Ras is mutated to remain in the active oncogenic state in many cancers. As Ras has proven difficult to target therapeutically, we searched for secreted, druggable proteins induced by Ras that are required for tumorigenesis. We found that Ras induces the secretion of cytokine IL6 in different cell types, and that knockdown of IL6, genetic ablation of the IL6 gene, or treatment with a neutralizing IL6 antibody retard Ras-driven tumorigenesis. IL6 appears to act in a paracrine fashion to promote angiogenesis and tumor growth. Inhibiting IL6 may therefore have therapeutic utility for treatment of cancers characterized by oncogenic Ras mutations.Supplemental material is available at http://www.genesdev.org.

Cerebral cavernous malformations (CCMs) are sporadically acquired or inherited vascular lesions of the central nervous system consisting of clusters of dilated thin-walled blood vessels that predispose individuals to seizures and stroke. Familial CCM is caused by mutations in KRIT1 (CCM1) or in malcavernin (CCM2), the murine ortholog of which was concurrently characterized as osmosensing scaffold for MEKK3 (OSM). The roles of the CCM proteins in the pathogenesis of the disorder remain largely unknown. Here, we use co-immunoprecipitation, fluorescence resonance energy transfer and subcellular localization strategies to show that the CCM1 gene product, KRIT1, interacts with the CCM2 gene product, malcavernin/OSM. Analogous to the established interactions of CCM1 and beta1 integrin with ICAP1, the CCM1/CCM2 association is dependent upon the phosphotyrosine binding (PTB) domain of CCM2. A familial CCM2 missense mutation abrogates the CCM1/CCM2 interaction, suggesting that loss of this interaction may be critical in CCM pathogenesis. CCM2 and ICAP1 bound to CCM1 via their respective PTB domains differentially influence the subcellular localization of CCM1. Furthermore, we expand upon the established involvement of CCM2 in the p38 mitogen-activated protein kinase signaling module by demonstrating that CCM1 associates with CCM2 and MEKK3 in a ternary complex. These data indicate that the genetic heterogeneity observed in familial CCM may reflect mutation of different molecular members of a coordinated signaling complex.

No abstract

The small GTPase Ras, which transmits extracellular signals to the cell, and the kinase Aurora-A, which promotes proper mitosis, can both be inappropriately activated in human tumors. Here, we show that Aurora-A in conjunction with oncogenic Ras enhances transformed cell growth. Furthermore, such transformation and in some cases also tumorigenesis depend upon S194 of RalA, a known Aurora-A phosphorylation site. Aurora-A promotes not only RalA activation but also translocation from the plasma membrane and activation of the effector protein RalBP1. Taken together, these data suggest that Aurora-A may converge upon oncogenic Ras signaling through RalA.

In this prospective, randomized, controlled trial, we found that alcohol is not required for effective EUS-guided pancreatic cyst ablation, and when alcohol is removed from the ablation process, there is a significant reduction in associated adverse events. A multi-agent chemotherapeutic ablation admixture did not appear to significantly improve rates of complete ablation compared with the current standard of alcohol lavage followed by paclitaxel alone. ClinicalTrials.gov ID: NCT01475331.

No abstract

The Ras family of small guanosine triphosphatases normally transmit signals from cell surface receptors to the interior of the cell. Stimulation of cell surface receptors leads to the activation of guanine exchange factors, which, in turn, convert Ras from an inactive GDP-bound state to an active GTP-bound state. However, in one third of human cancers, RAS is mutated and remains in the constitutively active GTP-bound state. In this oncogenic state, RAS activates a constellation of signaling that is known to promote tumorigenesis. One consequence of this oncogenic RAS signal in cancer cells is the upregulation of the cytokines interleukin (IL)-6, IL-8, and chemokine growth-regulated oncogene 1 (GRO-1). We review the evidence supporting a role for these cytokines in oncogenic RAS-driven solid tumors.

Mortality from pancreatic ductal adenocarcinoma cancer (PDAC) is among the highest of any cancer and frontline therapy has changed little in years. Activation of endothelial nitric oxide synthase (eNOS or NOS III) has been implicated recently in the pathogenesis of PDAC. In this study, we used genetically engineered mouse and human xenograft models to evaluate the consequences of targeting eNOS in PDAC. Genetic deficiency in eNOS limited the development of pre-invasive pancreatic lesions and trended towards an extended lifespan in mice with advanced pancreatic cancer. These effects were also observed upon oral administration of the clinically evaluated NOS small molecule inhibitor L-NAME. Similarly, other transgenic models of oncogenic KRas-driven tumors responded to L-NAME treatment. Finally, these results were recapitulated in xenograft models of human pancreatic cancer, in which L-NAME was found to broadly inhibit tumorigenic growth. Taken together, our findings offer preclinical proof-of-principle to repurpose L-NAME for clinical investigations in treatment of PDAC and possibly other KRas-driven human cancers.