title: Determination of Ras-GTP and Ras-GDP in patients with acute myelogenous leukemia (AML), myeloproliferative syndrome (MPS), juvenile myelomonocytic leukemia (JMML), acute lymphocytic leukemia (ALL), and malignant lymphoma: assessment of mutational and indirect activation.
abstract: The 21-kD protein Ras of the low-molecular-weight GTP-binding (LMWG) family plays an important role in transduction of extracellular signals. Ras functions as a 'molecular switch' in transduction of signals from the membrane receptors of many growth factors, cytokines, and other second messengers to the cell nucleus. Numerous studies have shown that in multiple malignant tumors and hematopoietic malignancies, faulty signal transduction via the Ras pathway plays a key role in tumorigenesis. In this work, a non-radioactive assay was used to quantify Ras activity in hematologic malignancies. Ras activation was measured in six different cell lines and 24 patient samples, and sequence analysis of N- and K-ras was performed. The 24 patient samples comprised of seven acute myelogenous leukemia (AML) samples, five acute lymphocytic leukemia (ALL) samples, four myeloproliferative disease (MPD) samples, four lymphoma samples, four juvenile myelomonocytic leukemia (JMML) samples, and WBC from a healthy donor. The purpose of this study was to compare Ras activity determined by percentage of Ras-GTP with the mutational status of the Ras gene in the hematopoietic cells of the patients. Mutation analysis revealed ras mutations in two of the seven AML samples, one in codon 12 and one in codon 61; ras mutations were also found in two of the four JMML samples, and in one of the four lymphoma samples (codon 12). We found a mean Ras activation of 23.1% in cell lines with known constitutively activating ras mutations, which was significantly different from cell lines with ras wildtype sequence (Ras activation of 4.8%). Two of the five activating ras mutations in the patient samples correlated with increased Ras activation. In the other three samples, Ras was probably activated through "upstream" or "downstream" mechanisms.
authors.affiliation: Department of Medicine I, University of Freiburg Medical Center, Hugstetter Str. 55, 79106 Freiburg, Germany.
authors.forename: D
authors.initials: D
authors.lastname: Raepple
authors.forename: F
authors.initials: F
authors.lastname: von Lintig
authors.forename: T
authors.initials: T
authors.lastname: Zemojtel
authors.forename: M
authors.initials: M
authors.lastname: Duchniewicz
authors.forename: A
authors.initials: A
authors.lastname: Jung
authors.forename: M
authors.initials: M
authors.lastname: Lübbert
authors.forename: G R
authors.initials: GR
authors.lastname: Boss
authors.forename: J S
authors.initials: JS
authors.lastname: Scheele
mesh_terms: D004252:DNA Mutational Analysis; D006153:Guanosine Diphosphate / Q000032:analysis; D006160:Guanosine Triphosphate / Q000032:analysis; D019337:Hematologic Neoplasms / Q000737:chemistry* / Q000209:etiology / Q000235:genetics*; D006801:Humans; D015470:Leukemia, Myeloid, Acute; D054429:Leukemia, Myelomonocytic, Juvenile; D008223:Lymphoma; D009154:Mutation; D009196:Myeloproliferative Disorders; D009857:Oncogenes; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma; D015398:Signal Transduction / Q000235:genetics; D014407:Tumor Cells, Cultured; D018631:ras Proteins / Q000032:analysis* / Q000235:genetics*
chemical_list: D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D018631:ras Proteins
references.citation: Chin Med J (Engl). 1998 Apr;111(4):343-5
references.pmid: 10374400
references.citation: Cell Mol Life Sci. 2000 Dec;57(13-14):1950-63
references.pmid: 11215520
references.citation: Clin Cancer Res. 2000 May;6(5):1804-10
references.pmid: 10815901
references.citation: Growth Factors. 2005 Jun;23(2):143-9
references.pmid: 16019436
references.citation: Leukemia. 1998 Jun;12(6):887-92
references.pmid: 9639416
references.citation: Leukemia. 2004 Mar;18(3):466-75
references.pmid: 14737077
references.citation: Cell. 1990 Aug 10;62(3):599-608
references.pmid: 2116237
references.citation: Br J Haematol. 1991 Mar;77(3):323-7
references.pmid: 2012756
references.citation: Blood. 2005 Sep 15;106(6):2183-5
references.pmid: 15928039
references.citation: Mol Cell Biol. 1996 Aug;16(8):4107-16
references.pmid: 8754809
references.citation: Cell. 1997 Feb 7;88(3):333-46
references.pmid: 9039260
references.citation: Blood. 1994 Nov 15;84(10):3435-9
references.pmid: 7949098
references.citation: Nat Genet. 2007 Aug;39(8):1007-12
references.pmid: 17603483
references.citation: Nat Genet. 2003 Jun;34(2):148-50
references.pmid: 12717436
references.citation: J Exp Med. 1994 Jun 1;179(6):1855-65
references.pmid: 8195713
references.citation: Mol Med. 2000 Aug;6(8):693-704
references.pmid: 11055588
references.citation: Cell. 1992 Apr 17;69(2):265-73
references.pmid: 1568246
references.citation: Leukemia. 1990 Jul;4(7):486-9
references.pmid: 2142747
references.citation: N Engl J Med. 1997 Jun 12;336(24):1713-20
references.pmid: 9180088
references.citation: J Exp Med. 1995 Jan 1;181(1):307-13
references.pmid: 7807010
references.citation: Blood. 1999 May 1;93(9):3074-80
references.pmid: 10216104
references.citation: J Immunol. 1996 Oct 1;157(7):2844-50
references.pmid: 8816388
references.citation: Cell. 1994 Apr 22;77(2):307-16
references.pmid: 8168137
references.citation: Blood. 1994 Apr 15;83(8):2248-54
references.pmid: 8161790
references.citation: Proc Natl Acad Sci U S A. 1984 Jul;81(13):4008-12
references.pmid: 6330729
references.citation: Leuk Res. 1998 Nov;22(11):1003-7
references.pmid: 9783802
references.citation: Cancer. 2007 Nov 1;110(9):2000-6
references.pmid: 17849425
references.citation: Br J Haematol. 1995 Apr;89(4):905-7
references.pmid: 7772531
references.citation: Oncogene. 1987 May;1(2):157-65
references.pmid: 3325880
references.citation: Nat Genet. 2007 Aug;39(8):1013-7
references.pmid: 17603482
references.citation: Proc Natl Acad Sci U S A. 1995 Feb 14;92(4):1097-100
references.pmid: 7862641
references.citation: Mol Reprod Dev. 1997 Jan;46(1):96-103
references.pmid: 8981370
references.citation: Science. 2007 Oct 19;318(5849):463-7
references.pmid: 17947584
references.citation: Blood. 1995 Nov 1;86(9):3517-21
references.pmid: 7579458
references.citation: Blood. 2001 Mar 1;97(5):1399-403
references.pmid: 11222386