scholarly journals Effects of Growth Hormone on Pancreatic Cancer Derived Exosomes

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A1016-A1017
Author(s):  
Prateek Kulkarni ◽  
Reetobrata Basu ◽  
John J Kopchick
Keyword(s):  
Pancreatic Cancer ◽  
Growth Hormone ◽  
Drug Resistance ◽  
Efflux Pump ◽  
Treatment Options ◽  
The Body ◽  
Ductal Adenocarcinoma ◽  
Gh Treatment ◽  
Mesenchymal Transition ◽  
Pancreatic Cancer Cells

Abstract In 2020, the National Cancer Institute (NCI) estimates 57,600 new cases and 47,050 deaths in the US due to pancreatic ductal adenocarcinoma (PDAC). A dismal 10% five-year overall survival rate in PDAC is attributed to late diagnosis, limited treatment options, a remarkably high metastasis rate, and resistance of this cancer to available therapies. Therefore, a better understanding of the mechanisms of how PDAC tumors acquire drug resistance and spread to distal parts of the body are necessary for developing novel therapeutic approaches. Exosomes, microscopic vesicles released from most cells (both tumor and non-tumor) have been recently established to play a significant role in cell to cell communication. Exosomes modulate their target cell responses systematically depending on the nature of exosomal cargoes (nucleic acids, proteins, and lipids). PDAC derived exosomes have been implicated to promote metastasis via forming a pre-metastatic niche of cells as well as enhancing drug resistance. Growth hormone (GH) secreted primarily by the pituitary gland promotes metastasis and drug resistance as shown by plethora of studies. No study has directly assessed the effect of GH on exosomal cargoes in terms of promoting metastases and drug resistance. In this report, we show that GH modulates various pancreatic cancer cell exosomal cargoes which in turn potentially amplifies tumor invasion and metastases. Our data shows that GH treatment on human and mouse PDAC cells increases the exosomal protein levels of TGFβ - a critical inducer of epithelial-to-mesenchymal transition (EMT, a process leading to metastasis). In addition, GH treatment also increases extracellular matrix-degrading enzymes, MMP2 and 9, as well as multi-drug efflux pump ABCC1, ABCB1, and ABCG2 in PDAC cells. These results strongly implicate GH action in driving EMT and chemoresistance via exosomes in pancreatic cancer. Exosomes have a crucial impact especially in the areas of diagnostics and therapeutics. This report is the first to show that GH modulates the effects of exosomes secreted by pancreatic cancer cells. Acknowledgement: This work was supported in part by the State of Ohio’s Eminent Scholar Program that includes a gift from Milton and Lawrence Goll, by the AMVETS, and Ohio University’s Student Enhancement Award and Edison Biotechnology Institute.

scholarly journals Metabolic plasticity imparts erlotinib-resistance in pancreatic cancer by upregulating glucose-6-phosphate dehydrogenase

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Neha Sharma ◽  
Alok Bhushan ◽  
Jun He ◽  
Gagan Kaushal ◽  
Vikas Bhardwaj
Keyword(s):  
Pancreatic Cancer ◽  
Drug Resistance ◽  
Cancer Cells ◽  
Treatment Options ◽  
Pentose Phosphate ◽  
Metabolic Phenotype ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Resistant Cells

Abstract Pancreatic ductal adenocarcinoma (PDAC) is one of the most malignant forms of cancer. Lack of effective treatment options and drug resistance contributes to the low survival among PDAC patients. In this study, we investigated the metabolic alterations in pancreatic cancer cells that do not respond to the EGFR inhibitor erlotinib. We selected erlotinib-resistant pancreatic cancer cells from MiaPaCa2 and AsPC1 cell lines. Metabolic profiling of erlotinib-resistant cells revealed a significant downregulation of glycolytic activity and reduced level of glycolytic metabolites compared to the sensitive cells. The resistant cells displayed elevated expression of the pentose phosphate pathway (PPP) enzymes involved in ROS regulation and nucleotide biosynthesis. The enhanced PPP elevated cellular NADPH/NADP+ ratio and protected the cells from reactive oxygen species (ROS)-induced damage. Inhibition of PPP using 6-aminonicotinamide (6AN) elevated ROS levels, induced G1 cell cycle arrest, and sensitized resistant cells to erlotinib. Genetic studies identified elevated PPP enzyme glucose-6-phosphate dehydrogenase (G6PD) as an important contributor to erlotinib resistance. Mechanistically, our data showed that upregulation of inhibitor of differentiation (ID1) regulates G6PD expression in resistant cells thus contributing to altered metabolic phenotype and reduced response to erlotinib. Together, our results highlight an underlying role of tumor metabolism in PDAC drug response and identify G6PD as a target to overcome drug resistance.

scholarly journals Oncogenic KRAS engages an RSK1/NF1 pathway to inhibit wild-type RAS signaling in pancreatic cancer

2021 ◽  
Vol 118 (21) ◽  
pp. e2016904118
Author(s):  
Derek K. Cheng ◽  
Tobiloba E. Oni ◽  
Jennifer S. Thalappillil ◽  
Youngkyu Park ◽  
Hsiu-Chi Ting ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Clinical Success ◽  
Treatment Options ◽  
Mass Spectrometry Analysis ◽  
Ductal Adenocarcinoma ◽  
Ras Signaling ◽  
Wild Type ◽  
Feedback Mechanisms ◽  
Spectrometry Analysis ◽  
Pancreatic Cancer Cells

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignancy with limited treatment options. Although activating mutations of the KRAS GTPase are the predominant dependency present in >90% of PDAC patients, targeting KRAS mutants directly has been challenging in PDAC. Similarly, strategies targeting known KRAS downstream effectors have had limited clinical success due to feedback mechanisms, alternate pathways, and dose-limiting toxicities in normal tissues. Therefore, identifying additional functionally relevant KRAS interactions in PDAC may allow for a better understanding of feedback mechanisms and unveil potential therapeutic targets. Here, we used proximity labeling to identify protein interactors of active KRAS in PDAC cells. We expressed fusions of wild-type (WT) (BirA-KRAS4B), mutant (BirA-KRAS4BG12D), and nontransforming cytosolic double mutant (BirA-KRAS4BG12D/C185S) KRAS with the BirA biotin ligase in murine PDAC cells. Mass spectrometry analysis revealed that RSK1 selectively interacts with membrane-bound KRASG12D, and we demonstrate that this interaction requires NF1 and SPRED2. We find that membrane RSK1 mediates negative feedback on WT RAS signaling and impedes the proliferation of pancreatic cancer cells upon the ablation of mutant KRAS. Our findings link NF1 to the membrane-localized functions of RSK1 and highlight a role for WT RAS signaling in promoting adaptive resistance to mutant KRAS-specific inhibitors in PDAC.

scholarly journals BRM270 Inhibits the Proliferation of CD44 Positive Pancreatic Ductal Adenocarcinoma Cells via Downregulation of Sonic Hedgehog Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Do Luong Huynh ◽  
Hyebin Koh ◽  
Nisansala Chandimali ◽  
Jiao Jiao Zhang ◽  
Nameun Kim ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Pancreatic Ductal Adenocarcinoma ◽  
Sonic Hedgehog ◽  
Hedgehog Signaling ◽  
Ductal Adenocarcinoma ◽  
Cell Phenotype ◽  
Sonic Hedgehog Signaling ◽  
Mesenchymal Transition ◽  
Pancreatic Cancer Cells ◽  
Adenocarcinoma Cells

Pancreatic cancer has a poor survival rate as compared to other types of cancer. Surface marker CD44 plays important role in epithelial-mesenchymal transition and cancer stem cell phenotype. Therefore, targeting CD44 positive pancreatic cancer cells might enhance therapies effectiveness. Our previous studies indicated the antitumorigenesis effect of BRM270 in osteosarcoma, lung cancer, and glioblastoma; however there is no evidence on BRM270 impacts on pancreatic cancer growth. In this study, we investigated the effect of BRM270 on the isolated CD44 positive pancreatic ductal adenocarcinoma cells (CD44+PDAC). Results showed that CD44 positive cells undergo apoptosis induced by BRM270. Moreover, BRM270 also inhibits stemness and metastasis traits in CD44+PDAC via Sonic hedgehog signaling pathway and SALL4 expression.In vivostudy indicated that tumor growth derived from CD44+PDAC was suppressed as daily uptake by BRM270 5 mg/kg. These data suggest the alternative approach in antipancreatic tumorigenesis via herbal plants extract and selectively targeting CD44+PDAC cells in tumor.

scholarly journals Crosstalk between KRAS, SRC and YAP Signaling in Pancreatic Cancer: Interactions Leading to Aggressive Disease and Drug Resistance

Cancers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 5126
Author(s):  
Enrique Rozengurt ◽  
Guido Eibl
Keyword(s):  
Pancreatic Cancer ◽  
Drug Resistance ◽  
Recent Literature ◽  
Epithelial Mesenchymal Transition ◽  
Ductal Adenocarcinoma ◽  
Current Evidence ◽  
Src Tyrosine Kinase ◽  
Mesenchymal Transition ◽  
New Findings ◽  
Predominant Form

Pancreatic ductal adenocarcinoma (PDAC), the predominant form of pancreatic cancer, remains a devastating disease. The purpose of this review is to highlight recent literature on mechanistic and translational developments that advance our understanding of a complex crosstalk between KRAS, YAP and Src tyrosine kinase family (SFK) in PDAC development and maintenance. We discuss recent studies indicating the importance of RAS dimerization in signal transduction and new findings showing that the potent pro-oncogenic members of the SFK phosphorylate and inhibit RAS function. These surprising findings imply that RAS may not play a crucial role in maintaining certain subtypes of PDAC. In support of this interpretation, current evidence indicates that the survival of the basal-like subtype of PDAC is less dependent on RAS but relies, at least in part, on the activity of YAP/TAZ. Based on current evidence, we propose that SFK propels PDAC cells to a state of high metastasis, epithelial-mesenchymal transition (EMT) and reduced dependence on KRAS signaling, salient features of the aggressive basal-like/squamous subtype of PDAC. Strategies for PDAC treatment should consider the opposite effects of tyrosine phosphorylation on KRAS and SFK/YAP in the design of drug combinations that target these novel crosstalk mechanisms and overcome drug resistance.

scholarly journals Yap1-2 Isoform Is the Primary Mediator in TGF-β1 Induced EMT in Pancreatic Cancer

2021 ◽  
Vol 11 ◽  
Author(s):  
Chao Gao ◽  
Mei-Yu Quan ◽  
Qian-Jie Chen ◽  
Ruo Yang ◽  
Yuanyuan Wu ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Western Blot ◽  
Epithelial To Mesenchymal Transition ◽  
Hippo Pathway ◽  
Akt Signaling ◽  
Protein Isoforms ◽  
Ductal Adenocarcinoma ◽  
Mesenchymal Transition ◽  
Pancreatic Cancer Cells ◽  
Alternative Mrna Splicing

Pancreatic ductal adenocarcinoma (PDAC) is the most aggressive human malignancy and intrinsically resistant to conventional therapies. YAP1, as a key downstream effector of the Hippo pathway, plays an important role in tumorigenesis including PDAC. Alternative mRNA splicing of YAP1 results in at least 8 protein isoforms, which are divided into two subgroups (YAP1-1 and YAP1-2) based on the presence of either a single or double WW domains. We investigated the functions and regulatory mechanisms of YAP1-1 and YAP1-2 in PDAC cells induced by TGF-β to undergo epithelial-to-mesenchymal transition (EMT). CRISPR-Cas9 and shRNA were used to silence YAP1 expression in pancreatic cancer cells. Re-constituted lentivirus mediated overexpression of each single YAP1 isoform was generated in the parental knockout L3.6 cells. EMT was induced by treatment with TGF-β, EGF and bFGF in parental and the constructed stable cell lines. Western blot and qPCR were used to detect the expression of EMT markers. Scratch wound healing and transwell assays were used to detect cell migration. The stability and subcellular localization of YAP1 proteins were determined by Western blot analysis, immunofluorescence, as well as ubiquitination assays. We showed that TGF-β, EGF and bFGF all significantly promoted EMT in PDAC cells, which was inhibited by knockdown of YAP1 expression. Interestingly, YAP1-1 stable cells exhibited a stronger migratory ability than YAP1-2 cells under normal culture condition. However, upon TGF-β treatment, L3.6-YAP1-2 cells exhibited a stronger migratory ability than L3.6-YAP1-1 cells. Mechanistically, TGF-β treatment preferentially stabilizes YAP1-2 and enhances its nuclear localization. Furthermore, TGF-β-induced EMT and YAP1-2 activity were both blocked by inhibition of AKT signaling. Our results showed that both YAP1-1 and YAP1-2 isoforms are important mediators in the EMT process of pancreatic cancer. However, YAP1-2 is more important in mediating TGF-β-induced EMT, which requires AKT signaling.

scholarly journals Targeted intervention of eIF4A1 inhibits EMT and metastasis of pancreatic cancer cells via c-MYC/miR-9 signaling

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Yuchong Zhao ◽  
Yun Wang ◽  
Wei Chen ◽  
Shuya Bai ◽  
Wang Peng ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
The Cancer Genome Atlas ◽  
Ductal Adenocarcinoma ◽  
Mesenchymal Transition ◽  
Early Metastasis ◽  
Pancreatic Cancer Cells ◽  
E Cadherin

Abstract Background Owing to the lack of effective treatment options, early metastasis remains the major cause of pancreatic ductal adenocarcinoma (PDAC) recurrence and mortality. However, the molecular mechanism of early metastasis is largely unknown. We characterized the function of eukaryotic translation initiation factors (eIFs) in epithelial-mesenchymal-transition (EMT) and metastasis in pancreatic cancer cells to investigate whether eIFs and downstream c-MYC affect EMT and metastasis by joint interference. Methods We used The Cancer Genome Atlas (TCGA) and Genome Tissue Expression (GTEx) databases to analyze eIF4A1 expression in PDAC tissues and further validated the findings with a microarray containing 53 PDAC samples. Expression regulation and pharmacological inhibition of eIF4A1 and c-MYC were performed to determine their role in migration, invasion, and metastasis in pancreatic cancer cells in vitro and in vivo. Results Elevated eIF4A1 expression was positively correlated with lymph node infiltration, tumor size, and indicated a poor prognosis. eIF4A1 decreased E-cadherin expression through the c-MYC/miR-9 axis. Loss of eIF4A1 and c-MYC decreased the EMT and metastasis capabilities of pancreatic cancer cells, whereas upregulation of eIF4A1 attenuated the inhibition of EMT and metastasis induced by c-MYC downregulation. Treatment with the eIF4A1 inhibitor rocaglamide (RocA) or the c-MYC inhibitor Mycro3 either alone or in combination significantly decreased the expression level of EMT markers in pancreatic cancer cells in vitro. However, the efficiency and safety of RocA alone were not inferior to those of the combination treatment in vivo. Conclusion Overexpression of eIF4A1 downregulated E-cadherin expression through the c-MYC/miR-9 axis, which promoted EMT and metastasis of pancreatic cancer cells. Despite the potential feedback loop between eIF4A1 and c-MYC, RocA monotherapy is a promising treatment inhibiting eIF4A1-induced PDAC metastasis.

scholarly journals Downregulation of NEAT1 sensitizes gemcitabine-resistant pancreatic cancer cells to gemcitabine through modulation of the miR-506-3p/ZEB2/EMT axis

2020 ◽  
Author(s):  
Xiaowei Fu ◽  
Xueqiang Deng ◽  
Weidong Xiao ◽  
Bo Huang ◽  
Xuan Yi ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Drug Resistance ◽  
Epithelial To Mesenchymal Transition ◽  
Xenograft Model ◽  
Migration And Invasion ◽  
Mesenchymal Transition ◽  
Mouse Xenograft ◽  
Pancreatic Cancer Cells ◽  
Mouse Xenograft Model ◽  
Underlying Mechanisms

Abstract BackgroundChemoresistance is a major cause of treatment failure in pancreatic cancer (PC). It has been demonstrated that epithelial-to-mesenchymal transition (EMT) is closely related to drug resistance in PC; however, the underlying mechanisms are not yet fully understood. Recently found evidence has suggested that nuclear-enriched abundant transcript 1 (NEAT1) is involved in the development of chemoresistance. However, the role and mechanism of NEAT1 in PC gemcitabine resistance remain unknown.MethodsTwo independent gemcitabine-resistant (GR) PC cell lines, PANC-1/GR and SW1990/GR, were established. Transwell assays were used to validate whether GR cells acquired EMT. qRT-PCR and western blot were performed to detect the expression levels of NEAT1, miR-506-3p, and ZEB2 in GR cells. MTT and cell apoptosis assays were conducted to evaluate the sensitivity of GR cells to gemcitabine. Rescue experiments were employed to investigate whether NEAT1 mediates drug resistance of GR cells through modulation of the miR-506-3p/ZEB2/EMT axis. Furthermore, a mouse xenograft model was established to confirm these findings.ResultsGR cells displayed markedly enhanced migration and invasion abilities, decreased expression of E-cadherin, and upregulation of N-cadherin, Vimentin, Snail, ZEB1, and ZEB2. Furthermore, elevated expression of NEAT1 was observed in GR cells. Downregulation of NEAT1 sensitized GR cells to gemcitabine. More importantly, we demonstrated that downregulation of NEAT1 enhanced the sensitivity of GR cells to gemcitabine by reversing the EMT process. NEAT1 regulated ZEB2 expression by sponging miR-506-3p, and the function of NEAT1 in GR cells was dependent on miR-506-3p. These findings were further confirmed in a nude mouse xenograft model.ConclusionsTaken together, downregulation of NEAT1 sensitized the GR PC cells to gemcitabine through modulation of the miR-506-3p/ZEB2/EMT axis. These results provide a new direction for improving the chemotherapeutic effects in PC.

scholarly journals Overexpression of DCLK1-AL Increases Tumor Cell Invasion, Drug Resistance, and KRAS Activation and Can Be Targeted to Inhibit Tumorigenesis in Pancreatic Cancer

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Dongfeng Qu ◽  
Nathaniel Weygant ◽  
Jiannan Yao ◽  
Parthasarathy Chandrakesan ◽  
William L. Berry ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Drug Resistance ◽  
Mouse Models ◽  
Pancreatic Tumor ◽  
Fold Increase ◽  
Human Pancreatic Cancer ◽  
Ductal Adenocarcinoma ◽  
Pancreatic Cancer Cells ◽  
Pdac Tissue

Oncogenic KRAS mutation plays a key role in pancreatic ductal adenocarcinoma (PDAC) tumorigenesis with nearly 95% of PDAC harboring mutation-activated KRAS, which has been considered an undruggable target. Doublecortin-like kinase 1 (DCLK1) is often overexpressed in pancreatic cancer, and recent studies indicate that DCLK1+ PDAC cells can initiate pancreatic tumorigenesis. In this study, we investigate whether overexpressing DCLK1 activates RAS and promotes tumorigenesis, metastasis, and drug resistance. Human pancreatic cancer cells (AsPC-1 and MiaPaCa-2) were infected with lentivirus and selected to create stable DCLK1 isoform 2 (alpha-long, AL) overexpressing lines. The invasive potential of these cells relative to vector control was compared using Matrigel coated transwell assay. KRAS activation and interaction were determined by a pull-down assay and coimmunoprecipitation. Gemcitabine, mTOR (Everolimus), PI3K (LY-294002), and BCL-2 (ABT-199) inhibitors were used to evaluate drug resistance downstream of KRAS activation. Immunostaining of a PDAC tissue microarray was performed to detect DCLK1 alpha- and beta-long expression. Analysis of gene expression in human PDAC was performed using the TCGA PAAD dataset. The effects of targeting DCLK1 were studied using xenograft and Pdx1CreKrasG12DTrp53R172H/+ (KPC) mouse models. Overexpression of DCLK1-AL drives a more than 2-fold increase in invasion and drug resistance and increased the activation of KRAS. Evidence from TCGA PAAD demonstrated that human PDACs expressing high levels of DCLK1 correlate with activated PI3K/AKT/MTOR-pathway signaling suggesting greater KRAS activity. High DCLK1 expression in normal adjacent tissue of PDAC correlated with poor survival and anti-DCLK1 mAb inhibited pancreatic tumor growth in vivo in mouse models.

scholarly journals Cysteine catabolism and the serine biosynthesis pathway support pyruvate production during pyruvate kinase knockdown in pancreatic cancer cells

2019 ◽  
Vol 7 (1) ◽  
Author(s):  
Lei Yu ◽  
Shao Thing Teoh ◽  
Elliot Ensink ◽  
Martin P. Ogrodzinski ◽  
Che Yang ◽  
...  
Keyword(s):  
Pancreatic Cancer ◽  
Cancer Cells ◽  
Pyruvate Kinase ◽  
Metabolic Pathways ◽  
Treatment Options ◽  
Ductal Adenocarcinoma ◽  
Metabolic Enzyme ◽  
Biosynthesis Pathway ◽  
Pancreatic Cancer Cells ◽  
Serine Biosynthesis

Abstract Background Pancreatic ductal adenocarcinoma (PDAC) is an aggressive cancer with limited treatment options. Pyruvate kinase, especially the M2 isoform (PKM2), is highly expressed in PDAC cells, but its role in pancreatic cancer remains controversial. To investigate the role of pyruvate kinase in pancreatic cancer, we knocked down PKM2 individually as well as both PKM1 and PKM2 concurrently (PKM1/2) in cell lines derived from a KrasG12D/-; p53-/- pancreatic mouse model. Methods We used liquid chromatography tandem mass spectrometry (LC-MS/MS) to determine metabolic profiles of wildtype and PKM1/2 knockdown PDAC cells. We further used stable isotope-labeled metabolic precursors and LC-MS/MS to determine metabolic pathways upregulated in PKM1/2 knockdown cells. We then targeted metabolic pathways upregulated in PKM1/2 knockdown cells using CRISPR/Cas9 gene editing technology. Results PDAC cells are able to proliferate and continue to produce pyruvate despite PKM1/2 knockdown. The serine biosynthesis pathway partially contributed to pyruvate production during PKM1/2 knockdown: knockout of phosphoglycerate dehydrogenase in this pathway decreased pyruvate production from glucose. In addition, cysteine catabolism generated ~ 20% of intracellular pyruvate in PDAC cells. Other potential sources of pyruvate include the sialic acid pathway and catabolism of glutamine, serine, tryptophan, and threonine. However, these sources did not provide significant levels of pyruvate in PKM1/2 knockdown cells. Conclusion PKM1/2 knockdown does not impact the proliferation of pancreatic cancer cells. The serine biosynthesis pathway supports conversion of glucose to pyruvate during pyruvate kinase knockdown. However, direct conversion of serine to pyruvate was not observed during PKM1/2 knockdown. Investigating several alternative sources of pyruvate identified cysteine catabolism for pyruvate production during PKM1/2 knockdown. Surprisingly, we find that a large percentage of intracellular pyruvate comes from cysteine. Our results highlight the ability of PDAC cells to adaptively rewire their metabolic pathways during knockdown of a key metabolic enzyme.

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