In the course of modeling the naturally occurring tumor immunity seen in patients with paraneoplastic cerebellar degeneration (PCD), we discovered an unexpectedly high threshold for breaking CD8+ cytotoxic T cell (CTL) tolerance to the PCD autoantigen, CDR2. While CDR2 expression was previously found to be strictly restricted to immune-privileged cells (cerebellum, testes, and tumors), unexpectedly we have found that T cells also express CDR2. This expression underlies inhibition of CTL activation; CTLs that respond to epithelial cells expressing CDR2 fail to respond to T cells expressing CDR2. This was a general phenomenon, as T cells presenting influenza (flu) antigen also fail to activate otherwise potent flu-specific CTLs either in vitro or in vivo. Moreover, transfer of flu peptide–pulsed T cells into flu-infected mice inhibits endogenous flu-specific CTLs. Our finding that T cells serve as a site of immune privilege, inhibiting effector CTL function, uncovers an autorepressive loop with general biologic and clinical relevance.
Nathalie E. Blachère, Dana E. Orange, Emily C. Gantman, Bianca D. Santomasso, Graeme C. Couture, Teresa Ramirez-Montagut, John Fak, Kevin J. O’Donovan, Zhong Ru, Salina Parveen, Mayu O. Frank, Michael J. Moore, Robert B. Darnell
The complex signaling networks of the tumor microenvironment that facilitate tumor growth and progression toward metastatic disease are becoming a focus of potential therapeutic options. The chemokine IL-8 is overexpressed in multiple cancer types, including triple-negative breast cancer (TNBC), where it promotes the acquisition of mesenchymal features, stemness, resistance to therapies, and the recruitment of immune-suppressive cells to the tumor site. The present study explores the utility of a clinical-stage monoclonal antibody that neutralizes IL-8 (HuMax-IL8) as a potential therapeutic option for TNBC. HuMax-IL8 was shown to revert mesenchymalization in claudin-low TNBC models both in vitro and in vivo as well as to significantly decrease the recruitment of polymorphonuclear myeloid-derived suppressor cells (PMN-MDSCs) at the tumor site, an effect substantiated when used in combination with docetaxel. In addition, HuMax-IL8 enhanced the susceptibility of claudin-low breast cancer cells to immune-mediated lysis with NK and antigen-specific T cells in vitro. These results demonstrate the multifaceted way in which neutralizing this single chemokine reverts mesenchymalization, decreases recruitment of MDSCs at the tumor site, assists in immune-mediated killing, and forms the rationale for using HuMax-IL8 in combination with chemotherapy or immune-based therapies for the treatment of TNBC.
Charli Dominguez, Kristen K. McCampbell, Justin M. David, Claudia Palena
Pancreatic ductal adenocarcinomas (PDAs) are desmoplastic and can undergo epithelial-to-mesenchymal transition to confer metastasis and chemoresistance. Studies have demonstrated that phenotypically and functionally distinct stromal cell populations exist in PDAs. Fibroblast activation protein–expressing (FAP-expressing) cells act to enhance PDA progression, while α–smooth muscle actin myofibroblasts can restrain PDA. Thus, identification of precise molecular targets that mediate the protumorigenic activity of FAP+ cells will guide development of therapy for PDA. Herein, we demonstrate that FAP overexpression in the tumor microenvironment correlates with poor overall and disease-free survival of PDA patients. Genetic deletion of FAP delayed onset of primary tumor and prolonged survival of mice in the KPC mouse model of PDA. While genetic deletion of FAP did not affect primary tumor weight in advanced disease, FAP deficiency increased tumor necrosis and impeded metastasis to multiple organs. Lineage-tracing studies unexpectedly showed that FAP is not only expressed by stromal cells, but can also be detected in a subset of CD90+ mesenchymal PDA cells, representing up to 20% of total intratumoral FAP+ cells. These data suggest that FAP may regulate PDA progression and metastasis in cell-autonomous and/or non-cell-autonomous fashions. Together, these data support pursuing FAP as a therapeutic target in PDA.
Albert Lo, Chung-Pin Li, Elizabeth L. Buza, Rachel Blomberg, Priya Govindaraju, Diana Avery, James Monslow, Michael Hsiao, Ellen Puré
We have recently reported that tumor-associated macrophages (TAMs) promote early transcoelomic metastasis of ovarian cancer by facilitating TAM–ovarian cancer cell spheroid formation. ASK1 is known to be important for macrophage activation and inflammation-mediated tumorigenesis. In the present study, we show that ASK1 deficiency attenuates TAM-spheroid formation and ovarian cancer progression in an orthotopic ovarian cancer model. Interestingly, ASK1 in stroma, but not in TAMs, is critical for peritoneal tumor growth of ovarian cancer. Moreover, overexpression of an ASK1 inhibitory protein (suppressor of cytokine signaling-1; SOCS1) in vascular endothelium attenuates vascular permeability, TAM infiltration, and ovarian cancer growth. Mechanistically, we show that ASK1 mediates degradation of endothelial junction protein VE-cadherin via a lysosomal pathway to promote macrophage transmigration. Importantly, a pharmacological ASK1 inhibitor prevents tumor-induced vascular leakage, macrophage infiltration, and tumor growth in two mouse models. Since transcoelomic metastasis is also associated with many other cancers, such as pancreatic and colon cancers, our study provides ASK1 as a therapeutic target for the treatment of ovarian cancer and other transcoelomic metastasis cancers.
Mingzhu Yin, Huanjiao Jenny Zhou, Jiqin Zhang, Caixia Lin, Hongmei Li, Xia Li, Yonghao Li, Haifeng Zhang, David G. Breckenridge, Weidong Ji, Wang Min
The oncoprotein Mdm2 is a RING domain–containing E3 ubiquitin ligase that ubiquitinates G protein–coupled receptor kinase 2 (GRK2) and β-arrestin2, thereby regulating β-adrenergic receptor (βAR) signaling and endocytosis. Previous studies showed that cardiac Mdm2 expression is critical for controlling p53-dependent apoptosis during early embryonic development, but the role of Mdm2 in the developed adult heart is unknown. We aimed to identify if Mdm2 affects βAR signaling and cardiac function in adult mice. Using Mdm2/p53–KO mice, which survive for 9–12 months, we identified a critical and potentially novel role for Mdm2 in the adult mouse heart through its regulation of cardiac β1AR signaling. While baseline cardiac function was mostly similar in both Mdm2/p53–KO and wild-type (WT) mice, isoproterenol-induced cardiac contractility in Mdm2/p53–KO was significantly blunted compared with WT mice. Isoproterenol increased cAMP in left ventricles of WT but not of Mdm2/p53–KO mice. Additionally, while basal and forskolin-induced calcium handling in isolated Mdm2/p53–KO and WT cardiomyocytes were equivalent, isoproterenol-induced calcium handling in Mdm2/p53–KO was impaired. Mdm2/p53–KO hearts expressed 2-fold more GRK2 than WT. GRK2 polyubiquitination via lysine-48 linkages was significantly reduced in Mdm2/p53–KO hearts. Tamoxifen-inducible cardiomyocyte-specific deletion of Mdm2 in adult mice also led to a significant increase in GRK2, and resulted in severely impaired cardiac function, high mortality, and no detectable βAR responsiveness. Gene delivery of either Mdm2 or GRK2-CT in vivo using adeno-associated virus 9 (AAV9) effectively rescued β1AR-induced cardiac contractility in Mdm2/p53–KO. These findings reveal a critical p53-independent physiological role of Mdm2 in adult hearts, namely, regulation of GRK2-mediated desensitization of βAR signaling.
Pierre-Yves Jean-Charles, Samuel Mon-Wei Yu, Dennis Abraham, Reddy Peera Kommaddi, Lan Mao, Ryan T. Strachan, Zhu-Shan Zhang, Dawn E. Bowles, Leigh Brian, Jonathan A. Stiber, Stephen N. Jones, Walter J. Koch, Howard A. Rockman, Sudha K. Shenoy
Bone metastases (BoM) are a significant cause of morbidity in patients with estrogen receptor–positive (ER-positive) breast cancer; yet, characterizations of human specimens are limited. In this study, exome-capture RNA sequencing (ecRNA-seq) on aged (8–12 years), formalin-fixed, paraffin-embedded (FFPE), and decalcified cancer specimens was evaluated. Gene expression values and ecRNA-seq quality metrics from FFPE or decalcified tumor RNA showed minimal differences when compared with matched flash-frozen or nondecalcified tumors. ecRNA-seq was then applied on a longitudinal collection of 11 primary breast cancers and patient-matched synchronous or recurrent BoMs. Overtime, BoMs exhibited gene expression shifts to more Her2 and LumB PAM50 subtype profiles, temporally influenced expression evolution, recurrently dysregulated prognostic gene sets, and longitudinal expression alterations of clinically actionable genes, particularly in the CDK/Rb/E2F and FGFR signaling pathways. Taken together, this study demonstrates the use of ecRNA-seq on decade-old and decalcified specimens and defines recurrent longitudinal transcriptional remodeling events in estrogen-deprived breast cancers.
Nolan Priedigkeit, Rebecca J. Watters, Peter C. Lucas, Ahmed Basudan, Rohit Bhargava, William Horne, Jay K. Kolls, Zhou Fang, Margaret Q. Rosenzweig, Adam M. Brufsky, Kurt R. Weiss, Steffi Oesterreich, Adrian V. Lee
Advanced breast cancer is frequently associated with skeletal metastases and accelerated bone loss. Recombinant parathyroid hormone [teriparatide, PTH(1-34)] is the first anabolic agent approved in the US for treatment of osteoporosis. While signaling through the PTH receptor in the osteoblast lineage regulates bone marrow hematopoietic niches, the effects of anabolic PTH on the skeletal metastatic niche are unknown. Here, we demonstrate, using orthotopic and intratibial models of 4T1 murine and MDA-MB-231 human breast cancer tumors, that anabolic PTH decreases both tumor engraftment and the incidence of spontaneous skeletal metastasis in mice. Microcomputed tomography and histomorphometric analyses revealed that PTH increases bone volume and reduces tumor engraftment and volume. Transwell migration assays with murine and human breast cancer cells revealed that PTH alters the gene expression profile of the metastatic niche, in particular VCAM-1, to inhibit recruitment of cancer cells. While PTH did not affect growth or migration of the primary tumor, it elicited several changes in the tumor gene expression profile resulting in a less metastatic phenotype. In conclusion, PTH treatment in mice alters the bone microenvironment, resulting in decreased cancer cell engraftment, reduced incidence of metastases, preservation of bone microarchitecture and prolonged survival.
Srilatha Swami, Joshua Johnson, Lance A. Bettinson, Takaharu Kimura, Hui Zhu, Megan A. Albertelli, Rachelle W. Johnson, Joy Y. Wu
Adrenergic signaling is known to promote tumor growth and metastasis, but the effects on tumor stroma are not well understood. An unbiased bioinformatics approach analyzing tumor samples from patients with known biobehavioral profiles identified a prominent stromal signature associated with cancer-associated fibroblasts (CAFs) in those with a high biobehavioral risk profile (high Center for Epidemiologic Studies Depression Scale [CES-D] score and low social support). In several models of epithelial ovarian cancer, daily restraint stress resulted in significantly increased CAF activation and was abrogated by a nonspecific β-blocker. Adrenergic signaling–induced CAFs had significantly higher levels of collagen and extracellular matrix components than control tumors. Using a systems-based approach, we found INHBA production by cancer cells to induce CAFs. Ablating inhibin β A decreased CAF phenotype both in vitro and in vivo. In preclinical models of breast and colon cancers, there were increased CAFs and collagens following daily restraint stress. In an independent data set of renal cell carcinoma patients, there was an association between high depression (CES-D) scores and elevated expression of ACTA2, collagens, and inhibin β A. Collectively, our findings implicate adrenergic influences on tumor stroma as important drivers of CAFs and establish inhibin β A as an important regulator of the CAF phenotype in ovarian cancer.
Archana S. Nagaraja, Robert L. Dood, Guillermo Armaiz-Pena, Yu Kang, Sherry Y. Wu, Julie K. Allen, Nicholas B. Jennings, Lingegowda S. Mangala, Sunila Pradeep, Yasmin Lyons, Monika Haemmerle, Kshipra M. Gharpure, Nouara C. Sadaoui, Cristian Rodriguez-Aguayo, Cristina Ivan, Ying Wang, Keith Baggerly, Prahlad Ram, Gabriel Lopez-Berestein, Jinsong Liu, Samuel C. Mok, Lorenzo Cohen, Susan K. Lutgendorf, Steve W. Cole, Anil K. Sood
MTG16 is a member of the myeloid translocation gene (MTG) family of transcriptional corepressors. While MTGs were originally identified in chromosomal translocations in acute myeloid leukemia, recent studies have uncovered a role in intestinal biology. For example, Mtg16–/– mice have increased intestinal proliferation and are more sensitive to intestinal injury in colitis models. MTG16 is also underexpressed in patients with moderate/severe ulcerative colitis. Based on these findings, we postulated that MTG16 might protect against colitis-associated carcinogenesis. MTG16 was downregulated at the protein and RNA levels in patients with inflammatory bowel disease and in those with colitis-associated carcinoma. Mtg16–/– mice subjected to inflammatory carcinogenesis modeling exhibited worse colitis and increased tumor multiplicity and size. Loss of MTG16 also increased severity of dysplasia, apoptosis, proliferation, DNA damage, and WNT signaling. Moreover, transplantation of WT marrow into Mtg16–/– mice failed to rescue the Mtg16–/– protumorigenic phenotypes, indicating an epithelium-specific role for MTG16. While MTG dysfunction is widely appreciated in hematopoietic malignancies, the role of this gene family in epithelial homeostasis, and in colon cancer, was unrealized. This report identifies MTG16 as an important modulator of colitis and tumor development in inflammatory carcinogenesis.
Elizabeth M. McDonough, Caitlyn W. Barrett, Bobak Parang, Mukul K. Mittal, J. Joshua Smith, Amber M. Bradley, Yash A. Choksi, Lori A. Coburn, Sarah P. Short, Joshua J. Thompson, Baolin Zhang, Shenika V. Poindexter, Melissa A. Fischer, Xi Chen, Jiang Li, Frank L. Revetta, Rishi Naik, M. Kay Washington, Michael J. Rosen, Scott W. Hiebert, Keith T. Wilson, Christopher S. Williams
The tumor suppressor PTEN is frequently inactivated in breast and other cancers; yet, germ-line mutations in this gene induce nonmalignant hamartomas, indicating dependency on additional cooperating events. Here we show that most tumors derived from conditional deletion of mouse pten in mammary epithelium are highly differentiated and lack transplantable tumor-initiating cells (TICs) capable of seeding new tumors following orthotopic injection of FACS-sorted or tumorsphere cells. A rare group of poorly differentiated tumors did harbor transplantable TICs. These transplantable tumors exhibited distinct molecular classification, signaling pathways, chromosomal aberrations, and mutational landscape, as well as reduced expression of microRNA-143/145 (miR-143/145). Stable knockdown of miR-143/145 conferred tumorigenic potential upon poorly transplantable pten-deficient tumor cells through a mechanism involving induction of RAS signaling, leading to increased sensitivity to MEK inhibition. In humans, miR-145 deficiency significantly correlated with elevated RAS-pathway activity in basal-like breast cancer, and patients with combined PTEN/miR-145 loss or PTEN-loss/high RAS-pathway activity exhibited poor clinical outcome. These results underscore a selective pressure for combined PTEN loss together with RAS-pathway activation, either through miR-145 loss or other mechanisms, in basal-like breast cancer, and a need to identify and prioritize these tumors for aggressive therapy.
Sharon Wang, Jeff C. Liu, YoungJun Ju, Giovanna Pellecchia, Veronique Voisin, Dong-Yu Wang, Rajwinder Leha l, Yaacov Ben-David, Gary D. Bader, Eldad Zacksenhaus
No posts were found with this tag.