Anti-CAPG monoclonal antibody, clone FQS24205-45

The CapG protein, a Gelsolin-related actin-binding protein, is expressed at higher levels in breast cancer, especially in metastasizing breast cancer, than in normal breast epithelium. Furthermore, it is known that an increased expression of the CapG protein triggers an increase in cell motility. According to in vitro experiments, it was supposed that it is the nuclear fraction of the protein, which causes the increase in cell motility. Here, we examined the dynamical distribution of the CapG protein within the living cell, i.e. the import of the CapG protein into the nucleus. The nuclear import kinetics of invasive, metastasizing breast cancer cells were compared to the import kinetics of non-neoplastic cells similar to normal breast epithelium. FRAP kinetics showed a highly significant increase in the recovery of photobleached CapG-eGFP in the cancer cells, so that a differentiation of invasive, metastasizing cells and non-invasive, non-metastasizing cells on the basis of transport processes of the CapG protein between the nucleus and the cytoplasm seems to be possible. Comprehension of the mobility and compartmentalization of the CapG protein in normal and in cancer cells in vivo could constitute a new basis to characterize the invasiveness and metastasizing potential of breast cancer. (c) 2007 Wiley-Liss, Inc.

Research on vascular endothelial cell ageing helps elucidate the pathogenesis of diseases associated with cell ageing. To investigate endothelial senescence, we used 2-DE coupled with MS to perform a proteomic analysis of: (i) peripheral blood mononuclear cells (PBMCs) from donors in their 20 s ('young') or 60 s ('old') and (ii) human dermal microvascular endothelial cells (HDMECs) treated with sera from young and old donors. Identified proteins could be classified into several functional categories: (i) cytoskeletal regulators: CapG and cofilin 1; (ii) stress response and signal pathway proteins: TXNDC5 and RSU-1; and (iii) apoptosis proteins: Annexin V. We confirmed by Western blot a decrease of RSU-1, CapG and TXNDC5 in PBMCs from old donors. RSU-1, which regulates signal transduction of the downstream Ras, showed decreased mRNA and protein levels in PBMCs from old donors and decreased mRNA levels in HDMECs treated with sera from old donors. In addition, Ras protein levels were increased in PBMCs from old donors. These data indicate that reduced RSU-1 might induce Ras expression, which subsequently could provoke Ras-induced senescence. In conclusion, our data suggest that blood components that exhibit age-related changes, such as alterations in cytoskeletal regulators and stress proteins, may be associated with endothelial cell ageing.