Publications by authors named "Michael Skalski"

Great interest persists in useful prognostic and therapeutic targets in glioblastoma. In this study, we report the definition of miRNA (miR)-148a as a novel prognostic oncomiR in glioblastoma. miR-148a expression was elevated in human glioblastoma specimens, cell lines, and stem cells (GSC) compared with normal human brain and astrocytes.

View Article and Find Full Text PDF

Integrin signaling is central to cell growth and differentiation, and critical for the processes of apoptosis, cell migration and wound repair. Previous research has demonstrated a requirement for SNARE-dependent membrane traffic in integrin trafficking, as well as cell adhesion and migration. The goal of the present research was to ascertain whether SNARE-dependent membrane trafficking is required specifically for integrin-mediated signaling.

View Article and Find Full Text PDF

Background: Intracellular membrane traffic is an essential component of the membrane remodeling that supports lamellipodium extension during cell adhesion. The membrane trafficking pathways that contribute to cell adhesion have not been fully elucidated, but recent studies have implicated SNARE proteins. Here, the functions of several SNAREs (SNAP23, VAMP3, VAMP4 and syntaxin13) are characterized during the processes of cell spreading and membrane ruffling.

View Article and Find Full Text PDF

Cellular remodeling of the extracellular matrix (ECM), an essential component of many physiological and pathological processes, is dependent on the trafficking and secretion of matrix metalloproteinases (MMPs). Soluble NSF attachment protein receptor (SNARE)-mediated membrane traffic has documented roles in cell-ECM interactions and the present study specifically examines SNARE function in the trafficking of MMPs during ECM degradation. Using the invasive human fibrosarcoma cell line HT-1080, we demonstrate that a plasma membrane SNARE, SNAP23, and an endosomal v-SNARE, VAMP3 (also known as cellubrevin), partly colocalize with MMP2 and MMP9, and that inhibition of these SNAREs using dominant-negative SNARE mutants impaired secretion of the MMPs.

View Article and Find Full Text PDF

In the present study, we examined the role of soluble NSF attachment protein receptor (SNARE)-mediated membrane traffic in the formation of focal adhesions during cell spreading. CHO-K1 cells expressing a dominant-negative form of N-ethylmaleimide-sensitive factor (E329Q-NSF) were unable to spread as well as control cells and they formed focal adhesions (FAs) that were larger than those in control cells. FA formation was impaired in cells transfected with a dominant-negative form of RhoA, but, significantly, not in cells simultaneously expressing dominant-negative NSF.

View Article and Find Full Text PDF

In this study, the role of SNARE-mediated membrane traffic in regulating integrin localization was examined and the requirement for SNARE function in cellular spreading was quantitatively assessed. Membrane traffic was inhibited with the VAMP-specific catalytic light chain from tetanus toxin (TeTx-LC), a dominant-negative form (E329Q) of N-ethylmaleimide-sensitive fusion protein (NSF), and brefeldin A (BfA). Inhibition of membrane traffic with either E329Q-NSF or TeTx-LC, but not BfA, significantly inhibited spreading of CHO cells on fibronectin.

View Article and Find Full Text PDF

Cell migration occurs as a highly-regulated cycle of cell polarization, membrane extension at the leading edge, adhesion, contraction of the cell body, and release from the extracellular matrix at the trailing edge. In this study, we investigated the involvement of SNARE-mediated membrane trafficking in cell migration. Using a dominant-negative form of the enzyme N-ethylmaleimide-sensitive factor as a general inhibitor of SNARE-mediated membrane traffic and tetanus toxin as a specific inhibitor of VAMP3/cellubrevin, we conducted transwell migration assays and determined that serum-induced migration of CHO-K1 cells is dependant upon SNARE function.

View Article and Find Full Text PDF