Federica Callegari

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Yessotoxins (YTXs) are algal toxins that can be accumulated in edible molluscs. YTX treatment of MCF-7 breast cancer cells causes the accumulation of a 100 kDa fragment of E-cadherin, which we have named ECRA(100). A relative decrease in the concentrations of intact E-cadherin did not accompany the accumulation of ECRA(100) in cytosoluble extracts of MCF-7(More)
YTX has been shown to disrupt the E-cadherin-catenin system in cultured epithelial cells, raising some concern that ingestion of seafood contaminated by YTX might favour tumour spreading and metastasis formation in vivo. In order to probe whether YTX might affect cadherin systems in vivo, we have set up a study involving repeated oral dosing of the toxin in(More)
The effect of azaspiracid-1 (AZA-1) on the plasma membrane proteins E-cadherin, Na(+)/K(+)-ATPase, and prolactin receptor (R(prl)) has been investigated in MCF-7 cells. Cell treatment for 24 h with 1nM AZA-1 induced the accumulation of a proteolytic fragment of E-cadherin and significant increases in the levels of Na(+)/K(+)-ATPase and R(prl) at the level(More)
Previous in vitro and in vivo toxicological studies on the effects of yessotoxin (YTX) on E-cadherin have provided conflicting results with regard to alterations of its turnover. We have then studied the effects of YTX on the degradation pathway of E-cadherin in intact cells under controlled conditions, and found that the 100kDa E-cadherin fragment(More)
Azaspiracid-1 (AZA-1) inhibits endocytosis, but the consequences of this alteration on cellular processes are unknown. We hypothesized that the inhibition of endocytosis is a key step of the mode of action of AZA-1, leading to perturbation of cellular processes dependent on proper functioning of endocytic machinery. We tested this working hypothesis by(More)
Yessotoxin (YTX) is a sulphated polyether compound produced by some species of dinoflagellate algae, that can be accumulated in bivalve mollusks and ingested by humans upon eating contaminated shellfish. Experiments in mice have demonstrated the lethal effect of YTX after intraperitoneal injection, whereas its oral administration has only limited acute(More)
We originally developed a functional assay for the detection of yessotoxins (YTX) based on its capacity to induce dose-dependent changes in cellular levels of two marker proteins, consisting of E-cadherin and an E-cadherin fragment (ECRA100) in epithelial cells. The procedure is time-consuming and we have shortened it by a slot blot format, using antibodies(More)
Monitoring of okadaic acid (OA)-group toxins in seafood is of paramount importance for the protection of consumer health from diarrheic shellfish poisoning. The property of OA-group compounds to inhibit type 2A serine/threonine phosphoprotein phosphatase (PP2A) has been exploited for the detection of OA in several experimental settings, but the performance(More)
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