Effects of epidermal growth factor on the [3H]-thymidine uptake in the SK-N-SH and SH-SY5Y human neuroblastoma cell lines

Motta, Luiz Augusto Casulari Roxo da; Galli, Paola; Piva, Flavio; Maggi, Roberto

doi:10.1590/S0004-282X1997000300016

Abstracts

The studies on the factors that regulate the biology of the neuroblastoma cell lines may offer important information on the development of tissues and organs that derive from the neural crest. In the present paper we study the action of epidermal growth factor (EGF) on two human neuroblastoma cell lines: SK-N-SH which is composed at least of two cellular phenotypes (neuroblastic and melanocytic/glial cells), and its pure neuroblastic subclone SH-SY5Y. The results show that EGF (10 ng/ml) significantly stimulates the incorporation of [3H]-thymidine in the SK-N-SH cells only in the presence of fetal bovine serum (FBS) (control = 58285 ± 9327 cpm; EGF =75523 ± 4457; p<0.05). Such effect is not observed in the presence of a chemical defined medium, that is, in the absence of FBS (control = 100997 ± 4375; EGF = 95268 ± 4683; NS). In the SH-SY5Y cells the EGF does not modify the incorporation of [3H]thymidine either in the presence of 10% of BFS (control = 113838 ± 6978; EGF = 119434 ± 9441; NS) or in its absence (control = 46197 ± 3335; EGF = 44472 ± 3493; NS). The results here reported suggest that: a) EGF may affect the proliferation of cells derived from a primary human neuroblastoma; b) this is evident by the EGF-induced increase of [3H]-thymidine incorporation in SK-N-SH cells; c) it is required the presence of other growth factors, present in the FBS, for the mitogenic action to be accomplished; d) since the pure neuroblastic SH-SY5Y cell line are refractory to the EGF, the effects observed in SK-N-SH cells probably occur on the melanocytic/glial cell subpopulation.

epidermal growth factor; cells cultured; neuroblastoma; growth factors

Os estudos dos fatores que regulam a biologia das linhas celulares de neuroblastoma podem oferecer importantes informações sobre o desenvolvimento de tecidos e de órgãos que derivam da crista neural. No presente estudo analisamos a ação do fator de crescimento epidérmico (EGF) sobre duas linhas celulares de neuroblastoma humano: a linha SK-N-SH que é constituída de dois fenotipos celulares (neuroblástico e melanocítico/glial), e o seu subclone puro neuroblástico SH-SY5Y. Os resultados mostram que o EGF (10ng/ml) estimula significativamente a incorporação de [3H]-timidina na linha SK-N-SH somente na presença de 5% de soro fetal bovino (SFB) (controle = 58285 ± 9327 cpm; EGF = 75523 ± 4457; p<0,05). Tal efeito não é observado na presença de meio definido químico, isto é, na ausência de SFB (controle = 100997 ± 4375; EGF 95268 ± 4683; NS). Nas células SH-SY5Y o EGF não modificou a incorporação de [3H]-timidina nem na presença de 10% SFB (controle = 113838 ± 6978; EGF=119434 ± 9441; NS), nem na sua ausência (controle = 46197 ± 3335; EGF = 44472 ± 3493; NS). Os resultados aqui apresentados sugerem que: a) o EGF pode interferir na proliferação de células derivadas primariamente de um neuroblastoma humano; b) isso é evidente pelo aumento da incorporação de [3H] timidina pelas células SK-N-SH tratadas com EGF; c) é necessário a presença de outros fatores de crescimento, presentes no SFB, para que exerça esta ação mitógena; d) desde que a linha celular neuroblástica pura é refratária ao EGF, os efeitos descritos nas células SK-N-SH, provavelmente, ocorrem nas subpopulações de células melanocíticas/gliais.

fator de crescimento epidérmico; cultura de células; neuroblastoma; fatores de crescimento

Effects of epidermal growth factor on the [3H]-thymidine uptake in the SK-N-SH and SH-SY5Y human neuroblastoma cell lines

Efeitos do fator de crescimento epidérmico sobre a captação de [3H]-timidina nas linhas celulares de neuroblastoma humano SK-N-SH e SH-SY5Y

Luiz Augusto Casulari Roxo da Motta^I; Paola Galli^II; Flavio Piva^II; Roberto Maggi^II

^INeurosurgery Unit, Hospital de Base do Distrito Federal (Dr. Miguel Farage Filho, Director) and Gynecology and Obstetrics Department, Fundação Universidade de Brasília (Prof. Dr. A.A. Cantuária, Chairman)

^IIInstituto di Endocrinologia, Università degli Studi Milano, Italy

ABSTRACT

The studies on the factors that regulate the biology of the neuroblastoma cell lines may offer important information on the development of tissues and organs that derive from the neural crest. In the present paper we study the action of epidermal growth factor (EGF) on two human neuroblastoma cell lines: SK-N-SH which is composed at least of two cellular phenotypes (neuroblastic and melanocytic/glial cells), and its pure neuroblastic subclone SH-SY5Y. The results show that EGF (10 ng/ml) significantly stimulates the incorporation of [3H]-thymidine in the SK-N-SH cells only in the presence of fetal bovine serum (FBS) (control = 58285 ± 9327 cpm; EGF =75523 ± 4457; p<0.05). Such effect is not observed in the presence of a chemical defined medium, that is, in the absence of FBS (control = 100997 ± 4375; EGF = 95268 ± 4683; NS). In the SH-SY5Y cells the EGF does not modify the incorporation of [3H]thymidine either in the presence of 10% of BFS (control = 113838 ± 6978; EGF = 119434 ± 9441; NS) or in its absence (control = 46197 ± 3335; EGF = 44472 ± 3493; NS). The results here reported suggest that: a) EGF may affect the proliferation of cells derived from a primary human neuroblastoma; b) this is evident by the EGF-induced increase of [3H]-thymidine incorporation in SK-N-SH cells; c) it is required the presence of other growth factors, present in the FBS, for the mitogenic action to be accomplished; d) since the pure neuroblastic SH-SY5Y cell line are refractory to the EGF, the effects observed in SK-N-SH cells probably occur on the melanocytic/glial cell subpopulation.

Key words: epidermal growth factor, cells cultured, neuroblastoma, growth factors.

RESUMO

Os estudos dos fatores que regulam a biologia das linhas celulares de neuroblastoma podem oferecer importantes informações sobre o desenvolvimento de tecidos e de órgãos que derivam da crista neural. No presente estudo analisamos a ação do fator de crescimento epidérmico (EGF) sobre duas linhas celulares de neuroblastoma humano: a linha SK-N-SH que é constituída de dois fenotipos celulares (neuroblástico e melanocítico/glial), e o seu subclone puro neuroblástico SH-SY5Y. Os resultados mostram que o EGF (10ng/ml) estimula significativamente a incorporação de [3H]-timidina na linha SK-N-SH somente na presença de 5% de soro fetal bovino (SFB) (controle = 58285 ± 9327 cpm; EGF = 75523 ± 4457; p<0,05). Tal efeito não é observado na presença de meio definido químico, isto é, na ausência de SFB (controle = 100997 ± 4375; EGF 95268 ± 4683; NS). Nas células SH-SY5Y o EGF não modificou a incorporação de [3H]-timidina nem na presença de 10% SFB (controle = 113838 ± 6978; EGF=119434 ± 9441; NS), nem na sua ausência (controle = 46197 ± 3335; EGF = 44472 ± 3493; NS). Os resultados aqui apresentados sugerem que: a) o EGF pode interferir na proliferação de células derivadas primariamente de um neuroblastoma humano; b) isso é evidente pelo aumento da incorporação de [3H] timidina pelas células SK-N-SH tratadas com EGF; c) é necessário a presença de outros fatores de crescimento, presentes no SFB, para que exerça esta ação mitógena; d) desde que a linha celular neuroblástica pura é refratária ao EGF, os efeitos descritos nas células SK-N-SH, provavelmente, ocorrem nas subpopulações de células melanocíticas/gliais.

Palavras-chaves: fator de crescimento epidérmico, cultura de células, neuroblastoma, fatores de crescimento.

Texto completo disponível apenas em PDF.

Full text available only in PDF format.

Aceite: 4-março-1997.

Dr. Luiz Augusto Casulari Roxo da Morta - Unidade de Neurocirurgia, Hospital de Base do Distrito Federal -SMHS Q101 - 70335-900 Brasília DF - Brasil. Email: lmotta@fhdf.gov.br

This research has been perfomed at the Istituto di Endocrinologia, Università degli Studi di Milano, Via G. Balzaretti 9 - 20133 Milan, Italy.

1. Anchon RM, Reh TA, Angello J, Balliet A, Walker M. EGF and TGF-alfa stimulate retinal neuroepithelial cell proliferation in vitro. Neuron 1991;6:923-936.
2. Azar CG, Scavarda NJ, Reynolds CP, Brodeur GM. Multiple defects of the nerve growth factor receptor in human neuroblastomas. Cell Growth & Differentiation 1990;1:421-428.
3. Biedler JL, Helson L, Spengler BA. Morphology and growth, tumorigenicity, and cytogenetics of human neuroblastoma cells in continuous culture. Cancer Res 1973;33:2643-2652.
4. Biedler JL, Rozen MG, El-Badry O, Meyers MB, Melera PW, Ross RA, Spengler BA. Growth stage-related synthesis and secretion of proteins by human neuroblastoma cells and their variants. In Evans AE, D' Angio GJ, Knudson AG, Seeger RC (eds), Advances in neuroblastoma research. New York: Alan R. Liss 1985;2:209-221.
5. Biedler JL, Spengler BA, Chang T-d, Ross RA. Transdifferentiation of human neuroblastoma cells results in coordinate loss of neuronal and malignant properties. In Evans AE, D'Angio GJ, Knudson AG, Seeger RC (eds). Advances in neuroblastoma research. New York: Alan R. Liss 1985;2:265-276.
6. Birren SJ, Anderson DJ. A v-myc-immortalized sympathoadrenal progenitor cell line in which neuronal differentiation is initiated by FGF but not NGF. Neuron 1990;4:189-201.
7. Brown AB, Carpenter G. Acute regulation of the epidermal growth factor receptor in response to nerve growth factor. J Neurochem 1991;57:1740-1749.
8. Carpenter G, Cohen S. Epidermal growth factor. Annu Rev Biochem 1979:48:193-216.
9. Ciccarone V, Spengler BA, Meyers MB, Biedler JL, Ross RA. Phenotypic diversification in human neuroblastoma cells: expression of distinct neural crest lineages. Cancer Res 1989;49:219-225.
10. Cestelli A, Savettieri G, Salemi G, Di Liegro I. Neuronal cell cultures: a tool for investigations in developmental neurobiology. Neurochem Res 1992;17:1163-1180.
11. Cooper MJ, Hutchins GM, Cohen PS, Helman U, Mennie RJ, Israel MA. Human neuroblastoma tumor cell lines correspond to the arrested differentiation of chromaffin adrenal medullary neuroblasts. Cell Growth & Differentiation 1989;3:149-159.
12. Doupe AJ, Landis SC, Patterson PH. Environmental influences in the development of neural crest derivatives: glucocorticoids, growth factors, and chromaffin cell plasticity. J Neurosci 1985;5:2119-2142.
13. Doupe AJ, Patterson PH, Landis SC. Small intensely fluorescent cells in culture: role of glucocorticoids and growth factors in their development and interconversions with other neural crest derivatives. J Neurosci 1985;5:2143-2160.
14. Eidne KA, Flamagan CA, Harris NS, Millar RP. Gonadotropin-releasing hormone (GnRH) binding sites in human breast cancer cell lines and inhibitory effects of GnRH antagonists. J Clin Endocrinol Metab 1987;64:425-432.
15. Erickson CA, Turley EA. The effects of EGF on neural crest cells in tissue culture. Exp Cell Res 1987;169:267-279.
16. Fisher DA, Lakshmanan J. Metabolism and effects of epidermal growth factor and related growth factors in mammals. Endocr Rev 1990;11:418-442.
17. Goustin AS, Leof EB, Shipley GD, Moses HL. Growth factors and cancer. Cancer Res 1986;46:1015-1029.
18. Grisoni R. I tumori del sistema nervoso periférico e vegetativo. In Bucalossi & Veronesi (eds). Trattato di oncologia clinica. Milano: Casa Editrice Ambrosiana 1973;3:2407-2422.
19. Huff K. End D, Guroff G. Nerve growth factor-induced alteration in the response of PCI 2 pheochromocytoma cells to epidermal growth factor. J Cell Biol 1981;88:189-198.
20. Kenigsberg RL, Mazzoni IE, Collier B, Cuello AC. Epidermal growth factor affects both glia and cholinergic neurons in septal cell cultures. Neuroscience 1992;50:85-97.
21. Lambert DG, Ghataorre AS, Nahorski SR. Muscarinic receptor binding characteristics of a human neuroblastoma SK-N-SH and its clones SH-SY5Y and SH-EPI. Eur J Pharmacol 1989;165:71-77.
22. Le Douarin NM, Ziller C, Couly GF. Patterning of neural crest derivatives in the avian embryo: in vivo and in vitro studies. Dev Biol 1993;159:24-48.
23. Leventhal PS, Randolph AE, Vesbit TE, Schenone A, Windebank A, Feldman EL. Insulin like growth factor II as a paracrine growth factor in human neuroblastoma cells. Exper Cell Res 1995;221:179-186.
24. Levin ER, Frank HJ. Natriuretic peptides inhibit rat astroglial proliferation: mediation by C receptor. Am J Physiol 1991;261:R453-457
25. Ma YJ, Junier M-P, Costa ME, Ojeda SR. Transforming growth factor-alfa gene expression in the hypothalamus is developmentally regulated and linked to sexual maturation. Neuron 1992;9:657-670.
26. May JV, Bridge AJ, Gotcher ED, Gangrade BK. The regulation of porcine theca cell proliferation in vitro: synergistic actions of epidermal growth factor and platelet-derived growth factor. Endocrinology 1992;131.689-697.
27. Meyers MB, Shen WP, Spengler BA, Ciccarone V, O'Brien JP, Donner DB, Furth ME, Biedler JL. Increased epidermal growth factor receptor in multidrug-resistant human neuroblastoma cells. J Cell Biochem 1988;38:87-97.
28. Morton AJ, Emson PC. Expression of calbindin D-28K-like immunoreactivity in human SK-N-SH and SH-SY5Y neuroblastoma cells. Brain Res 1990;533:161-164.
29. Mummery CL, van der Saag PT, de Laat SW. Loss of EGF binding and cation transport response during differentiation of mouse neuroblastoma cells. J Cell Biochem 1983;21:63-75.
30. Mutoh T, Rudkin BB, Koizumi S, Guroff G. Nerve growth factor, a differentiating agent, and epidermal growth factor, a mitogen, increase the activities of different S6 kinases in PC 12 cells. J Biol Chem 1988;263:15853-15856.
31. Pahlman S, Johansson I, Westermark B, Nister M. Platelet-derived growth factor potentiates phorbol ester-induced neuronal differentiation of human neuroblastoma cells. Cell Growth & Differentiation 1992;3:783-790.
32. Pahlman S, Mamaeva S, Meyerson G, Mattsson MEK, Bjelfman Ortoft E, Hammerling U. Human neuroblastoma cells in culture: a model for neuronal cell differentiation and function. Acta Physiol Scand 1990;140(Suppl 592):25-37.
33. Rabinovsky ED, Le WD, McManaman JL. Differential effects of neurotrophic factors on neurotransmitter development in the IMR-32 human neuroblastoma cell line. J Neurosci 1992;12:171-179.
34. Reddy URR, Venkatakrishnan G, Roy AK, Chen J, Hardy M, Mavilio F, Rovera G, Pleasure D, Ross AH. Characterization of two neuroblastoma cell lines expressing recombinant nerve growth factor receptors. J Neurochem 1991;56:67-74.
35. Rosenberg RN. Neuroblastoma and glioma cell cultures in studies of neurologic functions: the clinician's Rosetta Stone? Neurology 1977;27:105-108.
36. Ross RA, Biedler JL. Presence and regulation of tyrosinase activity in human neuroblastoma cell variants in vitro. Cancer Res 1985;45:1628-1632.
37. Ross RA, Spengler B A, Biedler JL. Coordinate morphological and biochemical interconversion of human neuroblastoma cells. JNCI 1983;71:741-747.
38. Stemple DL, Anderson DJ. Lineage diversification of the neural crest: in vitro investigations. Dev Biol 1993; 159:12-23.
39. Stemple DL, Mahanthappa NK, Anderson DJ. Basic FGF induces neuronal differentiation, cell division, and NGF dependence in chromaffin cells: a sequence of events in sympathetic development. Neuron 1988;1:517-525.
40. Stoscheck CM, King LE Jr. Role of epidermal growth factor in carcinogenesis. Cancer Res 1986;46:1030-1037.
41. Thiele CJ, McKeon C, Triche TJ, Ross RA, Reynolds CP, Israel MA. Differential protooncogene expression characterizes histopathologically indistinguishable tumors of the peripheral nervous system. J Clin Invest 1987;80:804-811.
42. Westermark B. Density dependent proliferation of human glia cells stimulated by epidermal growth factor. Biochem Biophys Res Commun 1976;69:304-310.
43. Yu VC, Richards ML, Sadeè W. A human neuroblastoma cell line expresses mu and delta opioid receptor sites. J Biol Chem 1986;261:1065-1070.

Publication Dates

Publication in this collection
18 Oct 2010
Date of issue
Sept 1997

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

[1] 1. Anchon RM, Reh TA, Angello J, Balliet A, Walker M. EGF and TGF-alfa stimulate retinal neuroepithelial cell proliferation in vitro. Neuron 1991;6:923-936.

[2] 2. Azar CG, Scavarda NJ, Reynolds CP, Brodeur GM. Multiple defects of the nerve growth factor receptor in human neuroblastomas. Cell Growth & Differentiation 1990;1:421-428.

[3] 3. Biedler JL, Helson L, Spengler BA. Morphology and growth, tumorigenicity, and cytogenetics of human neuroblastoma cells in continuous culture. Cancer Res 1973;33:2643-2652.

[4] 4. Biedler JL, Rozen MG, El-Badry O, Meyers MB, Melera PW, Ross RA, Spengler BA. Growth stage-related synthesis and secretion of proteins by human neuroblastoma cells and their variants. In Evans AE, D' Angio GJ, Knudson AG, Seeger RC (eds), Advances in neuroblastoma research. New York: Alan R. Liss 1985;2:209-221.

[5] 5. Biedler JL, Spengler BA, Chang T-d, Ross RA. Transdifferentiation of human neuroblastoma cells results in coordinate loss of neuronal and malignant properties. In Evans AE, D'Angio GJ, Knudson AG, Seeger RC (eds). Advances in neuroblastoma research. New York: Alan R. Liss 1985;2:265-276.

[6] 6. Birren SJ, Anderson DJ. A v-myc-immortalized sympathoadrenal progenitor cell line in which neuronal differentiation is initiated by FGF but not NGF. Neuron 1990;4:189-201.

[7] 7. Brown AB, Carpenter G. Acute regulation of the epidermal growth factor receptor in response to nerve growth factor. J Neurochem 1991;57:1740-1749.

[8] 8. Carpenter G, Cohen S. Epidermal growth factor. Annu Rev Biochem 1979:48:193-216.

[9] 9. Ciccarone V, Spengler BA, Meyers MB, Biedler JL, Ross RA. Phenotypic diversification in human neuroblastoma cells: expression of distinct neural crest lineages. Cancer Res 1989;49:219-225.

[10] 10. Cestelli A, Savettieri G, Salemi G, Di Liegro I. Neuronal cell cultures: a tool for investigations in developmental neurobiology. Neurochem Res 1992;17:1163-1180.

[11] 11. Cooper MJ, Hutchins GM, Cohen PS, Helman U, Mennie RJ, Israel MA. Human neuroblastoma tumor cell lines correspond to the arrested differentiation of chromaffin adrenal medullary neuroblasts. Cell Growth & Differentiation 1989;3:149-159.

[12] 12. Doupe AJ, Landis SC, Patterson PH. Environmental influences in the development of neural crest derivatives: glucocorticoids, growth factors, and chromaffin cell plasticity. J Neurosci 1985;5:2119-2142.

[13] 13. Doupe AJ, Patterson PH, Landis SC. Small intensely fluorescent cells in culture: role of glucocorticoids and growth factors in their development and interconversions with other neural crest derivatives. J Neurosci 1985;5:2143-2160.

[14] 14. Eidne KA, Flamagan CA, Harris NS, Millar RP. Gonadotropin-releasing hormone (GnRH) binding sites in human breast cancer cell lines and inhibitory effects of GnRH antagonists. J Clin Endocrinol Metab 1987;64:425-432.

[15] 15. Erickson CA, Turley EA. The effects of EGF on neural crest cells in tissue culture. Exp Cell Res 1987;169:267-279.

[16] 16. Fisher DA, Lakshmanan J. Metabolism and effects of epidermal growth factor and related growth factors in mammals. Endocr Rev 1990;11:418-442.

[17] 17. Goustin AS, Leof EB, Shipley GD, Moses HL. Growth factors and cancer. Cancer Res 1986;46:1015-1029.

[18] 18. Grisoni R. I tumori del sistema nervoso periférico e vegetativo. In Bucalossi & Veronesi (eds). Trattato di oncologia clinica. Milano: Casa Editrice Ambrosiana 1973;3:2407-2422.

[19] 19. Huff K. End D, Guroff G. Nerve growth factor-induced alteration in the response of PCI 2 pheochromocytoma cells to epidermal growth factor. J Cell Biol 1981;88:189-198.

[20] 20. Kenigsberg RL, Mazzoni IE, Collier B, Cuello AC. Epidermal growth factor affects both glia and cholinergic neurons in septal cell cultures. Neuroscience 1992;50:85-97.

[21] 21. Lambert DG, Ghataorre AS, Nahorski SR. Muscarinic receptor binding characteristics of a human neuroblastoma SK-N-SH and its clones SH-SY5Y and SH-EPI. Eur J Pharmacol 1989;165:71-77.

[22] 22. Le Douarin NM, Ziller C, Couly GF. Patterning of neural crest derivatives in the avian embryo: in vivo and in vitro studies. Dev Biol 1993;159:24-48.

[23] 23. Leventhal PS, Randolph AE, Vesbit TE, Schenone A, Windebank A, Feldman EL. Insulin like growth factor II as a paracrine growth factor in human neuroblastoma cells. Exper Cell Res 1995;221:179-186.

[24] 24. Levin ER, Frank HJ. Natriuretic peptides inhibit rat astroglial proliferation: mediation by C receptor. Am J Physiol 1991;261:R453-457

[25] 25. Ma YJ, Junier M-P, Costa ME, Ojeda SR. Transforming growth factor-alfa gene expression in the hypothalamus is developmentally regulated and linked to sexual maturation. Neuron 1992;9:657-670.

[26] 26. May JV, Bridge AJ, Gotcher ED, Gangrade BK. The regulation of porcine theca cell proliferation in vitro: synergistic actions of epidermal growth factor and platelet-derived growth factor. Endocrinology 1992;131.689-697.

[27] 27. Meyers MB, Shen WP, Spengler BA, Ciccarone V, O'Brien JP, Donner DB, Furth ME, Biedler JL. Increased epidermal growth factor receptor in multidrug-resistant human neuroblastoma cells. J Cell Biochem 1988;38:87-97.

[28] 28. Morton AJ, Emson PC. Expression of calbindin D-28K-like immunoreactivity in human SK-N-SH and SH-SY5Y neuroblastoma cells. Brain Res 1990;533:161-164.

[29] 29. Mummery CL, van der Saag PT, de Laat SW. Loss of EGF binding and cation transport response during differentiation of mouse neuroblastoma cells. J Cell Biochem 1983;21:63-75.

[30] 30. Mutoh T, Rudkin BB, Koizumi S, Guroff G. Nerve growth factor, a differentiating agent, and epidermal growth factor, a mitogen, increase the activities of different S6 kinases in PC 12 cells. J Biol Chem 1988;263:15853-15856.

[31] 31. Pahlman S, Johansson I, Westermark B, Nister M. Platelet-derived growth factor potentiates phorbol ester-induced neuronal differentiation of human neuroblastoma cells. Cell Growth & Differentiation 1992;3:783-790.

[32] 32. Pahlman S, Mamaeva S, Meyerson G, Mattsson MEK, Bjelfman Ortoft E, Hammerling U. Human neuroblastoma cells in culture: a model for neuronal cell differentiation and function. Acta Physiol Scand 1990;140(Suppl 592):25-37.

[33] 33. Rabinovsky ED, Le WD, McManaman JL. Differential effects of neurotrophic factors on neurotransmitter development in the IMR-32 human neuroblastoma cell line. J Neurosci 1992;12:171-179.

[34] 34. Reddy URR, Venkatakrishnan G, Roy AK, Chen J, Hardy M, Mavilio F, Rovera G, Pleasure D, Ross AH. Characterization of two neuroblastoma cell lines expressing recombinant nerve growth factor receptors. J Neurochem 1991;56:67-74.

[35] 35. Rosenberg RN. Neuroblastoma and glioma cell cultures in studies of neurologic functions: the clinician's Rosetta Stone? Neurology 1977;27:105-108.

[36] 36. Ross RA, Biedler JL. Presence and regulation of tyrosinase activity in human neuroblastoma cell variants in vitro. Cancer Res 1985;45:1628-1632.

[37] 37. Ross RA, Spengler B A, Biedler JL. Coordinate morphological and biochemical interconversion of human neuroblastoma cells. JNCI 1983;71:741-747.

[38] 38. Stemple DL, Anderson DJ. Lineage diversification of the neural crest: in vitro investigations. Dev Biol 1993; 159:12-23.

[39] 39. Stemple DL, Mahanthappa NK, Anderson DJ. Basic FGF induces neuronal differentiation, cell division, and NGF dependence in chromaffin cells: a sequence of events in sympathetic development. Neuron 1988;1:517-525.

[40] 40. Stoscheck CM, King LE Jr. Role of epidermal growth factor in carcinogenesis. Cancer Res 1986;46:1030-1037.

[41] 41. Thiele CJ, McKeon C, Triche TJ, Ross RA, Reynolds CP, Israel MA. Differential protooncogene expression characterizes histopathologically indistinguishable tumors of the peripheral nervous system. J Clin Invest 1987;80:804-811.

[42] 42. Westermark B. Density dependent proliferation of human glia cells stimulated by epidermal growth factor. Biochem Biophys Res Commun 1976;69:304-310.

[43] 43. Yu VC, Richards ML, Sadeè W. A human neuroblastoma cell line expresses mu and delta opioid receptor sites. J Biol Chem 1986;261:1065-1070.