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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HLA class I and II antigen expression was studied in normal mucosa, adenoma and colon carcinoma. Alkaline phosphatase anti-alkaline phosphatase (APAAP) staining techniques were used in cryostatic sections with anti-HLA-ABC and DR,DP,DQ monoclonal antibodies. All normal mucosa were intensely positive for HLA class I antigen expression, while failing to express class II molecules, except in mucosa adjacent to tumors (15/19 cases). All adenomatous polyps expressed HLA class I antigen, while the intensity of class II expression (DR greater than DQ greater than DP) was paralleled by the degree of dysplasia. In colon carcinoma, the loss of class I expression was seen in 4 out of 32 cases, and class II expression was found to be heterogeneous in 16 of these 32 cases (DR greater than DP greater than DQ). No relationship was noted between class II expression and degree of differentiation. However a correlation was seen between HLA-DR antigen expression and degree of invasiveness, mononuclear infiltrate and prognosis, according to Jass's criteria.
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PMID:Class I and II HLA antigen distribution in normal mucosa, adenoma and colon carcinoma: relation with malignancy and invasiveness. 285 3

The loss of HLA antigens by neoplastic cells is considered important for tumor growth and metastasis, inasmuch as it may allow tumors to escape immune surveillance. We have observed reduced expression of HLA antigens in sporadic colon cancer and adenomas from familial adenomatous polyposis patients. We now studied the expression of HLA class I antigens in patients with sporadic adenomas, which are precursors of colorectal cancer. Expression of HLA class I antigens was studied by immunohistochemistry in (a) sporadic colon adenomas, (b) histologically normal mucosa distant from the adenomas, (c) histologically normal colonic mucosa from patients with history of sporadic colon adenomas, and (d) colonic mucosa from normal subjects. HLA class I antigen expression was moderately reduced in 56% and severely reduced in 44% of the adenomas; this reduction was significant when compared to controls (P < 0.0001). The reduction of HLA class I expression in adenomas was related to the grade of dysplasia of the adenomas. HLA class I expression of normal appearing mucosa was decreased in 76% of patients with adenoma (P < 0.0001) and in 54% of patients with history of adenoma (P < 0.005) compared to normal controls. These changes were antigen specific, inasmuch as the expression of carcinoembryonic antigen, a surface antigen, was not affected. Our findings suggest that reduced HLA class I expression is an early event in the cell transformation process from normal to neoplastic state, preceding in many cases the onset of histological changes. HLA class I could be potentially used as a premalignant marker in the colon.
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PMID:Expression of HLA class I antigens in sporadic adenomas and histologically normal mucosa of the colon. 848 24

We compared the expression of major histocompatibility complex (MHC; HLA class I and II) antigens and the presence of tumor-infiltrating mononuclear cells presenting S100 protein (S100), CD68 antigen, or CD45RO antigen in formalin-fixed, paraffin-embedded tissue sections of 10 renal cell carcinomas and 9 renal cell adenomas using immunohistochemistry. The expression of beta 2-microglobulin (B2MG) as an HLA class I antigen in all 10 cases (100%) and that of HLA-DR/alpha as an HLA class II antigen in 7 of 10 cases (70%) of carcinoma was stronger than that in the adjacent proximal convoluted tubule, but was respectively not different to weaker in 8 of 9 cases and not different to markedly weaker in all cases of adenoma. Furthermore, there was comparatively dense infiltration by S100(+) antigen-presenting cells in the carcinomas, but almost none in the adenomas and generally dense infiltration by CD45RO(+) T cells and CD68(+) macrophages in the carcinomas, but little to none in the adenomas. We concluded that the generally enhanced expression of MHC antigens in carcinomas must be an immunophenotypic deviation from not only the adjacent proximal convoluted tubule but also adenomas, and that the predominant infiltration of antigen-presenting cells, T cells and macrophages in the carcinomas, but not in the adenomas, reflects the anti-cancer immune reaction.
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PMID:Characteristics of MHC antigen expression and tumor-infiltrating mononuclear cells in renal cell adenomas and carcinomas. 857 98