Pancreatic Carcinoma Cell Line PANC-1 Research Articles

Synthesis of DNA-Boron Cluster Composites and Assembly into Functional Nanoparticles with Dual, Anti-EGFR, and Anti-c-MYC Oncogene Silencing Activity.

A versatile method for the automated synthesis of composites containing DNA-oligonucleotides and boron cluster scaffolds and their assembly into functional nanoparticles is described. The obtained, torus-like nanoparticles carry antisense oligonucleotides that target two different oncogenes simultaneously. The nanoparticles exhibited notable silencing efficiency in vitro in a pancreatic carcinoma cell line PANC-1 toward EGFR and c-Myc genes at the mRNA level, and a significant efficiency at the protein level. The proposed approach may be an attractive alternative to methods currently used, including one therapeutic nucleic acid, one genetic target, or the use of cocktails of therapeutic nucleic acids.

Trapping all ERBB ligands decreases pancreatic lesions in a murine model of pancreatic ductal adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is among the deadliest of cancers. Attempts to develop targeted therapies still need to be established. Some oncogenic mechanisms in PDAC carcinogenesis harness the EGFR/ERBB receptor family. To explore the effects on pancreatic lesions, we attempted simultaneous blockade of all ERBB ligands in a PDAC mouse model. To this end, we engineered a molecular decoy, TRAP-FC , comprising the ligand-binding domains of both EGFR and ERBB4 and able to trap all ERBB ligands. Next, we generated a transgenic mouse model (CBATRAP/0 ) expressing TRAP-FC ubiquitously under the control of the chicken beta-actin promoter and crossed these mice with KRASG12D/+ mice (Kras) to generate Trap/Kras mice. The resulting mice displayed decreased emergence of spontaneous pancreatic lesion areas and exhibited reduced RAS activity and decreased activities of ERBBs, with the exception of ERBB4, which showed increased activity. To identify the involved receptor(s), we employed CRISPR/Cas9 DNA editing to singly delete each ERBB receptor in the human pancreatic carcinoma cell line Panc1. Ablation of each ERBB family member, especially loss of EGFR or ERBB2/HER2, altered signaling downstream of the other three ERBB receptors and decreased cell proliferation, migration and tumor growth. We conclude that simultaneously blocking the entire ERBB receptor family is therapeutically more effective than individually inhibiting only one receptor or ligand in terms of reducing pancreatic tumor burden. In summary, trapping all ERBB ligands can reduce pancreatic lesion area and RAS activity in a murine model of pancreatic adenocarcinoma; hence, it might represent a promising approach to treat PDAC in patients.

Lipocalin-2 inhibits pancreatic cancer stemness via the AKT/c-Jun pathway.

Cancerstemcells(CSCs) are involved incancerrecurrenceandmetastasisowing to their self-renewal properties and drug-resistance capacity. Lipocalin-2 (Lcn2) of the lipocalin superfamily is highly expressed in pancreatic cancer. Nevertheless, reports on the involvement of Lcn2 in the regulation of pancreatic CSC properties are scant. This study is purposed to investigate whether Lcn2 plays a crucial role in CSC renewal and stemness maintenance in pancreatic carcinoma. Immunohistochemistry results of tumor tissue chips together with Gene Expression Omnibus sequencing files confirmed that Lcn2 is highly expressed in pancreatic carcinoma compared with that in normal tissues. The exogenous expression of Lcn2 attenuated CSC-associated SOX2, CD44, and EpCAM expression and suppressed sarcosphere formation and tumorigenesis in the pancreatic carcinoma cell line PANC-1, which showed low expression of Lcn2. However, Lcn2 knockout in BxPC-3 cell line, which presented high Lcn2 expression, promoted CSC stemness, further enhancing sarcosphere formation and tumorigenesis. Moreover, Lcn2 was found to regulate stemness in pancreatic cancer depending on the activation of AKT and c-Jun. Lcn2 suppresses stemness properties in pancreatic carcinoma by activating the AKT-c-Jun pathway, and thus, it may be a novel candidate to suppress the stemness of pancreatic cancer. This study provides a new insight into disease progression.

Изучение влияния детонационных наноалмазов и их конъюгатов с доксорубицином и диоксадэтом на функцию митохондрий

Targeted drug delivery is aimed at preventing drugs’ nonspecific distribution in different tissues. One of efficient ways for drug’s targeted delivery is using denonation nanodiamonds. These nanoparticles are an advantageous material for nanomedicine due to their low cost, biocompatibility, hardness and chemical stability. Majority of blood plasma proteins and blood cell surfaces are charged negatively. Therefore biocompatibility and long circulation lifetimes of carboxylated nanodiamonds can be partially attributed to their negative surface charge. The presence of different functional groups on nanodiamond surfaces enables their functionalization with a variety of therapeutic agents, including antitumour drugs. One of them is dioxadet, a derivative of symmetric triazine. It is becoming evident that mitochondria play crucial role in metastasis and chemoresistance of tumors, which makes them a very promising target for anticancer therapy. In particular, proton translocating F1Fo-ATPase/ATP synthase can be one of these targets. This enzyme is responsible for making the majority of ATP in the cell by oxidative phosphorylation. More than 300 natural and synthesized compounds are currently known to interact with or inhibit F1Fo, but a comparative study of their effects on energy metabolism has only recently started. In this work we estimated effects of the cytostatic drugs doxorubicin, dioxadet and their DND conjugates on the activity of F1Fo ATPase as well as on the membrane potential. Two model systems were employed: 1) E. coli F1Fo-ATPase reconstituted into phosphatidylcholine liposomes; 2) Pancreatic carcinoma cell line PANC1. It was found that the nanodiamonds and conjugates exhibited the same uncoupling effect, partially dissipating the proton gradient across the membrane of proteoliposomes containing F1Fo-ATPase. In addition, the nanodiamonds inhibited ATPase activity. In an experiment on the effect on the mitochondrial membrane potential (PANC 1 cell line), conjugates of nanodiamonds with doxorubicin demonstrated a more pronounced effect compared to doxorubicin, which may be due to a combination of the uncoupling effect of nanodiamonds and doxorubicin-dependent generation of reactive oxygen species. The data reported in this paper shed light on effect of the carboxylated nanodiamonds on the cellular bioenergetics. These findings are crucial for further development of nanodiamond-based targeted drug delivery systems, in particular decreasing their toxicity by selecting optimal strategies of nanodiamond synthesis as well as drug immobilization on their surfaces. The use of artificial models of natural membranes, along with cell cultures, is necessary for a deeper and more accurate understanding of the mechanism of action of cytostatics.

Phycocyanin inhibits pancreatic cancer metastasis via suppressing epithelial-mesenchymal transition and targeting Akt/β-catenin pathway.

According to our previous research, phycocyanin (PC) could inhibit pancreatic tumor growth obviously. However, little is known about the effects of phycocyanin on pancreatic tumor metastasis. This study was aimed to investigate whether phycocyanin inhibits pancreatic cancer cells' metastasis and the potential underlying mechanisms. Human pancreatic carcinoma cell lines PANC-1 and BxPC3 were treated with phycocyanin (5, 10, 20, and 40 μM) for 48 h or 72 h. BALB/c nude mice were inoculated intravenously with luciferase-PANC-1 cells to establish a tumor metastasis model. BALB/c nude mice were also inoculated subcutaneously with PANC-1 cells to establish a xenograft tumor model. Our results indicated that (1) phycocyanin inhibited migration, invasion, and movement of pancreatic cancer cells in vitro, and tumor metastasis in mouse xenograft tumor model; (2) phycocyanin significantly changed cell morphology and epithelial-mesenchymal transition (EMT) phenotype in pancreatic cancer cells; (3) phycocyanin decreased the phosphorylation level of Akt and the level of nuclear β-catenin. Moreover, administration of Akt activator SC79 counteracted the inhibitory effect of phycocyanin on the migration of pancreatic cancer cells, associated with the reversal of epithelial-mesenchymal transition and Akt/β-catenin signaling pathway. Taken together, our results suggest that phycocyanin inhibits pancreatic cancer metastasis via suppressing epithelial-mesenchymal transition and targeting the Akt/β-catenin pathway.

The Radiolabeling of a Gly-Sar Dipeptide Derivative with Flourine-18 and Its Use as a Potential Peptide Transporter PET Imaging Agent.

We have developed a novel fluorine-18 radiotracer, dipeptide 1, radiolabeled in two steps from mesylate 3. The initial radiolabeling is achieved in a short reaction time (10 min) and purified through solid-phase extraction (SPE) with modest radiochemical yields (rcy = 10 ± 2%, n = 5) in excellent radiochemical purity (rcp > 99%, n = 5). The de-protection of the tert-butyloxycarbonyl (Boc) and trityl group was achieved with mild heating under acidic conditions to provide 18F-tagged dipeptide 1. Preliminary analysis of 18F-dipeptide 1 was performed to confirm uptake by peptide transporters (PepTs) in human pancreatic carcinoma cell lines Panc1, BxPC3, and ASpc1, which are reported to express the peptide transporter 1 (PepT1). Furthermore, we confirmed in vivo uptake of 18F-dipeptide tracer 1 using microPET/CT in mice harboring subcutaneous flank Panc1, BxPC3, and Aspc1 tumors. In conclusion, we have established the radiolabeling of dipeptide 1 with fluoride-18, and demonstrated its potential as an imaging agent which may have clinical applications for the diagnosis of pancreatic carcinomas.

Design, synthesis, biological evaluation and molecular modeling study of new thieno[2,3-d]pyrimidines with anti-proliferative activity on pancreatic cancer cell lines.

Pancreatic cancer is one of the most challenging diseases with seven months only as median survival time due to its poor prognosis. Several enzymes are blamed for the progress of pancreatic cancer especially, platelet-derived growth factor receptors (PDGFRs), this in turn makes them promising targets for its treatment. In this study, twenty eight new compounds based on thieno[2,3-d]pyrimidine scaffold were synthesized as anti-pancreatic cancer agents mimicking the benzofuro[3,2-d]pyrimidine derivative, amuvatinib. Various linkers including amides, esters, ketones, urea and thiourea derivatives were utilized to study their effect on the anti-proliferative activity of these compounds. Most of the tested compounds revealed good cytotoxic activities against pancreatic carcinoma cell line PANC-1. Compound 9d showed the highest cytotoxicity with an IC50 value of 5.4µM. Furthermore, 9d showed excellent platelet derived growth factor receptor (PDGFR-α) inhibitory activity, with IC50 value 0.155µM. Docking study was carried out into PDGFR-α active site which showed comparable binding mode to that of FDA approved PDGFR-α inhibitor, imatinib. 3D-Quantitative structure activity relationship (QSAR) model was built up with five-featured pharmacophore which could be implemented for emerging effective lead structures. These compounds could serve as a new chemotype for discovering new agents for pancreatic cancer therapy.

Co-Delivery of Gemcitabine and Mcl-1 SiRNA via Cationic Liposome-Based System Enhances the Efficacy of Chemotherapy in Pancreatic Cancer.

Myeloid cell leukemia 1 (Mcl-1) overexpression is found in various human tumors and has emerged as a promising new target for pancreatic cancer treatment. Recent research has found that most pancreatic cancers develop resistance to the current first-line chemotherapeutic drug, gemcitabine (Gem), and high expression of Mcl-1 can reduce the sensitivity of pancreatic cancer cells to Gem chemotherapy. Therefore, novel strategies, such as combination therapy, to overcome resistance of Gem chemotherapy are needed urgently. Here, we employed a lipid-based delivery system (LPs) to codeliver Mcl-1 siRNA and Gem for pancreatic cancer treatment, named LP-Gem-siMcl-1. LP-Gem-siMcl-1 exhibited an increased cellular uptake, enhanced Mcl-1 down-regulation efficacy, and significant cytotoxicity in the human pancreatic carcinoma cell lines PANC-1 and BxPC-3. Furthermore, tumor inhibition in vivo proved that LP-Gem-siMcl-1 has higher anti-tumor efficiency than LP-siMcl-1 plus LP-Gem, indicating the synergistic anti-tumor effects of Gem and siMcl-1. Meanwhile, histological analysis demonstrated that LPs could efficiently co-deliver Gem and Mcl-1 siRNA to cancerous cells and overcome the resistance of Gem. Taken together, our results offer proof that LP-Gem-siMcl-1 is an effective co-delivery system to treat pancreatic cancers and may serve as a valuable tool for developing new strategies for cancer therapy.

The FGF1/CPP-C chimera protein protects against intestinal adverse effects of C-ion radiotherapy without exacerbating pancreatic carcinoma

Background and purposeCarbon ion (C-ion) beams are concentrated to irradiate pancreatic carcinoma in the upper abdomen; however, this radiotherapy potentially causes adverse reactions in the gastrointestinal tract. FGF1 is a candidate radioprotector for radiation-induced intestinal damage, but may promote the malignancy of pancreatic cancer. An FGF1/CPP-C chimeric protein was created to enhance the intracellular signaling mode of FGF1 instead of FGFR signaling. The present study investigated the effects of FGF1/CPP-C on the intestinal adverse reactions of C-ion radiotherapy as well as its influence on the malignancy of pancreatic cancer. Materials and methodsFGF1/CPP-C was administered intraperitoneally to BALB/c mice without heparin 12 h before total body irradiation (TBI) with low-LET C-ion (17 keV/μm) at 6–8 Gy. Several radioprotective effects were examined in the jejunum. The invasion and migration of the human pancreatic carcinoma cell lines MIAPaCa-2 and PANC-1 were assessed using Boyden chambers after cultures with FGF1/CPP-C. ResultsThe FGF1/CPP-C treatment promoted crypt survival after C-ion irradiation at 7–8 Gy significantly more than the FGF1 treatment. FGF1/CPP-C also inhibited C-ion radiotherapy-induced apoptosis and reduced γH2AX foci in crypt cells more than FGF1. However, FGF1/CPP-C inhibited the downstream signaling pathways of FGFRs and suppressed the activation of cell-cycle regulatory molecules in the intestine until 4 h after TBI. Furthermore, IEC6 cells were arrested in G2M after cultures with FGF1/CPP-C or FGF1, suggesting that DNA repair after irradiation is promoted by FGF1/CPP-C-induced G2M arrest. In contrast, FGF1/CPP-C appeared to be internalized into MIAPaCa-2 and PANC-1 cells more efficiently than FGF1. Therefore, FGF1/CPP-C reduced the in vitro proliferation, invasion, and migration of MIAPaCa-2 and PANC-1 cells significantly more than FGF1 through the cellular internalization of FGF1. ConclusionThese results suggest that the intracellular signaling mode of FGF1/CPP-C attenuates the intestinal adverse effects of C-ion radiotherapy without enhancing the malignancy of pancreatic carcinoma.

Porphyrins to restrict progression of pancreatic cancer by stabilizing KRAS G-quadruplex: In silico, in vitro and in vivo validation of anticancer strategy

KRAS, a frequently mutated G-quadruplex forming proto-oncogene is responsible for almost every type of cancer which can form a parallel G-quadruplex structure in the promoter region. G-quadruplex structure is one of the most important drug targets for modern cancer therapy for their unique structure and specificity. Here, we have screened several synthetic porphyrin-based compounds as potential KRAS G-quadruplex stabilizing ligands, using molecular modeling and docking studies. Two novel porphyrins: Porphyrin-1(Cobalt containing) and Porphyrin-2 (Palladium containing) evidenced high affinity towards KRAS-promoter/G-quadruplex. As KRAS mutation is prevalent in pancreatic cancer, the efficacy of these ligands against human pancreatic ductal carcinoma cell line PANC-1 and MiaPaCa2 were examined. Both the Porphyrins exhibited significant cytotoxicity and block metastasis by inhibiting Epithelial to messenchymal transition. In vivo studies confirmed both porphyrin compounds to be effective against EAC tumors along with significantly low toxicity against normal Swiss albino mice. The expression of KRAS gene in porphyrin-treated PANC-1, MiaPaCa2 and tumor-derived EAC cells were drastically reduced at both protein and RNA levels. Thus interaction of porphyrin-based ligands with G-quadruplex DNA at the promoter region of KRAS, might be utilized as a target for anticancer therapeutic strategy.

P38 differentially regulates ERK, p21, and mitogenic signalling in two pancreatic carcinoma cell lines.

Whereas the p38 MAP kinase has largely been associated with anti-proliferative functions, several observations have indicated that it may also have positive effects on proliferation. In hepatocytes, we have found that p38 has opposing effects on DNA synthesis when activated by EGF and HGF. Here we have studied the function of p38 in EGF- and HGF-induced DNA synthesis in the two pancreatic carcinoma cell lines AsPC-1 and Panc-1. In Panc-1 cells, the MEK inhibitor PD98059 reduced EGF- and HGF-induced DNA synthesis, while the p38 inhibitor SB203580 strongly increased the basal DNA synthesis and reduced expression of the cyclin-dependent kinase inhibitor (CDKI) p21. In contrast, in AsPC-1 cells, EGF- and HGF-induced DNA synthesis was not significantly reduced by PD98059 but was inhibited by SB203580. Treatment with SB203580 amplified the sustained ERK phosphorylation induced by these growth factors and caused a marked upregulation of the expression of p21, which could be blocked by PD98059. These results suggest that while DNA synthesis in Panc-1 cells is enhanced by ERK and strongly suppressed by p38, in AsPC-1 cells, p38 exerts a pro-mitogenic effect through MEK/ERK-dependent downregulation of p21. Thus, p38 may have suppressive or stimulatory effects on proliferation depending on the cell type, due to differential cross-talk between the p38 and MEK/ERK pathways.

An Efficient Synthesis of Angelmarin and its Analogs

Angelmarin, a naturally occurring coumarin, exhibited highly anti-austerity potency towards human pancreatic carcinoma cell line PANC-1. In this paper, an efficient and eco-friendly synthesis of angelmarin and its analogs from columbianetin has been developed via a ZnO mediated esterification and a Wittig reaction.

Effect of arenobufagin on human pancreatic carcinoma cells.

Pancreatic carcinoma (PC) is a deadly form of cancer with poor overall survival. Currently, chemotherapy such as gemcitabine and 5-fluorouracil (5-FU) are the most popular medications that can improve survival, but rapid drug-resistance makes the search for more effective drugs urgent. Upon looking for natural components to treat PC, it was found that arenobufagin, a cardiac glycosides-like compound, showed significant effects on the gemcitabine-resistant pancreatic carcinoma cell line Panc-1 and the gemcitabine-sensitive cell line ASPC-1 at nanomolar concentrations. The present study used MTT and clonogenic survival assays to examine survival and proliferation, and western blotting to assess changes in the associated mitogen activated protein kinase and phosphoinositide 3-kinase pathways and expression of apoptosis-related proteins. The current study also detected the cell cycle by flow cytometry. Arenobufagin inhibited cell survival and proliferation, decreased the phosphorylation of key downstream proteins of K-Ras, including protein kinase B and extracellular signal related kinase, induced cell cycle G2/M phase arrest and apoptosis, and downregulated the level of phosphorylated epidermal growth factor receptor. Notably, the present data also showed that arenobufagin can enhance the sensitivity of PC cells to gemcitabine and 5-FU. In conclusion, arenobufagin could enhance the effect of gemcitabine and 5-FU on PC cells by targeting multiple key proteins. Therefore, arenobufagin has potential as anadjuvant therapy for the treatment of PC.

TRAIL mutant membrane penetrating peptide alike-MuR6-TR enhances the antitumor effects of TRAIL in pancreatic carcinoma both in vitro and in vivo.

To remedy the drug resistance of natural tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) and enhance its antitumor effects, we prepared a type of TRAIL mutant membrane penetrating peptide alike (TMPPA)-TRAIL mutant R6 (MuR6-TR) by mutating the N-terminal of the soluble TRAIL gene sequence. The expressed MuR6-TR protein was purified to treat pancreatic carcinoma cell lines BxPC-3 and PANC-1. The inhibitory effects on the proliferation of BxPC-3 and PANC-1 cells was assessed with CCK-8 assay and compared with natural TRAIL. The antitumor effect of MuR6-TR was assessed on implant tumors derived from PANC-1 cells in nude mice and compared with gemcitabine. Finally, the soluble MuR6-TR gene was successfully mutated with 4 amino acids in the N-terminal of TRAIL and had a molecular size of 513 bp. The mutant MuR6-TR was connected to pET32a and verified by enzymatic digestion and sequencing. The recombinant MuR6-TR was transformed and expressed in Escherichia coli. The CCK-8 assay results indicated that MuR6-TR inhibited the growth of BxPC-3 and PANC-1 cells in a dose-dependent manner, with IC50 values of 4.63 and 7.84 ng/ml, respectively, which were much lower than that of natural TRAIL. MuR6-TR demonstrated a higher inhibitory effect on tumor growth (24.2%) than natural TRAIL (14.4%) and an effect similar to that of gemcitabine at an early period. Thus, the mutant MuR6-TR exhibited a stronger antitumor effect than that of natural TRAIL both in vivo and in vitro and may have potential therapeutic value for pancreatic carcinoma, which requires further validation.

Detecting changes in the cytoskeletal structure of malignant pancreatic cells using high-frequency ultrasound

Traditional classification of breast cancer subtype is determined based on protein expression and genetic profile. Determining the molecular subtype of breast cancer can make prognosis more accurate and help to personalize treatment. More aggressive subtypes of breast cancer, such as basal-like and Her2 + , have mutations that alter the protein regulation of the cell cytoskeleton. These cytoskeleton modulations can enable the cell to become more mobile and metastasize to other parts of the body. High-frequency ultrasound (10–100 MHz) has previously been studied for the real-time diagnosis of malignant tissue in breast conservation surgery. High-frequency ultrasound also has the potential of determining the molecular subtype of breast cancer. The objective of this work was to determine if chemically induced changes in the cytoskeleton of cancer cell lines are able to be detected using high-frequency ultrasound. Cell cultures of a human pancreatic carcinoma cell line (panc-1) were grown in monolayers and th...

Lysophosphatidic acid induces both EGFR-dependent and EGFR-independent effects on DNA synthesis and migration in pancreatic and colorectal carcinoma cells.

Lysophosphatidic acid (LPA) is a small glycerophospholipid ubiquitously present in tissues and plasma. It acts through receptors belonging to the G-protein-coupled receptor (GPCR) family, is involved in several biological processes, and is strongly implicated in different cancers. In this paper, we have investigated the effects of LPA on DNA synthesis and migration in a panel of pancreatic and colon cancer cells, with particular focus on the involvement of the epidermal growth factor (EGF) receptor (EGFR) in LPA-induced signaling. LPA stimulated DNA synthesis and/or migration in all the cell lines included in this study. In five of the six cell lines, LPA induced phosphorylation of the EGFR, and the effects on EGFR and Akt, and in some of the cells also ERK, were sensitive to the EGFR tyrosine kinase inhibitor gefitinib, strongly suggesting LPA-induced EGFR transactivation in these cells. In contrast, in one of the pancreatic carcinoma cell lines (Panc-1), we found no evidence of transactivation of the EGFR. In the pancreatic carcinoma cell lines where transactivation took place (BxPC3, AsPC1, HPAFII), gefitinib reduced LPA-induced DNA synthesis and/or migration. However, we also found evidence of transactivation in the two colon carcinoma cell lines (HT29, HCT116) although gefitinib did not inhibit LPA-induced DNA synthesis or migration in these cells. Taken together, the data indicate that in many gastrointestinal carcinoma cells, LPA uses EGFR transactivation as a mechanism when exerting such effects as stimulation of cell proliferation and migration, but EGFR-independent pathways may be involved instead of, or in concerted action with, the EGFR transactivation.

Prostaglandin E2 activates the mTORC1 pathway through an EP4/cAMP/PKA- and EP1/Ca2+-mediated mechanism in the human pancreatic carcinoma cell line PANC-1.

Obesity, a known risk factor for pancreatic cancer, is associated with inflammation and insulin resistance. Proinflammatory prostaglandin E2 (PGE2) and elevated insulin-like growth factor type 1 (IGF-1), related to insulin resistance, are shown to play critical roles in pancreatic cancer progression. We aimed to explore a potential cross talk between PGE2 signaling and the IGF-1/Akt/mammalian target of rapamycin complex 1 (mTORC1) pathway in pancreatic cancer, which may be a key to unraveling the obesity-cancer link. In PANC-1 human pancreatic cancer cells, we showed that PGE2 stimulated mTORC1 activity independently of Akt, as evaluated by downstream signaling events. Subsequently, using pharmacological and genetic approaches, we demonstrated that PGE2-induced mTORC1 activation is mediated by the EP4/cAMP/PKA pathway, as well as an EP1/Ca(2+)-dependent pathway. The cooperative roles of the two pathways were supported by the maximal inhibition achieved with the combined pharmacological blockade, and the coexistence of highly expressed EP1 (mediating the Ca(2+) response) and EP2 or EP4 (mediating the cAMP/PKA pathway) in PANC-1 cells and in the prostate cancer line PC-3, which also robustly exhibited PGE2-induced mTORC1 activation, as identified from a screen in various cancer cell lines. Importantly, we showed a reinforcing interaction between PGE2 and IGF-1 on mTORC1 signaling, with an increase in IL-23 production as a cellular outcome. Our data reveal a previously unrecognized mechanism of PGE2-stimulated mTORC1 activation mediated by EP4/cAMP/PKA and EP1/Ca(2+) signaling, which may be of great importance in elucidating the promoting effects of obesity in pancreatic cancer. Ultimately, a precise understanding of these molecular links may provide novel targets for efficacious interventions devoid of adverse effects.

Effect of PPARδ agonist on stearoyl-CoA desaturase 1 in human pancreatic cancer cells: role of MEK/ERK1/2 pathway.

The stearoyl-CoA desaturase 1 (SCD1), also known as Δ9-desaturase, is a regulatory enzyme in the cellular lipid modification process that has been linked to pancreatic cancer and diabetes. The aim of the present study was to investigate the effect of peroxisome proliferative-activated receptor δ (PPARδ) agonist and ERK1/2- and EGF receptor (EGFR)-dependent pathways on the expression of SCD1 in human pancreatic carcinoma cell line PANC-1. PANC-1 cells cultured in RPMI-1640 were exposed to the commonly used MEK inhibitor PD98059, EGFR-selective inhibitor AG1478, and PPARδ agonist GW0742. Changes in mRNA, protein expression and activity index of SCD1 were then determined using real-time reverse transcription polymerase chain reaction, Western blot and gas liquid chromatography, respectively. The activity index and expression of SCD1 (p<0.01) decreased following treatment with PPARδ agonist at both mRNA and protein levels, whereas significant increases were observed after treatment with MEK or EGFR inhibitor. It was also found that the activity index of SCD1 were lower (p<0.01) in the combined treatment compared to the incubation with either inhibitor alone. PPARδ and MEK/ERK1/2- and EGFR-dependent pathways affect the expression and activity of SCD1 in pancreatic cancer cells. Furthermore, the aforementioned kinase signalling pathways were involved in an inhibitory effect on the expression and activity of SCD1 in these cells, possibly via PPARδ activation.

Abstract 2273: c-Rel is a critical mediator of NF-κB-dependent apoptosis resistance of pancreatic cancer cells against TRAIL

Abstract Pancreatic ductal adenocarcinoma (PDAC) represents one of the deadliest malignancies with an overall life expectancy of six months despite palliative radio-chemotherapy. The transcription factor NF-κB has been shown to be a critical component of dysregulated transcription factor activity conferring this profound resistance against chemotherapeutic drugs and death receptor induced apoptosis. Despite extensive data on the role of the most abundant NF-κB subunit p65/RelA in PDAC apoptosis control, only little knowledge of the role of the subunit c-Rel in solid cancers exists. In the present study, three pancreatic carcinoma cell lines (Panc1, Patu8988t, MiaPaca2) were analysed for the role of c-Rel in resistance against TRAIL induced apoptosis. TRAIL resistant Panc1 and Patu8988 cells exhibit a strong TRAIL inducible NF-κB activity, whereas TRAIL sensitive MiaPaca2 cells displayed only a small increase in NF-κB binding activity. Transfection with siRNA against the c-Rel subunit of NF-κB sensitized the TRAIL resistant cells in a comparable fashion like siRNA targeting the p65/RelA subunit. Gel shift analysis revealed that together with the p65/RelA subunit, c-Rel is part of the TRAIL inducible NF-κB complex in PDAC. Array analysis results suggested NFATc2 as a c-Rel target gene that is one of the 15 strongest TRAIL inducible genes in apoptosis-resistant Panc1 cells. siRNA targeting c-Rel strongly reduced TRAIL induced NFATc2 activity in TRAIL resistant PDAC cells. Furthermore siRNA targeting NFATc2 sensitized these PDAC cells against TRAIL induced apoptosis. Finally, TRAIL induced expression of COX-2 was strongly reduced through siRNA targeting c-Rel or NFATc2 and pharmacological inhibition of COX-2 with celecoxib strongly increased TRAIL apoptosis. In conclusion, c-Rel is a critical mediator of NF-κB dependent anti-apoptotic signalling in PDAC through activation of NFATc2 and COX-2. Citation Format: Claudia Geismann, Frauke Grohmann, Gabriele Wirths, Susanne Sebens, Anita Dreher, Robert Häsler, Sebastian Zeissig, Stefan Schreiber, Philip Rosenstiel, Heiner Schäfer, Alexander Arlt. c-Rel is a critical mediator of NF-κB-dependent apoptosis resistance of pancreatic cancer cells against TRAIL. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2273. doi:10.1158/1538-7445.AM2014-2273

Epigenetically modified pancreatic carcinoma PANC-1 cells can act as cancer vaccine to enhance antitumor immune response in mice.

Pancreatic cancer is characterized as a type of gastrointestinal tumor with a poor prognosis and high degree of malignancy. CIITA gene was found highly methylated in pancreatic carcinoma cell line PANC-1 and responsible for the low expression of major histocompatability complex II (MHC-II) that may lead to immune evasion. Here, we prepared pancreatic cancer vaccine with PANC-1 cells via epigenetic modification to enhance the MHC-II expression. Then the vaccine was injected into C57BL/6J mice and the effect was examined. Our study found that the vaccine could promote the proliferation of antigen-specific T cells, enhance the killing activity of cytotoxic T lymphocytes (CTLs), promote Th1-type cell-mediated secretion of cytokines IFN-γ and IL-2 while inhibiting Th2-type cell-mediated secretion of IL-4, and inhibit the secretion of TGF-β. Generally, the epigenetically modified vaccine could enhance the body's antitumor immune response, providing feasibility research on cancer vaccine for therapy of pancreatic cancer.