Avanti lipid tools: connecting lipids, technology, and cell biology.

Lipid research is challenging owing to the complexity and diversity of the lipidome. Here we review a set of experimental tools developed for the seasoned lipid researcher, as well as, those who are new to the field of lipid research. Novel tools for probing protein-lipid interactions, applications for lipid binding antibodies, enhanced systems for the cellular delivery of lipids, improved visualization of lipid membranes using gold-labeled lipids, and advances in mass spectrometric analysis techniques will be discussed.

Triphendiol (NV-196), development of a novel therapy for pancreatic cancer.

Despite incremental progress in the treatment of pancreatic adenocarcinoma, the prognosis of patients remains poor. Here, we report the preclinical studies in pancreatic cancer cells that demonstrate the efficacy of triphendiol (NV-196, a synthetic isoflavene) both as a monotherapy and as a gemcitabine sensitizer. The in-vitro effects of triphendiol on the pancreatic cancer cell lines HPAC and MIAPaCa-2 were determined using cell proliferation, flow cytometry, and western blot analysis.

KSP inhibitor ARRY-520 as a substitute for Paclitaxel in Type I ovarian cancer cells.

Background: We previously described a sub-population of epithelial ovarian cancer (EOC) cells with a functional TLR-4/MyD88/NF-kappaB pathway (Type I EOC cells), which confers the capacity to respond to Paclitaxel, a known TLR-4 ligand, by enhancing NF-kappaB activity and upregulating cytokine secretion - events that are known to promote tumor progression. It is therefore important to distinguish those patients that should not receive Paclitaxel; it is also important to identify alternative chemotherapy options that would benefit this sub-group of patients. The objective of this study is to determine if the KSP inhibitor, ARRY-520, can be a substitute for Paclitaxel in patients with Type I EOC.

Basic residues in the Mason-Pfizer monkey virus gag matrix domain regulate intracellular trafficking and capsid-membrane interactions.

Mason-Pfizer monkey virus (M-PMV) capsids that have assembled in the cytoplasm must be transported to and associate with the plasma membrane prior to being enveloped by a lipid bilayer during viral release. Structural studies have identified a positive-charge density on the membrane-proximal surface of the matrix (MA) protein component of the Gag polyprotein. To investigate if basic amino acids in MA play a role in intracellular transport and capsid-membrane interactions, mutants were constructed in which lysine and arginine residues (R10, K16, K20, R22, K25, K27, K33, and K39) potentially exposed on the capsid surface were replaced singly and in pairs by alanine.

SCF(beta-TrCP1) controls Smad4 protein stability in pancreatic cancer cells.

Smad4, also known as deleted in pancreatic carcinoma locus 4 (DPC4), is a critical co-factor in signal transduction pathways activated by transforming growth factor (TGF)-beta-related ligands that regulate cell growth and differentiation. Mutations in Smad4/DPC4 have been identified in approximately 50% of pancreatic adenocarcinomas. Here we report that SCF(beta-TrCP1), a ubiquitin (E3) ligase, is a critical determinant for Smad4 protein degradation in pancreatic cancer cells.

Smad4 protein stability is regulated by ubiquitin ligase SCF beta-TrCP1.

Smad4 is a key intracellular mediator for the transforming growth factor-beta (TGF-beta) superfamily of growth factors and is also an important tumor suppressor. The receptor-regulated Smad (R-Smad) proteins are regulated by ubiquitin-mediated degradation, yet the precise control of Smad4 protein stability is unclear. We have identified SCF(beta-TrCP1), a ubiquitin (E3) ligase, as a critical determinant for the protein degradation of Smad4 protein.

The combination of calmodulin antagonists and interferon-gamma induces apoptosis through caspase-dependent and -independent pathways in cholangiocarcinoma cells.

Calmodulin (CaM) antagonists have been shown to inhibit tumor cell invasion and metastasis and to induce apoptosis in various tumor models, but the molecular mechanism of CaM antagonist-mediated apoptosis is poorly understood. Here, we demonstrate that interferon (IFN)-gamma induces susceptibility to CaM antagonist-mediated apoptosis in human cholangiocarcinoma cells weakly expressing Fas (Fas-low cells). During CaM antagonist-mediated apoptosis in IFN-gamma-pretreated Fas-low cells, cleavage of caspases-8, -9, and -3 and Bid, release of cytochrome c from the mitochondria and an increase in the free cytosolic calcium concentration were observed.