Cell biology
Abstract
Pancreatic ductal adenocarcinoma (PDA) is an extremely metastatic and lethal disease. Here in both murine and human PDA we demonstrate that extracellular matrix architecture regulates cell extrusion and subsequent invasion from intact ductal structures through Tumor-Associated Collagen Signatures (TACS). This results in early dissemination from histologically pre-malignant lesions and continual invasion from well-differentiated disease, and suggests TACS as a biomarker to aid in the pathologic assessment of early disease. Furthermore, we show that pancreatitis results in invasion-conducive architectures, thus priming the stroma prior to malignant disease. Analysis in novel microfluidics-derived microtissues and in vivo demonstrates decreased extrusion and invasion following focal adhesion kinase (FAK) inhibition, consistent with decreased metastasis. Thus, data suggest that targeting FAK or strategies to re-engineer and normalize tumor microenvironments, may have a role not only in also in very early disease but also for limiting continued dissemination from unresectable disease. Likewise, it may be beneficial to employ stroma targeting strategies to resolve precursor diseases such as pancreatitis in order to remove stromal architectures that increase risk for early dissemination.
Authors
Arja Ray, Mackenzie K. Callaway, Nelson J. Rodríguez-Merced, Alexandra L. Crampton, Marjorie Carlson, Kenneth B. Emme, Ethan A. Ensminger, Alexander A. Kinne, Jonathan H. Schrope, Haley R. Rasmussen, Hong Jiang, David G. DeNardo, David K. Wood, Paolo P. Provenzano
Abstract
Tumor necrosis factor (TNF) ligation of TNF receptor 1 (TNFR1) promotes either inflammation and cell survival by inhibiting RIPK1’s death-signaling function and activating NF-kB, or causes RIPK1 to associate with the death-inducing signaling complex to initiate apoptosis or necroptosis. The cellular source of TNF that results in RIPK1-dependent cell death remains unclear. To address this, we employed in vitro systems and murine models of T cell-dependent transplant or tumor rejection in which target cell susceptibility to RIPK1-dependent cell death could be genetically altered. We show that TNF released by T cells is necessary and sufficient to activate RIPK1-dependent cell death in target cells and thereby mediate target cell cytolysis, independent of T cell frequency. Activation of the RIPK1-dependent cell death program in target cells by T cell-derived TNF accelerates murine cardiac allograft rejection and synergizes with anti-PD1 administration to destroy checkpoint blockade-resistant, murine melanoma. Together, the findings uncover a distinct immunological role for TNF released by cytotoxic effector T cells following cognate interactions with their antigenic targets. Manipulating T cell TNF and/or target cell susceptibility to RIPK1-dependent cell death can be exploited to either mitigate or augment T cell-dependent destruction of allografts and malignancies to improve outcomes.
Authors
Nicholas Chun, Rosalind L. Ang, Mark Chan, Robert L. Fairchild, William M. Baldwin III, Julian K. Horwitz, Jesse D. Gelles, Jerry Edward Chipuk, Michelle A. Kelliher, Vasile I. Pavlov, Yansui Li, Dirk Homann, Peter S. Heeger, Adrian T. Ting
Abstract
Hypoxia is associated with tumor radioresistance; therefore, a predictive marker for tumor hypoxia and a rational target to overcome it have been sought to realize personalized radiotherapy. Here, we show that serine protease inhibitor Kazal type I (SPINK1) meets these 2 criteria. SPINK1 expression was induced upon hypoxia (O2 < 0.1%) at the transcription initiation level in a HIF-dependent manner, causing an increase in secreted SPINK1 levels. SPINK1 proteins were detected both within and around hypoxic regions of xenografted and clinical tumor tissues, and their plasma levels increased in response to decreased oxygen supply to xenografts. Secreted SPINK1 proteins enhanced radioresistance of cancer cells even under normoxic conditions in EGFR-dependent and nuclear factor erythroid 2–related factor 2–dependent (Nrf2-dependent) manners and accelerated tumor growth after radiotherapy. An anti-SPINK1 neutralizing antibody exhibited a radiosensitizing effect. These results suggest that SPINK1 secreted from hypoxic cells protects the surrounding and relatively oxygenated cancer cells from radiation in a paracrine manner, justifying the use of SPINK1 as a target for radiosensitization and a plasma marker for predicting tumor hypoxia.
Authors
Tatsuya Suwa, Minoru Kobayashi, Yukari Shirai, Jin-Min Nam, Yoshiaki Tabuchi, Norihiko Takeda, Shusuke Akamatsu, Osamu Ogawa, Takashi Mizowaki, Ester M. Hammond, Hiroshi Harada
Abstract
In response to liver injury, hepatic stellate cells activate and acquire proliferative and contractile features. The regression of liver fibrosis appears to involve the clearance of activated hepatic stellate cells, either by apoptosis or by reversion towards a quiescent-like state, a process denominated deactivation. Thus, deactivation of active hepatic stellate cells has emerged as a novel and promising therapeutic approach for liver fibrosis. However, our knowledge of the master regulators involved in the de/activation of fibrotic hepatic stellate cells is still limited. The transcription factor GATA4 has been previously shown to play an important role in embryonic hepatic stellate cells quiescence. In this work, we show that lack of GATA4 in adult mice causes hepatic stellate cell activation and consequently, liver fibrosis. During regression of liver fibrosis, Gata4 is reexpressed in deactivated hepatic stellate cells. Overexpression of Gata4 in hepatic stellate cells promotes liver fibrosis regression in CCl4-treated mice. GATA4 induces changes in the expression of fibrogenic and antifibrogenic genes promoting hepatic stellate cell deactivation. Finally, we show that GATA4 directly represses EPAS1 transcription in hepatic stellate cells and that stabilization of the HIF2α protein in hepatic stellate cells leads to liver fibrosis.
Authors
Noelia Arroyo, Laura Villamayor, Irene Díaz, Rita Carmona, Mireia Ramos-Rodríguez, Ramon Muñoz-Chapuli, Lorenzo Pasquali, Miguel G. Toscano, Franz Martin, David A. Cano, Anabel Rojas
Abstract
Immune cells exhibit low-level, constitutive signaling at rest (tonic signaling). Such tonic signals are required for fundamental processes, including the survival of B lymphocytes, but when elevated by genetic or environmental causes can lead to autoimmunity. Events that control ongoing signal transduction are therefore tightly regulated by submembrane cytoskeletal polymers like filamentous (F)-actin. The actin-binding proteins that underpin the process, however, are poorly described. By investigating patients with ARPC1B-deficiency, we report that ARPC1B-containing ARP2/3 complexes are stimulated by Wiskott Aldrich Syndrome protein (WASP) to nucleate the branched actin networks that control tonic signaling from the B cell receptor (BCR). Despite an upregulation of ARPC1A, ARPC1B-deficient cells were not capable of WASP-mediated nucleation by ARP2/3 and this caused the loss of WASP-dependent structures including podosomes in macrophages and lamellipodia in B cells. In the B cell compartment, ARPC1B-deficiency also led to weakening of the cortical F-actin cytoskeleton that normally curtails the diffusion of B cell receptors and ultimately resulted in increased tonic lipid signaling, oscillatory calcium release from the endoplasmic reticulum (ER), and phosphorylated Akt. These events contributed to skewing the threshold for B cell activation in response to microbial associated molecular patterns (MAMPs). Thus, ARPC1B is critical for ARP2/3 complexes to control steady-state signaling of immune cells.
Authors
Gabriella Leung, Yuhuan Zhou, Philip Ostrowski, Sivakami Mylvaganam, Parastoo Boroumand, Daniel J. Mulder, Conghui Guo, Aleixo M. Muise, Spencer Freeman
Abstract
Mounting evidence points to alterations in mitochondrial metabolism in renal cell carcinoma (RCC). However, the mechanisms that regulate the TCA cycle in RCC remain uncharacterized. Here, we demonstrate that loss of TCA cycle enzyme expression is retained in RCC metastatic tissues. Moreover, proteomic analysis demonstrates that reduced TCA cycle enzyme expression is far more pronounced in RCC relative to other tumor types. Loss of TCA cycle enzyme expression is correlated with reduced expression of the transcription factor peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) which is also lost in RCC tissues. PGC-1α re-expression in RCC cells restores the expression of TCA cycle enzymes in vitro and in vivo and leads to enhanced glucose carbon incorporation into TCA cycle intermediates. Mechanistically, TGF-β signaling, in concert with histone deacetylase 7 (HDAC7), suppresses TCA cycle enzyme expression. Our studies show that pharmacologic inhibition of TGF-β restores the expression of TCA cycle enzymes and suppresses tumor growth in an orthotopic model of RCC. Taken together, this investigation reveals a novel role for the TGF-β/HDAC7 axis in global suppression of TCA cycle enzymes in RCC and provides new insight into the molecular basis of altered mitochondrial metabolism in this malignancy.
Authors
Hyeyoung Nam, Anirban Kundu, Suman Karki, Garrett J. Brinkley, Darshan S. Chandrashekar, Richard L. Kirkman, Juan Liu, Maria V. Liberti, Jason W. Locasale, Tanecia Mitchell, Sooryanarayana Varambally, Sunil Sudarshan
Abstract
Fibrotic posterior capsular opacification (PCO), a major complication of cataract surgery, is driven by transforming growth factor β (TGFβ). Previously, αV integrins were found to be critical for the onset of TGFβ-mediated PCO in vivo, however, the functional heterodimer was unknown. Here, β8 integrin conditional knockout (β8ITGcKO) lens cells (LCs) were observed to attenuate their fibrotic responses, while both β5 and β6 integrin null LCs underwent fibrotic changes similar to WT at 5 days PCS. RNAseq revealed that β8ITGcKO LCs attenuated their upregulation of integrins and their ligands, as well as known targets of TGFβ induced signaling at 24 hours PCS. Treatment of β8ITGcKO eyes with active TGFβ1 at the time of surgery rescued the fibrotic response. Treatment of wild type mice with an anti- αVβ8 integrin function blocking antibody at the time of surgery ameliorated both canonical TGFβ signaling and LC fibrotic response PCS, and treatment at 5 days PCS, after surgically induced fibrotic responses are established, largely reversed this fibrotic response. These data suggest that αVβ8 integrin is a major regulator of TGFβ activation by LCs PCS and that therapeutics targeting αVβ8 integrin could be effective for fibrotic PCO prevention and treatment.
Authors
Mahbubul H. Shihan, Samuel G. Novo, Yan Wang, Dean Sheppard, Amha Atakilit, Thomas D. Arnold, Nicole M. Rossi, Adam P. Faranda, Melinda K. Duncan
Abstract
Large independent analyses on cancer cell lines followed by functional studies have identified Schlafen 11 (SLFN11), a putative helicase, as the strongest predictor of sensitivity to DNA-damaging agents (DDAs), including platinum. However, its role as a prognostic biomarker is undefined, partially due to the lack of validated methods to score SLFN11 in human tissues. Here, we implemented a pipeline to quantify SLFN11 in human cancer samples. By analyzing a cohort of high-grade serous ovarian carcinoma (HGSOC) specimens before platinum-based chemotherapy treatment, we show, for the first time to our knowledge, that SLFN11 density in both the neoplastic and microenvironmental components was independently associated with favorable outcome. We observed SLFN11 expression in both infiltrating innate and adaptive immune cells, and analyses in a second, independent, cohort revealed that SLFN11 was associated with immune activation in HGSOC. We found that platinum treatments activated immune-related pathways in ovarian cancer cells in an SLFN11-dependent manner, representative of tumor-immune transactivation. Moreover, SLFN11 expression was induced in activated, isolated immune cell subpopulations, hinting that SLFN11 in the immune compartment may be an indicator of immune transactivation. In summary, we propose SLFN11 is a dual biomarker capturing simultaneously interconnected immunological and cancer cell–intrinsic functional dispositions associated with sensitivity to DDA treatment.
Authors
Claudia Winkler, Matthew King, Julie Berthe, Domenico Ferraioli, Anna Garuti, Federica Grillo, Jaime Rodriguez-Canales, Lorenzo Ferrando, Nicolas Chopin, Isabelle Ray-Coquard, Oona Delpuech, Davide Bedognetti, Alberto Ballestrero, Elisabetta Leo, Gabriele Zoppoli
Abstract
Ozone is a highly reactive environmental pollutant with well-recognized adverse effects on lung health. Bronchial hyperactivity (BHR) is one consequence of ozone exposure, particularly for individuals with underlying lung disease. Our data demonstrate ozone induces substantial ATP release from human airway epithelia in vitro and into the airways of mice in vivo, and that ATP is a potent inducer of mast cell degranulation and BHR, acting through P2X7 receptors on mast cells. Both mast cell-deficient and P2X7 receptor-deficient (P2XT-/-) mice demonstrate markedly attenuated BHR to ozone. Re-constitution of mast cell-deficient mice with WT mast cells and P2X7-/- mast cells restores ozone-induced BHR. Despite equal numbers of mast cells in reconstituted mouse lungs, mice reconstituted with P2X7-/- mast cells demonstrated significantly less robust BHR than mice reconstituted with WT mast cells. These results support a model where P2X7 on both mast cells and other cell types contribute to ozone-induce BHR.
Authors
Xiaomei Kong, William C. Bennett, Corey M. Jania, Kelly D. Chason, Zachary German, Jennifer Adouli, Samuel D. Budney, Brandon T. Oby, Catharina van Heusden, Eduardo R. Lazarowski, Ilona Jaspers, Scott H. Randell, Barry A. Hedgespeth, Glenn Cruse, Xiaoyang Hua, Stephen A. Schworer, Gregory J. Smith, Samir N. P. Kelada, Stephen L. Tilley
Abstract
Mutations in the cilium-associated protein CEP290 cause retinal degeneration as part of multi-organ ciliopathies or as retina-specific diseases. The precise location and the functional roles of CEP290 within cilia and, specifically, the connecting cilia (CC) of photoreceptors, remain unclear. We used superresolution fluorescence microscopy and electron microscopy (TEM) to localize CEP290 in the CC and in primary cilia of cultured cells with sub-diffraction resolution, and to determine effects of CEP290 deficiency in three mutant models. Radially, CEP290 localizes in close proximity to the microtubule doublets in the region between the doublets and the ciliary membrane. Longitudinally, it is distributed throughout the length of the CC whereas it is confined to the very base of primary cilia in hRPE-1 cells. We found Y-shaped links, ciliary sub-structures between microtubules and membrane, throughout the length of the CC. Severe CEP290 deficiencies in mouse models did not prevent assembly of cilia or cause obvious mislocalization of ciliary components in early stages of degeneration. There were fewer cilia and no normal outer segments in the mutants, but the Y-shaped links were clearly present. These results point to photoreceptor-specific functions of CEP290 essential for CC maturation and stability following the earliest stages of ciliogenesis.
Authors
Valencia L. Potter, Abigail R. Moye, Michael A. Robichaux, Theodore G. Wensel
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