The presence of activated intratumoral T cells correlates clinically with better prognosis in patients with cancer. Although tumor vaccines can increase the number of tumor-specific CD8 þ T cells in systemic circulation,

The nucleus in eukaryotic cells can move within the cytoplasm, and its position is crucial for many cellular events, including migration and differentiation. Nuclear anchorage and movement can be achieved through association of outer nuclear membrane (ONM) proteins with the three cytoskeletal systems. Two decades ago studies described C. elegans mutants with defects in such events, but only recently has it been shown that the strategies for nuclear positioning are indeed conserved in C. elegans, Drosophila, mammals and potentially all eukaryotes. The integral ONM proteins implicated in these processes thus far all contain a conserved Klarsicht/ANC-1/Syne homology (KASH) domain at their C-terminus that can associate with Sad1p/UNC-84 (SUN)-domain proteins of the inner nuclear membrane within the periplasmic space of the nuclear envelope (NE). The complex thus formed is responsible not only for association with cytoplasmic elements but also for the integrity of the NE itself. Journal of Cell Science 5022 region and residues that lie within the PS, and a cytoplasmic N-terminus that does not show sequence similarity to any known protein (McGee et al., 2006). UNC-84 contains several potential transmembrane domains and a C-terminal region that is homologous to the yeast protein Sad1p and, accordingly, is called the Sad1p/UNC-84 (SUN) domain (Malone et al., 1999;McGee et al., 2006). The localization of UNC-84 to the INM is not dependent upon its SUN domain but rather on the presence of nuclear lamins, which probably interact with its Nterminus (Lee et al., 2002). Deletion of UNC-84, mutations in the UNC-84 SUN domain or mutations within the UNC-83 KASH domain can prevent the localization of UNC-83 at the ONM (McGee et al., 2006;Starr et al., 2001), presumably because of a loss of direct interaction between the UNC-83 KASH and UNC-84 SUN domains within the PS (McGee et al., 2006) (Fig. 2). This explains why the nuclear migration defects in unc-83 and unc-84 mutant worms are very similar (Malone et al., 1999). Curiously, UNC-83 is present at the NE in a limited number of cell types (including P, hyp7, intestinal, pharyngeal and uterine cells), unlike UNC-84, which is localized at the NE in nearly all cells (Starr et al., 2001).UNC-83 and UNC-84 were originally proposed to tether the nucleus to centrosomes, which was hypothesized to drive nuclear migration (Malone et al., 1999;Reinsch and Gonczy, 1998); however, later studies showed a normal association between the centrosomes and nuclei in unc-83 and unc-84 mutant cells whose nuclei fail to migrate (Lee et al., 2002;Starr et al., 2001). The proteins that interact with the N-terminus of UNC-83 to facilitate nuclear migration have not been identified. Recently, another ONM protein, was shown to mediate an association between the centrosomes and Journal of Cell Science 119 (24) the nucleus in C. elegans. In zygote defective (zyg)-12 mutant worms, the centrosome detachment defect in the developing embryo results in death as a consequence of chromosome segregation defects (...

BackgroundNumerous studies have demonstrated that functional mitochondria are required for tumorigenesis, suggesting that mitochondrial oxidative phosphorylation (OXPHOS) might be a potential target for cancer therapy. In this study, we investigated the effects of BAY 87-2243, a small molecule that inhibits the first OXPHOS enzyme (complex I), in melanoma in vitro and in vivo.ResultsBAY 87-2243 decreased mitochondrial oxygen consumption and induced partial depolarization of the mitochondrial membrane potential. This was associated with increased reactive oxygen species (ROS) levels, lowering of total cellular ATP levels, activation of AMP-activated protein kinase (AMPK), and reduced cell viability. The latter was rescued by the antioxidant vitamin E and high extracellular glucose levels (25 mM), indicating the involvement of ROS-induced cell death and a dependence on glycolysis for cell survival upon BAY 87-2243 treatment. BAY 87-2243 significantly reduced tumor growth in various BRAF mutant melanoma mouse xenografts and patient-derived melanoma mouse models. Furthermore, we provide evidence that inhibition of mutated BRAF using the specific small molecule inhibitor vemurafenib increased the OXPHOS dependency of BRAF mutant melanoma cells. As a consequence, the combination of both inhibitors augmented the anti-tumor effect of BAY 87-2243 in a BRAF mutant melanoma mouse xenograft model.ConclusionsTaken together, our results suggest that complex I inhibition has potential clinical applications as a single agent in melanoma and also might be efficacious in combination with BRAF inhibitors in the treatment of patients with BRAF mutant melanoma.Electronic supplementary materialThe online version of this article (doi:10.1186/s40170-015-0138-0) contains supplementary material, which is available to authorized users.

Integrin αvβ3, even when locked in high affinity conformations for the RGD recognition motif shows no appreciable binding of soluble fibronectin and, consequently, fails to support the typical fibroblast focal adhesion distribution, Rho activity and fibronectin fibrillogenesis in the absence of integrin α5β1. The ability of α5β1 integrin to interact with soluble fibronectin may thus drive the cell-matrix adhesion and cytoskeletal organization required for a contractile, fibroblast-like morphology, perhaps explaining why α5β1 integrin, similarly to fibronectin, is essential for development. Supplementary material available online at