Publications by authors named "Jason R Pitarresi"

21 Publications

  • Page 1 of 1

Mutant p53 regulates Survivin to foster lung metastasis.

Genes Dev 2021 Apr 18;35(7-8):528-541. Epub 2021 Mar 18.

Herbert Irving Comprehensive Cancer Center, Columbia University, New York, New York 10032, USA.

Esophageal squamous cell carcinoma (ESCC) is one of the most lethal cancers worldwide and evolves often to lung metastasis. (homologous to in mice) is a common hot spot mutation. How metastasis is regulated by p53 in ESCC remains to be investigated. To investigate p53-mediated molecular mechanisms, we used a carcinogen-induced approach in mice to model ESCC. In the primary tumor cell lines, we depleted Trp53 (shTrp53) and observed a marked reduction in cell invasion in vitro and lung metastasis burden in a tail-vein injection model in comparing isogenic cells (shCtrl). Furthermore, we performed bulk RNA-seq to compare gene expression profiles of metastatic and primary shCtrl and shTrp53 cells. We identified the YAP- axis as a potential mediator of -mediated metastasis. We demonstrate that expression of Survivin, an antiapoptotic protein encoded by , increases in the presence of Trp53 Furthermore, depletion of Survivin specifically decreases Trp53-driven lung metastasis. Mechanistically, Trp53 but not wild-type Trp53, binds with YAP in ESCC cells, suggesting their cooperation to induce Survivin expression. Furthermore, Survivin high expression level is associated with increased metastasis in several GI cancers. Taken together, this study unravels new insights into how mutant p53 mediates metastasis.
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http://dx.doi.org/10.1101/gad.340505.120DOI Listing
April 2021

PTHrP drives pancreatic cancer growth and metastasis and reveals a new therapeutic vulnerability.

Cancer Discov 2021 Feb 15. Epub 2021 Feb 15.

Columbia University Medical Center

Pancreatic cancer metastasis is a leading cause of cancer-related deaths, yet very little is understood regarding the underlying biology. As a result, targeted therapies to inhibit metastasis are lacking. Here, we report that the parathyroid hormone-related protein (PTHrP encoded by PTHLH) is frequently amplified as part of the KRAS amplicon in pancreatic cancer patients. PTHrP upregulation drives the growth of both primary and metastatic tumors in mice and is highly enriched in PDAC metastases. Loss of PTHrP - either genetically or pharmacologically - dramatically reduces tumor burden, eliminates metastasis, and enhances overall survival. These effects are mediated in part through a reduction in epithelial-to-mesenchymal transition, which reduces the tumor cells' ability to initiate the metastatic cascade. Spp1, which encodes Osteopontin, is revealed to be a downstream effector of PTHrP. Our results establish a new paradigm in pancreatic cancer whereby PTHrP is a driver of disease progression and emerges as a novel therapeutic vulnerability.
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http://dx.doi.org/10.1158/2159-8290.CD-20-1098DOI Listing
February 2021

Growth of pancreatic cancers with hemizygous chromosomal 17p loss of can be preferentially targeted by PARP inhibitors.

Sci Adv 2020 Dec 4;6(49). Epub 2020 Dec 4.

Institute for Regenerative Medicine, Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania , Philadelphia, PA 19104-5157, USA.

Here, we selectively target pancreatic ductal adenocarcinoma (PDAC) cells harboring a hemizygous gene essential for cell growth. (), encoding a chromatin-bound protein, is hemizygous in most of the PDAC due to a chromosome 17p deletion that also spans We find that hemizygous loss in isogenic PDAC cells promotes tumorigenesis but, paradoxically, homozygous loss is associated with impaired cell growth and decreased tumorigenesis. Poly-adenosine 5'-diphosphate-ribose polymerase 1 (PARP1) interacts with MYBBP1A and displaces it from chromatin. Small molecules, such as olaparib, that trap PARP1 to chromatin are able to evict the minimal pool of chromatin-bound MYBBP1A protein in hemizygous cells and impair cell growth, greater than its impact on wild-type cells. Our findings reveal how a cell essential gene with one allele lost in cancer cells can be preferentially susceptible to a specific molecular therapy, when compared to wild-type cells.
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http://dx.doi.org/10.1126/sciadv.abc4517DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7821900PMC
December 2020

EMT, MET, Plasticity, and Tumor Metastasis.

Trends Cell Biol 2020 10 13;30(10):764-776. Epub 2020 Aug 13.

Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY 10032, USA. Electronic address:

Cancer cell identity and plasticity are required in transition states, such as epithelial-mesenchymal transition (EMT) and mesenchymal-epithelial transition (MET), in primary tumor initiation, progression, and metastasis. The functional roles of EMT, MET, and the partial state (referred to as pEMT) may vary based on the type of tumor, the state of dissemination, and the degree of metastatic colonization. Herein, we review EMT, MET, pEMT, and plasticity in the context of tumor metastasis.
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http://dx.doi.org/10.1016/j.tcb.2020.07.003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7647095PMC
October 2020

Pharmacologic Activation of the G Protein-Coupled Estrogen Receptor Inhibits Pancreatic Ductal Adenocarcinoma.

Cell Mol Gastroenterol Hepatol 2020 4;10(4):868-880.e1. Epub 2020 May 4.

Perelman School of Medicine, Department of Dermatology, University of Pennsylvania, Philadelphia. Electronic address:

Background & Aims: Female sex is associated with lower incidence and improved clinical outcomes for most cancer types including pancreatic ductal adenocarcinoma (PDAC). The mechanistic basis for this sex difference is unknown. We hypothesized that estrogen signaling may be responsible, despite the fact that PDAC lacks classic nuclear estrogen receptors.

Methods: Here we used murine syngeneic tumor models and human xenografts to determine that signaling through the nonclassic estrogen receptor G protein-coupled estrogen receptor (GPER) on tumor cells inhibits PDAC.

Results: Activation of GPER with the specific, small molecule, synthetic agonist G-1 inhibited PDAC proliferation, depleted c-Myc and programmed death ligand 1 (PD-L1), and increased tumor cell immunogenicity. Systemically administered G-1 was well-tolerated in PDAC bearing mice, induced tumor regression, significantly prolonged survival, and markedly increased the efficacy of PD-1 targeted immune therapy. We detected GPER protein in a majority of spontaneous human PDAC tumors, independent of tumor stage.

Conclusions: These data, coupled with the wide tissue distribution of GPER and our previous work showing that G-1 inhibits melanoma, suggest that GPER agonists may be useful against a range of cancers that are not classically considered sex hormone responsive and that arise in tissues outside of the reproductive system.
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http://dx.doi.org/10.1016/j.jcmgh.2020.04.016DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7578406PMC
May 2020

Murine models for familial pancreatic cancer: Histopathology, latency and drug sensitivity among cancers of Palb2, Brca1 and Brca2 mutant mouse strains.

PLoS One 2019 26;14(12):e0226714. Epub 2019 Dec 26.

Department of Cancer Biology and Genetics, The Ohio State University Comprehensive Cancer Center, Columbus, Ohio, United States of America.

Alterations of the PALB2 tumor suppressor gene have been identified in familial breast, ovarian and pancreatic cancer cases. PALB2 cooperates with BRCA1/2 proteins through physical interaction in initiation of homologous recombination, in maintenance of genome integrity following DNA double-strand breaks. To determine if the role of PALB2 as a linker between BRCA1 and BRCA2 is critical for BRCA1/2-mediated tumor suppression, we generated Palb2 mouse pancreatic cancer models and compared tumor latencies, phenotypes and drug responses with previously generated Brca1/2 pancreatic cancer models. For development of Palb2 pancreatic cancer, we crossed conditional Palb2 null mouse with mice carrying the KrasG12D; p53R270H; Pdx1-Cre (KPC) constructs, and these animals were observed for pancreatic tumor development. Individual deletion of Palb2, Brca1 or Brca2 genes in pancreas per se using Pdx1-Cre was insufficient to cause tumors, but it reduced pancreata size. Concurrent expression of mutant KrasG12D and p53R270H, with tumor suppressor inactivated strains in Palb2-KPC, Brca1-KPC or Brca2-KPC, accelerated pancreatic ductal adenocarcinoma (PDAC) development. Moreover, most Brca1-KPC and some Palb2-KPC animals developed mucinous cystic neoplasms with PDAC, while Brca2-KPC and KPC animals did not. 26% of Palb2-KPC mice developed MCNs in pancreata, which resemble closely the Brca1 deficient tumors. However, the remaining 74% of Palb2-KPC animals developed PDACs without any cysts like Brca2 deficient tumors. In addition, the number of ADM lesions and immune cells infiltrations (CD3+ and F/480+) were significantly increased in Brca1-KPC tumors, but not in Brca2-KPC tumors. Interestingly, the level of ADM lesions and infiltration of CD3+ or F/480+ cells in Palb2-KPC tumors were intermediate between Brca1-KPC and Brca2-KPC tumors. As expected, disruption of Palb2 and Brca1/2 sensitized tumor cells to DNA damaging agents in vitro and in vivo. Altogether, Palb2-KPC PDAC exhibited features observed in both Brca1-KPC and Brca2-KPC tumors, which could be due to its role, as a linker between Brca1 and Brca2.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0226714PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6932818PMC
April 2020

Mechanisms Underlying Metastatic Pancreatic Cancer.

Adv Exp Med Biol 2019 ;1164:3-10

Herbert Irving Comprehensive Cancer Center, Columbia University Irving Medical Center, New York, NY, USA.

Pancreatic ductal adenocarcinoma is an overwhelming fatal disease that often presents with overt metastases and ultimately causes the majority of cancer-associated deaths. The mechanisms underlying the metastatic cascade are complex, and research in recent years has begun to provide insights into the underlying drivers of this phenomenon. It has become clear that cancer cells, in particular pancreatic cancer cells, possess properties of plasticity involving bidirectional transition between epithelial and mesenchymal identities. Furthermore, recent work has begun to establish that there are distinct hybrid states between purely epithelial and purely mesenchymal states that cancer cells may reside, in order to thrive at different stages of carcinogenesis. We discuss how this plasticity is important for different phases of the metastatic cascade, from delamination to colonization, and how different epithelial-mesenchymal states may affect metastatic organotropism. In this review, we summarize the current understanding of pancreatic cancer cell plasticity and metastasis, and highlight current model systems that can be used to study these phenomena.
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http://dx.doi.org/10.1007/978-3-030-22254-3_1DOI Listing
October 2019

PRRX1 isoforms cooperate with FOXM1 to regulate the DNA damage response in pancreatic cancer cells.

Oncogene 2019 05 31;38(22):4325-4339. Epub 2019 Jan 31.

Division of Gastroenterology, Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, 19104, USA.

PRRX1 is a homeodomain transcriptional factor, which has two isoforms, PRXX1A and PRRX1B. The PRRX1 isoforms have been demonstrated to be important in pancreatic cancer, especially in the regulation of epithelial-to-mesenchymal transition (EMT) in Pancreatic Ductal Adenocarcinoma (PDAC) and of mesenchymal-to-epithelial transition (MET) in liver metastasis. In order to determine the functional underpinnings of PRRX1 and its isoforms, we have unraveled a new interplay between PRRX1 and the FOXM1 transcriptional factors. Our detailed biochemical analysis reveals the direct physical interaction between PRRX1 and FOXM1 proteins that requires the PRRX1A/B 200-222/217 amino acid (aa) region and the FOXM1 Forkhead domain. Additionally, we demonstrate the cooperation between PRRX1 and FOXM1 in the regulation of FOXM1-dependent transcriptional activity. Moreover, we establish FOXM1 as a critical downstream target of PRRX1 in pancreatic cancer cells. We demonstrate a novel role for PRRX1 in the regulation of genes involved in DNA repair pathways. Indeed, we show that expression of PRRX1 isoforms may limit the induction of DNA damage in pancreatic cancer cells. Finally, we demonstrate that targeting FOXM1 with the small molecule inhibitor FDI6 suppress pancreatic cancer cell proliferation and induces their apoptotic cell death. FDI6 sensitizes pancreatic cancer cells to Etoposide and Gemcitabine induced apoptosis. Our data provide new insights into PRRX1's involvement in regulating DNA damage and provide evidence of a possible PRRX1-FOXM1 axis that is critical for PDAC cells.
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http://dx.doi.org/10.1038/s41388-019-0725-6DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6542713PMC
May 2019

Disruption of stromal hedgehog signaling initiates RNF5-mediated proteasomal degradation of PTEN and accelerates pancreatic tumor growth.

Life Sci Alliance 2018 Oct 26;1(5):e201800190. Epub 2018 Oct 26.

Hollings Cancer Center and Department of Biochemistry & Molecular Biology, Medical University of South Carolina, Charleston, SC, USA.

The contribution of the tumor microenvironment to pancreatic ductal adenocarcinoma (PDAC) development is currently unclear. We therefore examined the consequences of disrupting paracrine Hedgehog (HH) signaling in PDAC stroma. Herein, we show that ablation of the key HH signaling gene () in stromal fibroblasts led to increased proliferation of pancreatic tumor cells. Furthermore, deletion resulted in proteasomal degradation of the tumor suppressor PTEN and activation of oncogenic protein kinase B (AKT) in fibroblasts. An unbiased proteomic screen identified RNF5 as a novel E3 ubiquitin ligase responsible for degradation of phosphatase and tensin homolog (PTEN) in -null fibroblasts. () knockdown or pharmacological inhibition of glycogen synthase kinase 3β (GSKβ), the kinase that marks PTEN for ubiquitination, rescued PTEN levels and reversed the oncogenic phenotype, identifying a new node of PTEN regulation. In PDAC patients, low stromal PTEN correlated with reduced overall survival. Mechanistically, PTEN loss decreased hydraulic permeability of the extracellular matrix, which was reversed by hyaluronidase treatment. These results define non-cell autonomous tumor-promoting mechanisms activated by disruption of the HH/PTEN axis and identifies new targets for restoring stromal tumor-suppressive functions.
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http://dx.doi.org/10.26508/lsa.201800190DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6238420PMC
October 2018

The LIN28B-IMP1 post-transcriptional regulon has opposing effects on oncogenic signaling in the intestine.

Genes Dev 2018 08;32(15-16):1020-1034

Department of Medicine, Division of Gastroenterology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania 19014, USA.

RNA-binding proteins (RBPs) are expressed broadly during both development and malignant transformation, yet their mechanistic roles in epithelial homeostasis or as drivers of tumor initiation and progression are incompletely understood. Here we describe a novel interplay between RBPs LIN28B and IMP1 in intestinal epithelial cells. Ribosome profiling and RNA sequencing identified as a principle node for gene expression regulation downstream from In vitro and in vivo data demonstrate that epithelial IMP1 loss increases expression of WNT target genes and enhances LIN28B-mediated intestinal tumorigenesis, which was reversed when we overexpressed IMP1 independently in vivo. Furthermore, IMP1 loss in wild-type or LIN28B-overexpressing mice enhances the regenerative response to irradiation. Together, our data provide new evidence for the opposing effects of the LIN28B-IMP1 axis on post-transcriptional regulation of canonical WNT signaling, with implications in intestinal homeostasis, regeneration and tumorigenesis.
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http://dx.doi.org/10.1101/gad.314369.118DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6075153PMC
August 2018

Regulation of Epithelial Plasticity Determines Metastatic Organotropism in Pancreatic Cancer.

Dev Cell 2018 06;45(6):696-711.e8

Division of Gastroenterology, Perelman School of Medicine, University of Pennsylvania, 900 Biomedical Research Building II/III, 415 Curie Boulevard, Philadelphia, PA 19104, USA; Department of Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA; Abramson Cancer Center, Perelman School of Medicine, University of Pennsylvania, 900 Biomedical Research Building II/III, 415 Curie Boulevard, Philadelphia, PA 19104, USA. Electronic address:

The regulation of metastatic organotropism in pancreatic ductal a denocarcinoma (PDAC) remains poorly understood. We demonstrate, using multiple mouse models, that liver and lung metastatic organotropism is dependent upon p120catenin (p120ctn)-mediated epithelial identity. Mono-allelic p120ctn loss accelerates Kras-driven pancreatic cancer formation and liver metastasis. Importantly, one p120ctn allele is sufficient for E-CADHERIN-mediated cell adhesion. By contrast, cells with bi-allelic p120ctn loss demonstrate marked lung organotropism; however, rescue with p120ctn isoform 1A restores liver metastasis. In a p120ctn-independent PDAC model, mosaic loss of E-CADHERIN expression reveals selective pressure for E-CADHERIN-positive liver metastasis and E-CADHERIN-negative lung metastasis. Furthermore, human PDAC and liver metastases support the premise that liver metastases exhibit predominantly epithelial characteristics. RNA-seq demonstrates differential induction of pathways associated with metastasis and epithelial-to-mesenchymal transition in p120ctn-deficient versus p120ctn-wild-type cells. Taken together, P120CTN and E-CADHERIN mediated epithelial plasticity is an addition to the conceptual framework underlying metastatic organotropism in pancreatic cancer.
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http://dx.doi.org/10.1016/j.devcel.2018.05.025DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6011231PMC
June 2018

ETV5 regulates ductal morphogenesis with Sox9 and is critical for regeneration from pancreatitis.

Dev Dyn 2018 06 19;247(6):854-866. Epub 2018 Apr 19.

Division of Gastroenterology, University of Pennsylvania, Philadelphia, Pennsylvania.

Background: The plasticity of pancreatic acinar cells to undergo acinar to ductal metaplasia (ADM) has been demonstrated to contribute to the regeneration of the pancreas in response to injury. Sox9 is critical for ductal cell fate and important in the formation of ADM, most likely in concert with a complex hierarchy of, as yet, not fully elucidated transcription factors.

Results: By using a mouse model of acute pancreatitis and three dimensional organoid culture of primary pancreatic ductal cells, we herein characterize the Ets-transcription factor Etv5 as a pivotal regulator of ductal cell identity and ADM that acts upstream of Sox9 and is essential for Sox9 expression in ADM. Loss of Etv5 is associated with increased severity of acute pancreatitis and impaired ADM formation leading to delayed tissue regeneration and recovery in response to injury.

Conclusions: Our data provide new insights in the regulation of ADM with implications in our understanding of pancreatic homeostasis, pancreatitis and epithelial plasticity. Developmental Dynamics 247:854-866, 2018. © 2018 Wiley Periodicals, Inc.
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http://dx.doi.org/10.1002/dvdy.24626DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5980739PMC
June 2018

Generation of a pancreatic cancer model using a Pdx1-Flp recombinase knock-in allele.

PLoS One 2017 21;12(9):e0184984. Epub 2017 Sep 21.

Hollings Cancer Center, Medical University of South Carolina, Charleston, South Carolina, United States of America.

The contribution of the tumor microenvironment to the development of pancreatic adenocarcinoma (PDAC) is unclear. The LSL-KrasG12D/+;LSL-p53R172H/+;Pdx-1-Cre (KPC) tumor model, which is widely utilized to faithfully recapitulate human pancreatic cancer, depends on Cre-mediated recombination in the epithelial lineage to drive tumorigenesis. Therefore, specific Cre-loxP recombination in stromal cells cannot be applied in this model, limiting the in vivo investigation of stromal genetics in tumor initiation and progression. To address this issue, we generated a new Pdx1FlpO knock-in mouse line, which represents the first mouse model to physiologically express FlpO recombinase in pancreatic epithelial cells. This mouse specifically recombines Frt loci in pancreatic epithelial cells, including acinar, ductal, and islet cells. When combined with the Frt-STOP-Frt KrasG12D and p53Frt mouse lines, simultaneous Pdx1FlpO activation of mutant Kras and deletion of p53 results in the spectrum of pathologic changes seen in PDAC, including PanIN lesions and ductal carcinoma. Combination of this KPF mouse model with any stroma-specific Cre can be used to conditionally modify target genes of interest. This will provide an excellent in vivo tool to study the roles of genes in different cell types and multiple cell compartments within the pancreatic tumor microenvironment.
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http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0184984PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5608307PMC
October 2017

IL-18 Drives ILC3 Proliferation and Promotes IL-22 Production via NF-κB.

J Immunol 2017 10 25;199(7):2333-2342. Epub 2017 Aug 25.

The James Cancer Hospital and Solove Research Institute, The Ohio State University Comprehensive Cancer Center, Columbus, OH 43210;

Group 3 innate lymphoid cells (ILC3s) are important regulators of the immune system, maintaining homeostasis in the presence of commensal bacteria, but activating immune defenses in response to microbial pathogens. ILC3s are a robust source of IL-22, a cytokine critical for stimulating the antimicrobial response. We sought to identify cytokines that can promote proliferation and induce or maintain IL-22 production by ILC3s and determine a molecular mechanism for this process. We identified IL-18 as a cytokine that cooperates with an ILC3 survival factor, IL-15, to induce proliferation of human ILC3s, as well as induce and maintain IL-22 production. To determine a mechanism of action, we examined the NF-κB pathway, which is activated by IL-18 signaling. We found that the NF-κB complex signaling component, p65, binds to the proximal region of the promoter and promotes transcriptional activity. Finally, we observed that CD11c dendritic cells expressing IL-18 are found in close proximity to ILC3s in human tonsils in situ. Therefore, we identify a new mechanism by which human ILC3s proliferate and produce IL-22, and identify NF-κB as a potential therapeutic target to be considered in pathologic states characterized by overproduction of IL-18 and/or IL-22.
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http://dx.doi.org/10.4049/jimmunol.1601554DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5624342PMC
October 2017

Long-lived keratin 15+ esophageal progenitor cells contribute to homeostasis and regeneration.

J Clin Invest 2017 Jun 8;127(6):2378-2391. Epub 2017 May 8.

Division of Gastroenterology, Department of Medicine, and.

The esophageal lumen is lined by a stratified squamous epithelium comprised of proliferative basal cells that differentiate while migrating toward the luminal surface and eventually desquamate. Rapid epithelial renewal occurs, but the specific cell of origin that supports this high proliferative demand remains unknown. Herein, we have described a long-lived progenitor cell population in the mouse esophageal epithelium that is characterized by expression of keratin 15 (Krt15). Genetic in vivo lineage tracing revealed that the Krt15 promoter marks a long-lived basal cell population able to self-renew, proliferate, and generate differentiated cells, consistent with a progenitor/stem cell population. Transcriptional profiling demonstrated that Krt15+ basal cells are molecularly distinct from Krt15- basal cells. Depletion of Krt15-derived cells resulted in decreased proliferation, thereby leading to atrophy of the esophageal epithelium. Further, Krt15+ cells were radioresistant and contributed to esophageal epithelial regeneration following radiation-induced injury. These results establish the presence of a long-lived and indispensable Krt15+ progenitor cell population that provides additional perspective on esophageal epithelial biology and the widely prevalent diseases that afflict this epithelium.
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http://dx.doi.org/10.1172/JCI88941DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5451220PMC
June 2017

The ETS family of oncogenic transcription factors in solid tumours.

Nat Rev Cancer 2017 06 28;17(6):337-351. Epub 2017 Apr 28.

The Comprehensive Cancer Center, The Ohio State University.

Findings over the past decade have identified aberrant activation of the ETS transcription factor family throughout all stages of tumorigenesis. Specifically in solid tumours, gene rearrangement and amplification, feed-forward growth factor signalling loops, formation of gain-of-function co-regulatory complexes and novel cis-acting mutations in ETS target gene promoters can result in increased ETS activity. In turn, pro-oncogenic ETS signalling enhances tumorigenesis through a broad mechanistic toolbox that includes lineage specification and self-renewal, DNA damage and genome instability, epigenetics and metabolism. This Review discusses these different mechanisms of ETS activation and subsequent oncogenic implications, as well as the clinical utility of ETS factors.
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http://dx.doi.org/10.1038/nrc.2017.20DOI Listing
June 2017

IL-6 and PD-L1 antibody blockade combination therapy reduces tumour progression in murine models of pancreatic cancer.

Gut 2018 02 21;67(2):320-332. Epub 2016 Oct 21.

Department of Hematology and Medical Oncology, Winship Cancer Institute of Emory University, Atlanta, Georgia, USA.

Objective: Limited efficacy of immune checkpoint inhibitors in pancreatic ductal adenocarcinoma (PDAC) has prompted investigation into combination therapy. We hypothesised that interleukin 6 (IL-6) blockade would modulate immunological features of PDAC and enhance the efficacy of anti-programmed death-1-ligand 1 (PD-L1) checkpoint inhibitor therapy.

Design: Transcription profiles and IL-6 secretion from primary patient-derived pancreatic stellate cells (PSCs) were analyzed via Nanostring and immunohistochemistry, respectively. In vivo efficacy and mechanistic studies were conducted with antibodies (Abs) targeting IL-6, PD-L1, CD4 or CD8 in subcutaneous or orthotopic models using Panc02, MT5 or KPC-luc cell lines; and the aggressive, genetically engineered PDAC model (Kras, Trp53, Pdx1-cre, Brca2 (KPC-Brca2 mice)). Systemic and local changes in immunophenotype were measured by flow cytometry or immunohistochemical analysis.

Results: PSCs (n=12) demonstrated prominent IL-6 expression, which was localised to stroma of tumours. Combined IL-6 and PD-L1 blockade elicited efficacy in mice bearing subcutaneous MT5 (p<0.02) and Panc02 tumours (p=0.046), which was accompanied by increased intratumoural effector T lymphocytes (CD62LCD44). CD8-depleting but not CD4-depleting Abs abrogated the efficacy of combined IL-6 and PD-L1 blockade in mice bearing Panc02 tumours (p=0.0016). This treatment combination also elicited significant antitumour activity in mice bearing orthotopic KPC-luc tumours and limited tumour progression in KPC-Brca2 mice (p<0.001). Histological analysis revealed increased T-cell infiltration and reduced α-smooth muscle actin cells in tumours from multiple models. Finally, IL-6 and PD-L1 blockade increased overall survival in KPC-Brca2 mice compared with isotype controls (p=0.0012).

Conclusions: These preclinical results indicate that targeted inhibition of IL-6 may enhance the efficacy of anti-PD-L1 in PDAC.
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http://dx.doi.org/10.1136/gutjnl-2016-311585DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5406266PMC
February 2018

Stromal ETS2 Regulates Chemokine Production and Immune Cell Recruitment during Acinar-to-Ductal Metaplasia.

Neoplasia 2016 09;18(9):541-52

Comprehensive Cancer Center, The Ohio State University, Columbus, OH 43210, USA; Department of Cancer Biology & Genetics, The Ohio State University, Columbus, OH 43210, USA. Electronic address:

Preclinical studies have suggested that the pancreatic tumor microenvironment both inhibits and promotes tumor development and growth. Here we establish the role of stromal fibroblasts during acinar-to-ductal metaplasia (ADM), an initiating event in pancreatic cancer formation. The transcription factor V-Ets avian erythroblastosis virus E26 oncogene homolog 2 (ETS2) was elevated in smooth muscle actin-positive fibroblasts in the stroma of pancreatic ductal adenocarcinoma (PDAC) patient tissue samples relative to normal pancreatic controls. LSL-Kras(G12D/+); LSL-Trp53(R172H/+); Pdx-1-Cre (KPC) mice showed that ETS2 expression initially increased in fibroblasts during ADM and remained elevated through progression to PDAC. Conditional ablation of Ets-2 in pancreatic fibroblasts in a Kras(G12D)-driven mouse ADM model decreased the amount of ADM events. ADMs from fibroblast Ets-2-deleted animals had reduced epithelial cell proliferation and increased apoptosis. Surprisingly, fibroblast Ets-2 deletion significantly altered immune cell infiltration into the stroma, with an increased CD8+ T-cell population, and decreased presence of regulatory T cells (Tregs), myeloid-derived suppressor cells, and mature macrophages. The mechanism involved ETS2-dependent chemokine ligand production in fibroblasts. ETS2 directly bound to regulatory sequences for Ccl3, Ccl4, Cxcl4, Cxcl5, and Cxcl10, a group of chemokines that act as potent mediators of immune cell recruitment. These results suggest an unappreciated role for ETS2 in fibroblasts in establishing an immune-suppressive microenvironment in response to oncogenic Kras(G12D) signaling during the initial stages of tumor development.
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http://dx.doi.org/10.1016/j.neo.2016.07.006DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5031867PMC
September 2016

Genetic ablation of Smoothened in pancreatic fibroblasts increases acinar-ductal metaplasia.

Genes Dev 2016 09 15;30(17):1943-55. Epub 2016 Sep 15.

Comprehensive Cancer Center, The Ohio State University, Columbus, Ohio 43210, USA; Cancer Biology and Genetics Department, The Ohio State University, Columbus, Ohio 43210, USA;

The contribution of the microenvironment to pancreatic acinar-to-ductal metaplasia (ADM), a preneoplastic transition in oncogenic Kras-driven pancreatic cancer progression, is currently unclear. Here we show that disruption of paracrine Hedgehog signaling via genetic ablation of Smoothened (Smo) in stromal fibroblasts in a Kras(G12D) mouse model increased ADM. Smo-deleted fibroblasts had higher expression of transforming growth factor-α (Tgfa) mRNA and secreted higher levels of TGFα, leading to activation of EGFR signaling in acinar cells and increased ADM. The mechanism involved activation of AKT and noncanonical activation of the GLI family transcription factor GLI2. GLI2 was phosphorylated at Ser230 in an AKT-dependent fashion and directly regulated Tgfa expression in fibroblasts lacking Smo Additionally, Smo-deleted fibroblasts stimulated the growth of Kras(G12D)/Tp53(R172H) pancreatic tumor cells in vivo and in vitro. These results define a non-cell-autonomous mechanism modulating Kras(G12D)-driven ADM that is balanced by cross-talk between Hedgehog/SMO and AKT/GLI2 pathways in stromal fibroblasts.
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http://dx.doi.org/10.1101/gad.283499.116DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5066238PMC
September 2016

Single agent BMS-911543 Jak2 inhibitor has distinct inhibitory effects on STAT5 signaling in genetically engineered mice with pancreatic cancer.

Oncotarget 2015 Dec;6(42):44509-22

Division of Medical Oncology, Department of Internal Medicine, The Arthur G. James Cancer Hospital and Richard J. Solove Research Institute, The Ohio State University, Columbus, OH 43210, USA.

The Jak/STAT pathway is activated in human pancreatic ductal adenocarcinoma (PDAC) and cooperates with mutant Kras to drive initiation and progression of PDAC in murine models. We hypothesized that the small-molecule Jak2 inhibitor (BMS-911543) would elicit anti-tumor activity against PDAC and decrease immune suppressive features of the disease. We used an aggressive genetically engineered PDAC model with mutant KrasG12D, tp53R270H, and Brca1 alleles (KPC-Brca1 mice). Mice with confirmed tumor burden were treated orally with vehicle or 30 mg/kg BMS-911543 daily for 14 days. Histologic analysis of pancreata from treated mice revealed fewer foci of adenocarcinoma and significantly decreased Ki67+ cells versus controls. In vivo administration of BMS-911543 significantly reduced pSTAT5 and FoxP3 positive cells within the pancreas, but did not alter STAT3 phosphorylation. Continuous dosing of KPC-Brca1 mice with BMS-911543 resulted in a median survival of 108 days, as compared to a median survival of 87 days in vehicle treated animals, a 23% increase (p = 0.055). In vitro experiments demonstrated that PDAC cell lines were poorly sensitive to BMS-911543, requiring high micromolar concentrations to achieve targeted inhibition of Jak/STAT signaling. Similarly, BMS-911543 had little in vitro effect on the viability of both murine and human PDAC-derived stellate cell lines. However, BMS-911543 potently inhibited phosphorylation of pSTAT3 and pSTAT5 at low micromolar doses in human PBMC and reduced in vitro differentiation of Foxp3+ T regulatory cells. These results indicate that single agent Jak2i deserves further study in preclinical models of PDAC and has distinct inhibitory effects on STAT5 mediated signaling.
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http://dx.doi.org/10.18632/oncotarget.6332DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4792572PMC
December 2015

Protein kinase C Beta in the tumor microenvironment promotes mammary tumorigenesis.

Front Oncol 2014 23;4:87. Epub 2014 Apr 23.

Department of Molecular and Cellular Biochemistry, College of Medicine, The Ohio State University , Columbus, OH , USA ; Comprehensive Cancer Center, The Ohio State University , Columbus, OH , USA.

Protein kinase C beta (PKCβ) expression in breast cancer is associated with a more aggressive tumor phenotype, yet the mechanism for how PKCβ is pro-tumorigenic in this disease is still unclear. Interestingly, while it is known that PKCβ mediates angiogenesis, immunity, fibroblast function and adipogenesis, all components of the mammary tumor microenvironment (TME), no study to date has investigated whether stromal PKCβ is functionally relevant in breast cancer. Herein, we evaluate mouse mammary tumor virus-polyoma middle T-antigen (MMTV-PyMT) induced mammary tumorigenesis in the presence and absence of PKCβ. We utilize two model systems: one where PKCβ is deleted in both the epithelial and stromal compartments to test the global requirement for PKCβ on tumor formation, and second, where PKCβ is deleted only in the stromal compartment to test its role in the TME. MMTV-PyMT mice globally lacking PKCβ live longer and develop smaller tumors with decreased proliferation and decreased macrophage infiltration. Similarly, when PKCβ is null exclusively in the stroma, PyMT-driven B6 cells form smaller tumors with diminished collagen deposition. These experiments reveal for the first time a tumor promoting role for stromal PKCβ in MMTV-PyMT tumorigenesis. In corroboration with these results, PKCβ mRNA (Prkcb) is increased in fibroblasts isolated from MMTV-PyMT tumors. These data were confirmed in a breast cancer patient cohort. Combined these data suggest the continued investigation of PKCβ in the mammary TME is necessary to elucidate how to effectively target this signaling pathway in breast cancer.
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http://dx.doi.org/10.3389/fonc.2014.00087DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4006052PMC
May 2014