Activating mutations of the RET oncogene cause the inheritance of multiple endocrine neoplasia type 2 (MEN2). The RET pre-mRNA is spliced into several transcripts coding for multiple isoforms, including Ret9 and Ret51. When harboring activating mutations in the cytoplasmic region, the Ret51 protein displays a higher in vitro transforming efficiency as compared to the corresponding Ret9 isoform. We investigated whether a more transforming isoform was preferentially expressed in MEN2 tumors as compared to normal tissues or sporadic pheochromocytomas. By quantitative RNases protection assays, we measured the absolute abundance of the 3′ splice variants in pheochromocytomas and in normal tissues. The proportion of RET51 transcripts was highly dispersed between tumors and normal tissues. In familial tumors the proportion of RET51 transcripts was significantly larger (48.1%) than in sporadic tumors (36.75%). This result suggests that the preferential expression of the Ret51 protein isoform, even though moderate, is a growth advantage for MEN2 tumors.

Keywords:
Cancer, Pheochromocytoma, RET, Splicing, RNA, Adrenal medulla
1.
Takahashi M, Cooper GM: Ret transforming gene encodes a fusion protein homologous to tyrosine kinases. Mol Cell Biol 1987;7:1378–1385.
2.
Durbec PL, Marcos-Gutierrez CV, Kilkenny C, Grigoriou M, Wartiowaara K, Suvanto P, Smith D, Ponder B, Costantini F, Saarma M, Sariola H, Pachnis V: GDNF signaling through the Ret receptor tyrosine kinase. Nature 1996;381:789–793.
3.
Jing S, Weng D, Yu Y, Holst PL, Luo Y, Fang M, Tamir R, Antonio L, Hu Z, Cupples R, Louis JC, Hu S, Altrock BW, Fox GM: GDNF-induced activation of the RET protein kinase is mediated by GDNFR-a, a novel receptor for GDNF. Cell 1996;85:1113–1124.
4.
Treanor JJS, Goodman L, de Sauvage F, Stone DM, Poulsen KT, Beck CD, Gray C, Armanini MP, Pollock RA, Hefti F, Phillips HS, Goddard A, Moore MW, Buj-Bello A, Davies AM, Asai N, Takahashi M, Vandlen R, Hendersen CE, Rosenthal A: Characterization of a multicomponent receptor for GDNF. Nature 1996;382:80–83.
5.
Sanicola M, Hession C, Worley D, Carmillo P, Ehrenfels C, Walus L, Robinson S, Jaworski G, Wei H, Tizard R, Whitty A, Pepinsky RB, Cate RL: Glial cell line-derived neurotrophic factor-dependent Ret activation can be mediated by two different cell-surface accessory proteins. Proc Natl Acad Sci USA 1997;94:6238–6243.
6.
Buj-Bello A, Adu J, Pinon LG, Horton A, Thompson J, Rosenthal A, Chinchetru M, Buchman VL, Davies AM: Neurturin responsiveness requires a GPI-linked receptor and the Ret receptor tyrosine kinase. Nature 1997;12:721–724.
7.
Baloh RH, Tansey MG, Golden JP, Creedon DJ, Heuckeroth RO, Keck CL, Zimonjic DB, Popescu NC, Johnson EM Jr, Milbrandt J: TrnR2, a novel receptor that mediates neurturin and GDNF signaling through ret. Neuron 1997;18:793–802.
8.
Klein RD, Sherman D, Ho WH, Stone D, Bennett GL, Moffat B, Vandlen R, Simmons L, Gu Q, Hongo JA, Devaux B, Poulsen K, Armanini M, Nozaki C, Asai N, Goddard A, Phillips H, Henderson CE, Takahashi M, Rosenthal A: A GPI-linked protein that interacts with Ret to form a candidate neurturin receptor. Nature 1997;387:717–721.
9.
Baloh RH, Tansey MG, Lampe PA, Fahrner TJ, Enomoto H, Simburger KS, Leitner ML, Araki T, Johnson EM Jr, Milbrandt J: Artemin, a novel member of the GDNF ligand family supports peripheral and central neurons and signals through the GFRalpha3-RET receptor complex. Neuron 1998;21:1291–1302.
10.
Milbrandt J, de Sauvage FJ, Fahrner TJ, Baloh RH, Leitner ML, Tansey MG, Lampe PA, Heuckeroth RO, Kotzbauer PT, Simburger KS, Golden JP, Davies JA, Vejsada R, Kato AC, Hynes M, Sherman D, Nishimura M, Wang LC, Vandlen R, Moffat B, Klein RD, Poulsen K, Gray C, Garces A, Johnson EM Jr, et al: Persephin, a novel neurotrophic factor related to GDNF and neurturin. Neuron 1998;20:245–253.
11.
Pachnis V, Mankoo B, Costantini F: Expression of the c-ret proto-oncogene during mouse embryogenesis. Development 1993;119:1005–1017.
12.
Avantaggiato V, Dathan NA, Grieco M, Fabien N, Lazzaro D, Fusco A, Simeone A, Santoro M: Developmental expression of the RET protooncogene. Cell Growth Differ 1994;5:305–311.
13.
Schuchardt A, D’Agati V, Larsson-Blomberg L, Costantini F, Pachnis V: Defects in the kidney and enteric nervous system of mice lacking the tyrosine kinase receptor Ret. Nature 1994;367:380–383.
14.
Tsuzuki T, Takahashi M, Asai N, Iwashita T, Matsuyama M, Asai J: Spatial and temporal expression of the ret proto-oncogene product in embryonic, infant and adult rat tissues. Oncogene 1995;10:191–198.
15.
Colucci-D’Amato GL, D’Alessio A, Filliatreau G, Florio T, Di Giamberardino L, Chiappetta G, Vecchio G, Fusco A, Santoro M, de Franciscis V: Presence of physiologically stimulated RET in adult rat brain: Induction of RET expression during nerve regeneration. Cell Growth Differ 1996;7:1081–1086.
16.
Santoro M, Carlomagno F, Romano A, Bottaro DP, Dathan NA, Grieco M, Fusco A, Vecchio G, Matoskova B, Kraus MH, Di Fiore PP: Activation of RET as a dominant transforming gene by germline mutations of MEN2A and MEN2B. Science 1995;267:381–383.
17.
Asai N, Iwashita T, Matsuyama M, Takahashi M: Mechanism of activation of the ret proto-oncogene by multiple endocrine neoplasia 2A mutation. Mol Cell Biol 1995;15:1613–1619.
18.
Pasini B, Ceccherini I, Romeo G: RET mutations in human disease. Trends Genet 1996;12:138–144.
19.
Goodfellow PJ: Inherited cancers associated with the RET proto-oncogene. Curr Opin Genet Dev 1994;4:446–452.
20.
Tahira T, Ishizaka Y, Itoh F, Sugimura T, Nagao M: Characterization of ret proto-oncogene mRNAs encoding two isoforms of the protein product in a human neuroblastoma cell line. Oncogene 1990;5:97–102.
21.
Myers SM, Eng C, Ponder BA, Mulligan LM: Characterization of RET proto-oncogene 3′ splicing variants and polyadenylation sites: A novel C-terminus for RET. Oncogene 1995;11:2039–2045.
22.
Asai N, Murakami H, Iwashita T, Takahashi M: A mutation at tyrosine 1062 in MEN2A-Ret and MEN2B-Ret impairs their transforming activity and association with Shc adaptor protein. J Biol Chem 1996;271:17644–17649.
23.
Arighi E, Alberti L, Torriti F, Ghizzoni S, Rizzetti MG, Pelicci G, Pasini B, Bongarzone I, Piutti C, Pierotti MA, Borrello MG: Identification of Shc docking site on Ret tyrosine kinase. Oncogene 1997;14:773–782.
24.
Liu X, Vega QC, Decker RA, Pandey A, Worby CA, Dixon JE: Oncogenic RET receptors display different autophosphorylation sites and substrate binding specificities. J Biol Chem 1996;271:5309–5312.
25.
Lorenzo MJ, Gish GD, Houghton C, Stonehouse TJ, Pawson T, Ponder BA, Smith DP: RET alternate splicing influences the interaction of activated RET with the SH2 and PTB domains of Shc, and the SH2 domain of Grb2. Oncogene 1997;14:763–771.
26.
Borrello MG, Pelicci G, Arighi E, De Filippis L, Greco A, Bongarzone I, Rizzetti M, Pelicci PG, Pierotti MA: The oncogenic versions of the Ret and Trk tyrosine kinases bind Shc and Grb2 adaptor proteins. Oncogene 1995;9:1661–1668.
27.
Alberti L, Borrello MG, Ghizzoni S, Torriti F, Rizzetti MG, Pierotti MA: Grb2 binding to the different isoforms of Ret tyrosine kinase. Oncogene 1998;3:1079–1087.
28.
Califano D, Monaco C, de Vita G, D’Alessio A, Dathan NA, Possenti R, Vecchio G, Fusco A, Santoro M, de Franciscis V: Activated RET/PTC oncogene elicits immediate early and delayed response genes in PC12 cells. Oncogene 1995;11:107–112.
29.
Califano D, D’Alessio A, Colucci-D’Amato GL, De Vita G, Monaco C, Santelli G, Di Fiore PP, Vecchio G, Fusco A, Santoro M, de Franciscis V: A potential pathogenetic mechanism for multiple endocrine neoplasia type 2 syndromes involves ret-induced impairment of terminal differentiation of neuroepithelial cells. Proc Natl Acad Sci USA 1996;93:7933–7937.
30.
Rossel M, Pasini A, Chappuis S, Geneste O, Fournier L, Schuffenecker I, Takahashi M, van Grunsven LA, Urdiales JL, Rudkin BB, Lenoir GM, Billaud M: Distinct biological properties of two RET isoforms activated by MEN 2A and MEN 2B mutations. Oncogene 1997;14:265–275.
31.
Pasini A, Geneste O, Legrand P, Schlumberger M, Rossel M, Fournier L, Rudkin BB, Schuffenecker I, Lenoir GM, Billaud M: Oncogenic activation of RET by two distinct FMTC mutations affecting the tyrosine kinase domain. Oncogene 1997;15:393–402.
32.
Ivanchuk SM, Myers SM, Mulligan LM: Expression of RET 3′ splicing variants during human kidney development. Oncogene 1998;16:991–996.
33.
Smith DP, Eng C, Ponder BAJ: Mutations of the RET proto-oncogene in the multiple endocrine neoplasia type 2 syndromes and Hirschsprung disease. J Cell Sci Suppl 1994;18:1133–1139.
34.
Ponder BAJ, Pierotti MA: Mutations in Ret in MEN 2; in Nelkiri BD (ed): Genetic Mechanisms in Multiple Endocrine Neoplasia Type 2. Landes Bioscience, 1996, pp 21–25.
35.
Rodien P, Jeunemaitre X, Dumont C, Beldjord C, Plouin PF: Genetic alterations of the RET protooncogene in familial and sporadic pheochromocytomas. Horm Res 1997;47:263–268.
36.
Smith DP, Houghton C, Ponder BA: Germline mutation of RET codon 883 in two cases of de novo MEN 2B. Oncogene 1997;15:1213–1217.
37.
Nilsson O, Tisell LE, Jansson S, Ahlman H, Gimm O, Eng C: Adrenal and extra-adrenal pheochromocytomas in a family with germline RET V804L mutation. JAMA 1999;281:1587–1588.
38.
Lorenzo MJ, Eng C, Mulligan LM, Stonehouse TJ, Healey CS, Ponder BA, Smith DP: Multiple mRNA isoforms of the human RET proto-oncogene generated by alternate splicing. Oncogene 1995;10:1377–1383.
39.
Fu XD: The super-family of arginine/serine-rich splicing factors. RNA 1995;1:663–680.
40.
Wang J, Manley JL: Regulation of pre-mRNA splicing in metazoa. Curr Opin Genet Dev 1997;7:205–211.
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