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We have recently shown that the adaptor protein p140Cap regulates tumor properties in terms of cell motility and growth. Here, by using the highly metastatic rat adenocarcinoma cell line MTLn3-epidermal growth factor receptor (EGFR), we assess the role of p140Cap in metastasis formation. Orthotopic transplantation of MTLn3-EGFR cells over-expressing p140Cap in Rag2−/−γc−/− mice resulted in normal primary tumor growth compared with the controls. Strikingly, p140Cap over-expression causes an 80% inhibition in the number of lung metastases. p140Cap over-expressing cells display a 50% reduction in directional cell migration, an increased number and size of focal adhesions, and a strong impairment in the ability to invade in a 3D matrix. p140Cap over-expression affects EGFR signaling and tyrosine phosphorylation of cortactin in response to EGF stimulation. Intriguingly, p140Cap associates with cortactin via interaction with its second proline-rich domain to the cortactin SH3 domain. The phosphomimetic cortactin tyrosine 421 mutant rescues migration and invasive properties in p140Cap over-expressing cells. Taken together, these data demonstrate that p140Cap suppresses the invasive properties of highly metastatic breast carcinoma cells by inhibiting cortactin-dependent cell motility. [ABSTRACT FROM AUTHOR]

The physico-chemical properties of poly(ethylene) glycol solutions in water have been studied with use of pressure perturbation calorimetry. The three PEGs of average molecular mass ( M r) 6000, 10000, 20000 were used. The concentration of polymers was changed in the range 0–30% mass per volume ( w/ v%). On the basic of VP-DSC measurements with use of PPC technique the dependencies of thermal expansion coefficient (α) and excess specific heat capacity ( C p,exc) on temperature were determinated for PEG–water solutions. [ABSTRACT FROM AUTHOR]

Investigations of lysozyme–polyethylene glycol system were made by differential scanning calorimetry, fluorescence and density techniques. The values of unfolding enthalpies, Δ H N U, unfolding temperatures, T m, excess molar heat capacities, Δ C p, and apparent molar volumes, V Φ , were determined as functions of PEG concentration. The three PEGs of average molecular mass ( MW) 6000, 10000, 20000 were used as macromolecular crowding agents. The concentration of polymers was changed in the range 0–30% mass per volume ( w/ v). The values of Δ H N U remained constant with no dependence on PEG concentration, while PEG addition to buffered lysozyme solutions caused linear decrease of T m. The values of Δ C p and V Φ of lysozyme dramatically changed in the range of 8–10% of PEG concentration. The fluorescence spectroscopy was used in order to investigate the polymer influence on possible solvent–lysozyme interactions. The electrical properties of polymer–water and polymer–buffer systems, the dielectric constants of solutions were determined with use of impedance spectroscopy. [ABSTRACT FROM AUTHOR]