ELSEVIER Biochimica et Biophysica Acta 1264 (1995) 254-256 Biochi~ic~a et Biophysica A~ta Short Sequence-Paper Cloning and sequencing of a tpr-met oncogene cDNA isolated from MNNG-transformed human XP fibroblasts l Ren6 Wicker a,*, Ali Bounacer a, Ana Gascon a, Olivier Brison b, Alain Sarasin a, Horacio G. SuArez a a C.N.R.S., lnstitut de Recherches sur le Cancer, IFC HOI, Laboratoire de G£n£tique Mol~culaire UPR 42, 7, rue Guy MOquet, BP 8, 94801 Villejuif Cedex, France lnstitut GustaL'e Roussy, Laboratoire d'Oncologie Mol£culaire, URA 1158 CNRS, 94805 Villejuif Cedex, France Received 7 July 1995; accepted 16 August 1995 Abstract A rearranged tpr-met oncogene was identified in a MNNG-transformed human Xeroderma pigmentosum (XP) cell line (ASKMN). A 2016 bp cDNA was cloned and sequenced, disclosing an ORF with a coding capacity for a 523 aa protein. The sequence of this tpr-met cDNA was very similar to that previously reported in another human MNNG-transformed cell line (MNNG-HOS). Keywords: c-met; HGF/SF; Tyrosine-kinase receptor; Oncogenic activation; Rearrangement; cDNA cloning; cDNA sequencing In 1984, Cooper et al. [1] detected a new oncogene in a human osteosarcoma cell line (MNNG-HOS) following the treatment of these cells with MNNG. This oncogene was denominated tpr-met as it was shown to result from a rearrangement between the 5' part of the tpr gene located on chr.1 and the 3' region of a gene located on chr.7, which was later identified as the c-met proto-oncogene (reviews: [2,3]). To date, the most characteristic feature of the tpr gene lies in its ability to activate, through rear- rangement, proto-oncogenes from the tyrosine kinase (TK) receptor family [4]. The c-met proto-oncogene codes for the HGF/SF transmembrane TK receptor [2,3]. In epithe- lial cells, the binding of HGF/SF to its receptor has pleiotropic effects, inducing through the TK transduction pathway(s) mitogenesis, motogenesis and morphogenesis [2,3]. Moreover, this HGF-SF/c-MET interaction may Abbreviations: XP, Xeroderma pigmentosum; MNNG, N-methyl-N'- nitro-N-nitrosoguanidine; Chr., chromosome; ORF, open reading frame; aa, amino acid(s); TK, tyrosine kinase; HGF/SF, hepatocyte growth factor/scatter factor; HMW DNA, high molecular weight DNA; C, cytidine; T, thymidine. * Corresponding author. Fax: +33 I 49583443; e-mail: wicker@ge- nome.vjf.inserm.fr. 1 The sequence data reported in this paper have been submitted to the EMBL/GenBank Data Libraries under the accession number U19348. 0167-4781/95/$09.50 © 1995 Elsevier Science B.V. All rights reserved SSDI 0167-4781(95)00174-3 lead cancer cells to be more aggressive through uncon- trolled cell proliferation, cell migration, matrix invasion and angiogenesis [2]. In MNNG-HOS cells, fusion of Tpr and Met proteins is associated with the deletion of most of c-Met, preserving only its cytoplasmic TK domain which is then constitutively activated. In naturally occurring tu- mors and in vitro cultivated cancer cells, the c-met proto- oncogene has been found amplified and/or overexpressed [2,3] while tpr-met rearrangements have been reported only by one group [5]. Indeed, in some human gastric carcinoma and precursor lesions, these authors detected tpr-met mRNAs by reverse transcription and PCR amplifi- cation of a 205 bp DNA fragment surrounding the junction point of coding sequences. Recently our group succeeded in transforming normal human XP fibroblasts by treating them with MNNG. The transformed cell line (ASKMN) retained the XP phenotype and exhibited a genomic tpr-met rearrangement very simi- lar to that previously observed in MNNG-HOS cells [6]. In Fig. 1 is shown the nucleotide sequence of a cloned ASKMN tpr-met cDNA that we have isolated. It encom- passes a large ORF coding for a Tpr-Met fusion protein as deduced from comparisons with published sequences of tpr [4], c-met [7,8] and with a partial sequence of the MNNG-HOS tpr-met cDNA [9]. The junction point be- tween tpr and met coding sequences is localized between