PDX1

Gene Summary

Gene:PDX1; pancreatic and duodenal homeobox 1
Aliases: GSF, IPF1, IUF1, IDX-1, MODY4, PDX-1, STF-1, PAGEN1
Location:13q12.2
Summary:The protein encoded by this gene is a transcriptional activator of several genes, including insulin, somatostatin, glucokinase, islet amyloid polypeptide, and glucose transporter type 2. The encoded nuclear protein is involved in the early development of the pancreas and plays a major role in glucose-dependent regulation of insulin gene expression. Defects in this gene are a cause of pancreatic agenesis, which can lead to early-onset insulin-dependent diabetes mellitus (NIDDM), as well as maturity onset diabetes of the young type 4 (MODY4). [provided by RefSeq, Jul 2008]
Databases:VEGA, OMIM, HGNC, Ensembl, GeneCard, Gene
Protein:pancreas/duodenum homeobox protein 1
Source:NCBIAccessed: 11 March, 2017

Ontology:

What does this gene/protein do?
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Pathways:What pathways are this gene/protein implicaed in?
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Cancer Overview

Research Indicators

Publications Per Year (1992-2017)
Graph generated 11 March 2017 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Mice, Transgenic
  • SOX9 Transcription Factor
  • Wnt Signaling Pathway
  • Proto-Oncogene Proteins p21(ras)
  • Chromosome 13
  • Insulinoma
  • RAS Genes
  • Immunohistochemistry
  • Disease Models, Animal
  • Knockout Mice
  • Neoplastic Cell Transformation
  • Promoter Regions
  • Metaplasia
  • Mice, Mutant Strains
  • Homeodomain Proteins
  • Pancreatic Cancer
  • Disease Progression
  • Proto-Oncogene Proteins
  • Genome-Wide Association Study
  • Pancreas
  • Tumor Microenvironment
  • Precancerous Conditions
  • Cell Differentiation
  • Western Blotting
  • Genetic Predisposition
  • Cell Proliferation
  • Survival Rate
  • Stomach Cancer
  • Adenocarcinoma
  • Cell Movement
  • Down-Regulation
  • Signal Transduction
  • Carcinoma in Situ
  • Transcription Factors
  • Cancer Gene Expression Regulation
  • RTPCR
  • ras Proteins
  • Messenger RNA
  • Mutation
  • Ductan Pancreatic Carcinoma
Tag cloud generated 11 March, 2017 using data from PubMed, MeSH and CancerIndex

Specific Cancers (3)

Data table showing topics related to specific cancers and associated disorders. Scope includes mutations and abnormal protein expression.

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Latest Publications: PDX1 (cancer-related)

Kondratyeva LG, Sveshnikova AA, Grankina EV, et al.
Downregulation of expression of mater genes SOX9, FOXA2, and GATA4 in pancreatic cancer cells stimulated with TGFβ1 epithelial-mesenchymal transition.
Dokl Biochem Biophys. 2016; 469(1):257-9 [PubMed] Related Publications
We show characteristic morphological changes corresponding to epithelial-mesenchymal transition (EMT) program fulfillment in PANC1 cell line stimulated with TGFβ1. Our results support downregulation of E-cadherin protein. We show 5- and 28-fold increase in SNAI1 and SNAI2 expression levels and 25- and 15-fold decrease in CDH1 and KRT8 expression levels, respectively, which confirms the EMT-program fulfillment. We demonstrate downregulation of expression of pancreatic master genes SOX9, FOXA2, and GATA4 (2-, 5-, and 4-fold, respectively) and absence of significant changes in HES1, NR5A2, and GATA6 expression levels in the cells stimulated with TGFβ1. Our results indicate the absence of induction of expression of PTF1A, PDX1, HNF1b, NEUROG3, RPBJL, NKX6.1, and ONECUT1 genes, which are inactive in PANC1 cell line after the EMT stimulated by TGFβ1.

Gui X, Meng Z, McConnell YJ, et al.
Differing expression profiles of Notch/enterocyte and Wnt/secretory lineage signallings are associated with morphological diversity of appendiceal tumours.
J Clin Pathol. 2017; 70(1):40-50 [PubMed] Related Publications
BACKGROUND: Tumours of appendix, including classic carcinoid tumour (CCT), goblet cell carcinoid (GCC), low-grade appendiceal mucinous neoplasm, high-grade appendiceal mucinous neoplasm/mucinous carcinoma (MCA) and non-mucinous adenocarcinoma (NMA), show different and sometimes mixed morphological features. It was hypothesised that these tumours originate from common tumour stem cell(s) with potential of various cell lineage differentiation. In normal intestinal epithelium, absorptive lineage (enterocytes) differentiation is driven by Notch-Hes1 pathway, while secretory lineage is driven by Wnt-Math1 pathway and further separated by different downstream signallings into three sublineages (Gfi1-Klf4/Elf3 for goblet cells, Gfi1-Sox9 for Paneth cells and Ngn3-Pdx1/Beta2/Pax4 for enteroendocrine cells).
METHODS: The expressions of various signalling proteins in different appendiceal tumours were detected by immunohistochemistry on tumour tissue microarray.
RESULTS: CCT showed reduced Hes1/Elf3 and Sox9/Klf4 coupled with elevated Math1, in keeping with endocrine phenotype. As compared with CCT, GCC showed higher Klf4 and similar Ngn3/Pax4, indicative of a shift of differentiation towards goblet cells as well as endocrine cells. GCC displayed a Notch signalling similar to adenocarcinoma. Mucinous tumours showed lower Elf3 than normal appendiceal epithelium and higher Math1/Gfi1/Klf4, suggestive of a differentiation towards less enterocytes but more goblet cells. NMA showed Notch signalling similar to other glandular tumours, but lower Klf4. However, some seemingly paradoxical changes were also observed, probably suggesting gene mutations and/or our incomplete understanding of the intestinal cell differentiation.
CONCLUSIONS: Wnt/secretory lineage protein and Notch/absorptive lineage protein expression profiles are generally associated with the tumour cell differentiation and morphological diversity of common appendiceal tumours.

Bailey P, Chang DK, Nones K, et al.
Genomic analyses identify molecular subtypes of pancreatic cancer.
Nature. 2016; 531(7592):47-52 [PubMed] Related Publications
Integrated genomic analysis of 456 pancreatic ductal adenocarcinomas identified 32 recurrently mutated genes that aggregate into 10 pathways: KRAS, TGF-β, WNT, NOTCH, ROBO/SLIT signalling, G1/S transition, SWI-SNF, chromatin modification, DNA repair and RNA processing. Expression analysis defined 4 subtypes: (1) squamous; (2) pancreatic progenitor; (3) immunogenic; and (4) aberrantly differentiated endocrine exocrine (ADEX) that correlate with histopathological characteristics. Squamous tumours are enriched for TP53 and KDM6A mutations, upregulation of the TP63∆N transcriptional network, hypermethylation of pancreatic endodermal cell-fate determining genes and have a poor prognosis. Pancreatic progenitor tumours preferentially express genes involved in early pancreatic development (FOXA2/3, PDX1 and MNX1). ADEX tumours displayed upregulation of genes that regulate networks involved in KRAS activation, exocrine (NR5A2 and RBPJL), and endocrine differentiation (NEUROD1 and NKX2-2). Immunogenic tumours contained upregulated immune networks including pathways involved in acquired immune suppression. These data infer differences in the molecular evolution of pancreatic cancer subtypes and identify opportunities for therapeutic development.

Purohit A, Varney M, Rachagani S, et al.
CXCR2 signaling regulates KRAS(G¹²D)-induced autocrine growth of pancreatic cancer.
Oncotarget. 2016; 7(6):7280-96 [PubMed] Free Access to Full Article Related Publications
Pharmacological inhibition of RAS, the master regulator of pancreatic ductal adenocarcinoma (PDAC), continues to be a challenge. Mutations in various isoforms of RAS gene, including KRAS are known to upregulate CXC chemokines; however, their precise role in KRAS-driven pancreatic cancer remains unclear. In this report, we reveal a previously unidentified tumor cell-autonomous role of KRAS(G12D)-induced CXCR2 signaling in mediating growth of neoplastic PDAC cells. Progressively increasing expression of mCXCR2 and its ligands was detected in the malignant ductal cells of Pdx1-cre;LSL-Kras(G12D) mice. Knocking-down CXCR2 in KRAS(G12D)-bearing human pancreatic duct-derived cells demonstrated a significant decrease in the in vitro and in vivo tumor cell proliferation. Furthermore, CXCR2 antagonists showed selective growth inhibition of KRAS(G12D)-bearing cells in vitro. Intriguingly, both genetic and pharmacological inhibition of CXCR2 signaling in KRAS(G12D)-bearing pancreatic ductal cells reduced the levels of KRAS protein, strongly implying the presence of a KRAS-CXCR2 feed-forward loop. Together, these data demonstrate the role of CXCR2 signaling in KRAS(G12D)-induced growth transformation and progression in PDAC.

de Latouliere L, Manni I, Iacobini C, et al.
A bioluminescent mouse model of proliferation to highlight early stages of pancreatic cancer: A suitable tool for preclinical studies.
Ann Anat. 2016; 207:2-8 [PubMed] Related Publications
Transgenic mouse models designed to recapitulate genetic and pathologic aspects of cancer are useful to study early stages of disease as well as its progression. Among several, two of the most sophisticated models for pancreatic ductal adenocarcinoma (PDAC) are the LSL-Kras(G12D/+);Pdx-1-Cre (KC) and LSL-Kras(G12D/+);LSL-Trp53(R172H/+);Pdx-1-Cre (KPC) mice, in which the Cre-recombinase regulated by a pancreas-specific promoter activates the expression of oncogenic Kras alone or in combination with a mutant p53, respectively. Non-invasive in vivo imaging offers a novel approach to preclinical studies introducing the possibility to investigate biological events in the spatio/temporal dimension. We recently developed a mouse model, MITO-Luc, engineered to express the luciferase reporter gene in cells undergoing active proliferation. In this model, proliferation events can be visualized non-invasively by bioluminescence imaging (BLI) in every body district in vivo. Here, we describe the development and characterization of MITO-Luc-KC- and -KPC mice. In these mice we have now the opportunity to follow PDAC evolution in the living animal in a time frame process. Moreover, by relating in vivo and ex vivo BLI and histopathological data we provide evidence that these mice could represents a suitable tool for pancreatic cancer preclinical studies. Our data also suggest that aberrant proliferation events take place early in pancreatic carcinogenesis, before tumour appearance.

Zhou G, Yu J, Wang A, et al.
Metformin Restrains Pancreatic Duodenal Homeobox-1 (PDX-1) Function by Inhibiting ERK Signaling in Pancreatic Ductal Adenocarcinoma.
Curr Mol Med. 2016; 16(1):83-90 [PubMed] Free Access to Full Article Related Publications
Pancreatic ductal adenocarcinoma (PDAC) is one of the most potent and perilous diseases known, with a median survival rate of 3-5 months due to the combination of only advanced stage diagnosis and ineffective therapeutic options. Metformin (1,1-Dimethylbiguanide hydrochloride), the leading drug used for type 2 diabetes mellitus, emerges as a potential therapy for PDAC and other human cancers. Metformin exerts its anticancer action via a variety of adenosine monophosphate (AMP)-activated protein kinase (AMPK)- dependent and/or AMPK-independent mechanisms. We present data here showing that metformin downregulated pancreatic transcription factor pancreatic duodenal homeobox-1 (PDX-1), suggesting a potential novel mechanism by which metformin exerts its anticancer action. Metformin inhibited PDX-1 expression at both protein and mRNA levels and PDX-1 transactivity as well in PDAC cells. Extracellular signal-regulated kinase (ERK) was identified as a PDX-1-interacting protein by antibody array screening in GFP-PDX-1 stable HEK293 cells. Co-transfection of ERK1 with PDX-1 resulted in an enhanced PDX-1 expression in HEK293 cells in a dose-dependent manner. Immunoprecipitation/Western blotting analysis confirmed the ERK-PDX-1 interaction in PANC-1 cells stimulated by epidermal growth factor (EGF). EGF induced an enhanced PDX-1 expression in PANC-1 cells and this stimulation was inhibited by MEK inhibitor PD0325901. Metformin inhibited EGF-stimulated PDX-1 expression with an accompanied inhibition of ERK kinase activation in PANC- 1 cells. Taken together, our studies show that PDX-1 is a potential novel target for metformin in PDAC cells and that metformin may exert its anticancer action in PDAC by down-regulating PDX-1 via a mechanism involving inhibition of ERK signaling.

Rachagani S, Macha MA, Menning MS, et al.
Changes in microRNA (miRNA) expression during pancreatic cancer development and progression in a genetically engineered KrasG12D;Pdx1-Cre mouse (KC) model.
Oncotarget. 2015; 6(37):40295-309 [PubMed] Free Access to Full Article Related Publications
Differential expression of microRNAs (miRNAs) has been demonstrated in various cancers, including pancreatic cancer (PC). Due to the lack of tissue samples from early-stages of PC, the stage-specific alteration of miRNAs during PC initiation and progression is largely unknown. In this study, we investigated the global miRNA expression profile and their processing machinery during PC progression using the KrasG12D;Pdx1-Cre (KC) mouse model. At 25 weeks, the miRNA microarray analysis revealed significant downregulation of miR-150, miR-494, miR-138, miR-148a, miR-216a, and miR-217 and upregulation of miR-146b, miR-205, miR-31, miR-192, and miR-21 in KC mice compared to controls. Further, expression of miRNA biosynthetic machinery including Dicer, Exportin-5, TRKRA, and TARBP2 were downregulated, while DGCR8 and Ago2 were upregulated in KC mice. In addition, from 10 to 50 weeks of age, stage-specific expression profiling of miRNA in KC mice revealed downregulation of miR-216, miR-217, miR-100, miR-345, miR-141, miR-483-3p, miR-26b, miR-150, miR-195, Let-7b and Let-96 and upregulation of miR-21, miR-205, miR-146b, miR-34c, miR-1273, miR-223 and miR-195 compared to control mice. Interestingly, the differential expression of miRNA in mice also corroborated with the miRNA expression in human PC cell lines and tissue samples; ectopic expression of Let-7b in CD18/HPAF and Capan1 cells resulted in the downregulation of KRAS and MSST1 expression. Overall, the present study aids an understanding of miRNA expression patterns during PC pathogenesis and helps to facilitate the identification of promising and novel early diagnostic/prognostic markers and therapeutic targets.

Cavalloni G, Peraldo-Neia C, Varamo C, et al.
Establishment and characterization of a human intrahepatic cholangiocarcinoma cell line derived from an Italian patient.
Tumour Biol. 2016; 37(3):4041-52 [PubMed] Free Access to Full Article Related Publications
Biliary tract carcinoma is a rare malignancy with multiple causes, which underlie the different genetic and molecular profiles. Cancer cell lines are affordable models, reflecting the characteristics of the tumor of origin. They represent useful tools to identify molecular targets for treatment. Here, we established and characterized from biological, molecular, and genetic point of view, an Italian intrahepatic cholangiocarcinoma cell line (ICC), the MT-CHC01. MT-CHC01 cells were isolated from a tumor-derived xenograft. Immunophenotypical characterization was evaluated both at early and after stabilization passages. In vitro biological, genetic, and molecular features were also investigated. In vivo tumorigenicity was assessed in NOD/SCID mice. MT-CHC01cells retain epithelial cell markers, EPCAM, CK7, and CK19, and some stemness and pluripotency markers, i.e., SOX2, Nanog, CD49f/integrin-α6, CD24, PDX1, FOXA2, and CD133. They grow as a monolayer, with a population double time of about 40 h; they show a low migration and invasion potential. In low attachment conditions, they are able to form spheres and to growth in anchorage-independent manner. After subcutaneous injection, they retain in vivo tumorigenicity; the expression of biliary markers as CA19-9 and CEA were maintained from primary tumor. The karyotype is highly complex, with a hypotriploid to hypertriploid modal number (3n+/-) (52 to 77 chromosomes); low level of HER2 gene amplification, TP53 deletion, gain of AURKA were identified; K-RAS G12D mutation were maintained from primary tumor to MT-CHC01 cells. We established the first ICC cell line derived from an Italian patient. It will help to study either the biology of this tumor or to test drugs both in vitro and in vivo.

Vasseur R, Skrypek N, Duchêne B, et al.
The mucin MUC4 is a transcriptional and post-transcriptional target of K-ras oncogene in pancreatic cancer. Implication of MAPK/AP-1, NF-κB and RalB signaling pathways.
Biochim Biophys Acta. 2015; 1849(12):1375-84 [PubMed] Related Publications
The membrane-bound mucinMUC4 is a high molecularweight glycoprotein frequently deregulated in cancer. In pancreatic cancer, one of the most deadly cancers in occidental countries, MUC4 is neo-expressed in the preneoplastic stages and thereafter is involved in cancer cell properties leading to cancer progression and chemoresistance. K-ras oncogene is a small GTPase of the RAS superfamily, highly implicated in cancer. K-ras mutations are considered as an initiating event of pancreatic carcinogenesis and K-ras oncogenic activities are necessary components of cancer progression. However, K-ras remains clinically undruggable. Targeting early downstream K-ras signaling in cancer may thus appear as an interesting strategy and MUC4 regulation by K-ras in pancreatic carcinogenesis remains unknown. Using the Pdx1-Cre; LStopL-K-rasG12D mouse model of pancreatic carcinogenesis, we show that the in vivo early neo-expression of the mucin Muc4 in pancreatic intraepithelial neoplastic lesions (PanINs) induced by mutated K-ras is correlated with the activation of ERK, JNK and NF-κB signaling pathways. In vitro, transfection of constitutively activated K-rasG12V in pancreatic cancer cells led to the transcriptional upregulation of MUC4. This activation was found to be mediated at the transcriptional level by AP-1 and NF-κB transcription factors via MAPK, JNK and NF-κB pathways and at the posttranscriptional level by a mechanism involving the RalB GTPase. Altogether, these results identify MUC4 as a transcriptional and post-transcriptional target of K-ras in pancreatic cancer. This opens avenues in developing new approaches to target the early steps of this deadly cancer.

Qiu W, Tang SM, Lee S, et al.
Loss of Activin Receptor Type 1B Accelerates Development of Intraductal Papillary Mucinous Neoplasms in Mice With Activated KRAS.
Gastroenterology. 2016; 150(1):218-228.e12 [PubMed] Free Access to Full Article Related Publications
BACKGROUND & AIMS: Activin, a member of the transforming growth factor-β (TGFB) family, might be involved in pancreatic tumorigenesis, similar to other members of the TGFB family. Human pancreatic ductal adenocarcinomas contain somatic mutations in the activin A receptor type IB (ACVR1B) gene, indicating that ACVR1B could be a suppressor of pancreatic tumorigenesis.
METHODS: We disrupted Acvr1b specifically in pancreata of mice (Acvr1b(flox/flox);Pdx1-Cre mice) and crossed them with LSL-KRAS(G12D) mice, which express an activated form of KRAS and develop spontaneous pancreatic tumors. The resulting Acvr1b(flox/flox);LSL-KRAS(G12D);Pdx1-Cre mice were monitored; pancreatic tissues were collected and analyzed by histology and immunohistochemical analyses. We also analyzed p16(flox/flox);LSL-Kras(G12D);Pdx1-Cre mice and Cre-negative littermates (controls). Genomic DNA, total RNA, and protein were isolated from mouse tissues and primary pancreatic tumor cell lines and analyzed by reverse-transcription polymerase chain reaction, sequencing, and immunoblot analyses. Human intraductal papillary mucinous neoplasm (IPMN) specimens were analyzed by immunohistochemistry.
RESULTS: Loss of ACVR1B from pancreata of mice increased the proliferation of pancreatic epithelial cells, led to formation of acinar to ductal metaplasia, and induced focal inflammatory changes compared with control mice. Disruption of Acvr1b in LSL-KRAS(G12D);Pdx1-Cre mice accelerated the growth of pancreatic IPMNs compared with LSL-KRAS(G12D);Pdx1-Cre mice, but did not alter growth of pancreatic intraepithelial neoplasias. We associated perinuclear localization of the activated NOTCH4 intracellular domain to the apical cytoplasm of neoplastic cells with the expansion of IPMN lesions in Acvr1b(flox/flox);LSL-KRAS(G12D);Pdx1-Cre mice. Loss of the gene that encodes p16 (Cdkn2a) was required for progression of IPMNs to pancreatic ductal adenocarcinomas in Acvr1b(flox/flox);LSL-Kras(G12D);Pdx1-Cre mice. We also observed progressive loss of p16 in human IPMNs of increasing grades.
CONCLUSIONS: Loss of ACVR1B accelerates growth of mutant KRAS-induced pancreatic IPMNs in mice; this process appears to involve NOTCH4 and loss of p16. ACVR1B suppresses early stages of pancreatic tumorigenesis; the activin signaling pathway therefore might be a therapeutic target for pancreatic cancer.

Childs EJ, Mocci E, Campa D, et al.
Common variation at 2p13.3, 3q29, 7p13 and 17q25.1 associated with susceptibility to pancreatic cancer.
Nat Genet. 2015; 47(8):911-6 [PubMed] Free Access to Full Article Related Publications
Pancreatic cancer is the fourth leading cause of cancer death in the developed world. Both inherited high-penetrance mutations in BRCA2 (ref. 2), ATM, PALB2 (ref. 4), BRCA1 (ref. 5), STK11 (ref. 6), CDKN2A and mismatch-repair genes and low-penetrance loci are associated with increased risk. To identify new risk loci, we performed a genome-wide association study on 9,925 pancreatic cancer cases and 11,569 controls, including 4,164 newly genotyped cases and 3,792 controls in 9 studies from North America, Central Europe and Australia. We identified three newly associated regions: 17q25.1 (LINC00673, rs11655237, odds ratio (OR) = 1.26, 95% confidence interval (CI) = 1.19-1.34, P = 1.42 × 10(-14)), 7p13 (SUGCT, rs17688601, OR = 0.88, 95% CI = 0.84-0.92, P = 1.41 × 10(-8)) and 3q29 (TP63, rs9854771, OR = 0.89, 95% CI = 0.85-0.93, P = 2.35 × 10(-8)). We detected significant association at 2p13.3 (ETAA1, rs1486134, OR = 1.14, 95% CI = 1.09-1.19, P = 3.36 × 10(-9)), a region with previous suggestive evidence in Han Chinese. We replicated previously reported associations at 9q34.2 (ABO), 13q22.1 (KLF5), 5p15.33 (TERT and CLPTM1), 13q12.2 (PDX1), 1q32.1 (NR5A2), 7q32.3 (LINC-PINT), 16q23.1 (BCAR1) and 22q12.1 (ZNRF3). Our study identifies new loci associated with pancreatic cancer risk.

Galivo FH, Dorrell C, Grompe MT, et al.
Novel surface markers directed against adult human gallbladder.
Stem Cell Res. 2015; 15(1):172-81 [PubMed] Free Access to Full Article Related Publications
Novel cell surface-reactive monoclonal antibodies generated against extrahepatic biliary cells were developed for the isolation and characterization of different cell subsets from normal adult human gallbladder. Eleven antigenically distinct gallbladder subpopulations were isolated by fluorescence-activated cell sorting. They were classified into epithelial, mesenchymal, and pancreatobiliary (PDX1(+)SOX9(+)) subsets based on gene expression profiling. These antigenically distinct human gallbladder cell subsets could potentially also reflect different functional properties in regards to bile physiology, cell renewal and plasticity. Three of the novel monoclonal antibodies differentially labeled archival sections of primary carcinoma of human gallbladder relative to normal tissue. The novel monoclonal antibodies described herein enable the identification and characterization of antigenically diverse cell subsets within adult human gallbladder and are putative tumor biomarkers.

He Z, Hu B, Tang L, et al.
The overexpression of MRP4 is related to multidrug resistance in osteosarcoma cells.
J Cancer Res Ther. 2015 Jan-Mar; 11(1):18-23 [PubMed] Related Publications
Doxorubicin (Adriamycin, ADM) is an antimitotic drug used in the treatment of a wide range of malignant tumors, including acute leukemia, lymphoma, osteosarcoma, breast cancer, and lung cancer. Multidrug resistance-associated proteins (MRPs) are members of a superfamily of ATP-binding cassette (ABC) transporters, which can transport various molecules across extra- and intra-cellular membranes. The aim of this study was to investigate whether there was a correlation between MRP4 and primary ADM resistance in osteosarcoma cells. In this paper, we chose the human osteosarcoma cell line MG63, ADM resistant cell line MG63/DOX, and the patient's primary cell GSF-0686. We checked the ADM sensitivity and cytotoxicity of all the three cells by cell proliferation assay. The intracellular drug concentrations were measured by using LC-MS/MS. We also examined MRP4 gene expression by RT-PCR and Western Blot. We found that the intracellular ADM concentration of the parent osteosarcoma cell line MG63 was higher than the ADM resistant osteosarcoma MG63/DOX cell line or the GSF-0686 cell after ADM treatment (P < 0.05). In addition, MRP4 mRNA and protein levels in ADM resistant osteosarcoma cells were higher than in MG63 cell (P < 0.05). Taking together, this work suggests that overexpression of MRP4 may confer ADM resistance in osteosarcoma cells.

Pedica F, Beccari S, Pedron S, et al.
PDX-1 (pancreatic/duodenal homeobox-1 protein 1).
Pathologica. 2014; 106(4):315-21 [PubMed] Related Publications
The homeodomain-containing transcription factor pancreatic duodenal homeobox 1 (PDX-1) plays a key role in pancreatic development and β-cell function. It is a major regulator of transcription in pancreatic cells, and transactivates the insulin gene by binding to a specific DNA motif in its promoter region. Glucose also regulates insulin gene transcription through PDX-1. It has been shown that PDX-1 is required for maintaining pancreatic islet functions by activating gene expression and has a dual role in pancreatic development. It initially contributes to pancreatic formation during embryogenesis and subsequently regulates the pancreatic islet cell physiology in mature islet cells. Because of this key role in the embryologic development of the pancreas, PDX-1 expression has been investigated in pancreatic cancer cell lines and human tumors. Moreover, a few reports have described expression of PDX-1 in other human neoplasms and have investigated its potential role in differential diagnosis, but data on normal human tissues are lacking. Understanding the molecular mechanisms of pancreas formation, and especially the function of PDX-1, may contribute to the improved treatment and prevention of debilitating diseases such as diabetes, insulinomas and pancreatic carcinomas. Nevertheless, further studies are needed concerning its possible application in routine practice.

Hashimoto H, Higuchi Y, Kawai K
Forced expression of PDX-1 gene makes hepatoma cells to acquire glucose-responsive insulin secretion while maintaining hepatic characteristic.
Cell Mol Biol (Noisy-le-grand). 2015; 61(1):20-9 [PubMed] Related Publications
Evidence shows that forced expression of the PDX1 gene converts hepatoma cells, mouse liver epithelial cells (MLECs) and HepaRG cells, into insulin—producing cells, β—cells, or islets of Langerhans. However, no reports have investigated the characteristics of mouse or human hepatocytes introduced with the PDX1 gene over prolonged observation periods. In this study, we immunohistologically and molecularly investigated the alternative processes induced by PDX1 gene introduction in mouse and human hepatocytes over prolonged observation periods using immunocytochemistry, immunofluorescence, polymerase chain reaction (PCR), Western blotting, and flow cytometry (FCM) analysis. Immunocytochemical and immunofluorescent observations showed that MLECs and HepaRG cells on 2 and 21 days after introduction of the PDX1 gene comprised cells double—positive for insulin and albumin. Additionally, they showed MAFA expression and glucose—responsive insulin secretion with glucokinase expression. However mouse embryonic fibroblasts introduced with PDX1—GFP could not acquire glucose—responsive insulin secretion and glucokinase expression. Subsequently, we hypothesized that the number of albumin—positive MLECs and HepaRG cells would decrease after introduction of PDX1 due to the conversion of MLECs and HepaRG cells into insulin—producing cells. However, FCM analysis indicated that the number of albumin—positive MLECs and HepaRG cells was not altered by the introduction of PDX1. We thought that MLECs and HepaRG cells introduced with the PDX1 gene could acquire a functional insulin secretory capacity without conversion to β—cells, or islets of Langerhans, and the acquisition could need glucokinase expression.

Hilderink J, Spijker S, Carlotti F, et al.
Controlled aggregation of primary human pancreatic islet cells leads to glucose-responsive pseudoislets comparable to native islets.
J Cell Mol Med. 2015; 19(8):1836-46 [PubMed] Free Access to Full Article Related Publications
Clinical islet transplantation is a promising treatment for patients with type 1 diabetes. However, pancreatic islets vary in size and shape affecting their survival and function after transplantation because of mass transport limitations. To reduce diffusion restrictions and improve islet cell survival, the generation of islets with optimal dimensions by dispersion followed by reassembly of islet cells, can help limit the length of diffusion pathways. This study describes a microwell platform that supports the controlled and reproducible production of three-dimensional pancreatic cell clusters of human donor islets. We observed that primary human islet cell aggregates with a diameter of 100-150 μm consisting of about 1000 cells best resembled intact pancreatic islets as they showed low apoptotic cell death (<2%), comparable glucose-responsiveness and increasing PDX1, MAFA and INSULIN gene expression with increasing aggregate size. The re-associated human islet cells showed an a-typical core shell configuration with beta cells predominantly on the outside unlike human islets, which became more randomized after implantation similar to native human islets. After transplantation of these islet cell aggregates under the kidney capsule of immunodeficient mice, human C-peptide was detected in the serum indicating that beta cells retained their endocrine function similar to human islets. The agarose microwell platform was shown to be an easy and very reproducible method to aggregate pancreatic islet cells with high accuracy providing a reliable tool to study cell-cell interactions between insuloma and/or primary islet cells.

Lastraioli E, Perrone G, Sette A, et al.
hERG1 channels drive tumour malignancy and may serve as prognostic factor in pancreatic ductal adenocarcinoma.
Br J Cancer. 2015; 112(6):1076-87 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: hERG1 channels are aberrantly expressed in human cancers. The expression, functional role and clinical significance of hERG1 channels in pancreatic ductal adenocarcinoma (PDAC) is lacking.
METHODS: hERG1 expression was tested in PDAC primary samples assembled as tissue microarray by immunohistochemistry using an anti-hERG1 monoclonal antibody (α-hERG1-MoAb). The functional role of hERG1 was studied in PDAC cell lines and primary cultures. ERG1 expression during PDAC progression was studied in Pdx-1-Cre,LSL-Kras(G12D/+),LSL-Trp53(R175H/+) transgenic (KPC) mice. ERG1 expression in vivo was determined by optical imaging using Alexa-680-labelled α-hERG1-MoAb.
RESULTS: (i) hERG1 was expressed at high levels in 59% of primary PDAC; (ii) hERG1 blockade decreased PDAC cell growth and migration; (iii) hERG1 was physically and functionally linked to the Epidermal Growth Factor-Receptor pathway; (iv) in transgenic mice, ERG1 was expressed in PanIN lesions, reaching high expression levels in PDAC; (v) PDAC patients whose primary tumour showed high hERG1 expression had a worse prognosis; (vi) the α-hERG1-MoAb could detect PDAC in vivo.
CONCLUSIONS: hERG1 regulates PDAC malignancy and its expression, once validated in a larger cohort also comprising of late-stage, non-surgically resected cases, may be exploited for diagnostic and prognostic purposes in PDAC either ex vivo or in vivo.

Chen NM, Singh G, Koenig A, et al.
NFATc1 Links EGFR Signaling to Induction of Sox9 Transcription and Acinar-Ductal Transdifferentiation in the Pancreas.
Gastroenterology. 2015; 148(5):1024-1034.e9 [PubMed] Free Access to Full Article Related Publications
BACKGROUND & AIMS: Oncogenic mutations in KRAS contribute to the development of pancreatic ductal adenocarcinoma, but are not sufficient to initiate carcinogenesis. Secondary events, such as inflammation-induced signaling via the epidermal growth factor receptor (EGFR) and expression of the SOX9 gene, are required for tumor formation. Herein we sought to identify the mechanisms that link EGFR signaling with activation of SOX9 during acinar-ductal metaplasia, a transdifferentiation process that precedes pancreatic carcinogenesis.
METHODS: We analyzed pancreatic tissues from Kras(G12D);pdx1-Cre and Kras(G12D);NFATc1(Δ/Δ);pdx1-Cre mice after intraperitoneal administration of caerulein, vs cyclosporin A or dimethyl sulfoxide (controls). Induction of EGFR signaling and its effects on the expression of Nuclear factor of activated T cells c1 (NFATc1) or SOX9 were investigated by quantitative reverse-transcription polymerase chain reaction, immunoblot, and immunohistochemical analyses of mouse and human tissues and acinar cell explants. Interactions between NFATc1 and partner proteins and effects on DNA binding or chromatin modifications were studied using co-immunoprecipitation and chromatin immunoprecipitation assays in acinar cell explants and mouse tissue.
RESULTS: EGFR activation induced expression of NFATc1 in metaplastic areas from patients with chronic pancreatitis and in pancreatic tissue from Kras(G12D) mice. EGFR signaling also promoted formation of a complex between NFATc1 and C-JUN in dedifferentiating mouse acinar cells, leading to activation of Sox9 transcription and induction of acinar-ductal metaplasia. Pharmacologic inhibition of NFATc1 or disruption of the Nfatc1 gene inhibited EGFR-mediated induction of Sox9 transcription and blocked acinar-ductal transdifferentiation and pancreatic cancer initiation in mice.
CONCLUSIONS: EGFR signaling induces expression of NFATc1 and Sox9, leading to acinar cell transdifferentiation and initiation of pancreatic cancer. Strategies designed to disrupt this pathway might be developed to prevent pancreatic cancer initiation in high-risk patients with chronic pancreatitis.

Wu JX, Liu SH, Nemunaitis JJ, Brunicardi FC
Liposomal insulin promoter-thymidine kinase gene therapy followed by ganciclovir effectively ablates human pancreatic cancer in mice.
Cancer Lett. 2015; 359(2):206-10 [PubMed] Free Access to Full Article Related Publications
PDX1 is overexpressed in pancreatic cancer, and activates the insulin promoter (IP). Adenoviral IP-thymidine kinase and ganciclovir (TK/GCV) suppresses human pancreatic ductal carcinoma (PDAC) in mice, but repeated doses carry significant toxicity. We hypothesized that multiple cycles of liposomal IP-TK/GCV ablate human PDAC in SCID mice with minimal toxicity compared to adenoviral IP-TK/GCV. SCID mice with intraperitoneal human pancreatic cancer PANC-1 tumor implants were given a single cycle of 35 µg iv L-IP-TK, or four cycles of 1, 10, 20, 30, or 35 µg iv L-IP-TK (n = 20 per group), followed by intraperitoneal GCV. Insulin and glucose levels were monitored in mice treated with four cycles of 35 µg iv L-IP-TK. We found that four cycles of 10-35 µg L-IP-TK/GCV ablated more PANC-1 tumor volume compared to a single cycle with 35 µg. Mice that received four cycles of 10 µg L-IP-TK demonstrated the longest survival (P < 0.05), with a median survival of 126 days. In comparison, mice that received a single cycle of 35 µg L-IP-TK/GCV or GCV alone survived a median of 92 days and 68.7 days, respectively. There were no significant changes in glucose or insulin levels following treatment. In conclusion, multiple cycles of liposomal IP-TK/GCV ablate human PDAC in SCID mice with minimal toxicity, suggesting non-viral vectors are superior to adenoviral vectors for IP-gene therapy.

Masjkur J, Arps-Forker C, Poser SW, et al.
Hes3 is expressed in the adult pancreatic islet and regulates gene expression, cell growth, and insulin release.
J Biol Chem. 2014; 289(51):35503-16 [PubMed] Free Access to Full Article Related Publications
The transcription factor Hes3 is a component of a signaling pathway that supports the growth of neural stem cells with profound consequences in neurodegenerative disease models. Here we explored whether Hes3 also regulates pancreatic islet cells. We showed that Hes3 is expressed in human and rodent pancreatic islets. In mouse islets it co-localizes with alpha and beta cell markers. We employed the mouse insulinoma cell line MIN6 to perform in vitro characterization and functional studies in conditions known to modulate Hes3 based upon our previous work using neural stem cell cultures. In these conditions, cells showed elevated Hes3 expression and nuclear localization, grew efficiently, and showed higher evoked insulin release responses, compared with serum-containing conditions. They also exhibited higher expression of the transcription factor Pdx1 and insulin. Furthermore, they were responsive to pharmacological treatments with the GLP-1 analog Exendin-4, which increased nuclear Hes3 localization. We employed a transfection approach to address specific functions of Hes3. Hes3 RNA interference opposed cell growth and affected gene expression as revealed by DNA microarrays. Western blotting and PCR approaches specifically showed that Hes3 RNA interference opposes the expression of Pdx1 and insulin. Hes3 overexpression (using a Hes3-GFP fusion construct) confirmed a role of Hes3 in regulating Pdx1 expression. Hes3 RNA interference reduced evoked insulin release. Mice lacking Hes3 exhibited increased islet damage by streptozotocin. These data suggest roles of Hes3 in pancreatic islet function.

Conway K, Edmiston SN, May R, et al.
DNA methylation profiling in the Carolina Breast Cancer Study defines cancer subclasses differing in clinicopathologic characteristics and survival.
Breast Cancer Res. 2014; 16(5):450 [PubMed] Free Access to Full Article Related Publications
INTRODUCTION: Breast cancer is a heterogeneous disease, with several intrinsic subtypes differing by hormone receptor (HR) status, molecular profiles, and prognosis. However, the role of DNA methylation in breast cancer development and progression and its relationship with the intrinsic tumor subtypes are not fully understood.
METHODS: A microarray targeting promoters of cancer-related genes was used to evaluate DNA methylation at 935 CpG sites in 517 breast tumors from the Carolina Breast Cancer Study, a population-based study of invasive breast cancer.
RESULTS: Consensus clustering using methylation (β) values for the 167 most variant CpG loci defined four clusters differing most distinctly in HR status, intrinsic subtype (luminal versus basal-like), and p53 mutation status. Supervised analyses for HR status, subtype, and p53 status identified 266 differentially methylated CpG loci with considerable overlap. Genes relatively hypermethylated in HR+, luminal A, or p53 wild-type breast cancers included FABP3, FGF2, FZD9, GAS7, HDAC9, HOXA11, MME, PAX6, POMC, PTGS2, RASSF1, RBP1, and SCGB3A1, whereas those more highly methylated in HR-, basal-like, or p53 mutant tumors included BCR, C4B, DAB2IP, MEST, RARA, SEPT5, TFF1, THY1, and SERPINA5. Clustering also defined a hypermethylated luminal-enriched tumor cluster 3 that gene ontology analysis revealed to be enriched for homeobox and other developmental genes (ASCL2, DLK1, EYA4, GAS7, HOXA5, HOXA9, HOXB13, IHH, IPF1, ISL1, PAX6, TBX1, SOX1, and SOX17). Although basal-enriched cluster 2 showed worse short-term survival, the luminal-enriched cluster 3 showed worse long-term survival but was not independently prognostic in multivariate Cox proportional hazard analysis, likely due to the mostly early stage cases in this dataset.
CONCLUSIONS: This study demonstrates that epigenetic patterns are strongly associated with HR status, subtype, and p53 mutation status and may show heterogeneity within tumor subclass. Among HR+ breast tumors, a subset exhibiting a gene signature characterized by hypermethylation of developmental genes and poorer clinicopathologic features may have prognostic value and requires further study. Genes differentially methylated between clinically important tumor subsets have roles in differentiation, development, and tumor growth and may be critical to establishing and maintaining tumor phenotypes and clinical outcomes.

Hermann PC, Sancho P, Cañamero M, et al.
Nicotine promotes initiation and progression of KRAS-induced pancreatic cancer via Gata6-dependent dedifferentiation of acinar cells in mice.
Gastroenterology. 2014; 147(5):1119-33.e4 [PubMed] Related Publications
BACKGROUND & AIMS: Although smoking is a leading risk factor for pancreatic ductal adenocarcinoma (PDAC), little is known about the mechanisms by which smoking promotes initiation or progression of PDAC.
METHODS: We studied the effects of nicotine administration on pancreatic cancer development in Kras(+/LSLG12Vgeo);Elas-tTA/tetO-Cre (Ela-KRAS) mice, Kras(+/LSLG12D);Trp53+/LSLR172H;Pdx-1-Cre (KPC) mice (which express constitutively active forms of KRAS), and C57/B6 mice. Mice were given nicotine for up to 86 weeks to produce blood levels comparable with those of intermediate smokers. Pancreatic tissues were collected and analyzed by immunohistochemistry and reverse transcriptase polymerase chain reaction; cells were isolated and assayed for colony and sphere formation and gene expression. The effects of nicotine were also evaluated in primary pancreatic acinar cells isolated from wild-type, nAChR7a(-/-), Trp53(-/-), and Gata6(-/-);Trp53(-/-) mice. We also analyzed primary PDAC cells that overexpressed GATA6 from lentiviral expression vectors.
RESULTS: Administration of nicotine accelerated transformation of pancreatic cells and tumor formation in Ela-KRAS and KPC mice. Nicotine induced dedifferentiation of acinar cells by activating AKT-ERK-MYC signaling; this led to inhibition of Gata6 promoter activity, loss of GATA6 protein, and subsequent loss of acinar differentiation and hyperactivation of oncogenic KRAS. Nicotine also promoted aggressiveness of established tumors as well as the epithelial-mesenchymal transition, increasing numbers of circulating cancer cells and their dissemination to the liver, compared with mice not exposed to nicotine. Nicotine induced pancreatic cells to acquire gene expression patterns and functional characteristics of cancer stem cells. These effects were markedly attenuated in K-Ras(+/LSL-G12D);Trp53(+/LSLR172H);Pdx-1-Cre mice given metformin. Metformin prevented nicotine-induced pancreatic carcinogenesis and tumor growth by up-regulating GATA6 and promoting differentiation toward an acinar cell program.
CONCLUSIONS: In mice, nicotine promotes pancreatic carcinogenesis and tumor development via down-regulation of Gata6 to induce acinar cell dedifferentiation.

Vaz AP, Ponnusamy MP, Rachagani S, et al.
Novel role of pancreatic differentiation 2 in facilitating self-renewal and drug resistance of pancreatic cancer stem cells.
Br J Cancer. 2014; 111(3):486-96 [PubMed] Free Access to Full Article Related Publications
BACKGROUND: Cancer stem cells (CSCs) contribute towards disease aggressiveness and drug resistance. Specific identification of CSC maintenance genes and targeting can improve the efficiency of currently available treatment modalities. Pancreatic differentiation 2 (PD2) has a major role in the self-renewal of mouse embryonic stem cells. In the present study, we investigated the role of PD2 in pancreatic CSCs.
METHODS: Characterisation of CSCs and non-CSCs from mouse models, pancreatic cancer cells and human tissues by CSC and self-renewal marker analysis using confocal assay. Effect of PD2 knockdown in CSCs (after gemcitabine treatment) was studied by immunoblot and apoptosis assays.
RESULTS: A subpopulation of cells displayed PD2 overexpression in mouse (Kras(G12D); Pdx1-Cre and Kras(G12D); Trp53(R172H/+); Pdx1-Cre) and human pancreatic tumours, which co-express CSC markers. Cancer stem cells exhibited elevated expression of PD2 and self-renewal markers, such as Oct3/4, Shh and β-catenin. Gemcitabine treatment maintained the CSC population with simultaneous maintenance of PD2 and CSC marker expression. Knockdown of PD2 in CSCs resulted in reduced viability of cells and enhanced apoptosis along with abrogated expression of CD133 and MDR2.
CONCLUSIONS: Our results suggest that PD2 is a novel CSC maintenance protein, loss of which renders the CSCs more susceptible to drug-induced cell death.

Ali S, Ahmad A, Aboukameel A, et al.
Deregulation of miR-146a expression in a mouse model of pancreatic cancer affecting EGFR signaling.
Cancer Lett. 2014; 351(1):134-42 [PubMed] Free Access to Full Article Related Publications
Aberrant expression of microRNAs (miRNAs) plays important roles in the development and progression of pancreatic cancer (PC). Expression analysis of miR-146a in human PC tissues showed decreased expression in about 80% of samples compared to corresponding non-cancerous tissue. Moreover, expression of miR-146a in eight PC cell lines, and in pancreatic tissues obtained from transgenic mouse models of K-Ras (K), Pdx1-Cre (C), K-Ras;Pdx1-Cre (KC) and K-Ras;Pdx1-Cre;INK4a/Arf (KCI), showed down-regulation of miR-146a expression in KCI mice which was in part led to over-expression of its target gene, epidermal growth factor receptor (EGFR). Treatment of PC cells with CDF, a novel synthetic compound, led to re-expression of miR-146a, resulting in the down-regulation of EGFR expression. Moreover, re-expression of miR-146a by stable transfection or treatment with CDF in vivo (xenograft animal model) resulted in decreased tumor growth which was consistent with reduced EGFR, ERK1, ERK2, and K-Ras expression. Further knock-down of miR-146a in AsPC-1 cells led to the up-regulation of EGFR expression and showed increased clonogenic growth. In addition, knock-down of EGFR by EGFR siRNA transfection of parental AsPC-1 cells and AsPC-1 cells stably transfected with pre-miR-146a resulted in decreased invasive capacity, which was further confirmed by reduced luciferase activity in cells transfected with pMIR-Luc reporter vector containing miR-146a binding site. Collectively, these results suggest that the loss of expression of miR-146a is a fundamental mechanism for over-expression of EGFR signaling and that re-expression of miR-146a by CDF treatment could be useful in designing personalized strategy for the treatment of human PC.

Thiel G, Müller I, Rössler OG
Expression, signaling and function of Egr transcription factors in pancreatic β-cells and insulin-responsive tissues.
Mol Cell Endocrinol. 2014; 388(1-2):10-9 [PubMed] Related Publications
Egr-1 and the related zinc finger transcription factors Egr-2, Egr-3, and Egr-4 are stimulated by many extracellular signaling molecules and represent a convergence point for intracellular signaling cascades. Egr-1 expression is induced in insulinoma cells and pancreatic β-cells following stimulation with either glucose, or pregnenolone sulfate. Moreover, stimulation of Gαq and Gαs-coupled receptors enhances EGR-1 gene transcription. Functional studies revealed that Egr transcription factors control insulin biosynthesis via regulation of Pdx-1 expression. Glucose homeostasis and pancreatic islet size are regulated by Egr transcription factors, indicating that these proteins control central physiological parameters regulated by pancreatic β-cells. In addition, Egr-1 is an integral part of the insulin receptor signaling cascade in insulin-responsive tissues and influences insulin resistance.

Lahdaoui F, Delpu Y, Vincent A, et al.
miR-219-1-3p is a negative regulator of the mucin MUC4 expression and is a tumor suppressor in pancreatic cancer.
Oncogene. 2015; 34(6):780-8 [PubMed] Related Publications
Pancreatic ductal adenocarcinoma (PDAC) is among the most lethal cancers in the world with one of the worst outcome. The oncogenic mucin MUC4 has been identified as an actor of pancreatic carcinogenesis as it is involved in many processes regulating pancreatic cancer cell biology. MUC4 is not expressed in healthy pancreas whereas it is expressed very early in pancreatic carcinogenesis. Targeting MUC4 in these early steps may thus appear as a promising strategy to slow-down pancreatic tumorigenesis. miRNA negative regulation of MUC4 could be one mechanism to efficiently downregulate MUC4 gene expression in early pancreatic neoplastic lesions. Using in silico studies, we found two putative binding sites for miR-219-1-3p in the 3'-UTR of MUC4 and showed that miR-219-1-3p expression is downregulated both in PDAC-derived cell lines and human PDAC tissues compared with their normal counterparts. We then showed that miR-219-1-3p negatively regulates MUC4 mucin expression via its direct binding to MUC4 3'-UTR. MiR-219-1-3p overexpression (transient and stable) in pancreatic cancer cell lines induced a decrease of cell proliferation associated with a decrease of cyclin D1 and a decrease of Akt and Erk pathway activation. MiR-219-1-3p overexpression also decreased cell migration. Furthermore, miR-219-1-3p expression was found to be conversely correlated with Muc4 expression in early pancreatic intraepithelial neoplasia lesions of Pdx1-Cre;LSL-Kras(G12D) mice. Most interestingly, in vivo studies showed that miR-219-1-3p injection in xenografted pancreatic tumors in mice decreased both tumor growth and MUC4 mucin expression. Altogether, these results identify miR-219-1-3p as a new negative regulator of MUC4 oncomucin that possesses tumor-suppressor activity in PDAC.

Wang Q, Jiang H, Ping C, et al.
Exploring the Wnt pathway-associated LncRNAs and genes involved in pancreatic carcinogenesis driven by Tp53 mutation.
Pharm Res. 2015; 32(3):793-805 [PubMed] Related Publications
PURPOSE: Study the contribution of long non-coding RNAs (lncRNAs) to progression of pancreatic intraepithelial neoplasia (PanIN) to pancreatic ductal adenocarcinoma (PDAC).
METHODS: We explored lncRNAs profilings in PanIN cell line (SH-PAN) isolated from Pdx-1-Cre; LSL-Kras (G12D/+) mice and PDAC cell line (DT-PCa) isolated from Pdx-1-Cre; LSL- Kras (G12D/+) ; LSL- Tp53 (R172H/+) mice by lncRNAs microarray, and detected expression of lncRNAs and genes in PDAC by Real-time PCR, Western blot, ChIP and immunohistochemistry.
RESULTS: Eight lncRNAs and five protein-coding genes, associated with Wnt pathway, were identified with more than five-fold changes between DT-PCa cells and SH-PAN cells. Of them, lincRNA1611 and Ppp3ca were validated significantly high expression in DT-PCa cells and in 22 of 26 fresh resected human PDAC tissues, compared to SH-PAN cells and normal pancreatic tissues, respectively. Moreover, Tp53 mutation status displayed a positive correlation with lincRNA1611 or Ppp3ca level. Immunohistochemical staining for Ppp3ca was weak or lack in 91 of 107 normal pancreatic tissues, 24 of 29 PanIN-I and 13 of 16 PanIN-II tissues, however, was strong in 10 of 27 PanIN-III and 62 of 107 PDAC tissues post operation.
CONCLUSIONS: LincRNA1611 and Ppp3ca were high expression in PDAC and may serve as new potential targets for intervention of the disease.

Wu J, Liu S, Yu J, et al.
Vertically integrated translational studies of PDX1 as a therapeutic target for pancreatic cancer via a novel bifunctional RNAi platform.
Cancer Gene Ther. 2014; 21(2):48-53 [PubMed] Related Publications
RNA interference (RNAi) represents a powerful, new tool for scientific investigation as well as a promising new form of targeted gene therapy, with applications currently in clinical trials. Bifunctional short hairpin RNA (shRNA) are synthetic RNAi molecules, engineered to utilize multiple endogenous RNAi pathways to specifically silence target genes. Pancreatic and duodenal homeobox 1 (PDX1) is a key regulator of pancreatic development, β-cell differentiation, normal β-cell function and pancreatic cancer. Our aim is to review the process of identifying PDX1 as a specific, potential RNAi target in pancreatic cancer, as well as the underlying mechanisms and various forms of RNAi, with subsequent testing and development of PDX1-targeted bifunctional shRNA therapy.

Nakanuma Y, Sato Y
Hilar cholangiocarcinoma is pathologically similar to pancreatic duct adenocarcinoma: suggestions of similar background and development.
J Hepatobiliary Pancreat Sci. 2014; 21(7):441-7 [PubMed] Related Publications
Routine experiences suggest that cholangiocarcinomas (CCAs) show different clinicopathological behaviors along the biliary tree, and hilar CCA apparently resembles pancreatic duct adenocarcinoma (PDAC). Herein, the backgrounds for these similarities were reviewed. While all cases of PDAC, hilar CCA, intrahepatic CCA (ICCA) and CCA components of combined hepatocellular-cholangiocarcinoma (cHC-CCA) were adenocarcinomas, micropapillary patterns and columnar carcinoma cells were common in PDAC and hilar CCA, and trabecular components and cuboidal carcinoma cells were common in ICCA and CCA components of cHC-CCA. Anterior gradient protein-2 and S100P were frequently expressed in perihilar CCA and PDAC, while neural cell adhesion molecule and luminal epithelial membrane antigen were common in CCA components of c-HC-CCA. Pdx1 and Hes1 were frequently and markedly expressed aberrantly in PDAC and perihilar CCA, although their expression was rare and mild in CCA components in cHC-CCA and ICCA. Hilar CCA showed a similar postoperative prognosis to PDAC but differed from ICCA and cHC-CCA. Taken together, hilar CCA may differ from ICCA and CCA components of cHC-CCA but have a similar development to PDAC. These similarities may be explained by the unique anatomical, embryological and reactive nature of the pancreatobiliary tract. Further studies of these intractable malignancies are warranted.

Yuan Y, Hartland K, Boskovic Z, et al.
A small-molecule inducer of PDX1 expression identified by high-throughput screening.
Chem Biol. 2013; 20(12):1513-22 [PubMed] Free Access to Full Article Related Publications
Pancreatic and duodenal homeobox 1 (PDX1), a member of the homeodomain-containing transcription factor family, is a key transcription factor important for both pancreas development and mature β cell function. The ectopic overexpression of Pdx1, Neurog3, and MafA in mice reprograms acinar cells to insulin-producing cells. We developed a quantitative PCR-based gene expression assay to screen more than 60,000 compounds for expression of each of these genes in the human PANC-1 ductal carcinoma cell line. We identified BRD7552, which upregulated PDX1 expression in both primary human islets and ductal cells, and induced epigenetic changes in the PDX1 promoter consistent with transcriptional activation. Prolonged compound treatment induced both insulin mRNA and protein and also enhanced insulin expression induced by the three-gene combination. These results provide a proof of principle for identifying small molecules that induce expression of transcription factors to control cellular reprogramming.

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