title: Immunohistochemical study of ras p21 expression in human gastric cancers and benign lesions.
abstract: Expression of ras p21 in human gastric cancers, benign lesions and normal tissues was immunohistochemically evaluated by the avidin-biotin peroxidase complex (ABC) method with anti-ras p21 monoclonal antibody rp-28. Positive p21 immunoreactivity was shown in 23 (77%) of 30 gastric cancers, in 13 (48%) of 27 benign lesions and in 10 (22%) of 46 normal mucosa cases. Among them, strong staining was demonstrated only in 11 (37%) of 30 gastric cancers, but not in benign lesions and normal tissues. Cases showing more than 20% positive cell ratio were observed in 22 (73%) gastric cancers, in 11 (41%) benign lesions and 6 (13%) normal mucosa cases. Further, intracellular distribution of ras p21 is heterogeneous in gastric cancers, while it is homogeneous in benign lesions or normal tissues. The ABC method with rp-28 could be helpful for clinical differential diagnosis between gastric cancers and benign lesions by investigating three factors: staining intensity, positive cell ratio and intracellular distribution of ras p21.
authors.affiliation: Second Department of Surgery, Hokkaido University School of Medicine, Sapporo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakajima
authors.forename: N
authors.initials: N
authors.lastname: Kuzumaki
authors.forename: A
authors.initials: A
authors.lastname: Oda
authors.forename: H
authors.initials: H
authors.lastname: Kobayashi
authors.forename: H
authors.initials: H
authors.lastname: Katoh
authors.forename: T
authors.initials: T
authors.lastname: Tanabe
mesh_terms: D000230:Adenocarcinoma / Q000032:analysis*; D000911:Antibodies, Monoclonal; D006801:Humans; D007124:Immunoenzyme Techniques; D008565:Membrane Proteins / Q000032:analysis; D011518:Proto-Oncogene Proteins / Q000032:analysis*; D016283:Proto-Oncogene Proteins p21(ras); D013272:Stomach Diseases / Q000378:metabolism*; D013274:Stomach Neoplasms / Q000032:analysis*
chemical_list: D000911:Antibodies, Monoclonal; D008565:Membrane Proteins; D011518:Proto-Oncogene Proteins; C501009:HRAS protein, human; D016283:Proto-Oncogene Proteins p21(ras)