title: R-RAS2 overexpression in tumors of the human central nervous system.
abstract: Malignant tumors of the central nervous system (CNS) are the 10th most frequent cause of cancer mortality. Despite the strong malignancy of some such tumors, oncogenic mutations are rarely found in classic members of the RAS family of small GTPases. This raises the question as to whether other RAS family members may be affected in CNS tumors, excessively activating RAS pathways. The RAS-related subfamily of GTPases is that which is most closely related to classical Ras and it currently contains 3 members: RRAS, RRAS2 and RRAS3. While R-RAS and R-RAS2 are expressed ubiquitously, R-RAS3 expression is restricted to the CNS. Significantly, both wild type and mutated RRAS2 (also known as TC21) are overexpressed in human carcinomas of the oral cavity, esophagus, stomach, skin and breast, as well as in lymphomas. Hence, we analyzed the expression of R-RAS2 mRNA and protein in a wide variety of human CNS tumors and we found the R-RAS2 protein to be overexpressed in all of the 90 CNS cancer samples studied, including glioblastomas, astrocytomas and oligodendrogliomas. However, R-Ras2 was more strongly expressed in low grade (World Health Organization grades I-II) rather than high grade (grades III-IV) tumors, suggesting that R-RAS2 is overexpressed in the early stages of malignancy. Indeed, R-RAS2 overexpression was evident in pre-malignant hyperplasias, both at the mRNA and protein levels. Nevertheless, such dramatic changes in expression were not evident for the other two subfamily members, which implies that RRAS2 is the main factor triggering neural transformation.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Gutierrez-Erlandsson
authors.forename: Pedro
authors.initials: P
authors.lastname: Herrero-Vidal
authors.forename: Marcos
authors.initials: M
authors.lastname: Fernandez-Alfara
authors.forename: Susana
authors.initials: S
authors.lastname: Hernandez-Garcia
authors.forename: Sandra
authors.initials: S
authors.lastname: Gonzalo-Flores
authors.forename: Alberto
authors.initials: A
authors.lastname: Mudarra-Rubio
authors.forename: Manuel
authors.initials: M
authors.lastname: Fresno
authors.affiliation: Centro de Biología Molecular Severo Ochoa, Departamento de Biología Molecular, Universidad Autónoma de Madrid, Madrid 28049, Spain. bcubelos@cbm.uam.es.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Cubelos
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001932:Brain Neoplasms / Q000378:metabolism*; D005260:Female; D015870:Gene Expression; D005910:Glioma / Q000378:metabolism*; D006801:Humans; D008297:Male; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D020559:Monomeric GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D046888:Tissue Array Analysis; D055815:Young Adult
chemical_list: D008565:Membrane Proteins; D012333:RNA, Messenger; C087360:RRAS2 protein, human; D020559:Monomeric GTP-Binding Proteins