Palladin Mutation Causes Familial Pancreatic Cancer and Suggests a New Cancer Mechanism

BACKGROUND: Pancreatic cancer is a deadly disease. Discovery of the mutated genes that cause the inherited form(s) of the disease may shed light on the mechanism(s) of oncogenesis. Previously we isolated a susceptibility locus for familial pancreatic cancer to chromosome location 4q32–34. In this study, our goal was to discover the identity of the familial pancreatic cancer gene on 4q32 and determine the function of that gene. METHODS AND FINDINGS: A customized microarray of the candidate chromosomal region affecting pancreatic cancer susceptibility revealed the greatest expression change in palladin (PALLD), a gene that encodes a component of the cytoskeleton that controls cell shape and motility. A mutation causing a proline (hydrophobic) to serine (hydrophilic) amino acid change (P239S) in a highly conserved region tracked with all affected family members and was absent in the non-affected members. The mutational change is not a known single nucleotide polymorphism. Palladin RNA, measured by quantitative RT-PCR, was overexpressed in the tissues from precancerous dysplasia and pancreatic adenocarcinoma in both familial and sporadic disease. Transfection of wild-type and P239S mutant palladin gene constructs into HeLa cells revealed a clear phenotypic effect: cells expressing P239S palladin exhibited cytoskeletal changes, abnormal actin bundle assembly, and an increased ability to migrate. CONCLUSIONS: These observations suggest that the presence of an abnormal palladin gene in familial pancreatic cancer and the overexpression of palladin protein in sporadic pancreatic cancer cause cytoskeletal changes in pancreatic cancer and may be responsible for or contribute to the tumor's strong invasive and migratory abilities

Human Embryonic Stem Cell-Derived Cardiomyocytes Migrate in Response to Gradients of Fibronectin and Wnt5a: Implications for cardiac repair & congenital heart defects

Thesis (Ph.D.)--University of Washington, 2013An improved understanding of the factors that regulate the migration of human embryonic stem cell-derived cardiomyocytes (hESC-CMs) would provide new insights into human heart development and suggest novel strategies to improve their electromechanical integration following intra-cardiac transplantation. Until now, nothing has been reported as to the factors controlling hESC-CM migration. Here we hypothesized that hESC-CMs would migrate in response to extracellular matrix and soluble signaling molecules previously implicated in heart morphogenesis. To test this, we screened candidate factors by transwell assay for effects on hESC-CM motility, followed by validation via live cell imaging and/or gap-closure assays. Fibronectin (FN) elicited a haptotactic response from hESC-CMs, with cells seeded on a steep FN gradient showing nearly five-fold greater migratory activity than cells on uniform FN. Studies with neutralizing antibodies indicated that adhesion and migration on FN are mediated by integrins α-5 and α-V. Next, we screened 10 soluble candidates by transwell assay and found that the non-canonical Wnt, Wnt5a, elicited a ~two-fold increase in migration over controls. This effect was confirmed using the gap closure assay, in which Wnt5a-treated hESC-CMs showed ~two-fold greater closure than untreated cells. Studies with microfluidics-generated Wnt5a gradients showed that this factor was chemoattractive as well as chemokinetic, and Wnt5a-mediated responses were inhibited by the Frizzled-1/2 receptor antagonist, UM206. In summary, hESC-CMs show robust pro-migratory responses to FN and Wnt5a, findings that have implications for both cardiac development and cell based therapies

Developing immunotherapeutic strategies to target brain tumors

<p><b>Introduction</b>: Recent years have seen rapid growth in cancer treatments that enhance the anti-tumor activities of the immune system. Collectively known as immunotherapy, modulation of the immune system has shown success treating some hematological malignancies, but has yet to be successfully applied to the treatment of patients with brain tumors.</p> <p><b>Areas covered</b>: This review highlights mechanistic insights from murine studies and compiled recent clinical trial data, focusing on the most aggressive brain tumor, glioblastoma (GBM). The field has recently accumulated a critical mass of data, and we discuss past treatment failures in the context of newly developed approaches now entering clinical trials. This article provides an overview of the immunotherapeutic armamentarium currently in development for the treatment of patients with GBM, who are in dire need of safe and effective therapies.</p> <p><b>Expert commentary</b>: Themes that emerge include the importance of mitigating the effects of an immunosuppressive tumor microenvironment and the potential for innate immune cell activation to enhance cytotoxic anti-tumor activity. Consideration of these studies as a collective may inform the design of new immunotherapies, as well as the immune monitoring protocols for patients participating in clinical trials</p

Human Embryonic Stem Cell-Derived Cardiomyocytes Migrate in Response to Gradients of Fibronectin and Wnt5a

Lincoln meteorological observations have been taken at a range of sites over the years. A NIWA report (Mullan, A.B; Stuart, S.J; Hadfield, M.G; Smith, M.J (2010). Report on the Review of NIWA's 'Seven-Station' Temperature Series. NIWA Information Series No. 78. pp.129-154) records a number of these along with the work undertaken to reconcile the data between different sites. It is not yet clear which site(s) these measurements were taken at as we have not yet identified a correspondence with NIWA's records.The datasets had been stored as .DAT files. The .DAT files have been uploaded as is, and also standardised and converted into .csv format.Headers: The original .DAT files were stored without headers. Most of these could be recovered for the .csv by running the data through an old program that had been used in conjunction with the data, but one column remains "unknown".Missing data: In the .DAT files, missing measurements are variously recorded, depending on context, as 0, -9, -99 or (in the case of Cloud cover) 9. In the .csv these values have been removed and left blank.Units are most likely:* solar radiation - probably MJ/m2 (megajoules per square metre)* temperatures - Celsius (in early years possibly converted from an original measurement in Fahrenheit)* rainfall - millimetres* cloud - oktas (eighths of the sky taken up by cloud)* wind run - kilometres* vapour pressure - probably Pa (pascals

Immune evasion mediated by tumor-derived lactate dehydrogenase induction of NKG2D ligands on myeloid cells in glioblastoma patients.

Myeloid cells are key regulators of the tumor microenvironment, governing local immune responses. Here we report that tumor-infiltrating myeloid cells and circulating monocytes in patients with glioblastoma multiforme (GBM) express ligands for activating the Natural killer group 2, member D (NKG2D) receptor, which cause down-regulation of NKG2D on natural killer (NK) cells. Tumor-infiltrating NK cells isolated from GBM patients fail to lyse NKG2D ligand-expressing tumor cells. We demonstrate that lactate dehydrogenase (LDH) isoform 5 secreted by glioblastoma cells induces NKG2D ligands on monocytes isolated from healthy individuals. Furthermore, sera from GBM patients contain elevated amounts of LDH, which correlate with expression of NKG2D ligands on their autologous circulating monocytes. NKG2D ligands also are present on circulating monocytes isolated from patients with breast, prostate, and hepatitis C virus-induced hepatocellular carcinomas. Together, these findings reveal a previously unidentified immune evasion strategy whereby tumors produce soluble factors that induce NKG2D ligands on myeloid cells, subverting antitumor immune responses

Anti-PD-L1 antibody direct activation of macrophages contributes to a radiation-induced abscopal response in glioblastoma

BACKGROUND Most glioblastoma recurrences occur near prior radiation treatment sites. Future clinical success will require achieving and optimizing an 'abscopal effect', whereby un-irradiated neoplastic cells outside treatment sites are recognized and attacked by the immune system. Radiation combined with anti-PD-L1 demonstrated modest efficacy in phase II human glioblastoma clinical trials, but the mechanism and relevance of the abscopal effect during this response remains unknown. METHODS We modified an immune-competent, genetically-driven mouse glioma model (forced PDGF expression + PTEN loss) where a portion of the tumor burden is irradiated (PDGF) and another un-irradiated luciferase expressing tumor (PDGF+Luciferase) is used as a readout of the abscopal effect following systemic anti-PD-L1 immunotherapy. We assessed relevance of tumor neoepitope during the abscopal response by inducing expression of EGFRvIII (PDGF+EGFRvIII). Statistical tests were two-sided. RESULTS Following radiation of one lesion, anti-PD-L1 immunotherapy enhanced the abscopal response to the un-irradiated lesion. In PDGF-driven gliomas without tumor neoepitope (PDGF+Luciferase, n=8), the abscopal response occurred via anti-PD-L1-driven, ERK-mediated, bone marrow-derived macrophage phagocytosis of adjacent un-irradiated tumor cells, with modest survival implications (median survival 41 days vs. radiation alone 37.5 days, P=.03). In PDGF-driven gliomas with tumor neoepitope (PDGF+EGFRvIII, n=8), anti-PD-L1-enhanced abscopal response was associated with macrophage and T-cell infiltration and increased survival benefit (median survival 36 days vs. radiation alone 28 days, P=.001). CONCLUSION Our results indicate that anti-PD-L1 immunotherapy enhances a radiation induced abscopal response via canonical T-cell activation and direct macrophage activation in glioblastoma

Palladin Is an Alpha-Actinin Binding Protein that Controls Cytoskeletal Formation and Cell Movement

<p>Palladin binds other key proteins such as Ezrin [<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0030516#pmed-0030516-b016" target="_blank">16</a>]. Previous studies have shown that Ezrin and S100P are proteins that are abnormally regulated in pancreatic cancer [<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0030516#pmed-0030516-b035" target="_blank">35</a>,<a href="http://www.plosmedicine.org/article/info:doi/10.1371/journal.pmed.0030516#pmed-0030516-b036" target="_blank">36</a>].</p

The 90 kDa Palladin Is the Major Isoform Expressed in Human Pancreatic Epithelium

<p>Proteins were detected using polyclonal antibody to palladin raised in rabbit (ab 621) in this Western blot. The major palladin isoform expressed in normal HPDE and cultured epithelial cells is the 90 kDa isoform (solid arrows). The positive control sample (MSC, human mesenchymal stem cells) also has the major 90 kDa isoform, but the 140 kDa isoform is also present (dashed arrow). Mesenchymal stem cells express high levels of palladin.</p