title: Abnormalities and the implication of retinoblastoma locus and its protein product in head and neck cancers.
abstract: Abnormalities in the Retinoblastoma tumor suppressor gene (Rb) have been observed in a large number of human cancers. Loss of heterozygosity (LOH) is a common mode of allelic inactivation of Rb and other tumor suppressor genes. We investigated DNA from 45 primary human head and neck cancers to determine LOH at the Rb locus using a polymerase chain reaction-based restriction fragment length polymorphism assay. Of informative cases, we found LOH in 4 of 28 (14%) head and neck cancers. Of immunohistochemical staining of Rb protein, we found that in one of ten LOH negative cases the nuclei of fibroblasts were stained with anti-Rb antibody but there was no nuclear staining tumor cells. These results suggest that inactivation of Rb protein is involved in the carcinogenesis of head and neck cancer at all levels of the process of protein expression: DNA, mRNA and protein.
authors.affiliation: Department of Otolaryngology, Tohoku University School of Medicine, Sendai, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Yokoyama
authors.forename: K
authors.initials: K
authors.lastname: Shiga
authors.forename: H
authors.initials: H
authors.lastname: Sasano
authors.forename: M
authors.initials: M
authors.lastname: Suzuki
authors.forename: T
authors.initials: T
authors.lastname: Takasaka
mesh_terms: D001483:Base Sequence; D017353:Gene Deletion; D016161:Genes, Retinoblastoma / Q000235:genetics*; D006258:Head and Neck Neoplasms / Q000737:chemistry / Q000235:genetics*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000737:chemistry / Q000235:genetics; D008441:Maxillary Neoplasms / Q000737:chemistry / Q000235:genetics; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000032:analysis; D010610:Pharyngeal Neoplasms / Q000737:chemistry / Q000235:genetics; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D016160:Retinoblastoma Protein / Q000032:analysis; D014062:Tongue Neoplasms / Q000737:chemistry / Q000235:genetics
chemical_list: D009363:Neoplasm Proteins; D016160:Retinoblastoma Protein