title: DLC1 is unlikely to be a primary target for deletions on chromosome arm 8p22 in head and neck squamous cell carcinoma.
abstract: Allelic imbalance on chromosome arm 8p is common in head and neck squamous cell carcinoma (HNSCC). DLC1, a tumour suppressor gene inactivated in liver carcinogenesis and encoding a Rho GTPase activating protein (RhoGAP) maps to one of the deleted regions (8p21.3-22). In order to determine whether inactivation of DLC1 is involved in HNSCC, we have screened tumour cell lines for DLC1 mutations and expression. Pathological mutations were not identified in any of the 17 cell lines tested. Seven polymorphisms were identified; 13 of the 17 of cell lines were homozygous for all seven polymorphisms compared to only 2 of 17 controls suggesting a loss of heterozygosity in a majority of the cell lines. DLC1 expression was observed in all 11 HNSCC cell lines tested, thus excluding the possibility of transcriptional silencing of DLC1 by promoter hypermethylation. Overall, our data suggest that hemizygous deletions of the DLC1 locus are frequent in HNSCCs but this gene is unlikely to be primary target for inactivation on this chromosomal arm.
authors.affiliation: Unit of Medical Genetics, University of Manchester, St Mary's Hospital, Hathersage Road, Manchester M13 0JH, UK.
authors.forename: Chelsee
authors.initials: C
authors.lastname: Hewitt
authors.forename: Peter
authors.initials: P
authors.lastname: Wilson
authors.forename: Edwina
authors.initials: E
authors.lastname: McGlinn
authors.forename: Gary
authors.initials: G
authors.lastname: MacFarlane
authors.forename: Anne
authors.initials: A
authors.lastname: Papageorgiou
authors.forename: Robert T M
authors.initials: RT
authors.lastname: Woodwards
authors.forename: Philip
authors.initials: P
authors.lastname: Sloan
authors.forename: Susanne M
authors.initials: SM
authors.lastname: Gollin
authors.forename: Ian
authors.initials: I
authors.lastname: Paterson
authors.forename: Kenneth K
authors.initials: KK
authors.lastname: Parkinson
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Read
authors.forename: Nalin
authors.initials: N
authors.lastname: Thakker
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000235:genetics* / Q000473:pathology; D002872:Chromosome Deletion; D002898:Chromosomes, Human, Pair 8 / Q000235:genetics*; D020690:GTPase-Activating Proteins; D006258:Head and Neck Neoplasms / Q000235:genetics* / Q000473:pathology; D006801:Humans; D019656:Loss of Heterozygosity; D018895:Microsatellite Repeats; D009154:Mutation; D011110:Polymorphism, Genetic; D014407:Tumor Cells, Cultured; D025521:Tumor Suppressor Proteins / Q000235:genetics* / Q000378:metabolism
chemical_list: C112352:DLC1 protein, human; D020690:GTPase-Activating Proteins; D025521:Tumor Suppressor Proteins