Nrf2-peroxiredoxin I axis in polymorphous adenocarcinoma is associated with low matrix metalloproteinase 2 level.

Polymorphous adenocarcinoma (PAC) is a malignant epithelial neoplasm that affects almost exclusively the minor salivary glands, generally described as having a relatively good prognosis. Aberrant nuclear factor erythroid 2 (NF-E2)-related factor (Nrf2) activation in tumor cells has been associated with induction of antioxidant enzymes, such as peroxiredoxin I (Prx I) and increased matrix metalloproteinase (MMP) expression. In this context, the aim of the present study was to evaluate the expression of Nrf2 and correlate it with Prx I and MMP-2 secretion in PAC. Thirty-one cases of PAC from oral biopsies were selected and immunohistochemically analyzed for Nrf2 and Prx I. MMP-2 quantification was performed on primary cell cultures derived from PAC. Oral squamous cell carcinoma (OSCC) cell cultures were used as control. A high immunoexpression of Nrf2 was observed in both the cytoplasm and the nucleus of neoplastic cells from PAC. Nuclear staining for Nrf2 suggested its activation in the majority of the PAC cells, which was confirmed by the high expression of its target gene, Prx I. Quantification of MMP-2 secretion showed lower levels in PAC cell cultures when compared to OSCC cell cultures (p < 0.05). In conclusion, although Nrf2 overexpression has been frequently associated with high-grade malignancies, such relationship is not infallible and, in fact, the opposite may occur in low-grade tumors, such as PAC of minor salivary glands.

ICAM-1 expression on immune cells in chronic villitis.

INTRODUCTION: ICAM-1 expression on the villous syncytiotrophoblast (ST) is believed to participate in migration of maternal cells into the inflamed villi regardless of villitis etiology. However, its expression on immune cells in chronic villitis (CV) has yet to be analyzed. ICAM-1 induces cell-cell adhesion allowing intercellular communication, T cell-mediated defense mechanism, and inflammatory response. MATERIAL AND METHODS: 21 cases of CV (all without an identifiable etiologic agent) and 3 control placentas were analyzed using ICAM-1, and for immune cells CD45, CD3 and CD68. These cells were subdivided according to their location in inflamed villi: a) within the inflamed villi and b) outside forming perivillous aggregates. RESULTS: Large amounts of CD45, CD3 and CD68 were found within the inflamed villi and forming perivillous aggregates attached to areas of trophoblastic loss. Inflamed villi usually showed ICAM-1+ ST. The majority of immune cells surrounding areas of trophoblastic rupture presented marked expression of ICAM-1. In contrast, a small number of immune cells within the inflamed villi exhibited ICAM-1 expression. Only some (<5%) inflamed villi without trophoblastic rupture and with ICAM-1+ ST presented adherence of immune cells. DISCUSSION: In inflamed villi of chronic villitis, the level of ICAM-1 expression on immune cells depends on their location: high in number of cells in the perivillous region and low within the villi. The strongest expression of ICAM-1 on immune cells attached to areas of trophoblastic rupture suggests that the loss of trophoblast can lead to an amplification of the inflammatory response.