The marked correlation between H. pylori and Cag-A, found in ATDs, could be dependent on the different expression of adhesion molecules in the gastric mucosa.

The association between the Helicobacter pylori and Graves' disease suggests a possible role of this bacterium in the onset and/or the maintenance of the disease.

No abstract

To assess the expression of the very late antigens family of the integrin superfamily in normal and diseased thyroid glands, tissue specimens were digested to a single cell suspension and analyzed by flow cytometry with antibodies against the common beta 1 chain and the six alpha chains known to be associated to beta 1. In multinodular goiters, two cell populations were recognized. The thyroglobulin containing follicular cell population, represented the majority of cells; a minor population was composed of leukocytes. In normal glands, more than 97% of follicular cells expressed the beta 1 chain, associated with high levels of alpha 3 and very low levels of alpha 1, alpha 5, and alpha 6. The remaining cells (< 3%) expressed the beta 1 chain with a 10-fold higher intensity, associated with relatively high levels of alpha 1, alpha 5, and alpha 6, in addition to alpha 3. This small subset was much more represented in multinodular goiters, where it ranged from 10-60% of the total follicular cell population. Immunofluorescence on tissue sections showed that very late antigens were mostly located on the basal cell membrane and that in multinodular goiters cells expressing the alpha 1, alpha 5, and alpha 6 chains occurred in clusters.

The expression of intercellular adhesion molecule-1 (ICAM-1) in tumoral tissues may promote their interaction with the immune system and cytotoxic effect on tumoral cells. This observation led to the investigation of ICAM-1 expression and modulation in different tumoral cell systems in vitro. Recently, retinoic acid-responsive elements have been found in the 5'-regulatory region of the human ICAM-1 gene. In the present study, we investigated, by flow cytometry, the effect of retinoic acid on the surface expression of ICAM-1 in human thyroid carcinoma cell lines. Two papillary (NPA and TPC-1), one follicular (WRO), one anaplastic (ARO) and one immortalized fetal (TAD-2) cell line have been studied. All of them produced constitutively ICAM-1; its surface expression and specific messenger ribonucleic acid (mRNA) levels were increased significantly by retinoic acid in all except the WRO cell line. ICAM-1 hyperexpression by retinoic acid was time dependent, reversible, and dependent on mRNA and protein synthesis. Furthermore, cytokines, such as interferon-gamma and tumor necrosis factor-alpha, both individually and, to a greater extent, in combination with retinoic acid, increased ICAM-1 surface expression and its mRNA levels. In conclusion, retinoic acid is able to induce ICAM-1 up-regulation via mRNA accumulation in human thyroid carcinoma cell lines.