Pancreatic Cancer Cell Lines BxPC-3 Research Articles

A missing link between RON expression and oncological outcomes in resected left-sided pancreatic cancer.

Alteration and activation of recepteur d'origine nantais (RON) expression is known to be associated with cancer progression and decreased survival in various types of human cancer, including pancreatic cancer. Therefore, in the present study, RON expression levels were determined in resected left-sided pancreatic cancer to evaluate the potential oncological role of RON in the clinical setting of distal pancreatic cancer. From January 2005 to December 2011, a total of 57 patients underwent radical distal pancreatectomy for left-sided pancreatic cancer. Ductal adenocarcinoma was confirmed in all patients. Among these patients, 17 patients who received preoperative neoadjuvant treatment and 7 patients without available paraffin-embedded tissue blocks were excluded from the present study. RON expression in a the pancreatic cancer cell lines ASPC-1, BxPC-3, MiaPaCa-3 and Panc-1, as well as in resected left-sided pancreatic cancer specimens was determined by Western blot analysis. RON and vascular endothelial growth factor (VEGF) overexpression in resected left-sided pancreatic cancer was also evaluated by immunohistochemistry using pre-diluted anti-RON and anti-VEGF antibodies. An association was identified between the oncological outcome and RON overexpression. Increased levels of RON expression were observed in two pancreatic cancer cell lines, AsPC-1 and BxPC-3. RON overexpression was detected in specimens from 15/33 patients (45.5%) using immunohistochemistry. No significant association was identified between RON overexpression and VEGF overexpression (25.5 vs. 87.9%; P=0.667). No significant differences in disease-free survival or disease-specific survival associated with RON overexpression were identified. Although the results of previous studies have suggested that RON is a potential target for the treatment of pancreatic cancer, in the present study no association between RON overexpression and any adverse oncological effect was identified.

Imaging the Role of Multinucleate Pancreatic Cancer Cells and Cancer-Associated Fibroblasts in Peritoneal Metastasis in Mouse Models.

The interaction between pancreatic-cancer cells and stromal cells in the tumor microenvironment (TME) is of particular importance in cancer progression and metastasis. The present report demonstrates the role of cancer-associated fibroblasts (CAFs) and multinucleate pancreatic-cancer cells in peritoneal metastasis. An orthotopic mouse model of pancreatic cancer was established with the human pancreatic cancer cell line BxPC3, which stably expresses green fluorescent protein (GFP). BxPC3-GFP cells formed peritoneal metastases by week 18 after orthotopic implantation. Using an Olympus FV1000 confocal microscope, multi-nucleated cancer cells were frequently observed in the peritoneal metastases. The primary pancreatic tumor and peritoneal-metastases were harvested, cultured and then transplanted subcutaneously. Subcutaneous tumors established from peritoneal-metastatic cells were larger than subcutaneous tumors established from primary-tumor cells. Subcutaneous tumors of each type were subsequently cultured in vitro. CAFs were observed growing out from the tumors established from peritoneal-metastatic cells, but not the tumors established from the primary cancer. The results of the present study suggest that multi-nucleated cancer cells and CAFs were related to peritoneal metastasis of pancreatic cancer.

Abstract 1075: JQ1 induces DNA damage, inhibits expression of DNA repair proteins, and synergizes with PARP inhibitors in pancreatic cancer cells

Abstract Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer. PDAC is a highly aggressive tumor with a 5-year survival of <6%. Surgery remains the only curative treatment for PDAC patients, but only 20% of newly diagnosed patients have resectable disease. The remaining 80% present with locally advanced or metastatic disease, and receive systemic chemotherapy with gemcitabine. The median survival of this patient population is ~6 months. Development of more effective therapy for this chemorefractory disease is imperative. The goal of the current study was to develop effective combination therapy for PDAC by identifying agents that might be combined with the BET bromodomain inhibitor JQ1, which we have shown to inhibit the growth in vivo of PDAC patient derived xenografts (PDX). Expression profile analysis of tumors from vehicle control and JQ1 treated mice revealed that JQ1 inhibited the expression of multiple gene products involved in DNA repair. Notably, JQ1 inhibited expression of DNA double-strand break (DSB) repair proteins BRCA2 and Ku80. Immunohistochemical staining confirmed down-regulation of expression of both proteins in tumors of mice treated with JQ1. Further, immunoblot and immunofluorescence analyses demonstrated that decreased expression of BRCA2 and Ku80 was coincident with increased levels of DNA damage, as reflected by expression of the DNA DSB marker gamma-H2AX. Data generated in vivo in three independent PDX models corroborated in vitro data generated using pancreatic cancer cell lines BxPC3 and Panc1. The data suggest that JQ1 induces DNA damage by inhibiting DNA repair. Because DNA repair deficiency sensitizes cells to PARP inhibitors, we hypothesized that JQ1-induced DNA repair deficiency would sensitize PDAC cells to PARP inhibitors. To address this hypothesis, we exposed Panc1 and BxPC3 to JQ1 or to a PARP 1/2 inhibitor (veliparib or olaparib) or to the combinations, and assessed the efficacy of each. Growth inhibition data, analyzed using Compusyn software and reported as combination indices, demonstrated that the combinations of JQ1 + veliparib or olaparib exert synergistic cytotoxicity. Further, the combination of JQ1 + a PARP inhibitor increased the accumulation of DNA damage in vitro, compared to either agent alone. We conclude that JQ1 induces DNA damage due at least in part to DNA repair deficiency, and propose that this mechanism sensitizes PDAC cells to PARP inhibitors. Citation Format: Aubrey Lynn Miller, Tracy Gamblin, Leona Council, Robert van Waardenburg, Eddy Yang, James Bradner, Karina Yoon. JQ1 induces DNA damage, inhibits expression of DNA repair proteins, and synergizes with PARP inhibitors in pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 1075. doi:10.1158/1538-7445.AM2017-1075

Abstract 4422: Capsaicin suppresses pancreatic tumor growth by inhibiting tumor cell metabolism

Abstract Tumor cell metabolism is considered to be a hallmark of tumorigenic progression. Pancreatic cancer cells are shown to develop addiction towards the metabolic pathways like glycolysis and mitochondrial respiration to meet energy demands. Pancreatic tumor cells predominantly utilize cytosolic aerobic glycolysis for energy production. In our previous studies, we have reported that capsaicin treatment inhibits the survival of AsPC-1 and BxPC-3 pancreatic cancer cell lines. In this study, we evaluated the effect of capsaicin on glycolysis and mitochondrial respiration in pancreatic cancer cells. Our results showed that capsaicin treatment reduced the extra-cellular acidification rate (glycolysis) and oxygen consumption rate (mitochondrial respiration) in AsPC-1 and BxPC-3 cells in a concentration-dependent manner after 24h of treatment. Capsaicin treatment caused 86% and 55% down-regulation of glycolysis process in AsPC-1and BxPC-3 cells respectively. Our results also indicate the inhibition of glycolytic capacity and glycolytic reserve by capsaicin treatment indicating the potential of capsaicin to inhibit glycolysis. In addition, capsaicin treatment reduced 98% of basal oxygen consumption rate and ATP production in AsPC-1 cells. Furthermore, capsaicin treatment inhibited spare respiratory capacity & proton leak in a concentration dependent manner in AsPC-1 cells. Treatment of AsPC-1 and BxPC-3 with capsaicin for 48h also inhibited the expression of LDH-A and its upstream regulators such as HIF-1α, pSTAT3 (Y705) and EGFR as evaluated by Western blot. Our study thus indicate that capsaicin suppresses pancreatic tumor growth by down-regulating glycolysis and mitochondrial respiration. Further mechanistic studies are in progress. [Supported in part by R01 grant CA129038, awarded to (S.K.S.) by the National Cancer Institute]. Citation Format: Sharavan Ramachandran, Sanjay K. Srivastava. Capsaicin suppresses pancreatic tumor growth by inhibiting tumor cell metabolism [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4422. doi:10.1158/1538-7445.AM2017-4422

Abstract 2698: IL-17A alone or in combination with IL-4/IFN-γ induces Duox2/DuoxA2 expression and reactive oxygen production in human colon and pancreatic cancer cells

Abstract NADPH oxidase (NOX)-derived reactive oxygen species (ROS) contribute significantly to inflammation-associated carcinogenesis. Expression of dual oxidase 2 (Duox2), one of seven members of the NOX gene family, is up-regulated in inflammatory bowel disease, chronic pancreatitis, and in many human malignancies including carcinomas of the colon, pancreas, prostate, lung, and breast. Previously, we demonstrated that Stat1 and/or NF-kB play a critical role in modulating the enhanced expression of Duox2, and its cognate maturation factor DuoxA2, by the pro-inflammatory mediators IFN-γ and lipopolysaccharide in human pancreatic cancer cells. This cytokine-mediated increase in Duox2 expression was responsible for a significant increase in tumor cell H2O2 production, DNA damage, and HIF-1α and VEGFA upregulation in pancreatic cancer cell lines. Using the T84 human colon cancer line, and BxPC-3, AsPC-1, and HTB134 pancreatic cancer cell lines, we now report that the pro-inflammatory cytokine IL-17A, pivotal in the adaptive immune response against various pathogens, and in the promotion of colon and pancreatic cancer progression, strongly induces Duox2/DuoxA2 mRNA and protein expression (alone or in combination with IL-4 or IFN-γ). In BxPC-3 cells, IL-17A enhances the expression of Duox2/DuoxA2 in a time- and concentration-dependent manner, which leads to a significant increase in the generation of extracellular H2O2. When IL-17A is combined with IL-4 in either T-84 or AsPc-1 lines, Duox2-mediated ROS formation is sufficient to produce a DNA damage response, indicated by the strong induction of γH2AX expression; moreover, in AsPc-1 cells, Duox2-specific siRNA significantly attenuated cytokine-induced ROS production and γH2AX phosphorylation. IL-17A in combination with IL-4 also significantly increases Stat3 phosphorylation and promotes proliferation in AsPC-1 cells. Ongoing cellular experiments are focused on whether the cytokine-mediated upregulation of Duox2/DuoxA2 is responsible for Stat3 activation and cell growth promotion in the K-ras mutated AsPC-1 cells. Bio-informatic analysis with the TCGA data set, as well as RT-PCR using surgically-resected human colon cancer samples compared to adjacent, uninvolved colonic epithelium revealed that Duox2 was significantly upregulated in human colon cancers. These studies, in concert with our previous data demonstrating high-level Duox protein expression in pancreatitis, pancreatic intra-epithelial neoplasia (PanIN), and frank pancreatic cancer, strongly suggest that ROS, produced as a consequence of cytokine-related Duox2 up-regulation, may be associated with the development of inflammation-related gastrointestinal malignancies. Citation Format: James H. Doroshow, Yongzhong Wu, Jiamo Lu, Smitha Antony, Jennifer Meitzler, Agnes Juhasz, Guojian Jiang, Iris Dahan, Mariam Konate, Krishnendu Roy. IL-17A alone or in combination with IL-4/IFN-γ induces Duox2/DuoxA2 expression and reactive oxygen production in human colon and pancreatic cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 2698. doi:10.1158/1538-7445.AM2017-2698

Penfluridol induces endoplasmic reticulum stress leading to autophagy in pancreatic cancer.

Pancreatic cancer is one of the most aggressive and difficult to treat cancers. Experimental and clinical evidence suggests that high basal state autophagy in pancreatic tumors could induce resistance to chemotherapy. Recently, we have demonstrated that penfluridol suppresses pancreatic tumor growth by autophagy-mediated apoptosis both in vitro and in vivo; however, the mechanism of autophagy induction by penfluridol was not clear. Several studies have established that endoplasmic reticulum stress could lead to autophagy and inhibit tumor progression. In this study, we demonstrated that penfluridol induced endoplasmic reticulum stress in BxPC-3, AsPC-1, and Panc-1 pancreatic cancer cell lines as indicated by upregulation of endoplasmic reticulum stress markers such as binding protein (BIP), C/EBP homologous protein (CHOP) and inositol requiring 1α (IRE1α) after treatment with penfluridol in a concentration-dependent manner. Inhibiting endoplasmic reticulum stress by pretreatment with pharmacological inhibitors such as sodium phenylbutyrate and mithramycin or by silencing CHOP using CHOP small interfering RNA, blocked penfluridol-induced autophagy. These results clearly indicate that penfluridol-induced endoplasmic reticulum stress lead to autophagy in our model. Western blot analysis of subcutaneously implanted AsPC-1 and BxPC-3 tumors as well as orthotopically implanted Panc-1 tumors demonstrated upregulation of BIP, CHOP, and IRE1α expression in the tumor lysates from penfluridol-treated mice as compared to tumors from control mice. Altogether, our study establishes that penfluridol-induced endoplasmic reticulum stress leads to autophagy resulting in reduced pancreatic tumor growth. Our study opens a new therapeutic target for advanced chemotherapies against pancreatic cancer.

LPS promotes resistance to TRAIL-induced apoptosis in pancreatic cancer

BackgroundThough TRAIL has been hailed as a promising drug for tumour treatment, it has been observed that many tumour cells have developed escape mechanisms against TRAIL-induced apoptosis. As a receptor of LPS, TLR 4, which is expressed on a variety of cancer cells, can be associated with TRAIL-resistance of tumour cells and tumour progression as well as with the generation of an anti-tumour immune response.MethodsIn this study, the sensitivity to TRAIL-induced apoptosis as well as the influence of LPS-co-stimulation on the cell viability of the pancreatic cancer cell lines PANC-1, BxPC-3 and COLO 357 was examined by FACS analyses and a cell viability assay. Subsequently, the expression of TRAIL-receptors was detected via FACS analyses. Levels of osteoprotegerin (OPG) were also determined using an enzyme-linked immunosorbent assay.ResultsPANC-1 cells were shown to be resistant to TRAIL-induced apoptosis. This was accompanied by significantly increased osteoprotegerin levels and a significantly decreased expression of DR4.In contrast, TRAIL significantly induced apoptosis in COLO 357 cells and to a lesser degree in BxPC-3 cells. Co-stimulation of COLO 357 as well as BxPC-3 cells combining TRAIL and LPS resulted in a significant decrease in TRAIL-induced apoptosis. In COLO 357 cells TRAIL-stimulation decreased the levels of OPG thereby not altering the expression of the TRAIL-receptors 1–4 resulting in a high susceptibility to TRAIL-induced apoptosis. Co-stimulation with LPS and TRAIL completely reversed the effect of TRAIL on OPG levels reaching a 2-fold increase beyond the level of non-stimulated cells resulting in a lower susceptibility to apoptosis.In BxPC-3, TRAIL stimulation decreased the expression of DR4 and significantly increased the decoy receptors TRAIL-R3 and TRAIL-R4 leading to a decrease in TRAIL-induced apoptosis. OPG levels remained unchanged. Co-stimulation with TRAIL and LPS further enhanced the changes in TRAIL-receptor-expression promoting apoptosis resistance.ConclusionsHere it has been shown that TRAIL-resistance in pancreatic cancer cells can be mediated by the inflammatory molecule LPS as well as by different expression patterns of functional and non-functional TRAIL-receptors.

Baicalein inhibits pancreatic cancer cell proliferation and invasion via suppression of NEDD9 expression and its downstream Akt and ERK signaling pathways.

Baicalein, a flavone ingredient of Scutellaria baicalensis Georgi, is a promising anti-cancer agent. However, its potential anti-pancreatic cancer effects and the underlying mechanisms are still unclear. In this study, we showed that Baicalein not only induced apoptosis, but also suppressed proliferation, migration and invasion of two pancreatic cancer cell lines BxPC-3 and PANC-1 in a dose- and time-dependent manner. Notably, Baicalein exhibited low toxicity to normal human liver or kidney cells. We further discovered that Baicalein suppressed BxPC-3 and PANC-1 cell proliferation and invasion through targeting the expression of NEDD9, a Cas scaffolding protein, to decrease Akt and ERK activities. Especially, Baicalein decreased Akt phosphorylation at T-308 via lowering NEDD9-dependent PDK1 expression. Overexpression of NEDD9 effectively rescued proliferation and invasion of BxPC-3 and PANC-1 cells dampened by Baicalein. Taken together, our findings suggest that Baicalein is a potent remedy applied to pancreatic cancer treatment in the future.

Overcoming erlotinib resistance with STAT3 inhibition in pancreatic cancer.

304 Background: Pancreatic ductal adenocarcinoma (PDAC) remains a major therapeutic challenge. Cytotoxic chemotherapy remains the standard approach in PDAC, but results in minimal survival benefit for patients, highlighting a desperate need for novel treatment strategies. Epidermal growth factor receptor (EGFR) is overexpressed in 25-90% of PDACs and has been shown to be an adverse prognostic marker for survival, making it a rational target. To date, the combination of the EGFR tyrosine kinase inhibitor, erlotinib, with gemcitabine remains the only approved targeted therapy based on a significant, yet modest, improved overall survival when compared to gemcitabine alone in a phase III clinical trial. We have previously shown that constitutively activated signal transducer and activator of transcription 3 (STAT3) signaling is a biomarker of resistance to both gemcitabine and erlotinib. Therefore, we hypothesized that combined STAT3 and EGFR inhibition would overcome resistance to erlotinib and gemcitabine in PDAC. Methods: Human pancreatic cancer cell lines MiaPaca2 ( KRASG12C ; TP53mut ; EGFRwt) or BxPC-3 ( KRASwt ; TP53mut ; EGFRwt) were treated in a dose dependent manner with erlotinib in the presence or absence of gemcitabine. PDAC cells were additionally treated with EC50doses of a STAT3 inhibitor (AZD1480), erlotinib, and/or gemcitabine. Lysates were then collected and western blot analysis was performed to detect total and phosphorylated extracellular signal regulated kinase (ERK) or STAT3. Results: EGFR inhibition with erlotinib, with or without gemcitabine, results in decreased ERK activation, however, causes an increased activation of STAT3 signaling in both MiaPaca2 and BxPC-3 cells. Combined STAT3 and EGFR inhibition results in sustained attenuation of both phosphorylated ERK and STAT3 levels. Conclusions: Our study demonstrates that activated STAT3 signaling appears to be a mechanism of resistance to erlotinib and gemicitabine treatment in PDAC. Combining STAT3 inhibition with EGFR inhibition overcomes this resistance.

Silencing pancreatic adenocarcinoma up-regulated factor increases the sensitivity of pancreatic cancer cell line to gemcitabine

Objective To observe the influence on the sensitivity of pancreatic cancer cell line BxPC-3 to gemcitabine of silencing PAUF gene. Methods BxPC-3 cells, which overexpress PAUF, was stably transfected with PAUF-shCtrl and PAUF-shRNA to establish BxPC-3_shCtrl and BxPC-3_shPAUF cells as control and experiment group. Then the mRNA and protein expression level of PAUF in these two cell lines were detected by RT-PCR and western blot, respectively. The growth inhibition rates of these two cell lines treated with different concentrations of gemcitabine (0, 3.1, 6.25, 12.5, 25, 50, 100, 200 nmol/L) were detected by MTT. Apoptosis rates in the cells treated with different concentrations of gemcitabine (0, 75, 100 nmol/L) were then observed by flow cytometry. Results The relative PAUF mRNA expression level in BxPC-3_shCtrl and BxPC-3 cells were 1.00±0.06 and 0.83±0.07, which were significantly higher than that in BxPC-3_shPAUF cells (0.25±0.02; both P<0.05). The relative PAUF protein expression level in BxPC-3_shCtrl and BxPC-3 cells were 0.89±0.07 and 0.95±0.04, which were significantly higher than that in BxPC-3_shPAUF cells (0.31±0.03; both P<0.05). The IC50 value of gemcitabine to BxPC-3_shCtrl cell was (22.88±2.43) nmol/L, which was significantly higher than that of BxPC-3_shPAUF cells [(1.06±0.02) nmol/L; P<0.05]; apoptosis rate of BxPC-3_shPAUF cells treated by gemcitabine increased faster than that of BxPC-3_shCtrl cells. Conclusion PAUF silencing could greatly enhance the sensitivity of BxPC-3 cells to gemcitabine. Key words: Pancreatic cancer cell line; Pancreatic adenocarcinoma up-regulated factor; Gemcitabine; Drug sensitization

Detection of tissue factor-positive extracellular vesicles by laser scanning confocal microscopy

IntroductionIncreased levels of tissue factor-positive extracellular vesicles (TF+EVs) have been detected in the plasma of patients with various diseases, including cancer and endotoxemia. Levels of TF+EVs in plasma samples can be measured by antigen and activity assays. The aim of the present study was to visualize TF+EVs by laser scanning confocal microscopy (LSCM). MethodsEVs were isolated from the supernatant of two cultured human pancreatic cancer cell lines (Panc-1 and BxPc-3), from untreated or lipopolysaccharide (LPS) treated whole blood, and from plasma of pancreatic cancer patients. EV-TF activity was determined using an in-house assay. The EVs were labeled with 5(6)-carboxyfluorescein diacetate N-succinimidyl ester, which is converted to the impermeant green fluorescent molecule carboxyfluorescein inside the EVs. EVs were either captured using annexin V and detected using a fluorescent-labeled anti-TF antibody, or captured using an anti-TF antibody and detected using fluorescent-labeled annexin V. EVs were visualized by LSCM. ResultsTF+EVs were easily detected from high TF-expressing BxPc-3 cells using annexin V capture, whereas the addition of tyramide amplification was required to detect TF+EVs from low TF-expressing Panc-1 cells. Visualization of TF+EVs in plasma from LPS treated whole human blood and in plasma from pancreatic cancer patients required either capture with annexin V and detection with a fluorescent-labeled anti-TF antibody with tyramide signal amplification, or capture with an anti-TF antibody and detection with a fluorescent-labeled annexin V. ConclusionLSCM enables visualization of TF+EVs in the supernatant from cultured cells and in clinical samples.

Chidamide Inhibits Aerobic Metabolism to Induce Pancreatic Cancer Cell Growth Arrest by Promoting Mcl-1 Degradation.

Pancreatic cancer is a fatal malignancy worldwide and urgently requires valid therapies. Previous research showed that the HDAC inhibitor chidamide is a promising anti-cancer agent in pancreatic cancer cell lines. In this study, we elucidate a probable underlying anti-cancer mechanism of chidamide involving the degradation of Mcl-1. Mcl-1 is frequently upregulated in human cancers, which has been demonstrated to participate in oxidative phosphorylation, in addition to its anti-apoptotic actions as a Bcl-2 family member. The pancreatic cancer cell lines BxPC-3 and PANC-1 were treated with chidamide, resulting in Mcl-1 degradation accompanied by induction of Mcl-1 ubiquitination. Treatment with MG132, a proteasome inhibitor reduced Mcl-1 degradation stimulated by chidamide. Chidamide decreased O2 consumption and ATP production to inhibit aerobic metabolism in both pancreatic cancer cell lines and primary cells, similar to knockdown of Mcl-1, while overexpression of Mcl-1 in pancreatic cancer cells could restore the aerobic metabolism inhibited by chidamide. Furthermore, chidamide treatment or Mcl-1 knockdown significantly induced cell growth arrest in pancreatic cancer cell lines and primary cells, and Mcl-1 overexpression could reduce this cell growth inhibition. In conclusion, our results suggest that chidamide promotes Mcl-1 degradation through the ubiquitin-proteasome pathway, suppressing the maintenance of mitochondrial aerobic respiration by Mcl-1, and resulting in inhibition of pancreatic cancer cell proliferation. Our work supports the claim that chidamide has therapeutic potential for pancreatic cancer treatment.

310 - Knocking Down Delta-5 Desaturase and Exploiting High Expression Level of COX-2 to Inhibit Cancer Migration and Invasion

Our recent research has shown that knockdown of delta-5 desaturase (D5D, a key enzyme that converts dihomo-γ-linolenic acid to arachidonic acid) and treatment dihomo-γ-linolenic exerted growth inhibitory effect on both colon and pancreatic cancer cells (Xu Y et al, FRBM 96: 67-77, 2016 and Yang X et al, FRBM 97: 342-350, 2016) due to formation of an anti-cancer byproduct 8-hydroxyoctanoic acid (8-HOA) from COX-catalyzed peroxidation. Here, we further tested whether knockdown of D5D could also be used to inhibit cancer migration and invasion using colon cancer cell line HCA-7 colony 29 and pancreatic cancer cell line BxPC-3 (both express high levels of COX-2). Cell migration and invasion were assessed by wound healing assay and transwell assay along with western blot to investigate the possible molecular mechanism. Our results showed that promoted 8-HOA formation in cancer cells via knocking down D5D (shRNA transfection) can significantly inhibit cell migration. D5D knockdown can also significantly improve the efficacies of 5-flurouracil and gemcitabine on colon and pancreatic cancer cell migration and invasion. The underlying mechanism might be that 8-HOA, serving as histone deacetylase inhibitor, downregulates MMP-2 and 9, consequently leading to altered expression in key proteins involved in epithelial mesenchymal transition (EMT) e.g. E-cadherin and vimentin. For the first time, we demonstrated high COX expression in cancers could be taken advantage to inhibit cancer cell migration and invasion. The research outcome may provide us a promising strategy for cancer metastasis by taking advantage of abundant ω-6 fatty acids in daily diet and exploiting the high COX expression level in cancer (a paradigm shifting concept). This work supported by NIH R15CA195499 and Sanford Health-NDSU Collaborative Research Seed Grant Program.

128P - Modulation of specificity protein 1 (SP1) is a novel therapeutic strategy for pancreatic cancer

Pancreatic cancer is one of the most aggressive and lethal malignancies. Specificity Protein 1 (SP1) is a transcription factor regulates and promotes tumor progression. Some studies have reported SP1 promotes epithelial-mesenchymal transition (EMT) and is associated with aggressive and poor patient prognosis. However, there is a paucity of clinical evidence regarding the role of SP1 in pancreatic cancer. In this study, we aimed to confirm the function of SP1 in invasiveness of pancreatic cancer cells and to evaluate the clinical impact in patients with pancreatic cancer. Between June 2002 and December 2012, 81 patients underwent radical curative resection for pancreatic cancer at Gangnam Severance Hospital, Seoul, Korea. Pancreatic cancer cell lines MIA PaCa-2, PANC-1, AsPC-1, and BxPC-3 were used for in vitro study. To evaluate the endogenous expression level of SP1, we purified the whole RNA and protein to perform the qPCR, RT-PCR and Western blot. si-SP1 was used for specifically inhibit the function of SP1. The invasive potential of pancreatic cancer cells were assessed in matrigel coated chambers. Among the 81 patients, 32 (39.5%) were positive for SP1. On univariate and multivariate analyses, poor differentiation tumor and SP1-positive status were identified as independent prognostic factors for DFS. High expression of SP1 was observed and correlated with the expression of mesenchymal markers (Snail, L1CAM, Vimentin) unlike epithelial markers (CDH1). Importantly, silencing of SP1 showed markedly decrease in motility and the invasiveness of cancer cells (p < 0.001) as determined from transwell invasion and transendothelial migration assays, respectively. Our results demonstrated that SP1 is an independent marker for metastatic disease and death in patients with pancreatic cancer. Additionally, our in vitro study demonstrated that SP1 expression promotes EMT and the invasiveness of pancreatic cancer cell lines, a finding compatible with the results of previous in vitro studies. These findings suggest that SP1 can potentially be a valuable target for the improvement of survival rates in patients with pancreatic cancer.

Effect of PPM1H on malignant phenotype of human pancreatic cancer cells.

The objective of this study was to investigate the effect of silencing gene protein phosphatase 1H (PPM1H) on malignant phenotype of human pancreatic cancer cell line BxPC-3. In order to explore the function of PPM1H in pancreatic cancer cells, real-time PCR and western blotting were used to detect the expression of PPM1H in different pancreatic cancer cell lines. Human pancreatic cancer cell line BxPC-3 was treated with 10ng/ml TGF-β1 and 200ng/ml BMP2 for 72h, respectively, and the mRNA and protein expression levels of PPM1H and EMT-related markers (E-cadherin, vimentin) were detected by real-time PCR and western blotting, respectively. Using exogenous RNA interference technology to silence the PPM1H gene, the expression of PPM1H and EMT-related markers at mRNA and protein levels were detected by real-time PCR and western blotting. The cell migration and invasion were measured using Transwell assays. Finally, cell counting kit-8 (CCK-8) and flow cytometry were used to determine the effect of PPM1H on cell proliferation and apoptosis of BxPC-3 cells. The expression levels of PPM1H in all of the examined pancreatic cancer cell lines (BxPC-3, MIA-PACA2, PANC-1, SW1990, PANC-03.27) were lower than that of normal pancreatic ductal epithelial cells (HPDE6-C7) at both mRNA and protein levels. Both TGF-β1 and BMP2 treatment induced EMT and downregulation of PPM1H in BxPC-3 cells. By using RNA interference to transiently knock down PPM1H expression in BxPC-3 cells, we found that the expression of E-cadherin was downregulated while vimentin was up-regulated. The data suggested that silencing PPM1H gene can induce EMT in BxPC-3 cells. In addition, Transwell migration assays showed that silencing PPM1H gene can promote the invasion and metastasis of BxPC-3 cells. Cell proliferation and apotosis detection demonstrated that silencing PPM1H gene can promote the proliferation and inhibit apoptosis of BxPC-3 cells. In conclusion, PPM1H is aberrantly expressed in human pancreatic cancer cell lines and can be downregulated when EMT is induced by cytokine stimulation. Silencing PPM1H gene can induce EMT in BxPC-3 cells, and promote the invasion and metastasis of BxPC-3 cells. Moreover, silencing PPM1H gene can promote the proliferation and inhibit apoptosis of BxPC-3 cells. PPM1H may be a new tumor-suppressor factor for pancreatic cancer and provides new insight into molecular targets for gene therapy of pancreatic cancer.

A Size-Selective Intracellular Delivery Platform.

Identifying and separating a subpopulation of cells from a heterogeneous mixture are essential elements of biological research. Current approaches require detailed knowledge of unique cell surface properties of the target cell population. A method is described that exploits size differences of cells to facilitate selective intracellular delivery using a high throughput microfluidic device. Cells traversing a constriction within this device undergo a transient disruption of the cell membrane that allows for cytoplasmic delivery of cargo. Unique constriction widths allow for optimization of delivery to cells of different sizes. For example, a 4 μm wide constriction is effective for delivery of cargo to primary human T-cells that have an average diameter of 6.7 μm. In contrast, a 6 or 7 μm wide constriction is best for large pancreatic cancer cell lines BxPc3 (10.8 μm) and PANC-1 (12.3 μm). These small differences in cell diameter are sufficient to allow for selective delivery of cargo to pancreatic cancer cells within a heterogeneous mixture containing T-cells. The application of this approach is demonstrated by selectively delivering dextran-conjugated fluorophores to circulating tumor cells in patient blood allowing for their subsequent isolation and genomic characterization.

Leiodermatolide, a novel marine natural product, has potent cytotoxic and antimitotic activity against cancer cells, appears to affect microtubule dynamics, and exhibits antitumor activity.

Pancreatic cancer, the fourth leading cause of cancer death in the United States, has a negative prognosis because metastasis occurs before symptoms manifest. Leiodermatolide, a polyketide macrolide with antimitotic activity isolated from a deep water sponge of the genus Leiodermatium, exhibits potent and selective cytotoxicity toward the pancreatic cancer cell lines AsPC-1, PANC-1, BxPC-3, and MIA PaCa-2, and potent cytotoxicity against skin, breast and colon cancer cell lines. Induction of apoptosis by leiodermatolide was confirmed in the AsPC-1, BxPC-3 and MIA PaCa-2 cells. Leiodermatolide induces cell cycle arrest but has no effects on in vitro polymerization or depolymerization of tubulin alone, while it enhances polymerization of tubulin containing microtubule associated proteins (MAPs). Observations through confocal microscopy show that leiodermatolide, at low concentrations, causes minimal effects on polymerization or depolymerization of the microtubule network in interphase cells, but disruption of spindle formation in mitotic cells. At higher concentrations, depolymerization of the microtubule network is observed. Visualization of the growing microtubule in HeLa cells expressing GFP-tagged plus end binding protein EB-1 showed that leiodermatolide stopped the polymerization of tubulin. These results suggest that leiodermatolide may affect tubulin dynamics without directly interacting with tubulin and hint at a unique mechanism of action. In a mouse model of metastatic pancreatic cancer, leiodermatolide exhibited significant tumor reduction when compared to gemcitabine and controls. The antitumor activities of leiodermatolide, as well as the proven utility of antimitotic compounds against cancer, make leiodermatolide an interesting compound with potential chemotherapeutic effects that may merit further research.

Abstract 2114: Glycosyltransferase ST6Gal-I protects against chemotherapy induced DNA damage and subsequent apoptosis in pancreatic adenocarcinoma cells

Abstract ST6Gal-I is a sialyltransferase that adds α2-6 linked sialic acids to cell surface proteins as they pass through the trans-Golgi. Sialic acids, being negatively charged, are able to alter the function of selected cell surface receptors, which leads to dysregulation of various downstream cellular pathways. Overexpression of ST6Gal-I has been observed in various cancers including ovarian and pancreatic cancer. We have previously shown that knockdown of ST6Gal-I expression increases ovarian cancer cell susceptibility to the chemotherapeutic drug cisplatin. In the present study we further investigate whether resistance to additional drugs such as gemcitabine, the front line treatment for pancreatic cancer, is affected by ST6Gal-I activity. MiaPaCa-2 and BxPC3 pancreatic cancer cell lines, having high ST6Gal-I expression, were employed for our studies. To elucidate the mechanistic role of ST6Gal-I in gemcitabine resistance we created stable ST6Gal-I knockdown lines of MiaPaCa-2 and BxPC3 cells. Gemcitabine induced cell death was more pronounced in the knockdown cell lines, indicated by heightened activation of caspase-3. Gemcitabine is metabolized to a nucleoside analogue, gemcitabine triphosphate, which induces apoptosis by promoting DNA damage. Increased single stand DNA damage in the knockdown cells was confirmed using alkaline comet assay. Gemcitabine treatment led to greater activation of DNA damage markers and response elements (γH2AX, phospho CHK1, phospho CHK2), along with increased levels of cleaved caspase-3 in the knockdown cells as compared to empty vector control cells. We next developed a stable gemcitabine resistant MiaPaCa-2 cell line by growing parental cells in gemcitabine. We selected for the population of cells that survived and were able to replicate in gemcitabine containing media. ST6Gal-I levels were found to be increased in the stable gemcitabine resistant lines relative to parental cell lines, suggesting that cells with high ST6Gal-I expression selectively survive gemcitabine treatment. By measuring the levels of genes involved in activation over those responsible for inactivation of gemcitabine, we were able to obtain a gemcitabine sensitivity predictive ratio for MiaPaCa-2 and BxPC3 ST6Gal-I knockdown, empty vector, parental and stable gemcitabine resistant cell lines. This ratio has been described previously in literature as a metric for gauging gemcitabine resistance. According to the ratios obtained, ST6Gal-I knockdown enhanced drug sensitivity whereas high expression of ST6Gal-I offered protection against gemcitabine induced apoptosis. Collectively these data indicate that upregulation of ST6Gal-I imparts tumor cell survival through prevention of gemcitabine induced DNA damage. Citation Format: Asmi Chakraborty, Matthew Schultz, Hoa Q. Trummell, James A. Bonner, Susan Bellis. Glycosyltransferase ST6Gal-I protects against chemotherapy induced DNA damage and subsequent apoptosis in pancreatic adenocarcinoma cells. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 2114.

Investigation of juglone effects on metastasis and angiogenesis in pancreatic cancer cells

Juglone, a natural component, is shown to have cytotoxic and apoptotic effects in several cancer cell lines. However, little is known about its effects on invasion and metastasis. In this study, we aimed to determine the antimetastatic effect of juglone in the BxPC-3 and PANC-1 pancreatic cancer cell lines. Cytotoxic effect of juglone was evaluated by using MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide) test. The cells were treated with juglone at <IC50 doses (5, 10, 15 and 20μM ) for 24h. After the cell adhesion and invasion analysis, expression profiles of the MMP-2, MMP-9 and Phactr-1 genes were determined by qPCR. The IC50 dose of juglone was found to be 21.05μM in the BxPC-3 cell line and 21.25μM in the PANC-1 cell line for 24h. According to the cell adhesion and invasion analysis, treatment of juglone for 24h reduced the adhesion and invasion features of pancreatic cancer cells. A significant reduction of MMP-2, MMP-9 and Phactr-1 expressions was observed in pancreatic cancer cells after the treatment of juglone at <IC50 doses. By this study, it has been shown for the first time that juglone inhibits cell invasion and metastasis in pancreatic cancer line and can be evaluated as an effective anticancer agent in pancreatic cancer.

A novel small-molecule YLT256 inhibits proliferation and induces apoptosis both in vitro and in vivo in solid tumors

Pancreatic carcinoma is a still unsolved health problem all over the world with poor prognosis and high mortality rate. YLT256, a novel synthesized chemical small inhibitor, displays potent antineoplastic activities via inducing apoptosis both in vitro and in vivo. In this study, we found that YLT256 showed growth inhibition against a broad spectrum of human cancer cell lines and pancreatic cancer cell line BxPc-3 was the most sensitive with an IC50 of 0.42μM. We also found YLT256 could induce apoptosis of BxPc-3 cells in a dose-dependent manner. Western blot analysis revealed that the occurrence of its apoptosis was associated with activation of caspases-3 and -9, up-regulation of pro-apoptotic Bak, and down-regulation of anti-apoptotic Bcl-2. Moreover, YLT256-treated resulted in changes of mitochondrial membrane potential (Δψm), and generation of reactive oxygen species (ROS). Furthermore, our data also revealed that YLT256 suppressed the growth of established tumor-bearing xenograft models without obvious side effects. Immunohistochemical analyses and TUNEL assay revealed an increase in cleaved caspase-3-positive cells and TUNEL-positive cells, a decrease in Ki67-positive cells upon YLT256. Together, all the results of present study provided evidence demonstrating that YLT256 could be a promising potential drug candidate for pancreatic cancer therapy.