Transition In Pancreatic Cancer Research Articles

The xenobiotic transporter ABCC4/MRP4 promotes epithelial mesenchymal transition in pancreatic cancer.

The xenobiotic transporter ABCC4/MRP4 is highly expressed in pancreatic ductal adenocarcinoma (PDAC) and correlates with a more aggressive phenotype and metastatic propensity. Here, we show that ABCC4 promotes epithelial-mesenchymal transition (EMT) in PDAC, a hallmark process involving the acquisition of mesenchymal traits by epithelial cells, enhanced cell motility, and chemoresistance. Modulation of ABCC4 levels in PANC-1 and BxPC-3 cell lines resulted in the dysregulation of genes present in the EMT signature. Bioinformatic analysis on several cohorts including tumor samples, primary patient-derived cultured cells, patient-derived xenografts, and cell lines, revealed a positive correlation between ABCC4 expression and EMT markers. We also characterized the ABCC4 cistrome and identified four candidate clusters in the distal promoter and intron one that showed differential binding of pro-epithelial FOXA1 and pro-mesenchymal GATA2 transcription factors in low ABCC4-expressing HPAF-II and high ABCC4-expressing PANC-1 xenografts. HPAF-II xenografts showed exclusive binding of FOXA1, and PANC-1 xenografts exclusive binding of GATA2, at ABCC4 clusters, consistent with their low and high EMT phenotype respectively. Our results underscore ABCC4/MRP4 as a valuable prognostic marker and a potential therapeutic target to treat PDAC subtypes with prominent EMT features, such as the basal-like/squamous subtype, characterized by worse prognosis and no effective therapies.

Abstract 699: Targeting radiation-driven invasion and metastasis in pancreatic cancer

Abstract Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with a dismal prognosis. Standard of care includes chemotherapy and radiotherapy (RT) for locally advanced, unresectable disease. Despite radiotherapy being an effective and sometimes curative option for many cancer types, radio-resistance is common, and pre-clinical research in recent years has found that RT can initiate a more aggressive, pro-invasive phenotype in the remaining cells post treatment (1,2). Little is known about the molecular mechanisms responsible for this phenomenon.There is accumulating evidence highlighting a role for the RhoGTPase family in mediating radioresistance and enhanced invasion (2, 3). Understanding their role in PDAC progression may aid the identification of novel chemotherapeutics that could be used alongside RT in the future. We present in vitro data that confirms the pro-migratory effect of RT and importantly indicates a significant increase in metastases formed in a clinically relevant model of PDAC (KPC Pdx1-Cre; KrasG12D/+; Trp53R172H/+) after treatment using a small animal radiation research platform (n=31, p<0.0001). In concurrence with previous literature, we found that PDAC cell motility was dependent on the RhoGTPase pathway, RhoA/ROCK1 (p=0.004). However, post-RT, this dependency was switched to an alternative pathway, CDC42/Rac1/MRCK, indicating a clear change in the balance of RhoGTPase signaling (p=0.002). This switch was confirmed via high-throughput immunofluorescence analysis. To widen this investigation further, we performed an siRNA screen targeting all members of the RhoGTPase family. Preliminary results indicate signaling dependency on Rac2, Rac3 and CDC42 post-RT. Additionally, we have performed RNAseq to investigate pro-invasive gene signatures arising from the acute irradiation of pancreatic cancer cells. This was done at sufficient depth to identify splice variants, with differential transcript expression (DTE) analysis identifying 236 differentially expressed transcripts and the differential transcript usage (DTU) analysis identifying 28 transcripts and 23 genes. Initial functional enrichment analysis found gene signatures relating to cell migration and adhesion, which may be indicative of an invasive phenotype. In conclusion, we present in vitro and in vivo data suggesting RT may promote a more invasive phenotype in PDAC at least in part due to a switch in RhoGTPase signaling. 1. Mueller, A.C., et al., Induction of ADAM10 by Radiation Therapy Drives Fibrosis, Resistance, and Epithelial-to-Mesenchyal Transition in Pancreatic Cancer. Cancer Res, 2021. 81(12): p. 3255-3269. 2. Birch, J.L., et al., A Novel Small-Molecule Inhibitor of MRCK Prevents Radiation-Driven Invasion in Glioblastoma. Cancer Res, 2018. 78(22): p. 6509-6522. Citation Format: Kathy Mclay, Mathias Tesson, Dion Gilmour, Jennifer P. Morton, Joanna L. Birch. Targeting radiation-driven invasion and metastasis in pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 699.

Satellite double-stranded RNA induces mesenchymal transition in pancreatic cancer by regulating alternative splicing

Human satellite II (HSATII), composed of tandem repeats in pericentromeric regions, is aberrantly transcribed in epithelial cancers, particularly pancreatic cancer. Dysregulation of repetitive elements in cancer tissues can facilitate incidental dsRNA formation; however, it remains controversial whether dsRNAs play tumor-promoting or tumor-suppressing roles during cancer progression. Therefore, we focused on the double-stranded formation of HSATII RNA and explored its molecular function. The overexpression of double-stranded HSATII (dsHSATII) RNA promoted mesenchymal-like morphological changes and enhanced the invasiveness of pancreatic cancer cells. We identified an RNA-binding protein, spermatid perinuclear RNA-binding protein (STRBP), which preferentially binds to dsHSATII RNA rather than single-stranded HSATII RNA. The mesenchymal transition of dsHSATII-expressing cells was rescued by STRBP overexpression. Mechanistically, STRBP is involved in the alternative splicing of genes associated with epithelial-mesenchymal transition (EMT). We also confirmed that isoform switching of CLSTN1, driven by dsHSATII overexpression or STRBP depletion, induced EMT-like morphological changes. These findings reveal a novel tumor-promoting function of dsHSATII RNA, inducing EMT-like changes and cell invasiveness, thus enhancing our understanding of the biological significance of aberrant expression of satellite arrays in malignant tumors.

Abstract 3932: Targeting cyclin K in pancreatic cancer

Abstract This study focuses on investigating the role of Cyclin K in pancreatic cancer growth and chemotherapeutic sensitivity, aiming to provide pre-clinical evidence for Cyclin K-targeted therapy in pancreatic cancer. Unlike other well-known cyclins, Cyclin K is largely understudied in cancers. Data extracted from the TCGA database indicated that Cyclin K was overexpressed in pancreatic ductal adenocarcinoma (PDAC) and associated with reduced overall survival. Consistently, western blotting showed that Cyclin K was abundantly expressed in human and mouse PDAC cell lines. By using a Tet-On inducible system, we established Cyclin K-depleted and Cyclin K-overexpressed cell lines to evaluate the function of Cyclin K in pancreatic cancer. The proliferation assay showed that Cyclin K depletion led to retarded PDAC cell proliferation, whereas Cyclin K overexpression boosted cell growth. We further confirmed that Cyclin K was required for pancreatic cancer growth in vivo. In addition, cell cycle analysis showed that Cyclin K deficiency resulted in G1-S arrest, while Cyclin K overexpression promoted G1-S progression. By using an RT2 cell cycler array, we identified CDC20 as an important target of Cyclin K that mediated Cyclin K-induced PDAC cell proliferation. To investigate the influence of Cyclin K on chemo-sensitivity, we treated the PDAC cell lines with two newly synthesized Cyclin K molecular glue degraders (HQ461 and NCT02). We found that these degraders specifically ablated Cyclin K and its cognate kinase CDK12 in a very efficient manner. Importantly, we demonstrated that Cyclin K abrogation, either by Cyclin K degrader or Cyclin K knockdown, rendered PDAC cells more sensitive to GemTaxol (gemcitabine plus Taxol) treatment and PARP inhibitors (olaparib or niraparib), as indicated by increased cleavage of PARP or caspase 3. Together, our current results suggest: 1. Cyclin K promotes cell proliferation and G1-S transition in pancreatic cancer; 2. CDC20 mediates the function of Cyclin K on pancreatic cancer cell proliferation; 3. Cyclin K depletion synergizes with GemTaxol or PARP inhibitor in pancreatic cancer treatment. Our study revealed for the first time that Cyclin K plays an essential role in pancreatic cancer growth and chemo-sensitivity, and targeting Cyclin K may offer a great therapeutic avenue for pancreatic cancer patients. Citation Format: Yi Xiao, Jixin Dong, Yuanhong Chen. Targeting cyclin K in pancreatic cancer. [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3932.

Histone Modifications Represent a Key Epigenetic Feature of Epithelial-to-Mesenchyme Transition in Pancreatic Cancer

Pancreatic cancer is one of the most lethal malignant diseases due to its high invasiveness, early metastatic properties, rapid disease progression, and typically late diagnosis. Notably, the capacity for pancreatic cancer cells to undergo epithelial-mesenchymal transition (EMT) is key to their tumorigenic and metastatic potential, and is a feature that can explain the therapeutic resistance of such cancers to treatment. Epigenetic modifications are a central molecular feature of EMT, for which histone modifications are most prevalent. The modification of histones is a dynamic process typically carried out by pairs of reverse catalytic enzymes, and the functions of these enzymes are increasingly relevant to our improved understanding of cancer. In this review, we discuss the mechanisms through which histone-modifying enzymes regulate EMT in pancreatic cancer.

Intracellular C3 Modulates EMT via the Akt/Smad Pathway in Pancreatic Cancer Cells.

We aimed to explore the role of intracellular C3 in pancreatic ductal adenocarcinoma (PDAC). We evaluated C3 expression in PDAC using a gene expression database and tissue microarray. To clarify the role of C3 expression in PDAC, we conducted knockdown experiments using C3 short hairpin RNA (shRNA) in BxPC-3 cells. Differences in protein expression and cell behaviours were analysed. C3 was highly expressed in PDAC and correlated with cancer metastasis. In vitro experiments using BxPX-3 cells showed that C3 and its active form, C3a, were expressed in tumour cells. C3 knockdown reduced cell migration and invasion by inhibiting Akt/Smad pathway activation. TNF-α, not IL-6, enhanced C3 expression in this PDAC cell line. Intracellular C3 may regulate epithelial-mesenchymal transition in pancreatic cancer.

Numb-PRRL promotes TGF-\u03b21- and EGF-induced epithelial-to-mesenchymal transition in pancreatic cancer

Isoform-specific functions of Numb in the development of cancers, especially in the initiation of epithelial-to-mesenchymal transition (EMT) remains controversial. We study the specific function of Numb-PRRL isoform in activated EMT of pancreatic ductal adenocarcinoma (PC), which is distinguished from our previous studies that only focused on the total Numb protein. Numb-PRRL isoform was specifically overexpressed and silenced in PC cells combining with TGF-β1 and EGF stimulus. We systematically explored the potential effect of Numb-PRRL in the activated EMT of PC in vitro and in vivo. The total Numb protein was overexpressed in the normal pancreatic duct and well-differentiated PC by IHC. However, Numb-PRRS isoform but not Numb-PRRL showed dominant expression in PC tissues. Numb-PRRL overexpression promoted TGF-β1-induced EMT in PANC-1 and Miapaca-2 cells. TGF-β1-induced EMT-like cell morphology, cell invasion, and migration were enhanced in Numb-PRRL overexpressing groups following the increase of N-cadherin, Vimentin, Smad2/3, Snail1, Snail2, and cleaved-Notch1 and the decrease of E-cadherin. Numb-PRRL overexpression activated TGFβ1-Smad2/3-Snail1 signaling was significantly reversed by the Notch1 inhibitor RO4929097. Conversely, Numb-PRRL silencing inhibited EGF-induced EMT in AsPC-1 and BxPC-3 cells following the activation of EGFR-ERK/MAPK signaling via phosphorylating EGFR at tyrosine 1045. In vivo, Numb-PRRL overexpression or silencing promoted or inhibited subcutaneous tumor size and distant liver metastases via regulating EMT and Snail signaling, respectively. Numb-PRRL promotes TGF-β1- and EGF-induced EMT in PC by regulating TGF-β1-Smad2/3-Snail and EGF-induced EGFR-ERK/MAPK signaling.

TGFβ Drives Metabolic Perturbations during Epithelial Mesenchymal Transition in Pancreatic Cancer: TGFβ Induced EMT in PDAC.

Simple SummaryPancreatic cancer is an aggressive disease with most patients diagnosed at late stages resulting in poor outcomes. While it is known that pancreatic tumor cells undergo epithelial to mesenchymal transition, the metabolic alterations accompanying that transition are not characterized. This study leveraged a metabolomics approach to understand the small molecule and biochemical perturbations that can be targeted for designing strategies for improving outcomes in pancreatic cancer.Pancreatic ductal adenocarcinoma (PDAC) is a highly lethal malignancy wherein a majority of patients present metastatic disease at diagnosis. Although the role of epithelial to mesenchymal transition (EMT), mediated by transforming growth factor beta (TGFβ), in imparting an aggressive phenotype to PDAC is well documented, the underlying biochemical pathway perturbations driving this behaviour have not been elucidated. We used high-resolution mass spectrometry (HRMS) based molecular phenotyping approach in order to delineate metabolic changes concomitant to TGFβ-induced EMT in pancreatic cancer cells. Strikingly, we observed robust changes in amino acid and energy metabolism that may contribute to tumor invasion and metastasis. Somewhat unexpectedly, TGFβ treatment resulted in an increase in intracellular levels of retinoic acid (RA) that in turn resulted in increased levels of extracellular matrix (ECM) proteins including fibronectin (FN) and collagen (COL1). These findings were further validated in plasma samples obtained from patients with resectable pancreatic cancer. Taken together, these observations provide novel insights into small molecule dysregulation that triggers a molecular cascade resulting in increased EMT-like changes in pancreatic cancer cells, a paradigm that can be potentially targeted for better clinical outcomes.

Silencing of Long Non-Coding RNA HOTAIR Alleviates Epithelial-Mesenchymal Transition in Pancreatic Cancer via the Wnt/β-Catenin Signaling Pathway.

PurposePancreatic cancer (PC) is a malignancy with poor prognosis and controversial treatment options. Long non-coding RNA (lncRNA) is a significant factor in the development of PC. In the current study, the possible effects of HOTAIR on the epithelial–mesenchymal transition (EMT) of PC and the related mechanisms were investigated.MethodsThe PC models were induced by 10 mg/100 g dimethylbenzoanthracene (DMBA) in pancreas. Mice were injected with the HOTAIR mimic and HOTAIR shRNA to determine the role of HOTAIR in PC. Subsequently, the expression of HOTAIR in PC cells was assayed. To determine the mechanism of HOTAIR in PC, human PC cell line PANC-1, Miapaca-2 and human normal pancreatic ductal epithelial cell line HPDE6-C7 were transfected with the HOTAIR mimic, the shRNA against HOTAIR, the Wnt/b-catenin activator (LiCl), and the Wnt/b-catenin inhibitor (XAV939), respectively. Moreover, the expressions of the Wnt/β-catenin signaling pathway-related genes (β-catenin, cyclinD1, c-myc, LEF-1 and c-Jun) and the levels of the EMT markers (E-cadherin, N-cadherin and Vimentin) were determined. Finally, the cell biological processes were evaluated by functional experiments.ResultsHOTAIR was found to be highly expressed in the PC cells in mice. The expression of β-catenin, cyclinD1, c-myc, LEF-1 and c-Jun, N-cadherin and Vimentin was found to be decreased, while the expression of E-cadherin was found to be increased subsequent to the silencing of HOTAIR in human PC cell lines PANC-1 and Miapaca-2. Additionally, it was observed that the silencing of HOTAIR could inhibit the Wnt/β-catenin signaling pathway to alleviate EMT of tumor cells and inhibit the capacities of cell proliferation, migration, and invasion.ConclusionThe key finding of the present study is that the silencing of HOTAIR could potentially inhibit EMT and growth of PC through the Wnt/β-catenin signaling pathway, providing a novel therapy for PC.

Induction of ADAM10 by Radiation Therapy Drives Fibrosis, Resistance, and Epithelial-to-Mesenchyal Transition in Pancreatic Cancer.

Stromal fibrosis activates prosurvival and proepithelial-to-mesenchymal transition (EMT) pathways in pancreatic ductal adenocarcinoma (PDAC). In patient tumors treated with neoadjuvant stereotactic body radiation therapy (SBRT), we found upregulation of fibrosis, extracellular matrix (ECM), and EMT gene signatures, which can drive therapeutic resistance and tumor invasion. Molecular, functional, and translational analysis identified two cell-surface proteins, a disintegrin and metalloprotease 10 (ADAM10) and ephrinB2, as drivers of fibrosis and tumor progression after radiation therapy (RT). RT resulted in increased ADAM10 expression in tumor cells, leading to cleavage of ephrinB2, which was also detected in plasma. Pharmacologic or genetic targeting of ADAM10 decreased RT-induced fibrosis and tissue tension, tumor cell migration, and invasion, sensitizing orthotopic tumors to radiation killing and prolonging mouse survival. Inhibition of ADAM10 and genetic ablation of ephrinB2 in fibroblasts reduced the metastatic potential of tumor cells after RT. Stimulation of tumor cells with ephrinB2 FC protein reversed the reduction in tumor cell invasion with ADAM10 ablation. These findings represent a model of PDAC adaptation that explains resistance and metastasis after RT and identifies a targetable pathway to enhance RT efficacy. SIGNIFICANCE: Targeting a previously unidentified adaptive resistance mechanism to radiation therapy in PDAC tumors in combination with radiation therapy could increase survival of the 40% of PDAC patients with locally advanced disease.See related commentary by Garcia Garcia et al., p. 3158 GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/81/12/3255/F1.large.jpg.

Epithelial-to-Mesenchymal Transition in Pancreatic Cancer is associated with Restricted Water Diffusion in Diffusion-Weighted Magnetic Resonance Imaging.

Purpose: This study aimed to evaluate the potential of diffusion-weighted magnetic resonance imaging (DW-MRI) as imaging biomarker for epithelial-to-mesenchymal transition (EMT) in pancreatic ductal adenocarcinoma (PDAC).Methods: In forty-two patients, preoperative apparent diffusion coefficient (ADC) values of therapy-naive PDAC were compared with immunohistochemical expression profiles of the epithelial marker E-cadherin as well as mesenchymal transcription factors Runt-related transcription factor 2 (Runx2) and Zinc finger E-box-binding homeobox 1 (Zeb1), as determined by Allred immunoreactivity score.Results: We observed a significant positive rank correlation between the ADC and the E-cadherin Allred score (ρ = 0.553, p < 0.001) and significant negative rank correlations between the ADC and the Runx2 Allred score (ρ = -0.526, p < 0.001) as well as the Zeb1 Allred score (ρ = -0.710, p < 0.001). Compared to tumors with low ADC values < 1.3 µm2/s, tumors with ADC values ≥ 1.3 µm2/s had significantly higher Allred scores for E-cadherin (median, 4 versus 5; p < 0.001) and significantly lower Allred scores for Runx2 (median, 3 versus 2; p = 0.003) as well as Zeb1 (median, 4 versus 0; p < 0.001).Conclusion: In PDAC, tumor plasticity in terms of EMT is well reflected by ADC values from DW-MRI. In the near future, DW-MRI could be beneficial for identification of PDAC patients that might profit from personalized EMT-targeted therapies.

Exploration of Exosomal Micro RNA Biomarkers Related to Epithelial-to-Mesenchymal Transition in Pancreatic Cancer

Epithelial-to-mesenchymal transition (EMT) plays important roles in cancer progression. This study aimed to identify the exosomal miRNA (exo-miRNA) profiles related to the EMT status in pancreatic cancer (PC). Comprehensive exo-miRNA-expression profiles in the culture media of PC cell lines were analyzed through microarray technology. The identified miRNAs were analyzed to investigate their clinical implication using The Cancer Genome Atlas (TCGA) dataset and clinical samples. We prioritized 291 exo-miRNAs differentially expressed between epithelial and mesenchymal cell types. Among them, survival analysis based on the TCGA dataset revealed that mir-196b and mir-204 significantly stratify the prognosis of PC cases. In addition, analysis of cell lines indicated miR-196b-3p as a mesenchymal marker and miR-204-3p as an epithelial marker. Finally, we demonstrated that miR-196b-3p and miR-204-3p in serum exosomes were differentially expressed among intraductal papillary mucinous neoplasms, mucinous cystic neoplasms, and PC. Serum exo-miRNA biomarkers potentially identify the pancreatic tumor status through less-invasive methods.

AREG mediates the epithelial‑mesenchymal transition in pancreatic cancer cells via the EGFR/ERK/NF‑κB signalling pathway.

Amphiregulin (AREG) is a member of the epidermal growth factor (EGF) family and is expressed in a plethora of cancers. The biological roles of AREG in the regulation of the epithelial-mesenchymal transition (EMT) in pancreatic cancer remain unclear. To investigate the expression of epidermal growth factor receptor (EGFR) and AREG in pancreatic cancer cell lines, RT-qPCR, western blot analysis, and ELISA were performed. RNAi and exogenous AREG treatment were used to alter AREG expression. Wound-healing and Transwell assays were performed to evaluate cell migration and invasion abilities. Western blot analysis and immunofluorescence staining were utilized to detect the expression of EMT markers. The protein expression of potential key factors involved in EMT, as well as those of the ERK, AKT, STAT3 and NF-κB pathways, were analysed by western blotting. The role of AREG in tumour growth in vivo was further determined using an orthotopic model of pancreatic cancer. Knockdown of AREG inhibited AsPC-1 cell migration and invasion. AREG knockdown upregulated E-cadherin but downregulated vimentin, Snail and Slug expression in AsPC-1 cells. In addition, AREG stimulation increased cell migration, invasion and EMT in PANC-1 cells, and an NF-κB inhibitor decreased AREG-induced cell migration, invasion and EMT in PANC-1 cells. AREG stimulation increased the nuclear accumulation of NF-κB through the EGFR/ERK signalling pathway to induce EMT. Tumour growth and metastasis were decreased by AREG silencing in an orthotopic model of pancreatic cancer. AREG may play a critical role in cell migration, invasion, and EMT by activating the EGFR/ERK/NF-κB signalling pathway in pancreatic cancer cells.

Abstract C11: Linoleic acid elevates sirtuin 6 expression and modulates glycolysis and epithelial-mesenchymal transition of pancreatic cancer with loss of Krüpple like factor 10

Abstract Introduction: Pancreatic adenocarcinoma (PDAC) is well known for its deregulated TGFβ signaling. TGFβ signaling exerts a contextual effect that suppresses malignant growth early in epithelial tumorigenesis but promotes metastasis at later stages. The Krüppel-like factor 10 (Klf10) is an early response gene that mediates the antiproliferative effects of TGFβ but opposes the prometastatic effects of TGFβ by limiting its ability to induce epithelial-to-mesenchymal transition (EMT). The distinction between the antiproliferative versus prometastatic functions of TGFβ makes Klf10 a potential target for the development of therapy in cancers with aberrant TGFβ pathway such as PDAC. Klf10 knock-out mice do not have abnormal pancreas development or carcinogenesis. However, ablating Klf10 in murine PDAC models increases pancreatic tumorigenesis and distant metastasis. Genome-wide comparison of mRNA profiles from wild-type and Klf10 knock-out mice revealed significant enrichment for transcripts involved in glucose metabolism. We propose that Klf10 modulates PDAC progression via enhanced glycolysis, which leads to EMT and cancer stemness phenotypes. Materials and Methods: Genetically manipulated Klf10 of human PDAC cell lines was established to measure EMT markers, glycolysis activity and stemness related proteins, cell migration, and murine liver metastasis after intrasplenic injection. Chip-Chip assay was performed to find sirtuin 6 (Sirt6), governing both cancer metabolism and progression, to be one of the candidate molecules regulated by Klf10. The interaction between Klf10 and Sirt6 was evaluated by ChIP-PCR and luciferase reporter assay. PDAC cell lines with or without Klf10 mRNA silencing were overexpressed with Sirt6 to reverse malignant phenotypes induced by Klf10 deficiency. Linoleic acid, a specific Sirt6 activator, was used in vitro and in vivo to ameliorate the aberrant glucose metabolism, EMT phenotype, and distant metastasis of PDAC with loss of Klf10 expression. Results: In vitro and in vivo studies demonstrated Klf10 deficiency in pancreatic cancer enhanced metastasis, EMT, stemness, and glycolysis. Klf10 bond to the promoter and transcriptionally regulated Sirt6. Sirt6 expression paralleled the level of Klf10 in PDAC. Modulating Sirt6 genetically or pharmacologically, by linoleic acid, reversed the EMT, glycolysis, and metastatic phenotypes of PDAC with KLF10 deficiency. Using PDK1, a glycolysis inhibitor, and BSI#38, an EMT inhibitor, we demonstrated the interaction of cancer metabolism and EMT phenotypes in PDAC. Discussion: Loss of Klf10 contributes to pancreatic cancer progression and enhances glycolysis, EMT, and cancer stemness by transcriptionally regulating Sirt6. Overexpressing Sirt6 genetically or pharmacologically by linoleic acid may ameliorate PDAC progression. Targeting Klf10/Sirt6 signaling is a potential strategy to modulate glycolysis and EMT simultaneously in PDAC for preventing malignant progression. Citation Format: Hui-Ju Ch'ang, Yi-Chih Tsai, Su-Liang Chen, Vincent H.S. Chang. Linoleic acid elevates sirtuin 6 expression and modulates glycolysis and epithelial-mesenchymal transition of pancreatic cancer with loss of Krüpple like factor 10 [abstract]. In: Proceedings of the AACR Special Conference on Pancreatic Cancer: Advances in Science and Clinical Care; 2019 Sept 6-9; Boston, MA. Philadelphia (PA): AACR; Cancer Res 2019;79(24 Suppl):Abstract nr C11.

Effect of ARK5 on the anti-tumour activity of OSI-027 via regulation of epithelial-mesenchymal transition in pancreatic cancer.

e15758 Background: Pancreatic cancer (PC) is one of the most common lethal malignancies,OSI-027, a selective inhibitor of mTOR, has anti-tumour activity in PC and is currently in phase II clinical trials. According to the results of our previous study, OSI-027 sensitivity varies across pancreatic cancer cell lines; however, the underlying mechanisms are unclear. Methods: In this study,We sought to investigate the regulatory mechanisms underlying OSI-027 resistance in PC under both in vitro and in vivo conditions. Results: We demonstrated that in PC, sensitivity to OSI-027 was negatively correlated with ARK5 expression, and ARK5 knockdown could enhance OSI-027 sensitivity. Further, the mechanistic experiments showed that ARK5 inhibition could reverse EMT induced by OSI-027. Suppression of EMT by Twist siRNA could sensitize pancreatic cancer cells to OSI-027, but the combination of Twist siRNA and ARK5 siRNA did not enhance the anti-tumour effect of OSI-027. Moreover, under hypoxia-induced EMT, the cancer cells were less sensitive to OSI-027, but ARK5 siRNA could block the EMT process. The in vivo experiments showed that the combination of ARK5 and Twist siRNAs could enhance the anti-tumour effect of OSI-027 and restrain OSI-027-induced EMT. Conclusions: The results indicate that ARK5 plays a role in the resistance of pancreatic cancer cells to OSI-027 by regulating EMT and lay the groundwork for future clinical studies.

Long noncoding RNA XIST regulates the EGF receptor to promote TGF-β1-induced epithelial-mesenchymal transition in pancreatic cancer.

This study focuses on the lncRNA XIST (X inactive-specific transcript), an lncRNA involved in multiple human cancers, and investigates the functional significance of XIST and the molecular mechanisms underlying the epithelial-mesenchymal transition (EMT) in pancreatic cancer (PC). Clinical specimens from 25 patients as well as 5 human PC cell lines were analyzed for XIST, YAP, and microRNA(miR)-34a by quantitative real-time PCR (qRT-PCR) and immunohistochemistry. To investigate how XIST influences cell proliferation, invasiveness, and apoptosis in PC, we performed the CCK-8 assays, Transwell assays, and flow cytometry. Luciferase reporter assays, qRT-PCR, and Western blot were applied to prove that miR-34a directly binds to XIST. Up-regulation of XIST and Yes associated protein (YAP) and down-regulation of miR-34a were consistently observed in the clinical specimens and PC cell lines. Silencing XIST reduced the expression of YAP and suppressed transforming growth factor (TGF)-β1-induced EMT, while over-expression of XIST increased the expression of YAP and promoted EMT. In addition, inhibition of epidermal growth factor receptor (EGFR) hampered the XIST-promoted EMT. The results from the luciferase reporter assays confirmed that miR-34a directly targets XIST and suggested that XIST regulates cell proliferation, invasiveness, and apoptosis in PC by sponging miR-34a. XIST promotes TGF-β1-induced EMT by regulating the miR-34a-YAP-EGFR axis in PC.

A phase Ib study evaluating olaratumab in combination with nab-paclitaxel and gemcitabine in first-line treatment of metastatic pancreatic cancer.

330 Background: Increased platelet-derived growth factor receptor alpha (PDGFRα) expression is linked to epithelial-mesenchymal transition in pancreatic cancer. Olaratumab (O) is a fully human monoclonal antibody against PDGFRα previously approved for the treatment of advanced soft tissue sarcoma. Here, we report the initial safety and antitumor activity data of O in combination with nab-paclitaxel + gemcitabine (nPG) in first-line metastatic pancreatic cancer patients (pts). Methods: In this 3+3 dose escalation study, pts with stage IV pancreatic cancer received intravenous 15 mg/kg (cohort 1) or 20 mg/kg (cohort 2) O + nPG (125 mg/m2/1000 mg/m2) on D1, 8, and 15 of a 28-day cycle. Following dose escalation, additional pts were enrolled in an expansion phase to confirm safety. Primary objective was to determine a dose of O that can be safely combined with nPG. Results: As of September 2018, 10 pts were treated in dose escalation (cohort 1: 3 pts; cohort 2: 7 pts) with no dose-limiting toxicities (DLTs) observed. Safety of 20 mg/kg O + nPG was confirmed in the expansion cohort; 1 of 12 pts (8.3%) experienced a DLT of grade 4 neutropenia. Most frequent adverse events (AEs) (≥ 25%) reported across all cohorts included fatigue (50%); neutropenia (50%); nausea (46%); thrombocytopenia (41%); and constipation (32%). Related grade ≥ 3 AEs reported in &gt; 2 pts were neutropenia (N = 7; 32%), infusion-related reaction, and neuropathy (both N = 3; 14%). There were no deaths related to study drugs. Among pts evaluable for response, 2 of 15 pts had a partial response and 11 pts had stable disease as best response for an objective response rate of 13%. Notably, 2 of 3 pts in cohort 1 continue on treatment for more than 12 months as of the data cut-off. Updated data will be presented at the meeting. Conclusions: Both dose levels were tolerated. Safety profile was similar to nPG chemotherapy with most toxicity manageable through dose adjustments of nPG. Clinical trial information: NCT03086369.

Histone deacetylase 1 suppresses metastasis by inhibiting epithelial-mesenchymal transition in pancreatic cancer

Histone deacetylase 1 suppresses metastasis by inhibiting epithelial-mesenchymal transition in pancreatic cancer

Loss of Transforming Growth Factor Beta/SMAD Function Induces Interleukin1α to Mediate Epithelial-to-Mesenchymal Transition in Pancreatic Cancer

Loss of Transforming Growth Factor Beta/SMAD Function Induces Interleukin1α to Mediate Epithelial-to-Mesenchymal Transition in Pancreatic Cancer

Overexpression of GP73 promotes cell invasion, migration and metastasis by inducing epithelial-mesenchymal transition in pancreatic cancer

Pancreatic cancer is one of the most difficult clinical cases to diagnose with a very low 5-year survival rate of 5%, regardless of the advances made in both the medical and surgical treatment of the disease. One of the contributing factors for the high mortality rate seen of pancreatic cancer patients is the lack of effective chemotherapies, which is believed to be due to drug-resistance. Based on recent evidence, epithelial-mesenchymal transition (ETM) of pancreatic cancer cells has been found to be associated with the development of drug resistance and an increase in cell invasion. Therefore, we conducted the present study in order to investigate the regulatory effects of Golgi protein-73 (GP73) on PC. GP73 and EMT-related gene expressions in PC, along with the adjacent and chronic pancreatitis tissues were determined by means of RT-qPCR and Western blot analysis. Cultured PC cells were treated with pAdTrack-CMV, si-NC, GP73 overexpression, Si-GP73, Snail-siRNA and GP73 + Snail-siRNA. Cell invasion, migration and metastasis were measured in vitro and in vivo. The results revealed that the PC tissues and chronic pancreatitis tissues exhibited diminished E-cadherin expression and amplified GP73, N-cadherin, Vimentin and Snail expression. In response to GP73 gene silencing, PC cells presented with increased E-cadherin expression and decreased N-cadherin, Vimentin, Snail expression in addition to the inhibition of the number of invasive cells, tumor volume and number of liver lesions. These findings highly indicated that the overexpression of GP73 promotes cell invasion, migration and metastasis by inducing EMT in PC.