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Ki‐ ras point mutation in codon 12 and expression of p53 in mucin‐producing tumor of the pancreas
Author(s) -
Nio Yoshinori,
Sato Yoshitoshi,
Song MouMing,
Sumi ShoIchiro,
Minari Yoshimitsu,
Yano Seiji,
Tamura Katsuhiro
Publication year - 1997
Publication title -
journal of hepato‐biliary‐pancreatic surgery
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.63
H-Index - 60
eISSN - 1868-6982
pISSN - 0944-1166
DOI - 10.1007/bf01211347
Subject(s) - mucin , point mutation , pancreas , microbiology and biotechnology , guanine , mutant , biology , immunohistochemistry , western blot , mutation , cancer research , gene , immunology , genetics , endocrinology , biochemistry , nucleotide
Mucin‐producing tumors (MPTs) of the pancreas show a variety of clinical characteristics, including massive production of mucin in the pancreatic duct, dilatation of the main pancreatic duct, and a better prognosis than common invasive ductal carcinoma (IDC). These characteristics suggest that MPTs and IDCs have different cytomolecular backgrounds. The present study was designed to assess the differences in cytomolecular background between MPTs and IDCs, especially the differences in Ki‐ ras point mutation (PM) and wild and mutant type p53 expression. Cytomolecular backgrounds were compared in a 13 MPTs [8 carcinomas (MPCas) and 5 benign tumors (MPBTs)] and 36 IDCs. Cytomolecular studies included the evaluation of Ki‐ ras PM and the expression of Ki‐ ras p21, wild‐type p53 (w‐ p53 ), and mutant‐type p53 (m‐ p 53). Ki‐ ras PM was assessed by the allele‐specific oligonucleotide dot blot hybridization method, and the expression of p21 and p53 was assessed by an immunohistochemical staining method with monoclonal antibodies. Ki‐ ras PM was seen in 97% of IDCs and in 77% of MPTs (100% of MPCas and 40% of MPBTs), and MPBTs showed a significantly lower incidence of Ki‐ ras PM (versus IDC, P < 0.01). Guanine‐Guanine‐Thymine (GGT) to Guanine‐Adenine‐Thymine (GAT) mutation was seen in 55% of IDCs and 62% MPTs (87% of MPCas and 20% of MPBTs), and MPCas showed a significantly higher incidence of percent GAT mutation (versus IDC, P < 0.05). Ki‐ ras p21 was expressed in 43% of IDCs and in 31 % of MPTs (50% of MPCas and 20% of MPBTs). w‐ p53 and m‐ p 53 were expressed in 51 % and 78% of IDCs and in 54% and 62% of MPTs (38% and 63% of MPCas and 20% and 60% of MPBTs), respectively. In MPBTs, hyperplasias showed higher rates of p21, w‐ p 53, and m‐ p 53 expression than cystadenomas. The study suggested that GAT mutation may be involved in the tumorigenesis of MPTs. It is suggested that MPBTs, especially hyperplasias, may be classified as low‐grade malignancies like MPCas.