Pancreatic Cancer Cells In Culture Research Articles

Surface-Enhanced Raman Scattering Monitoring of Tryptophan Dynamics in 3D Pancreatic Tumor Models.

In the intricate landscape of the tumor microenvironment, both cancer and stromal cells undergo rapid metabolic adaptations to support their growth. Given the relevant role of the metabolic secretome in fueling tumor progression, its unique metabolic characteristics have gained prominence as potential biomarkers and therapeutic targets. As a result, rapid and accurate tools have been developed to track metabolic changes in the tumor microenvironment with high sensitivity and resolution. Surface-enhanced Raman scattering (SERS) is a highly sensitive analytical technique and has been proven efficient toward the detection of metabolites in biological media. However, profiling secreted metabolites in complex cellular environments such as those in tumor-stroma 3D in vitro models remains challenging. To address this limitation, we employed a SERS-based strategy to investigate the metabolic secretome of pancreatic tumor models within 3D cultures. We aimed to monitor the immunosuppressive potential of stratified pancreatic cancer-stroma spheroids as compared to 3D cultures of either pancreatic cancer cells or cancer-associated fibroblasts, focusing on the metabolic conversion of tryptophan into kynurenine by the IDO-1 enzyme. We additionally sought to elucidate the dynamics of tryptophan consumption in correlation with the size, temporal evolution, and composition of the spheroids, as well as assessing the effects of different drugs targeting the IDO-1 machinery. As a result, we confirm that SERS can be a valuable tool toward the optimization of cancer spheroids, in connection with their tryptophan metabolizing capacity, potentially allowing high-throughput spheroid analysis.

Abstract 3250: LNA gapmer to gastrin inhibits growth and metastases of human pancreatic cancer in mice

Abstract Background: Pancreatic cancer has a poor prognosis and novel strategies are needed to improve the survival. Gastrin stimulates growth of pancreatic cancer by an autocrine mechanism and RNAi techniques that decrease gastrin expression have been shown to inhibit growth of this malignancy in vitro. Locked nucleic acid (LNA) Gapmers are antisense oligonucleotides (ASO) that have long half-life and stability in vivo, hence represent a potential method to deliver RNAi for cancer therapeutics. We developed an LNA Gapmer that selectively downregulates gastrin expression in pancreatic cancer cells in culture. The goal of this project was to test this anti-gastrin Gapmer in vivo as a novel therapy for pancreatic cancer. Methods: The anti-gastrin LNA Gapmer was modified using thiol-click chemistry to conjugate a peptide to the 5’ end and render the Gapmer target-specific with the ability to bind selectively to the cholecystokinin-B receptor that is over-expressed in pancreatic cancer. Forty athymic nude mice with established AsPC-1 human pancreatic orthotopic tumors were divided into four groups of equal tumor size. Mice (N=10 per group) were treated with PBS (controls), an untargeted LNA-Gapmer, the CCK-BR targeted Gapmer (60nM), and the CCK-BR targeted Gapmer (120nM) intraperitoneally twice a week for 4 weeks. Growth was monitored by luciferase IVIS imaging. At necropsy, tumors were excised, and metastases counted. Results: Mean tumor mass was 43% smaller in mice treated with the targeted Gapmer-120nM (P=0.0007). Untargeted and targeted Gapmer 60nM slightly decreased tumor mass but this difference was not significant. Compared to PBS control-treated mice, metastases were significantly less in mice treated with the untargeted Gapmer by -39% (p=0.01); in the targeted Gapmer-60nM by -44% (p=0.003), and with the targeted Gapmer-120nM by -72% (p<0.0001). Gastrin mRNA analysis of the tumors by qRT-PCR confirmed downregulation of gastrin. Conclusion: Novel LNA Gapmers that downregulate gastrin mRNA expression decrease growth and metastases of pancreatic cancer in a dose-related fashion. Citation Format: Godhanjali Chekuri, Wenqiang Chen, Narayan Shivapurkar, Hong Cao, Ruvanthi N. Kularatne, Stephan Stern, Jill P. Smith. LNA gapmer to gastrin inhibits growth and metastases of human pancreatic cancer in mice [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3250.

Abstract 6792: Investigating differential expression of Palladin isoform 3 in 2D and 3D pancreatic cancer cell cultures

Abstract Palladin (PALLD) is an actin-binding protein widely expressed in mammalian tissues that modulates cytoskeletal dynamics. Palladin is linked to the progression of breast, pancreatic, and renal cancers. There are at least 9 known isoforms of PALLD but isoforms 3 (iso3) and 4 (iso4) appear most significant in cancer cells and associated fibroblasts. Our goal is to understand iso3 in pancreatic cancer (PC) cell lines grown in various culture environments to shed light on the intricate interplay between culture conditions and gene regulation. Cell models were developed as 3D spheroids from hanging drops after optimizing culture conditions by utilizing a combination of inexpensive methylcellulose (MC) and rat tail collagen viscosity ranges across cell seeding densities. The quality of the developed spheroids was assessed using multiple parameters, like diameter, integrity, and circularity to determine ideal spheroid characteristics. Spheroids that formed at a lower MC viscosity range (350-550 mPa·s) led to peripheral loose cells and a higher viscosity range (7,000-10,000 mPa·s) resulted in elongated shapes. Moderate viscosity ranges (1,000-1,800 mPa·s and 3,500-5,600 mPa·s) consistently produced circular and compact spheroids. Optimal incubation times varied from 72 to 96 hr depending on the cell line. Invasion dynamics within collagen-MC gels revealed that PANC-1 had significantly higher invasion potential compared to BxPC-3 and a control cell line C2C12. RT-qPCR results show that PALLD iso3 was particularly overexpressed in the 3D culture environment of PANC-1, suggesting that elevated PALLD isoform 3 expression may be a characteristic of 3D culture, particularly in invasive PC types. Taken together, the study validates the importance of extracellular viscosity for influencing spheroid characteristics toward generating reproducible 3D spheroids. The investigation also highlights PALLD iso3 as a potentially valuable biomarker for aggressive forms of pancreatic cancer. Citation Format: Sonali Biswas, Jason A. Bush. Investigating differential expression of Palladin isoform 3 in 2D and 3D pancreatic cancer cell cultures [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 6792.

Pancreatic Cancer-Derived Exosomal miR-Let-7b-5p Stimulates Insulin Resistance in Skeletal Muscle Cells Through RNF20/STAT3/FOXO1 Axis Regulation.

Cancers trigger systemic metabolic disorders usually associated with glucose intolerance, which is an initially apparent phenomenon. One of the features of pancreatic cancer (PC) metabolic reprogramming is the crosstalk between PC and peripheral tissues (skeletal muscle and adipose tissues), emphasized by insulin resistance (IR). Our previous study reported that mice pancreatic cancer-derived exosomes could induce skeletal muscle cells (C2C12) IR, and exosomal microRNAs (miRNAs) may exert an important effect. However, the underlying mechanism remains to be further elucidated. qPCR was used to determine the expression of let-7b-5p in normal pancreatic islet cells and PC cells. Exosomes were purified from PC cell culture medium by ultracentrifugation. The role let-7b-5p on IR-mediated by PC cells-derived exosomes was asses by Oil Red O staining using miRNA inhibitor. Western blot assay was performed to examine the expression of IR-related genes and the activation of signaling pathways. A Luciferase experiment was applied to confirm how let-7b-5p regulated the expression of RNF20. IP/WB analysis further determined whether RNF20 promoted STAT3 ubiquitination. Rescue experiment using RNF20 overexpression plasmid was performed to confirm the role of RNF20 on IR-mediated using PC cell-derived exosomes in C2C12 myotube cells. miRNA-let-7b-5p was identified as the key exosomal miRNA, which could promote the IR in C2C12 myotube cells supported the lipid accumulation, the activation of STAT3/FOXO1 axis, and the decreased expression of IRS-1 and GLUT4. RNF20, an E3 ubiquitin ligase, was confirmed as the target gene of let-7b-5p and was found to improve IR by downregulating STAT3 protein expression via ubiquitination-mediated protein degradation. The ectopic expression of RNF20 could effectively attenuate the IR mediated by the pancreatic cancer-derived exosomes in C2C12 myotube cells. Our data suggest that exosomal miRNA-let-7b-5p may promote IR in C2C12 myotube cells by targeting RNF20 to activate the STAT3/FOXO1 axis.

Priming therapy by targeting enhancer-initiated pathways in patient-derived pancreatic cancer cells.

Systems biology leveraging multi-OMICs technologies, is rapidly advancing development of precision therapies and matching patients to targeted therapies, leading to improved responses. A new pillar of precision oncology lies in the power of chemogenomics to discover drugs that sensitizes malignant cells to other therapies. Here, we test a chemogenomic approach using epigenomic inhibitors (epidrugs) to reset patterns of gene expression driving the malignant behavior of pancreatic tumors. We tested a targeted library of ten epidrugs targeting regulators of enhancers and super-enhancers on reprogramming gene expression networks in seventeen patient-derived primary pancreatic cancer cell cultures (PDPCCs), of both basal and classical subtypes. We subsequently evaluated the ability of these epidrugs to sensitize pancreatic cancer cells to five chemotherapeutic drugs that are clinically used for this malignancy. To comprehend the impact of epidrug priming at the molecular level, we evaluated the effect of each epidrugs at the transcriptomic level of PDPCCs. The activating epidrugs showed a higher number of upregulated genes than the repressive epidrugs (χ2 test p-value <0.01). Furthermore, we developed a classifier using the baseline transcriptome of epidrug-primed-chemosensitized PDPCCs to predict the best epidrug-priming regime to a given chemotherapy. Six signatures with a significant association with the chemosensitization centroid (R≤-0.80; p-value < 0.01) were identified and validated in a subset of PDPCCs. We conclude that targeting enhancer-initiated pathways in patient-derived primary cells, represents a promising approach for developing new therapies for human pancreatic cancer. This work was supported by INCa (Grants number 2018-078 to ND and 2018- 079 to JI), Canceropole PACA (ND), Amidex Foundation (ND), and INSERM (JI).

Anticancer Activity of Sunitinib Analogues in Human Pancreatic Cancer Cell Cultures under Normoxia and Hypoxia

Pancreatic cancer remains one of the deadliest cancer types. It is usually characterized by high resistance to chemotherapy. However, cancer-targeted drugs, such as sunitinib, recently have shown beneficial effects in pancreatic in vitro and in vivo models. Therefore, we chose to study a series of sunitinib derivatives developed by us, that were proven to be promising compounds for cancer treatment. The aim of our research was to evaluate the anticancer activity of sunitinib derivatives in human pancreatic cancer cell lines MIA PaCa-2 and PANC-1 under normoxia and hypoxia. The effect on cell viability was determined by the MTT assay. The compound effect on cell colony formation and growth was established by clonogenic assay and the activity on cell migration was estimated using a 'wound healing' assay. Six out of 17 tested compounds at 1 µM after 72 h of incubation reduced cell viability by 90% and were more active than sunitinib. Compounds for more detailed experiments were chosen based on their activity and selectivity towards cancer cells compared to fibroblasts. The most promising compound EMAC4001 was 24 and 35 times more active than sunitinib against MIA PaCa-2 cells, and 36 to 47 times more active against the PANC-1 cell line in normoxia and hypoxia. It also inhibited MIA PaCa-2 and PANC-1 cell colony formation. Four tested compounds inhibited MIA PaCa-2 and PANC-1 cell migration under hypoxia, but none was more active than sunitinib. In conclusion, sunitinib derivatives possess anticancer activity in human pancreatic adenocarcinoma MIA PaCa-2 and PANC-1 cell lines, and they are promising for further research.

The effects of thymoquinone on pancreatic cancer and immune cells.

SUMMARYOBJECTIVES:Black cumin is widely used as a spice and as a traditional treatment. The active ingredient in black cumin seeds is thymoquinone. Thymoquinone has shown anticancer effects in some cancers. We planned to investigate its anticancer effect on pancreatic cancer cell lines.METHODS:Thymoquinone chemical component in various doses was prepared and inoculated on pancreatic cancer cell culture, healthy mesenchymal stem cells, and peripheral blood mononuclear cell culture. IC50 values were calculated by absorbance data and measuring cell viability by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide staining of cells incubated with thymoquinone at 24, 48, and 72 h.RESULTS:There was dose-related cytotoxicity. Maximal cytotoxicity was observed at 24 h and 100 μM thymoquinone concentrations in pancreatic cancer cell culture and mesenchymal stem cells. Any concentration of thymoquinone was not cytotoxic to peripheral blood mononuclear cell. Thymoquinone even caused proliferation at a concentration of 6.25 μM.CONCLUSIONS:Since the cytotoxic concentration of thymoquinone on pancreatic cancer cell culture and mesenchymal stem cells is the same, it is not appropriate to use thymoquinone to achieve cytotoxicity in pancreatic cancer. However, since thymoquinone provides proliferation in peripheral blood mononuclear cell at a noncytotoxic dose, it may have an immune activator effect. Therefore, in vivo studies are needed to investigate the effect of thymoquinone on the immune system.

Combination of LIGHT (TNFSF14)-Armed Myxoma Virus Pre-Loaded into ADSCs and Gemcitabine in the Treatment of Experimental Orthotopic Murine Pancreatic Adenocarcinoma.

Pancreatic ductal adenocarcinoma (PDAC) is a deadly neoplasm. Oncolytic viruses have tumorolytic and immune response-boosting effects and present great potential for PDAC management. We used LIGHT-armed myxoma virus (vMyx-LIGHT) loaded ex vivo into human adipose-derived mesenchymal stem cells (ADSCs) to evaluate murine PDAC treatment in conjunction with gemcitabine (GEM). The cytotoxicity of this treatment was confirmed in vitro using human and murine pancreatic cancer cell cultures, which were more sensitive to the combined approach and largely destroyed. Unlike cancer cells, ADSCs sustain significant viability after infection. The in vivo administration of vMyx-LIGHT-loaded ADSCs and gemcitabine was evaluated using immunocompetent mice with induced orthotopic PDAC lesions. The expression of virus-encoded LIGHT increased the influx of T cells to the tumor site. Shielded virus followed by gemcitabine improved tumor regression and survival. The addition of gemcitabine slightly compromised the adaptive immune response boost obtained with the shielded virus alone, conferring no survival benefit. ADSCs pre-loaded with vMyx-LIGHT allowed the effective transport of the oncolytic construct to PDAC lesions and yielded significant immune response; additional GEM administration failed to improve survival. In view of our results, the delivery of targeted/shielded virus in combination with TGF-β ablation and/or checkpoint inhibitors is a promising option to improve the therapeutic effects of vMyx-LIGHT/ADSCs against PDAC in vivo.

Optimizing the Pharmacological and Optical Dosimetry for Photodynamic Therapy with Methylene Blue and Nanoliposomal Benzoporphyrin on Pancreatic Cancer Spheroids

Photodynamic therapy (PDT) is a cancer treatment that relies on the remote-controlled activation of photocatalytic dyes (photosensitizers) in cancer tissues. To effectively treat cancer, a variety of pharmacological and optical parameters require optimization, which are dependent on the photosensitizer type. As most photosensitizers are hydrophobic molecules, nanoliposomes are frequently used to increase the biocompatibility of these therapeutics. However, as nanoliposomes can influence the therapeutic performance of photosensitizers, the most suitable treatment parameters need to be elucidated. Here, we evaluate the efficacy of PDT on spheroid cultures of PANC-1 and MIA PaCa-2 pancreatic cancer cells. Two strategies to photosensitize the pancreatic microtumors were selected, based on either nanoliposomal benzoporphyrin derivative (BPD), or non-liposomal methylene blue (MB). Using a comprehensive image-based assay, our findings show that the PDT efficacy manifests in distinct manners for each photosensitizer. Moreover, the efficacy of each photosensitizer is differentially influenced by the photosensitizer dose, the light dose (radiant exposure or fluence in J/cm2), and the dose rate (fluence rate in mW/cm2). Taken together, our findings illustrate that the most suitable light dosimetry for PDT strongly depends on the selected photosensitization strategy. The PDT dose parameters should therefore always be carefully optimized for different models of cancer.

Therapy-Naive and Radioresistant 3-Dimensional Pancreatic Cancer Cell Cultures Are Effectively Radiosensitized by β1 Integrin Targeting

Pancreatic ductal adenocarcinoma (PDAC) is a cancer with unmet needs. The role of highly conformal radiation therapy is still under debate for PDAC. Owing to its desmoplastic nature, integrin-mediated interactions between PDAC cells and extracellular matrix (ECM) profoundly contribute to PDAC therapy resistance. In this study, we investigated the radiochemosensitizing potential of β1 integrin targeting in therapy-naive and radioresistant PDAC cell cultures grown in 3-dimensional (3D) ECM.In a panel of 3D, ECM-based PDAC cell cultures, β1 integrin was inhibited by antibodies or siRNA-mediated knockdown. Together with x-ray irradiation and specific chemotherapies, we determined 3D colony formation capacity in therapy-naive and radioresistant PDAC cultures. We used kinome profiling, Western blotting, and immunofluorescence stainings to characterize these cell lines. Various siRNA screens were conducted to identify novel therapeutic targets.We found a significant radiosensitizing potential of β1 integrin inhibition both in therapy-naive and radioresistant PDAC cell cultures. Kinome profiling upon β1 integrin targeting identified a generally declined tyrosine and serine/threonine kinase activity, which presented less prominent in radioresistant than in therapy-naive PDAC cells. siRNA screens employing the top 34 deregulated kinases in combination with β1 integrin inhibition revealed less efficacy and less radiosensitization in radioresistant relative to therapy-naive PDAC cell cultures. Triple inhibition of β1 integrin, protein kinase D1, and rearranged during transfection turned out to be most effective in reducing 3D colony formation of radioresistant PDAC cells.Our study clearly shows that β1 integrins are robust targets for overcoming radioresistance in PDAC. This seems to apply equally to therapy-sensitive and radioresistant cells. Concerning tumor heterogeneity, this dual therapy-sensitizing potential might be exploitable for a significant improvement of patient survival.

Exosomal linc-ROR mediates crosstalk between cancer cells and adipocytes to promote tumor growth in pancreatic cancer

Exosomes are emerging as important mediators of the crosstalk between tumor cells and stromal cells in the microenvironment. However, the underlying molecular mechanism of pancreatic cancer (PC)-derived exosomes in the progression of the tumor microenvironment (TME) and crosstalk with adipocytes has not been elucidated. Exosomes isolated from PC cell culture supernatant through ultracentrifugation were rich in long intergenic non-coding ROR (linc-ROR). After constructing PC cell lines with stable linc-ROR knockdown or overexpression via the transfection of short hairpin RNA (shRNA) and pLent-U6-GFP-Puro, direct and indirect coculture systems were established to simulate the interaction between adipocytes and PC cells. Next, the effects of conditioned medium collected from dedifferentiated adipocytes on PC cell proliferation, motility, metastasis, and epithelial-mesenchymal transition (EMT) were evaluated by western blot analysis, colony forming, real-time cell analysis (RTCA), 5-ethynyl-2′-deoxyuridine (EdU), immunofluorescence (IF), Transwell, and wound-healing assays in vitro. Xenograft models were employed to identify whether conditioned medium loaded with interleukin-1β (IL-1β) promoted PC cell growth in vivo. Our results demonstrate that linc-ROR delivery via exosomes represents a brand-new perspective of dedifferentiating adipocytes in the TME of PC, which further induce PC cell EMT via the hypoxia inducible factor 1α (HIF1α)-ZEB1 axis. Moreover, exosomal linc-ROR may become a novel diagnostic marker for PC patients.

Heat Shock Protein 90 Inhibitor Effects on Pancreatic Cancer Cell Cultures.

Pancreatic ductal adenocarcinoma is one of the deadliest cancers for which few curative therapies are available to date. Heat shock protein 90 (Hsp90) inhibitors have shown activity against numerous cancers in vitro; therefore, we tested whether they could be used to target pancreatic ductal adenocarcinoma. Inhibitors of Hsp90 ATPase activity were applied on low-passage pancreatic cell line cultures (Panc10.05, Panc215, A6L) in a dose-response manner, and the inhibitor in vitro effect on cell growth was evaluated. Seven of novel Hsp90 inhibitors based on resorcinol fragment and 5 commercially available Hsp90 inhibitors (17-AAG, AT-13387, AUY-922, ganetespib, and rifabutin) as well as control compound triptolide were tested yielding IC50 values in 2- and 3-dimensional assays. The novel Hsp90 inhibitors exhibited strong effects on all 3 tested pancreatic cell line cultures (Panc10.05, Panc215, A6L) reaching the IC50 of 300 to 600 nM in 2- and 3-dimensional assays. Novel Hsp90 inhibitors can be developed as antipancreatic cancer agents. Their chemical structures are simpler, and they are likely to exhibit lower side effects than the much more complex inhibitors used as controls.

Establishment and characterization of paired primary cultures of human pancreatic cancer cells and stellate cells derived from the same tumor

Establishment and characterization of paired primary cultures of human pancreatic cancer cells and stellate cells derived from the same tumor

Aromatic Linkers Unleash the Antiproliferative Potential of 3-Chloropiperidines Against Pancreatic Cancer Cells.

In this study, we describe the synthesis and biological evaluation of a set of bis‐3‐chloropiperidines (B−CePs) containing rigid aromatic linker structures. A modification of the synthetic strategy also enabled the synthesis of a pilot tris‐3‐chloropiperidine (Tri‐CeP) bearing three reactive meta‐chloropiperidine moieties on the aromatic scaffold. A structure–reactivity relationship analysis of B−CePs suggests that the arrangement of the reactive units affects the DNA alkylating activity, while also revealing correlations between the electron density of the aromatic system and the reactivity with biologically relevant nucleophiles, both on isolated DNA and in cancer cells. Interestingly, all aromatic 3‐chloropiperidines exhibited a marked cytotoxicity and tropism for 2D and 3D cultures of pancreatic cancer cells. Therefore, the new aromatic 3‐chloropiperidines appear to be promising contenders for further development of mustard‐based anticancer agents aimed at pancreatic cancers.

Establishment and Characterization of Paired Primary Cultures of Human Pancreatic Cancer Cells and Stellate Cells Derived from the Same Tumor.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by an extremely poor prognosis, and its treatment remains a challenge. As the existing in vitro experimental models offer only a limited resemblance to human PDAC, there is a strong need for additional research tools to better understand PDAC tumor biology, particularly the impact of the tumor stroma. Here, we report for the first time the establishment and characterization of human PDAC-derived paired primary monolayer cultures of (epithelial) cancer cells (PCCs) and mesenchymal stellate cells (PSCs) derived from the same tumor by the outgrowth method. Characterization of cell morphology, cytostructural, and functional profiles and proteomics-based secretome analysis were performed. All PCCs harbored KRAS and TP53 mutations, and expressed cytokeratin 19, ki-67, and p53, while the expression of EpCAM and vimentin was variable. All PSCs expressed α-smooth muscle actin (α-SMA) and vimentin. PCCs showed a significantly higher growth rate and proliferation than PSCs. Secretome analysis confirmed the distinct nature of PCCs as compared to PSCs and allowed identification of potential molecular regulators of PSC-conditioned medium (PSC-CM)-induced migration of PCCs. Paired primary cultures of PCCs and PSCs derived from the same tumor specimen represent a novel experimental model for basic research in PDAC tumor biology.

Hepatocyte Growth Factor and Macrophage-stimulating Protein "Hinge" Analogs to Treat Pancreatic Cancer.

Pancreatic cancer (PC) ranks twelfth in frequency of diagnosis but is the fourth leading cause of cancer related deaths with a 5 year survival rate of less than 7 percent. This poor prognosis occurs because the early stages of PC are often asymptomatic. Over-expression of several growth factors, most notably vascular endothelial growth factor (VEGF), has been implicated in PC resulting in dysfunctional signal transduction pathways and the facilitation of tumor growth, invasion and metastasis. Hepatocyte growth factor (HGF) acts via the Met receptor and has also received research attention with ongoing efforts to develop treatments to block the Met receptor and its signal transduction pathways. Macrophage-stimulating protein (MSP), and its receptor Ron, is also recognized as important in the etiology of PC but is less well studied. Although the angiotensin II (AngII)/AT1 receptor system is best known for mediating blood pressure and body water/electrolyte balance, it also facilitates tumor vascularization and growth by stimulating the expression of VEGF. A metabolite of AngII, angiotensin IV (AngIV) has sequence homology with the "hinge regions" of HGF and MSP, key structures in the growth factor dimerization processes necessary for Met and Ron receptor activation. We have developed AngIV-based analogs designed to block dimerization of HGF and MSP and thus receptor activation. Norleual has shown promise as tested utilizing PC cell cultures. Results indicate that cell migration, invasion, and pro-survival functions were suppressed by this analog and tumor growth was significantly inhibited in an orthotopic PC mouse model.

Synergistic activity of Hsp90 inhibitors and anticancer agents in pancreatic cancer cell cultures

Heat shock protein 90 (Hsp90) is a widely investigated target for anticancer therapy. The experimental Hsp90 inhibitors ICPD47 and ICPD62 demonstrated anticancer activity against colorectal, osteosarcoma and cervical cancer cell lines. However, their anticancer activity has not been investigated against pancreatic cancer cell lines yet, and there are no data about synergistic activity of these compounds in combination with clinically used anticancer agents. Pancreatic cancer cell lines, MIA PaCa-2 and PANC-1 were exposed to ICPD47 and ICPD62 alone and in combinations with antimetabolites gemcitabine (GEM), 5-fluorouracil (5-FU) and topoisomerase inhibitor doxorubicin (DOX). Effects on cell viability were determined by MTT assay. The synergistic activity was evaluated using Chou-Talalay method. Also, 3D cell cultures were formed using 3D Bioprinting method and the activity of each compound and their combinations was examined by measuring the size change of spheroids. The strongest synergistic activities were determined in combinations using all ratios of ICPD47 with GEM and ICPD62 with GEM in MIA PaCa-2 cell line (combination index <0.5). The combinations of ICPD47 with 5-FU and ICPD47 with GEM in a ratio of 1:5 showed the greatest effect on tumour spheroid growth in both cell lines. The ICPD47 in combination with mild hyperthermia showed significant results, where the EC50 value in PANC-1 cell line dropped from 4.04 ± 0.046 to 1.68 ± 0.004 µM. The ICPD47 and ICPD62 under the same conditions could act synergistically with GEM, 5-FU and DOX and is worth of further investigations, and studies of synergistic effect is a promising path for more efficient anticancer therapies.

Copper oxide nanoparticles inhibit pancreatic tumor growth primarily by targeting tumor initiating cells

Cancer stem cells, also termed tumor initiating cells (TICs), are a rare population of cells within the tumor mass which initiate tumor growth and metastasis. In pancreatic cancer, TICs significantly contribute to tumor re-growth after therapy, due to their intrinsic resistance. Here we demonstrate that copper oxide nanoparticles (CuO-NPs) are cytotoxic against TIC-enriched PANC1 human pancreatic cancer cell cultures. Specifically, treatment with CuO-NPs decreases cell viability and increases apoptosis in TIC-enriched PANC1 cultures to a greater extent than in standard PANC1 cultures. These effects are associated with increased reactive oxygen species (ROS) levels, and reduced mitochondrial membrane potential. Furthermore, we demonstrate that CuO-NPs inhibit tumor growth in a pancreatic tumor model in mice. Tumors from mice treated with CuO-NPs contain a significantly higher number of apoptotic TICs in comparison to tumors from untreated mice, confirming that CuO-NPs target TICs in vivo. Overall, our findings highlight the potential of using CuO-NPs as a new therapeutic modality for pancreatic cancer.

Abstract 3828: Pritumumab mAb binds cell surface expressed vimentin on pancreatic cancer cells and inhibits tumor growth

Abstract Monoclonal antibodies (mAbs) as therapeutics for cancer have shown some success in the clinic. These biologics are useful if targeting a cancer specific epitope. Cancer patients can generate tumor-specific B lymphocytes which can be isolated to develop human mAbs against tumor-associated antigens. The best source of anti-tumor antibodies is from sentinel lymph nodes. Pritumumab (also referred to as CLNH-11, CLN-IgG, or ACA-11) is a classic example of a natural human anti-cancer antibody. It is a natural human IgG1 kappa antibody developed by the human hybridoma technology, using B lymphocytes isolated from a regional draining lymph node of a patient with cervical carcinoma. In the original patient from whom the B lymphocyte was isolated, the bioavailability of the target antigen induced a natural immune response resulting in the generation of the pritumumab IgG. The target antigen recognized by pritumumab is cell surface expressed vimentin, also referred to as ecto-domain vimentin (EDV). Vimentin is an intracellular cytoskeletal protein overexpressed during epithelial-to-mesenchymal transition (EMT), a process integral to cancer cell metastasis. Pancreatic cancer is a deadly disease with poor prognosis. No more than 6% of pancreatic cancer patients will survive beyond five years after diagnosis. There is a clear unmet need to help improve outcomes for patients. (A) Purpose of the study: to examine if pritumumab mAb can target pancreatic cancer cells and inhibit pancreatic tumor growth. (B) Experimental Procedures: Immunohistochemical analysis with horseradish peroxidase (HRP)-conjugated pritumumab on pancreatic cancer patient tissue sections along with immunofluorescence, flow cytometry, and In-Cell ELISA to demonstrate antibody binding. Antibody-dependent cell-mediated cytoxicity (ADCC) was performed to determine mechanism of action. In vivo subcutaneous xenograft mouse model treated with pritumumab to assess efficacy of the antibody for tumor inhibition. (C) Results: In this study we demonstrate pritumumab binds to the cell surface of patient pancreatic cancer tissue and binds the surface of established pancreatic cancer cells in culture. We show antibody binding to these cells induces antibody-dependent cell-mediated cytoxicity (ADCC). Furthermore, pritumumab effectively inhibits pancreatic tumor growth in a xenograft mouse model. (D) Statement of Conclusions: overall, these data provide pre-clinical validation of pritumumab mAb as a therapeutic for pancreatic cancer. Citation Format: Ivan Babic, Natsuko Nomura, Eric Glassy, Elmar Nurmemmedov, Venkata Yenugonda, Mark Glassy, Santosh Kesari. Pritumumab mAb binds cell surface expressed vimentin on pancreatic cancer cells and inhibits tumor growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 3828.

Molecular causes of elevated phosphoethanolamine in breast and pancreatic cancer cells.

Elevated phosphoethanolamine (PE) is frequently observed in MRS studies of human cancers and xenografts. The role of PE in cell survival and the molecular causes underlying this increase are, however, relatively underexplored. In this study, we investigated the roles of ethanolamine kinases (Etnk-1 and 2) and choline kinases (Chk-α and β) in contributing to increased PE in human breast and pancreatic cancer cells. We investigated the effect of silencing Etnk-1 and Etnk-2 on cell viability as a potential therapeutic strategy. Both breast and pancreatic cancer cells showed higher PE compared with their nonmalignant counterparts. We identified Etnk-1 as a major cause of the elevated PE levels in these cancer cells, with little or no contribution from Chk-α, Chk-β, or Etnk-2. The increase of PE observed in pancreatic cancer cells in culture was replicated in the corresponding tumor xenografts. Downregulation of Etnk-1 with siRNA resulted in cell cytotoxicity that correlated with PE levels in breast and pancreatic cancer cells. Etnk-1 may provide a potential therapeutic target in breast and pancreatic cancers.