We have studied the effects of brefeldin A (BFA) on endocytosis and intracellular traffic in polarized MDCK cells by using the galactose-binding protein toxin ricin as a membrane marker and HRP as a marker of fluid phase transport. We found that BFA treatment rapidly increased apical endocytosis of both ricin and HRP, whereas basolateral endocytosis was unaffected, as was endocytosis of HRP in ...

We have used a new monoclonal antibody, designated C-262, directed against the last 14 amino acids of the carboxy-terminus of human progesterone receptors (N.L. Weigel et al., Mol. Endocrinol., 6: 1585-1597, 1992) to analyze progesterone receptor structure. This new antibody recognizes the previously described B-receptors (M(r) 120,000) and the naturally occurring N-terminal truncated A-recepto...

The coordinated activity of estrogens and epidermal growth factor receptor (EGFR) family agonists represents the main determinant of breast cancer cell proliferation. Stromal cell-derived factor-1 (SDF-1) enhances extracellular signal-regulated kinases 1 and 2 (ERK1/2) activity via the transactivation of EGFR and 17beta-estradiol (E2) induces SDF-1 production to exert autocrine proliferative ef...

Decreased expression of the cell-cell adhesion molecule, E-cadherin, promotes dedifferentiation and invasiveness of human carcinoma cells, whereas this process can be reversed by reexpression of E-cadherin (U. H. Frixen et al., J. Cell Biol., ¡13:173-185, 1991; J. H. Schipper el al.. Cancer Res., 51: 6328-6337, 1991). In this work we studied the involvement of extracellular matrix-degrading pr...

Zearalenone (Zen) is a mycotoxin with estrogenic effect which contaminates cereals. In cell culture, Zen and its metabolite, alpha-Zearalenol (alpha-Zel), stimulate breast cancer cells growth. Today hormone-dependent cancers are important because of high incidence and death rate. Previous studies showed that Zen and alpha-Zel have an effect on hormone-dependent cancers. This study explains the ...

Bortezomib is a proteasome inhibitor with remarkable clinical antitumor activity in multiple myeloma (MM) and is under evaluation in clinical trials in various types of cancer including breast cancer. Although the initial rationale for its use in cancer treatment was the inhibition of NF-κB activity by blocking proteasomal degradation of IκBα, direct evidence indicating inhibition of constituti...

BACKGROUND In tumor cells, aberrant differentiation programs have been described. Several neuronal proteins have been found associated with morphological neuronal-glial changes in breast cancer (BCa). These neuronal proteins have been related to mechanisms that are involved in carcinogenesis; however, this regulation is not well understood. Microtubule-associated protein-tau (MAP-Tau) has been ...

During breast carcinoma progression, the three-dimensional (3D) microenvironment is continuously remodeled, and changes in the composition of the extracellular matrix (ECM) occur. High throughput screening platforms have been used to decipher the complexity of the microenvironment and to identify ECM components responsible for cancer progression. However, traditional screening platforms are typ...

Prolactin (PRL) stimulates breast cancer cell proliferation; however, the involvement of PRL-activated signaling molecules in cell proliferation is not fully established. Here we studied the role of c-Src on PRL-stimulated proliferation of T47D and MCF7 breast cancer cells. We initially observed that PRL-dependent activation of focal adhesion kinase (Fak), Erk1/2, and cell proliferation was med...

We have used a new monoclonal antibody, designated C-262, directed against the last 14 amino acids of the carboxy-terminus of human progesterone receptors (N. L. Weigel et al., Mol. Endocrinol., 6: 1585-1597, 1992) to analyze progesterone receptor structure. This new antibody recognizes the previously described B-receptors (Mr 120,000) and the naturally occurring N-terminal truncated A-receptor...