GENOMICS 38, 247–254 (1996) ARTICLE NO. 0625 Identification of New Members of the Gas2 and Ras Families in the 22q12 Chromosome Region J ESSICA Z UCMAN-R OSSI, 1 P ATRICIA L EGOIX, AND GILLES T HOMAS INSERM U434 Ge ´ne ´tique des Tumeurs, Institut Curie, Section de Recherche, 26 rue d’Ulm, 75231 Paris Cedex 05, France Received July 12, 1996; accepted October 2, 1996 al., 1993). This disease is mainly characterized by a Monitoring of loss of heterozygosity in human tu- susceptibility to develop schwannomas and meningio- mors has suggested that the 22q12 region may contain mas (Martuza and Eldridge, 1988). The biallelic inacti- another tumor suppressor gene(s) in addition to the vation of the NF2 gene was found in at least a third of NF2 gene. The genomic sequencing of a 40-kb region sporadic meningiomas and schwannomas (Ruttledge et bounded by the EWS and BAM22 genes and containing al., 1994; Merel et al., 1995). In addition, NF2 muta- a CpG-rich region has identified two new genes in the tions have been identified in about half of the screened q12 region of chromosome 22. One of them, GAR22, is mesotheliomas and only in rare cases of sporadic epen- closely related to mouse Gas2, a gene isolated as being dymoma, colon and breast cancers, and melanomas negatively regulated by serum and growth factors and (Merel et al., 1995; Rubio et al., 1994; Slavc et al., 1995; exhibiting a high expression in growth arrested mouse Bianchi et al., 1994, 1995; Yaegashi et al., 1995). fibroblasts. The other, RRP22, belongs to the Ras su- Screenings for NF2 mutation in the other tumor types perfamily, in which it defines a new subgroup. Its ex- known to lose chromosome 22 frequently have failed to pression appears to be strictly limited to the central reveal somatic mutations (Merel et al., 1995; Slavc et nervous system. Growth-arrest-specific and Ras-re- al., 1995; Bianchi et al., 1994; Hoang-Xuan et al., 1995). lated genes are likely candidates to be involved in tu- Based on the analyses of genomic alterations in large morigenic processes. Although no mutation was ob- series of meningiomas, several authors have suggested served in a small set of meningiomas and schwanno- that other tumor suppressor genes may lie in the vicin- mas, alteration of these new genes should now be ity of the NF2 gene. BAM22, a gene that is homozy- searched in other tumors with frequent allelic losses on chromosome 22 not associated with NF2 mutation. gously deleted in a meningioma (Peyrard et al., 1994),  1996 Academic Press, Inc. and MN1, a gene that is disrupted by a breakpoint of a balanced translocation in another meningioma (Lek- anne-Deprez et al., 1995), have been proposed as such INTRODUCTION candidate tumor suppressor genes. In the two meningi- omas, searches for NF2 mutation have failed. However, Chromosome 22 monosomy and loss of heterozygos- somatic mutations in BAM22 and MN1 genes appear ity for chromosome 22 alleles have been observed in infrequent (Peyrard et al., 1994; Lekanne-Deprez et al., a large variety of human tumor types that includes 1995), an observation that should stimulate the search meningioma, schwannoma, ependymoma, pheochro- for additional genes in their vicinity. mocytoma, glioma, melanoma, mesothelioma, lung, The BAM22 and MN1 genes are located centromeric breast, and colon cancers. These cytogenetic and molec- to the NF2 gene in the 22q11–q12 region that also ular observations have been taken as indicative of the contains the EWS gene, a gene that is recurrently al- involvement of a chromosome 22 tumor suppressor tered by chromosome translocation in a variety of hu- gene in each of these tumor types. man tumors (Delattre et al., 1992; Zucman et al., Positional cloning strategies have recently identified 1993a,b; Jeon et al., 1995; Kaneko et al., 1996; Ladanyi several genes from this chromosome segment that have and Gerald, 1994; Labelle et al., 1995). In the course been proposed to have tumor suppressor activity. The of the cloning of the EWS gene we identified two neigh- best documented case is the NF2 gene, a gene that boring clusters of restriction sites for rare-cutting en- when mutated at the constitutional level causes neuro- zymes. These clusters are at least partially unmethyl- fibromatosis type 2 (Rouleau et al., 1993; Trofatter et ated at cytosine residues (Zucman et al., 1992). Such an observation is indicative of the presence of CpG islands. Sequence data from this article have been deposited with the Gen- Subsequently, a strategy based on the phylogenetic Bank/EMBL Data Libraries under Accession Nos. Y07846 – Y07848. conservation of exons revealed that these islands were 1 To whom correspondence should be addressed. Telephone: (33) located in a region bounded by the 3  ends of the EWS 1 42 34 66 84. Fax: (33) 1 42 34 66 30. E-mail: Jessica.Zucman- rossi@curie.fr. and BAM22 genes (Rouleau et al., 1993; Peyrard et al., 247 0888-7543/96 $18.00 Copyright  1996 by Academic Press, Inc. All rights of reproduction in any form reserved. AID Genom 4441 / 6r24$$$$21 11-20-96 09:24:44 gnmal AP: Genomics