title: Expression of the farnesyltransferase beta-subunit gene in human ovarian carcinoma: correlation to K-ras mutation.
abstract: The ras signaling protein requires a posttranslational modification to localize it to the inner surface of plasma membrane. In this state it can behave as a signal transduction mediator. Farnesyltransferase plays an important role in this posttranslational processing of ras by attaching a farnesyl group to the cysteine of the ras C-terminal tetrapeptide. In this study, we investigated the relationship of K-ras expression and mutation with farnesyltransferase beta-subunit expression in 20 ovarian tumors (17 carcinomas and 3 low malignant potential tumors) and 4 normal ovaries. The expression level of mRNA was determined by using quantitative PCR and mutation analysis was performed by direct cDNA sequencing. K-ras mutations were found in 1 of 3 low malignant potential tumors and in 4 of 17 carcinoma cases. K-ras mRNA overexpression was found in 1 of 3 low malignant potential tumors (one with mutated ras) and in only 1 of 17 carcinoma cases. Farnesyltransferase beta-subunit mRNA overexpression was found in 2 of 3 low malignant potential tumors and in 7 of 17 carcinoma cases. Interestingly, all K-ras mutation cases showed farnesyltransferase beta-subunit overexpression. These findings suggest that there may be a direct relationship between K-ras (ras dysfunction) mutation and expression of farnesyltransferase beta-subunit gene.
authors.affiliation: Department of Obstetrics and Gynecology, University of Arkansas for Medical Sciences, Little Rock 72205-7199, USA.
authors.forename: H
authors.initials: H
authors.lastname: Tanimoto
authors.forename: K D
authors.initials: KD
authors.lastname: Mehta
authors.forename: T H
authors.initials: TH
authors.lastname: Parmley
authors.forename: K
authors.initials: K
authors.lastname: Shigemasa
authors.forename: G P
authors.initials: GP
authors.lastname: Parham
authors.forename: J
authors.initials: J
authors.lastname: Clarke
authors.forename: T J
authors.initials: TJ
authors.lastname: O'Brien
mesh_terms: D019883:Alkyl and Aryl Transferases; D004252:DNA Mutational Analysis; D051231:Farnesyltranstransferase; D005260:Female; D015972:Gene Expression Regulation, Neoplastic; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D009154:Mutation; D010051:Ovarian Neoplasms / Q000201:enzymology / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D014166:Transferases / Q000235:genetics*
chemical_list: D012333:RNA, Messenger; D014166:Transferases; D019883:Alkyl and Aryl Transferases; D051231:Farnesyltranstransferase