Yhu~, a quantitative change m gene transcnpuon or mRNA staNhty appears not to be a prereqmslte t\~r increased VIP expression, indicating that regulation can occur at translatmnal or post-tram, latlonal steps
Regulatory Peptides, 2002
We hypothesize that vasoactive intestinal peptide (VIP) promotes neural crest differentiation through VIP receptor type I (VPAC1). In order to test this hypothesis, SKNSH neuroblastoma cells were stably transfected with VPAC1 and receptor expression was verified by real-time RT-PCR. Overexpression of VPAC1 in SKNSH cells resulted in upregulation of endogenous retinoic acid receptor expression for both RARa and RXRa with no change in expression of RARh. Transfected cells demonstrated high affinity binding of VIP (K D = 0.2 nM) and VIP-mediated stimulation of adenylate cyclase and a shift in cell cycle kinetics to a near triploid DNA index in G1. SKNSH/VPAC1 cells treated with VIP were observed to express a more differentiated phenotype compared to wild type cells as characterized by an increase in tissue transglutaminase II and a decrease in bcl-2 immunostaining. VIP-induced differentiation effects were potentiated by retinoic acid. This differentiation resulted in decreased proliferative potential in a xenograft model. Whereas, wild type SKNSH cells induced tumor growth in 100% of nude mice within 13 days post-injection, SKNSH transfected with VPAC1 demonstrated no tumor formation in xenografts followed for 6 months. Taken together, these data support the hypothesis that VIP modulation of neural crest differentiation is mediated via VPAC1 and that high expression of VPAC1 induces differentiation in and decreases tumorigenicity of neuroblastoma cells. D
Regulatory Peptides, 2002
We hypothesize that vasoactive intestinal peptide (VIP) promotes neural crest differentiation through VIP receptor type I (VPAC1). In order to test this hypothesis, SKNSH neuroblastoma cells were stably transfected with VPAC1 and receptor expression was verified by real-time RT-PCR. Overexpression of VPAC1 in SKNSH cells resulted in upregulation of endogenous retinoic acid receptor expression for both RARa and RXRa with no change in expression of RARh. Transfected cells demonstrated high affinity binding of VIP (K D = 0.2 nM) and VIP-mediated stimulation of adenylate cyclase and a shift in cell cycle kinetics to a near triploid DNA index in G1. SKNSH/VPAC1 cells treated with VIP were observed to express a more differentiated phenotype compared to wild type cells as characterized by an increase in tissue transglutaminase II and a decrease in bcl-2 immunostaining. VIP-induced differentiation effects were potentiated by retinoic acid. This differentiation resulted in decreased proliferative potential in a xenograft model. Whereas, wild type SKNSH cells induced tumor growth in 100% of nude mice within 13 days post-injection, SKNSH transfected with VPAC1 demonstrated no tumor formation in xenografts followed for 6 months. Taken together, these data support the hypothesis that VIP modulation of neural crest differentiation is mediated via VPAC1 and that high expression of VPAC1 induces differentiation in and decreases tumorigenicity of neuroblastoma cells. D
Journal of Biological Chemistry, 2010
We have demonstrated previously that the Myc oncoprotein blocks cancer cell differentiation by forming a novel transcriptional repressor complex with histone deacetylase and inhibiting gene transcription of tissue transglutaminase (TG2). Moreover, induction of TG2 gene transcription and transamidase activity is essential for the differentiating effects of retinoids in cancer cells. Here, we show that two structurally distinct TG2 protein isoforms, the full-length (TG2-L) and the short form (TG2-S), exert opposing effects on cell differentiation. Repression of TG2-L with small interfering RNA, which did not affect TG2-S expression, induced dramatic neuritic differentiation in neuroblastoma cells. In contrast, overexpression of TG2-S or a GTP-binding-deficient mutant of TG2-L (R580A), both of which lack the GTP-binding Arg-580 residue, induced neuroblastoma cell differentiation, which was blocked by an inhibitor of transamidase activity. Whereas N-Myc repressed and retinoid activated both TG2 isoforms, repression of TG2-L, but not simultaneous repression of TG2-L and TG2-S, enhanced neuroblastoma cell differentiation due to N-Myc small interfering RNA or retinoid. Moreover, suppression of vasoactive intestinal peptide (VIP) expression alone induced neuroblastoma cell differentiation, and VIP was up-regulated by TG2-L, but not TG2-S. Taken together, our data indicate that TG2-L and TG2-S exert opposite effects on cell differentiation due to differences in GTP binding and modulation of VIP gene transcription. Our findings highlight the potential importance of repressing the GTP binding activity of TG2-L or activating the transamidase activity of TG2-L or TG2-S for the treatment of neuroblastoma, and possibly also other Myc-induced malignancies, and for enhancing retinoid anticancer effects.