Patterns of expression of trefoil peptides and mucins in gastric polyps with and without malignant transformation.
The expression of two trefoil peptides (TFF1 and TFF2) and four mucins (MUC1, MUC2, MUC5AC, and MUC6) was evaluated by immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) in 29 gastric polyps, 10 hyperplastic and 19 adenomatous, eight of which displayed malignant transformation. The aims of this study were to characterize the expression profile of these molecules in each type of polyp and to investigate possible modifications of the profile during the process of malignant transformation. All hyperplastic polyps displayed immunoreactivity for TFF1, MUC5AC, and MUC1 in more than 75 per cent of the cells. In adenomatous polyps, three main phenotypes could be identified: complete gastric phenotype (co-expression of TFF1 and MUC5AC)-nine cases (47.4 per cent); incomplete gastric phenotype (TFF1-positive and MUC5AC-negative)-seven cases (36.8 per cent); non-gastric (intestinal) phenotype (no expression of TFF1 or MUC5AC)-three cases (15.8 per cent). Data yielded by immunohistochemistry and RT-PCR showed a good correlation for both TFF1 and TFF2. One hyperplastic and seven adenomatous polyps with villous architecture displayed foci of diffuse and intestinal-type carcinoma, respectively; in all of these cases, MUC1 expression and signs of gastric differentiation were observed in both the non-malignant and the carcinomatous component. It is concluded that gastric differentiation is a feature of hyperplastic polyps and of a subset of adenomatous polyps which is shared by early carcinomas arising in some of these polyps, regardless of the histological type of polyp and of carcinoma.
Institute of Molecular Pathology and Immunology of the University of Porto (IPATIMUP), Porto, Portugal.
A M
AM
Nogueira
J C
JC
Machado
F
F
Carneiro
C A
CA
Reis
P
P
Gött
M
M
Sobrinho-Simões
D018256:Adenomatous Polyps / Q000378:metabolism; D002454:Cell Differentiation; D002471:Cell Transformation, Neoplastic; D006133:Growth Substances / Q000378:metabolism*; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006801:Humans; D006965:Hyperplasia / Q000378:metabolism / Q000473:pathology; D007124:Immunoenzyme Techniques; D009077:Mucins / Q000378:metabolism*; D009124:Muscle Proteins; D009363:Neoplasm Proteins / Q000378:metabolism*; D009479:Neuropeptides; D010455:Peptides / Q000378:metabolism*; D011127:Polyps / Q000378:metabolism* / Q000473:pathology; D011230:Precancerous Conditions / Q000378:metabolism* / Q000473:pathology; D011506:Proteins / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013270:Stomach / Q000473:pathology; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D000071163:Trefoil Factor-1; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3; D025521:Tumor Suppressor Proteins
D006133:Growth Substances; D006360:Heat-Shock Proteins; D009077:Mucins; D009124:Muscle Proteins; D009363:Neoplasm Proteins; D009479:Neuropeptides; D010455:Peptides; D011506:Proteins; C051838:TFF1 protein, human; C000604007:TFF2 protein, human; C099037:TFF3 protein, rat; C000604008:Tff2 protein, rat; D000071163:Trefoil Factor-1; D000071164:Trefoil Factor-2; D000071165:Trefoil Factor-3; D025521:Tumor Suppressor Proteins