title: K-ras activation and ras p21 expression in latent prostatic carcinoma in Japanese men.
abstract: Twenty-three clinically silent prostatic carcinomas discovered in Japanese men at autopsy were surveyed for ras proto-oncogene mutations by mutation-specific oligonucleotide probe hybridization after polymerase chain reaction (PCR) amplification from a section of formalin-fixed, paraffin-embedded tissue. Six of the 22 that were satisfactory amplified contained activating point mutations in codon 12 of K-ras, a significantly higher frequency than has been reported in patients with clinically advanced disease in the United States. Of the six cases with activating point mutations in codon 12 of K-ras, one had a GGT----GAT transition, four had GGT----GTT transversions, and one had both GGT----GAT and GGT----GTT mutations. Sections from the same tissues were immunohistochemically stained with an anti-ras p21 antibody. Carcinoma cells stained for ras p21 to some degree in 13 cases. Immunohistochemically detectable expression of p21 was always focal and was not necessarily associated with K-ras mutation. K-ras oncogene activation in prostatic carcinoma appears to merit additional study as a significant event in the pathogenesis of this neoplasm.
authors.affiliation: Second Department of Pathology, Nara Medical University, Kashihara, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Konishi
authors.forename: T
authors.initials: T
authors.lastname: Enomoto
authors.forename: G
authors.initials: G
authors.lastname: Buzard
authors.forename: M
authors.initials: M
authors.lastname: Ohshima
authors.forename: J M
authors.initials: JM
authors.lastname: Ward
authors.forename: J M
authors.initials: JM
authors.lastname: Rice
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D002454:Cell Differentiation / Q000502:physiology; D015972:Gene Expression Regulation, Neoplastic / Q000235:genetics*; D011905:Genes, ras / Q000235:genetics*; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D007564:Japan / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009361:Neoplasm Invasiveness / Q000235:genetics; D009693:Nucleic Acid Hybridization; D011471:Prostatic Neoplasms / Q000235:genetics* / Q000473:pathology; D000090063:Proto-Oncogene Mas; D016283:Proto-Oncogene Proteins p21(ras) / Q000235:genetics*
chemical_list: D000911:Antibodies, Monoclonal; C000715470:MAS1 protein, human; D000090063:Proto-Oncogene Mas; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)