[Retracted] Sulforaphane sensitizes human cholangiocarcinoma to cisplatin via the downregulation of anti‑apoptotic proteins

Following the publication of the above article and a corrigendum that was published in October 2023 to address the issue of misplaced control β‑actin western blots comparing between Figs. 3 and 4A (doi: 10.3892/or.2023.8646), an attentive reader drew to the authors' attention that the first author had apparently made additional unreported corrections to the revised version of Fig. 4 presented in the corrigendum. Although these image discrepancies did not alter the study's primary conclusions, they were such that they did cast doubt on the data's integrity. Consequently, the authors have decided to retract the paper and the Editor of Oncology Reports has agreed to the authors' request. The authors deeply regret any confusion or inconvenience this retraction may cause, and offer their sincere apologies to the Editor of Oncology Reports and the readership. [Oncology Reports 37: 3660‑3666, 2017; DOI: 10.3892/or.2017.5622].

Multi-Algorithm Analysis Reveals Pyroptosis-Linked Genes as Pancreatic Cancer Biomarkers

Pancreatic ductal adenocarcinoma (PDAC) is often diagnosed at late stages, limiting treatment options and survival rates. Pyroptosis-related gene signatures hold promise as PDAC prognostic markers, but limited gene pools and small sample sizes hinder their utility. We aimed to enhance PDAC prognosis with a comprehensive multi-algorithm analysis. Using R, we employed natural language processing and latent Dirichlet allocation on PubMed publications to identify pyroptosis-related genes. We collected PDAC transcriptome data (n = 1273) from various databases, conducted a meta-analysis, and performed differential gene expression analysis on tumour and non-cancerous tissues. Cox and LASSO algorithms were used for survival modelling, resulting in a pyroptosis-related gene expression-based prognostic index. Laboratory and external validations were conducted. Bibliometric analysis revealed that pyroptosis publications focus on signalling pathways, disease correlation, and prognosis. We identified 357 pyroptosis-related genes, validating the significance of BHLHE40, IL18, BIRC3, and APOL1. Elevated expression of these genes strongly correlated with poor PDAC prognosis and guided treatment strategies. Our accessible nomogram model aids in PDAC prognosis and treatment decisions. We established an improved gene signature for pyroptosis-related genes, offering a novel model and nomogram for enhanced PDAC prognosis.

[Corrigendum] Sulforaphane sensitizes human cholangiocarcinoma to cisplatin via the downregulation of anti‑apoptotic proteins

Following the publication of this article, an interested reader drew to the authors' attention that, in Figs. 3 and 4A on p. 3664, the respective β‑actin controls for the cell lines TFK‑1 and HuCCT‑1 appeared to have mixed up, comparing the western blots between the two figures. After re‑examining their data, the authors have realized that the control blots in Fig. 4A were inadvertently presented the wrong way around. The corrected version of Fig. 4, showing the correctly presented western blotting data in Fig. 4A, is shown on the next page. Note that this error did not grossly affect the results or the conclusions reported in this paper. The authors sincerely apologize for the error that was introduced during the preparation of this figure, and thank the Editor of Oncology Reports for allowing them the opportunity to publish a corrigendum. Furthermore, they regret any inconvenience caused to the readership. [Oncology Reports 37: 3660‑3666, 2017; DOI: 10.3892/or.2017.5622].

[Corrigendum] Establishment of hypoxia induction in an in vivo animal replacement model for experimental evaluation of pancreatic cancer

Subsequently to the publication of the above paper, an interested reader drew to the authors' attention that, on p. 156, the data panels shown to represent the 'CoCl2' and 'TRIP' data panels in Fig. 3 for the DAPI experiments were apparently the same, even though different experiments were being depicted here.  The authors were able to re‑examine their original data files, and realized that this figure had been assembled incorrectly: there was an inadvertent mix‑up of a pair of the DAPI control images. The revised version of Fig. 3, containing the correct DAPI data for the 'TRIP' experiment, is shown opposite. Note that the revisions made to this figure do not affect the overall conclusions reported in the paper. The authors are grateful to the Editor of Oncology Reports for allowing them the opportunity to publish this Corrigendum, and apologize to the readership for any inconvenience caused. [Oncology Reports 32: 153‑158, 2014; DOI: 10.3892/or.2014.3196].

[Corrigendum] Dexamethasone-induced inhibition of miR-132 via methylation promotes TGF-β-driven progression of pancreatic cancer

Subsequently to the publication of the above article, an interested reader drew to the authors' attention that two pairs of the culture plate images in Fig. 4A-C on p. 60 appeared to be the same, although the images were shown in different orientations; moreover, the 'NC/0 and DEX+miR132' and 'DEX and miR132' pairings of images in the scratch-wound assay experiments shown in Fig. 4B also appeared to be overlapping, such that these were apparently derived from the same original source where the results of differently performed experiments were intended to have been portrayed. After re‑examining their original data, the authors have realized that some of the data in Fig. 4A and B were inadvertently assembled incorrectly. The revised version of Fig. 4, showing all the correct data for the culture plate images in Fig. 4A-C (specifically, the images fifth along on the right for Fig. 4B and C have been revised) and the correct images for 'NC/0' and 'DEX/0' in Fig. 4D is shown on on the next page. The authors are grateful to the Editor of International Journal of Oncology for allowing them this opportunity to publish a Corrigendum, and all the authors agree with its publication. Furthermore, the authors apologize to the readership for any inconvenience caused. [International Journal of Oncology 54: 53‑64, 2019; DOI: 10.3892/ijo.2018.4616].

Corrigendum: Sulforaphane promotes dendritic cell stimulatory capacity through modulation of regulatory molecules, JAK/STAT3- and microRNA-signaling

[This corrects the article DOI: 10.3389/fimmu.2020.589818.].

Tumor and stroma COL8A1 secretion induces autocrine and paracrine progression signaling in pancreatic ductal adenocarcinoma

Several collagen subtypes are involved in pancreatic ductal adenocarcinoma (PDAC) desmoplasia, which constrains therapeutic efficacy. We evaluated collagen type VIII alpha 1 chain (COL8A1), whose function in PDAC is currently unknown. We identified COL8A1 expression in 7 examined PDAC cell lines by microarray analysis, western blotting, and RT‒qPCR. Higher COL8A1 expression occurred in 2 gemcitabine-resistant PDAC cell lines; pancreas tissue (n=15) from LSL-Kras^G12D/+; p48-Cre mice with advanced PDAC predisposition; and PDAC parenchyma and stroma of a patient tissue microarray (n=82). Bioinformatic analysis confirmed higher COL8A1 expression in PDAC patient tissue available from TCGA (n=183), GTEx (n=167), and GEO (n=261) databases. siRNA or lentiviral sh-mediated COL8A1 inhibition in PDAC cells reduced migration, invasion and gemcitabine resistance and resulted in lower cytidine deaminase and thymidine kinase 2 expression and was rescued by COL8A1-secreting cancer-associated fibroblasts (CAFs). The activation of COL8A1 expression involved cJun/AP-1, as demonstrated by CHIP assay and siRNA inhibition. Downstream of COL8A1, activation of ITGB1 and DDR1 receptors and PI3K/AKT and NF-κB signaling occurred, as detected by expression, adhesion and EMSA binding studies. Orthotopic transplantation of PDAC cells with downregulated COL8A1 expression resulted in reduced tumor xenograft growth and lower gemcitabine resistance but was prevented by cotransplantation of COL8A1-secreting CAFs. Most importantly, COL8A1 expression in PDAC patient tissues from our clinic (n=84) correlated with clinicopathological data, and we confirmed these findings by the use of patient data (n=177) from the TCGA database. These findings highlight COL8A1 expression in tumor and stromal cells as a new biomarker for PDAC progression.

Sulforaphane has an additive anticancer effect to FOLFOX in highly metastatic human colon carcinoma cells

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Patients with CRC may need chemotherapy (CTx) in a neoadjuvant, adjuvant or palliative setting through the course of the disease. Unfortunately, its effect is limited by chemoresistance and chemotoxicity. Novel more effective and non‑toxic CTx regimens are needed to further improve CRC treatment outcomes. Thus, the present study was designed to test the hypothesis that non‑toxic sulforaphane (SF) is effective against CRC and has additive effects in combination with conventional 5‑fluorouracil, oxaliplatin and folinic acid (FOLFOX) CTx in vitro. Highly metastatic human colon cancer cells, CX‑1, and fibroblasts were treated with FOLFOX ± SF. Cell viability was assessed using an MTT assay. The level of apoptosis and the expression of apoptotic proteins were measured by TUNEL assay and quantitative PCR analysis. Aldehyde dehydrogenase isoform 1 (ALDH1) and multidrug resistance protein 2 (MRP2) levels were evaluated. The ability of cells to form spheroids was measured in three‑dimensional cell culture. SF alone and in combination with FOLFOX effectively decreased the viability of the CX‑1 cells, promoted apoptosis within the CX‑1 cells, prevented cellular spheroid formation and decreased ALDH1 activity. However, SF promoted MRP2 expression and protein levels. In conclusion, SF together with conventional FOLFOX has additive anticancer effects against highly metastatic human CRC in vitro.

Nanosilver inhibits the progression of pancreatic cancer by inducing a paraptosis-like mixed type of cell death

Silver has been in clinical use since ancient times and silver nanoparticles (AgNPs) have attracted attention in cancer therapy. We investigated the mechanisms by which AgNPs inhibit pancreatic ductal adenocarcinoma (PDAC). AgNPs were synthesized and 3 human PDAC and 2 nonmalignant primary cell lines were treated with AgNPs. MTT, MAPK, colony, spheroid and scratch assays, Western blotting, TEM, annexin V, 7-AAD, and H2DCFDA staining, FACS analysis, mRNA array and bioinformatics analyses, tumor xenograft transplantation, and immunohistochemistry of the treated cells were performed. We found that minimal AgNPs amounts selectively eradicated PDAC cells within a few hours. AgNPs inhibited cell migration and spheroid and colony formation, damaged mitochondria, and induced paraptosis-like cell death with the presence of cytoplasmic vacuoles, dilation of the ER and mitochondria, ROS formation, MAPK activity, and p62 and LC3b expression, whereas effects on the nucleus, DNA fragmentation, or caspases were not detectable. AgNPs strongly decreased tumor xenograft growth without side effects and reduced the expression of markers for proliferation and DNA repair, but upregulated paraptosis markers. The results highlight nanosilver as complementary agent to improve the therapeutic efficacy in pancreatic cancer.

Toward 3D-bioprinting of an endocrine pancreas: A building-block concept for bioartificial insulin-secreting tissue

Three-dimensional bioprinting of an endocrine pancreas is a promising future curative treatment for patients with insulin secretion deficiency. In this study, we present an end-to-end concept from the molecular to the macroscopic level. Building-blocks for a hybrid scaffold device of hydrogel and functionalized polycaprolactone were manufactured by 3D-(bio)printing. Pseudoislet formation from INS-1 cells after bioprinting resulted in a viable and proliferative experimental model. Transcriptomics showed an upregulation of proliferative and ß-cell-specific signaling cascades, downregulation of apoptotic pathways, overexpression of extracellular matrix proteins, and VEGF induced by pseudoislet formation and 3D-culture. Co-culture with endothelial cells created a natural cellular niche with enhanced insulin secretion after glucose stimulation. Survival and function of pseudoislets after explantation and extensive scaffold vascularization of both hydrogel and heparinized polycaprolactone were demonstrated in vivo. Computer simulations of oxygen, glucose and insulin flows were used to evaluate scaffold architectures and Langerhans islets at a future perivascular transplantation site.

Machine-Learning-Based Bibliometric Analysis of Pancreatic Cancer Research Over the Past 25 Years

Machine learning and semantic analysis are computer-based methods to evaluate complex relationships and predict future perspectives. We used these technologies to define recent, current and future topics in pancreatic cancer research. Publications indexed under the Medical Subject Headings (MeSH) term 'Pancreatic Neoplasms' from January 1996 to October 2021 were downloaded from PubMed. Using the statistical computing language R and the interpreted, high-level, general-purpose programming language Python, we extracted publication dates, geographic information, and abstracts from each publication's metadata for bibliometric analyses. The generative statistical algorithm "latent Dirichlet allocation" (LDA) was applied to identify specific research topics and trends. The unsupervised "Louvain algorithm" was used to establish a network to identify relationships between single topics. A total of 60,296 publications were identified and analyzed. The publications were derived from 133 countries, mostly from the Northern Hemisphere. For the term "pancreatic cancer research", 12,058 MeSH terms appeared 1,395,060 times. Among them, we identified the four main topics "Clinical Manifestation and Diagnosis", "Review and Management", "Treatment Studies", and "Basic Research". The number of publications has increased rapidly during the past 25 years. Based on the number of publications, the algorithm predicted that "Immunotherapy", Prognostic research", "Protein expression", "Case reports", "Gemcitabine and mechanism", "Clinical study of gemcitabine", "Operation and postoperation", "Chemotherapy and resection", and "Review and management" as current research topics. To our knowledge, this is the first study on this subject of pancreatic cancer research, which has become possible due to the improvement of algorithms and hardware.

UHMK1 Is a Novel Marker for Personalized Prediction of Pancreatic Cancer Prognosis

Pancreatic ductal adenocarcinoma (PDAC) is among the leading causes of cancer mortality, and new therapeutic options are urgently needed. Long noncoding RNA H19 (H19) is known to promote PDAC progression, but the downstream genes of H19 are largely unknown. Five PDAC cell lines, nonmalignant pancreatic cells, TCGA, GEO-derived pancreatic tissues (malignant, n=413; nonmalignant, n=234), a pancreatic tissue array (n=96), and pancreatic tissues from our clinic (malignant, n=20; nonmalignant, n=20) were examined by a gene array, RT-qPCR, Western blotting, MTT, colony formation, wound-healing, siRNA-mediated gene silencing, bioinformatics, xenotransplantation, and immunohistochemistry assays. The cell cycle inhibitor, UHMK1, was identified to have the strongest correlation with H19. UHMK1 expression was enhanced in PDAC, and high UHMK1 expression correlated with tumor stage, and lower overall survival. siRNA-mediated UHMK1 downregulation inhibited progression signaling. siRNA-mediated downregulation of H19 or UHMK1 inhibited tumor proliferation and xenograft growth. Based on the correlation between UHMK1 expression and clinical parameters, we developed a nomogram that reliably predicts patient prognosis and overall survival. Together, we characterized UHMK1 as an H19-induced oncogene and verified it as a novel PDAC prognostic marker for overall survival.

Sulforaphane Targets TRA-1/GLI Upstream of DAF-16/FOXO to Promote C. elegans Longevity and Healthspan

Broccoli-derived isothiocyanate sulforaphane inhibits inflammation and cancer. Sulforaphane may support healthy aging, but the underlying detailed mechanisms are unclear. We used the C. elegans nematode model to address this question. Wild-type and 4 mutant C. elegans worm strains were fed in the presence or absence of sulforaphane and E. coli food bacteria transfected with RNA interference gene constructs. Kaplan-Meier survival analysis, live imaging of mobility and pharyngeal pumping, fluorescence microscopy, RT-qPCR, and Western blotting were performed. In the wild type, sulforaphane prolonged lifespan and increased mobility and food intake because of sulforaphane-induced upregulation of the sex-determination transcription factor TRA-1, which is the ortholog of the human GLI mediator of sonic hedgehog signaling. In turn, the tra-1 target gene daf-16, which is the ortholog of human FOXO and the major mediator of insulin/IGF-1 and aging signaling, was induced. By contrast, sulforaphane did not prolong lifespan and healthspan when tra-1 or daf-16 was inhibited by RNA interference or when worms with a loss-of-function mutation of the tra-1 or daf-16 genes were used. Conversely, the average lifespan of C. elegans with hyperactive TRA-1 increased by 8.9%, but this longer survival was abolished by RNAi-mediated inhibition of daf-16. Our data suggest the involvement of sulforaphane in regulating healthy aging and prolonging lifespan by inducing the expression and nuclear translocation of TRA-1/GLI and its downstream target DAF-16/FOXO.

Establishment of Tumor Treating Fields Combined With Mild Hyperthermia as Novel Supporting Therapy for Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with poor prognosis and limited therapeutic options. Alternating electrical fields with low intensity called "Tumor Treating Fields" (TTFields) are a new, non-invasive approach with almost no side effects and phase 3 trials are ongoing in advanced PDAC. We evaluated TTFields in combination with mild hyperthermia. Three established human PDAC cell lines and an immortalized pancreatic duct cell line were treated with TTFields and hyperthermia at 38.5°C, followed by microscopy, assays for MTT, migration, colony and sphere formation, RT-qPCR, FACS, Western blot, microarray and bioinformatics, and in silico analysis using the online databases GSEA, KEGG, Cytoscape-String, and Kaplan-Meier Plotter. Whereas TTFields and hyperthermia alone had weak effects, their combination strongly inhibited the viability of malignant, but not those of nonmalignant cells. Progression features and the cell cycle were impaired, and autophagy was induced. The identified target genes were key players in autophagy, the cell cycle and DNA repair. The expression profiles of part of these target genes were significantly involved in the survival of PDAC patients. In conclusion, the combination of TTFields with mild hyperthermia results in greater efficacy without increased toxicity and could be easily clinically approved as supporting therapy.

Alpha-Lipoic Acid Prevents Side Effects of Therapeutic Nanosilver without Compromising Cytotoxicity in Experimental Pancreatic Cancer

Silver nanoparticles (AgNPs) have attracted attention in cancer therapy and might support the treatment of pancreatic ductal adenocarcinoma (PDAC). Silver is in clinical use in wound dressings, catheters, stents and implants. However, the side effects of systemic AgNP treatment due to silver accumulation limit its therapeutic application. We evaluated whether the antioxidant and natural agent α-lipoic acid might prevent these side effects. We synthesized AgNPs using an Ionic-Pulser® Pro silver generator and determined the concentration by inductively coupled plasma-optical emission spectrometry. The effect of α-lipoic acid was examined in four PDAC and two nonmalignant cell lines by MTT, FACS analysis, TEM, xenotransplantation and immunohistochemistry. The viability of PDAC cells was nearly totally abolished by AgNP treatment, whereas nonmalignant cells largely resisted. α-Lipoic acid prevented AgNP-induced cytotoxicity in nonmalignant cells but not in PDAC cells, which might be due to the higher sensitivity of malignant cells to silver-induced cytotoxicity. α-Lipoic acid protected mitochondria from AgNP-induced damage and led to precipitation of AgNPs. AgNPs reduced the growth of tumor xenografts, and cotreatment with α-lipoic acid protected chick embryos from AgNP-induced liver damage. Together, α-lipoic acid strongly reduced AgNP-induced side effects without weakening the therapeutic efficacy.

Combining forces to hit cancer stem cells: TRAIL-lymphocytes and EpCAMxCD3 bispecific antibody show efficacy against pancreatic cancer

TRAIL selectively kills cancer cells while bispecific antibody EpCAMxCD3 guides effector lymphocytes to cancer cells. Arming of ex vivo constructed TRAIL-lymphocytes with EpCAMxCD3 enhances contact time and affinity between lymphocytes and tumor cells and enforces tumor elimination. This boosts endogenous immune responses and augments the effect of cytotoxic tumor therapy.

Sulforaphane promotes C. elegans longevity and healthspan via DAF-16/DAF-2 insulin/IGF-1 signaling

The broccoli-derived isothiocyanate sulforaphane inhibits inflammation, oxidative stress and cancer, but its effect on healthspan and longevity are unclear. We used the C. elegans nematode model and fed the wildtype and 9 mutant strains ±sulforaphane. The lifespan, phenotype, pharyngeal pumping, mobility, lipofuscin accumulation, and RNA and protein expression of the nematodes were assessed by using Kaplan-Meier survival analysis, in vivo live imaging, fluorescence microscopy, and qRT-PCR. Sulforaphane increased the lifespan and promoted a health-related phenotype by increasing mobility, appetite and food intake and reducing lipofuscin accumulation. Mechanistically, sulforaphane inhibited DAF-2-mediated insulin/insulin-like growth factor signaling and its downstream targets AGE-1, AKT-1/AKT-2. This was associated with increased nuclear translocation of the FOXO transcription factor homolog DAF-16. In turn, the target genes sod-3, mtl-1 and gst-4, known to enhance stress resistance and lifespan, were upregulated. These results indicate that sulforaphane prolongs the lifespan and healthspan of C. elegans through insulin/IGF-1 signaling. Our results provide the basis for a nutritional sulforaphane-enriched strategy for the promotion of healthy aging and disease prevention.

Sulforaphane Promotes Dendritic Cell Stimulatory Capacity Through Modulation of Regulatory Molecules, JAK/STAT3- and MicroRNA-Signaling

Introduction

The broccoli isothiocyanate sulforaphane was shown to inhibit inflammation and tumor progression, also in pancreatic cancer, while its effect on tumor immunity is poorly understood. We investigated the immunoregulatory effect of sulforaphane on human dendritic cells alone and in presence of pancreatic tumor antigens, as well as underlying molecular mechanisms.

Methods

Sulforaphane-treated human dendritic cells were matured in vitro with a cytokine cocktail, and the expression of regulatory molecules was examined by flow cytometry. The subsequent T-cell response was analyzed by T-cell proliferation assay and CD25 expression. To confirm the findings, dendritic cells pulsed with pancreatic cancer-derived tumor antigens were used. To identify the involved pathway- and microRNA-signaling in sulforaphane-treated dendritic cells, inhibitors of various signaling pathways, western blot analysis, microRNA array, and bioinformatic analysis were applied.

Results

Sulforaphane modulated the expression of the costimulatory CD80, CD83 and the suppressive B7-H1 molecules on dendritic cells and thereby promoted activation of T cells. The effect was verified in presence of pancreatic tumor antigens. Phosphorylation of STAT3 in dendritic cells was diminished by sulforaphane, and the inhibition of JAK/STAT3 led to downregulation of B7-H1 expression. Among the identified top 100 significant microRNA candidates, the inhibition of miR-155-5p, important for the expression of costimulatory molecules, and the induction of miR-194-5p, targeting the B7-H1 gene, were induced by sulforaphane.

Conclusion

Our findings demonstrate that sulforaphane promotes T-cell activation by dendritic cells through the modulation of regulatory molecules, JAK/STAT3- and microRNA-signaling in healthy conditions and in context of pancreatic cancer-derived antigens. They explore the immunoregulatory properties of sulforaphane and justify further research on nutritional strategies in the co-treatment of cancer.

Broccoli sprout supplementation in patients with advanced pancreatic cancer is difficult despite positive effects-results from the POUDER pilot study

Pancreatic ductal adenocarcinoma is a highly aggressive malignancy with short survival and limited therapeutic options. Broccoli sulforaphane is a promising new treatment due to the results of recent epidemiological, experimental and patient studies. Upon approval from the ethics committee and registration at ClinicalTrials.gov, 40 patients with palliative chemotherapy were placed into a placebo and treatment group in an unblinded fashion. Fifteen capsules with pulverized broccoli sprouts containing 90 mg/508 μmol sulforaphane and 180 mg/411 μmol glucoraphanin or methylcellulose were administered daily for up to 1 year. Twenty-nine patients were included in the treatment group and 11 patients were in the placebo group; these patients were followed for up to 1 year. The patient characteristics, overall survival and feasibility were assessed. Compared to those of the placebo group, the mean death rate was lower in the treatment group during the first 6 months after intake (day 30: 0%/18%, day 90: 0%/25%, and day 180: 25%/43%), and Kaplan-Meier analysis revealed a higher survival rate. There was a high drop-out rate (72% in the treatment group and 55% in the placebo group) after 1 year. We concluded from the Karnofsky index that the broccoli sprouts did not impact patient's self-care and overall abilities severely. The intake of 15 capsules daily was difficult for some patients, and the broccoli sprouts sometimes increased digestive problems, nausea and emesis. We did not obtain statistically significant results (p = 0.291 for the endpoint at day 180), but the knowledge about the feasibility is the basis for the development of new sulforaphane drugs.

Novel Broccoli Sulforaphane-Based Analogues Inhibit the Progression of Pancreatic Cancer without Side Effects

The naturally occurring isothiocyanate sulforaphane, found in Brassicaceae vegetables, is promising in cancer treatment, e.g., by the normalization of enhanced levels of NF-κB-signaling in tumor stem cells. We chemically synthesized seven sulforaphane analogues by substitution of the sulfinyl group (S(O)) to either sulfimidoyl (S(NR)) or sulfonimidoyl (S (O) (NR)) groups, and characterized them in the cell lines of pancreatic cancer and several other tumor entities, including the NCI-60 cell panel. MTT and colony forming assays, flow cytometry, immunohistochemistry, microRNA arrays, bioinformatics, tumor xenotransplantation, and Kaplan Meier survival curves were performed. Compared to sulforaphane, the analogue SF102 was most efficient in inhibition of viability, colony formation, tumor growth, and the induction of apoptosis, followed by SF134. Side effects were not observed, as concluded from the body weight and liver histology of chick embryos and survival of C. elegans nematodes. Among 6659 differentially regulated microRNAs, miR29b-1-5p, and miR-27b-5p were downregulated by sulforaphane compared to controls, but upregulated by SF102 and SF134 compared to sulforaphane, suggesting differential signaling. Each substance was involved in the regulation of several NF-κB-related target genes. In conclusion, sulforaphane analogues are promising for the development of highly active new drugs in cancer treatment.

Novel plant microRNAs from broccoletti sprouts do not show cross-kingdom regulation of pancreatic cancer

Food-derived plant microRNAs are suggested to control human genes by “cross-kingdom” regulation. We examined microRNAs in sprouts from Brassica rapa sylvestris, known as broccoletti, which are widely used as sulforaphane supplements, and assessed their influence on pancreatic cancer. RNA was isolated from 4-day-old sprouts, followed by deep sequencing and bioinformatic analysis. We identified 2 new and 745 known plant microRNA sequences in the miRbase database and predicted 15,494 human target genes and 76,747 putative 3′-UTR binding sites in these target genes. The most promising candidates were the already known microRNA sequence bra-miR156g-5p and the new sequence Myseq-330, both with predicted human target genes related to apoptosis. The overexpression of the respective oligonucleotides by lipofection did not alter the viability, apoptosis, clonogenicity, migration or associated protein expression patterns in pancreatic cancer cells. These data demonstrate that broccoletti sprouts contain microRNA sequences with putative binding sites in human genes, but the sequences evaluated here did not affect cancer growth. Our database of broccoletti-derived microRNA sequences provides a valuable tool for future analysis.

Sulforaphane Induces miR135b-5p and Its Target Gene, RASAL2, thereby Inhibiting the Progression of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDA) is one of the most lethal tumors, with poor therapeutic options in the advanced state. The broccoli-derived anti-inflammatory agent sulforaphane was shown to inhibit the progression of pancreatic cancer and other tumor entities. We examined the involvement of pancreatic cancer cell lines were evaluated by microRNA and gene expression arrays, bioinformatics, in silico analysis, qRT-PCR, western blotting, immunohistochemistry, in situ hybridization, self-renewal and differentiation assays, and in vivo xenograft studies. We selected the top nine differentially expressed microRNAs, and miR135b-5p was chosen as the most important candidate for the sulforaphane-induced upregulation of the tumor suppressor gene RASAL2. The expression of miR135b-5p and RASAL2 was almost absent in malignant pancreatic tissues and cell lines, but not in their normal counterparts. Lipofection of miR135b-5p enhanced RASAL2 expression and inhibited ERK1/2 signaling, viability, self-renewal capacity, and tumor growth. These results indicate that miR135b-5p acts as a tumor suppressor via the induction of RASAL2 in PDA.

Abstract P1-09-14: Demographic, clinical/disease characteristics, and treatment of patients with germline mutated metastatic breast cancer: A CancerLinQ study

Objective: To describe the demographics, clinical/disease characteristics and treatment patterns of patients with germline BRCA mutated (gBRCAm) metastatic breast cancer (mBC) as compared to those with gBRCA wild type (wt) and those who are untested for gBRCA mutations.

Methods: The CancerlinQ Discovery Database (CLQ), launched by the American Society of Clinical Oncology (ASCO) in 2016, consists of longitudinal, demographic and geographic diverse data aggregated from oncology practice electronic health record (EHR) databases. Natural language processing and technology-enabled curation are utilized to identify records of most interest, followed by manual curation to abstract information from unstructured EHR fields. This cohort consists of 7,889 patients diagnosed with mBC between 1982 and 2018, and is enriched for patients with gBRCA testing through the curation process.

Results: Overall most patients were female (99.0%), white (55.3%), and the median age at mBC diagnosis was 63 years (yrs). The majority were not tested for gBRCA mutation (88.4%); 2.0% were gBRCAm, 9.2% were gBRCAwt, 0.4% had an undetermined test result, and 0.1% had a variant of unknown significance. Among those tested for estrogen-receptor (ER) (n=6,700) and progesterone-receptor (PR) (n=6,737) status, 76.6% were ER positive (+) and 62.2% were PR+. Among those tested for human epidermal growth factor receptor 2 (HER2) (n=6,696), 21.7% were HER2+. Among those with known results for ER, PR, and HER2 (n=6,063), 10.1% were hormone receptor (HR)+/HER2+, 10.6% were HR negative (-)/HER2+, 65.0% were HR+/HER2-, and 14.3% were HR-/HER2-. The median age at mBC diagnosis was 50 yrs for gBRCAm, 51 yrs for gBRCAwt and 64 yrs among the gBRCA untested group. A similar proportion of patients were diagnosed with metastatic disease among the gBRCAm and gBRCAwt groups (25.3% and 20.3%, respectively), while the proportion was higher among the gBRCA untested group (38.0 %). The most common site of metastasis for all groups was bone (35.1% for gBRCAm, 41.7% for gBRCAwt, and 36.5 % for gBRCA untested), followed by liver (16.2% for gBRCAm, 13.3% for gBRCAwt, and 8.5% for gBRCA untested). The most common first-line therapies for gBRCAm patients were tamoxifen (7.7%), letrozole (7.0%), cyclophosphamide+doxorubicin (6.3%), and paclitaxel (6.3%); for gBRCAwt patients they were cyclophosphamide+doxorubicin (6.6%), paclitaxel (6.4%), and tamoxifen (6.4%); and for gBRCA untested patients they were letrozole (11.1%), fulvestrant (9.3%), and tamoxifen (4.6%). The mean number of lines of therapy (including lines of chemotherapy and hormone therapy) were 3.5, 3.8, and 3.4 for the gBRCAm, gBRCAwt, and gBRCA untested groups, respectively.

Conclusions: Patients with gBRCAm were younger than the gBRCA untested group, and more patients had metastatic disease at diagnosis in the gBRCA untested group. Further analyses accounting for HR and HER2 status will be conducted and presented. This is the first example of research using curated breast cancer data from ASCO's CLQ.

Citation Format: Dalvi T, Herr I, Maclachlan S, Briceno J, Bennett J, McLaurin K, Hettle R, McCutcheon S. Demographic, clinical/disease characteristics, and treatment of patients with germline mutated metastatic breast cancer: A CancerLinQ study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-09-14.

Dexamethasone-induced inhibition of miR-132 via methylation promotes TGF-β-driven progression of pancreatic cancer

Glucocorticoids (GCs) such as dexamethasone (DEX) are administered as cancer co-treatment for palliative purposes due to their pro-apoptotic effects in lymphoid cancer and limited side effects associated with cancer growth and chemotherapy. However, there is emerging evidence that GCs induce therapy resistance in most epithelial tumors. Our recent data reveal that DEX promotes the progression of pancreatic ductal adenocarcinoma (PDA). In the present study, we examined 1 primary and 2 established PDA cell lines, and 35 PDA tissues from patients who had received (n=14) or not received (n=21) GCs prior to surgery. Through microRNA microarray analysis, in silico, and RT-qPCR analyses, we identified 268 microRNAs differentially expressed between DEX-treated and untreated cells. With a focus on cancer progression, we selected miR-132 and its target gene, transforming growth factor-β2 (TGF-β2), as top candidates. miR-132 mimics directly bound to the 3′ untranslated region (3′UTR) of a TGF-β2 luciferase construct and enhanced expression, as shown by increased luciferase activity. By contrast, DEX inhibited miR-132 expression via promoter methylation. miR-132 mimics also reduced DEX-induced clonogenicity, migration and expression of vimentin and E-cadherin in vitro and in tumor xenografts. In patients, GC intake prior to surgery enhanced global hypermethylation and expression of TGF-β2 in tissues; expression of miR-132 was detected but could not be quantified. Our results demonstrate that DEX-mediated inhibition of miR-132 is a key mediator in the progression of pancreatic cancer, and the findings provide a foundation for miRNA-based therapies.

Simvastatin inhibits sonic hedgehog signaling and stemness features of pancreatic cancer

Pancreatic ductal adenocarcinoma (PDA) has poor therapeutic options. Recent patient studies indicate that cholesterol-lowering statins have anti-tumor capacities. We examined several established and primary PDA and normal cell lines as well as PDA patient tissues (n = 68). We found that simvastatin inhibited viability, stemness, tumor growth and metastasis and that it enhanced the efficacy of gemcitabine. These changes were associated with modulation of Shh-related gene expression. Overexpression of Shh prevented the anti-cancer effect of simvastatin, and inhibition of Shh mimicked the simvastatin effect. In PDA tissues, expression levels of Shh, downstream mediators of Shh and progression markers, namely, cMet, CxCR4 and Vimentin, were lower when patients were prescribed statin medication prior to surgery. These results suggested that statins are cost effective and well-tolerated drugs for prevention and co-treatment of PDA.

Intraductal papillary mucinous neoplasm of the pancreas rapidly xenografts in chicken eggs and predicts aggressiveness

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas has a high risk of progressing to invasive pancreatic ductal adenocarcinoma (PDA), but experimental models for IPMN are largely missing. New experimental systems for the molecular characterization of IPMN and for personalized prognosis and treatment options for IPMN are urgently needed. We analyzed the potential use of fertilized chicken eggs for the culture of freshly resected IPMN tissue. We transplanted 49 freshly resected IPMN tissues into eggs and compared the growth characteristics to IPMN tissues transplanted into mice; this was followed by an analysis of histology, morphology, and marker expression. Of the IPMN tissues transplanted into eggs, 63% formed tumor xenografts within 4 days, while none of the 12 IPMN tissues transplanted into immunodeficient mice engrafted. In the eggs, the grafting efficiency of high-grade (n = 14) and intermediate-grade (n = 17) dysplasia was 77% and was significantly higher than the 39% grafting efficiency of low-grade dysplasia (n = 18). According to mucinous expression, 46 IPMN tissues were classified into gastric (n = 6), intestinal (n = 3), oncocytic (n = 23), and pancreatobiliary (n = 14) subtypes. The grafting efficiency was highest for the pancreatobiliary subtype (86%), followed by the oncocytic (70%), gastric (33%) and intestinal (33%) subtypes. The morphology and expression patterns of mucins, progression markers and pancreatic ductal markers were comparable between the primary IPMN tissues and their xenograft copies. The individual tumor environment was largely maintained during subtransplantation, as evaluated upon passage 6. This new IPMN model may facilitate experimental studies and treatment decisions for the optimal personalized management of IPMN.

Dexamethasone mediates pancreatic cancer progression by glucocorticoid receptor, TGFβ and JNK/AP-1

Glucocorticoids such as dexamethasone are widely co-prescribed with cytotoxic therapy because of their proapoptotic effects in lymphoid cancer, reduction of inflammation and edema and additional benefits. Concerns about glucocorticoid-induced therapy resistance, enhanced metastasis and reduced survival of patients are largely not considered. We analyzed dexamethasone-induced tumor progression in three established and one primary human pancreatic ductal adenocarcinoma (PDA) cell lines and in PDA tissue from patients and xenografts by FACS and western blot analysis, immunohistochemistry, MTT and wound assay, colony and spheroid formation, EMSA and in vivo tumor growth and metastasis of tumor xenografts on chicken eggs and mice. Dexamethasone in concentrations observed in plasma of patients favored epithelial–mesenchymal transition, self-renewal potential and cancer progression. Ras/JNK signaling, enhanced expression of TGFβ, vimentin, Notch-1 and SOX-2 and the inhibition of E-cadherin occurred. This was confirmed in patient and xenograft tissue, where dexamethasone induced tumor proliferation, gemcitabine resistance and metastasis. Inhibition of each TGFβ receptor-I, glucocorticoid receptor or JNK signaling partially reversed the dexamethasone-mediated effects, suggesting a complex signaling network. These data reveal that dexamethasone mediates progression by membrane effects and binding to glucocorticoid receptor.

MiR-127 and miR-376a act as tumor suppressors by in vivo targeting of COA1 and PDIA6 in giant cell tumor of bone

Giant cell tumors of bone (GCTB) are generally benign bone tumors associated with expansive osteolytic defects, a high rate of recurrence and potential malignant transformation. We recently observed silencing of miR-127-3p and miR-376a-3p in GCTB and identified COA1 and PDIA6 as their target genes. Here, we investigate the impact of these microRNAs and their target genes on tumor engraftment and progression of giant cell tumor stromal cells (GCTSC) in vivo by xenotransplantation on the chorioallantoic membrane of chicken eggs. Prior to transplantation, the neoplastic GCTSCs were transfected with miRNA mimics or siRNAs directed against their target genes. Restoration of miR-127-3p and miR-376a-3p reduced the tumor take rate to 17% and 47% compared to 95% in the controls. The tumor volumes were significantly reduced to 29% by both miRNAs. Silencing of COA1 and PDIA6 significantly decreased the tumor volumes to 37.7% and 42.7%, while the tumor take rates remained stable. Our results indicate that re-expression of miR-127-3p and miR-376a-3p induces a strong tumor suppressor effect in GCTSC, which is partially mediated via COA1 and PDIA6.

Sulforaphane sensitizes human cholangiocarcinoma to cisplatin via the downregulation of anti-apoptotic proteins

Cholangiocarcinoma (CCC) is an aggressive malignancy with poor therapeutic options and pronounced chemotherapy resistance. The bioactive broccoli substance, sulforaphane (SFN), is a promising new therapeutic option since it has been found to induce therapeutic effects in both experimental and epidemiological studies in various tumor entities. Thus, the present study was designed to assess the effect of SFN on cisplatin sensitivity in CCC. Human HuCCT-1 and TFK-1 cells, representing intrahepatic and extrahepatic CCC, respectively, were treated with cisplatin and SFN. Viability, the platinated DNA content, and apoptosis were assessed using both MTT assay and flow cytometry, while western blotting was used to analyze the expression of proteins involved in apoptosis and DNA damage. Whereas cisplatin was largely ineffective, SFN only therapy significantly decreased the viability of both CCC cell lines. The combination of SFN with cisplatin increased cisplatin cytotoxicity, which was particularly pronounced relatively early at 36 h after treatment. Apoptosis, which was reflected by the cleavage of caspase-3 and PARP, was significantly enhanced. Notably, only cisplatin was found to induce the expression of proteins involved in the DNA damage response; however, the presence of SFN appeared to enable otherwise cisplatin-resistant cells to undergo apoptosis. Due to the fact that SFN did not enhance the DNA platination levels upon cisplatin treatment, SFN may have exerted its activity via the inhibition of the anti-apoptotic proteins Bcl-2 and XIAP, as we observed. Data presented in the present study clearly demonstrated that SFN significantly decreased the drug resistance to cisplatin in human CCC. This highlights dietary co-treatment as a viable new treatment option for CCC.

Melatonin promotes sorafenib-induced apoptosis through synergistic activation of JNK/c-jun pathway in human hepatocellular carcinoma

Melatonin has been shown to exert anticancer activity on hepatocellular carcinoma (HCC) through its antiproliferative and pro-apoptotic effect in both experimental and clinical studies, and sorafenib is the only approved drug for the systemic treatment of HCC. Thus, this study was designed to investigate the combined effect of melatonin and sorafenib on proliferation, apoptosis, and its possible mechanism in human HCC. Here, we found that both melatonin and sorafenib resulted in a dose-dependent growth inhibition of HuH-7 cells after 48 hours treatment, and the combination of them enhanced the growth inhibition in a synergistic manner. Colony formation assay indicated that co-treatment of HuH-7 cells with melatonin and sorafenib significantly decreased the clonogenicity compared to the treatment with single agent. Furthermore, FACS and TUNEL assay confirmed that melatonin synergistically augmented the sorafenib-induced apoptosis after 48 hours incubation, which was in accordance with the activation of caspase-3 and the JNK/c-jun pathway. Inhibition of JNK/c-jun pathway with its inhibitor SP600125 reversed the phosphorylation of c-jun and the activation of caspase-3 induced by co-treatment of HuH-7 cells with melatonin and sorafenib in a dose-dependent manner. Furthermore, SP600125 exhibited protective effect against apoptosis induced by the combination of melatonin and sorafenib. This study demonstrates that melatonin in combination with sorafenib synergistically inhibits proliferation and induces apoptosis in human HCC cells; therefore, supplementation of sorafenib with melatonin may serve as a potential therapeutic choice for advanced HCC.

Quercetin-induced miR-200b-3p regulates the mode of self-renewing divisions in pancreatic cancer

BACKGROUND

Cancer stem cells are suggested to contribute to the extremely poor prognosis of pancreatic ductal adenocarcinoma and dysregulation of symmetric and asymmetric stem cell division may be involved. Anticancer benefits of phytochemicals like the polyphenol quercetin, present in many fruits, nuts and vegetables, could be expedited by microRNAs, which orchestrate cell-fate decisions and tissue homeostasis. The mechanisms regulating the division mode of cancer stem cells in relation to phytochemical-induced microRNAs are poorly understood.

METHODS

Patient-derived pancreas tissue and 3 established pancreatic cancer cell lines were examined by immunofluorescence and time-lapse microscopy, microRNA microarray analysis, bioinformatics and computational analysis, qRT-PCR, Western blot analysis, self-renewal and differentiation assays.

RESULTS

We show that symmetric and asymmetric division occurred in patient tissues and in vitro, whereas symmetric divisions were more extensive. By microarray analysis, bioinformatics prediction and qRT-PCR, we identified and validated quercetin-induced microRNAs involved in Notch signaling/cell-fate determination. Further computational analysis distinguished miR-200b-3p as strong candidate for cell-fate determinant. Mechanistically, miR-200b-3p switched symmetric to asymmetric cell division by reversing the Notch/Numb ratio, inhibition of the self-renewal and activation of the potential to differentiate to adipocytes, osteocytes and chondrocytes. Low miR-200b-3p levels fostered Notch signaling and promoted daughter cells to become symmetric while high miR-200b-3p levels lessened Notch signaling and promoted daughter cells to become asymmetric.

CONCLUSIONS

Our findings provide a better understanding of the cross talk between phytochemicals, microRNAs and Notch signaling in the regulation of self-renewing cancer stem cell divisions.

Delivery of improved oncolytic adenoviruses by mesenchymal stromal cells for elimination of tumorigenic pancreatic cancer cells

Pancreatic ductal adenocarcinoma (PDA) is one of the most aggressive malignancies and has poor therapeutic options. We evaluated improved oncolytic adenoviruses (OAds), in which the adenoviral gene E1B19K was deleted or a TRAIL transgene was inserted. Bone marrow mesenchymal stromal cells (MSCs) served as carriers for protected and tumor-specific virus transfers. The infection competence, tumor migration, and oncolysis were measured in cancer stem cell (CSC) models of primary and established tumor cells and in tumor xenografts. All OAds infected and lysed CSCs and prevented colony formation. MSCs migrated into PDA spheroids without impaired homing capacity. Xenotransplantation of non-infected PDA cells mixed with infected tumor cells strongly reduced the tumor volume and the expression of the proliferation marker Ki67 along with a necrotic morphology. Adenoviral capsid protein was detected in tumor xenograft tissue after intravenous injection of infected MSCs, but not in normal tissue, implying tumor-specific migration. Likewise, direct in vivo treatment correlated with a strongly reduced tumor volume, lower expression of Ki67 and CD24, and enhanced activity of caspase 3. These data demonstrate that the improved OAds induced efficient oncolysis with the OAd-TRAIL as most promising candidate for future clinical application.

microRNA-210 overexpression inhibits tumor growth and potentially reverses gemcitabine resistance in pancreatic cancer

Resistance to first-line chemotherapies like gemcitabine contributes to high disease lethality in pancreatic cancer. By microarray and qRT-PCR, we observed significant downregulation of microRNA-210 in gemcitabine-resistant cells. The overexpression of microRNA-210 was toxic to gemcitabine-resistant cells and enhanced gemcitabine sensitivity. MicroRNA-210 overexpression induced caspase-3-mediated apoptosis, and inhibited colony formation. Computationally, ABCC5, a highly expressed gene in our array data, was identified as a potential target of microRNA-210 and the overexpression of ABCC5 in gemcitabine-resistant cells was confirmed by qRT-PCR. MicroRNA-210 overexpression reduced ABCC5 mRNA levels and inhibited a luciferase reporter expressing the ABCC5 3' UTR. The expression pattern of microRNA-210 and ABCC5 was mirrored in all of 5 pancreatic cancer cell lines used. Likewise, microRNA-210 transfection nearly totally inhibited tumor xenograft growth, proliferation and metastasis without obvious side effects in vivo. Also, an absence or low expression of microRNA-210 correlated to high ABCC5 expression in the majority of malignant patient tissues from a total of 101 patient tissues examined. Our observations provide at first glance, an important function for microRNA-210 in regulation of gemcitabine responsiveness by it's target gene ABCC5.

Up-regulation of microRNA let-7c by quercetin inhibits pancreatic cancer progression by activation of Numbl

Pancreatic Ductal Adenocarcinoma (PDA) is a highly malignant tumor with poor prognosis. MicroRNAs (miRs) may offer novel therapeutic approaches to treatment. The polyphenol quercetin, present in many fruits and vegetables, possesses anti-carcinogenic properties. To unravel the effect of quercetin to miR signaling we performed miR profiling in PDA cells before and after quercetin treatment, followed by biostatistical analysis. miR let-7c was among the top up-regulated candidates after quercetin treatment, as measured by qRT-PCR and confirmed in two established and one primary PDA cell lines. By computational analysis we identified the Notch-inhibitor Numbl as let-7c target gene. This was strengthened by luciferase assays, where lipofected let-7c mimics induced a Numbl 3-UTR wild type construct, but not the mutated counterpart. Let-7c induced Numbl mRNA and protein expression but inhibited Notch just like quercetin. It also inhibited colony formation, wound healing, and protein expression of progression markers. In vivo xenotransplantation of PDA cells and subsequent intravenous injection of let-7c resulted in a significant decrease in tumor mass without obvious toxic effects in the fertilized chick egg model. The delivery rate of the miR mimics to the tumor mass was 80%, whereas minor amounts were present in host tissue. By immunohistochemistry we demonstrated that let-7c inhibited Notch and progression markers but up-regulated Numbl. These findings show that quercetin-induced let-7c decreases tumor growth by posttranscriptional activation of Numbl and indirect inhibition of Notch.

Inhibition of glucose turnover by 3-bromopyruvate counteracts pancreatic cancer stem cell features and sensitizes cells to gemcitabine

According to the cancer stem cell (CSC) hypothesis, the aggressive growth and early metastasis of pancreatic ductal adenocarcinoma (PDA) is due to the activity of CSCs, which are not targeted by current therapies. Otto Warburg suggested that the growth of cancer cells is driven by a high glucose metabolism. Here, we investigated whether glycolysis inhibition targets CSCs and thus may enhance therapeutic efficacy. Four established and 3 primary PDA cell lines, non-malignant cells, and 3 patient-tumor-derived CSC-enriched spheroidal cultures were analyzed by glucose turnover measurements, MTT and ATP assays, flow cytometry of ALDH1 activity and annexin positivity, colony and spheroid formation, western blotting, electrophoretic mobility shift assay, xenotransplantation, and immunohistochemistry. The effect of siRNA-mediated inhibition of LDH-A and LDH-B was also investigated. The PDA cells exhibited a high glucose metabolism, and glucose withdrawal or LDH inhibition by siRNA prevented growth and colony formation. Treatment with the anti-glycolytic agent 3-bromopyruvate almost completely blocked cell viability, self-renewal potential, NF-κB binding activity, and stem cell-related signaling and reverted gemcitabine resistance. 3-bromopyruvate was less effective in weakly malignant PDA cells and did not affect non-malignant cells, predicting minimal side effects. 3-bromopyruvate inhibited in vivo tumor engraftment and growth on chicken eggs and mice and enhanced the efficacy of gemcitabine by influencing the expression of markers of proliferation, apoptosis, self-renewal, and metastasis. Most importantly, primary CSC-enriched spheroidal cultures were eliminated by 3-bromopyruvate. These findings propose that CSCs may be specifically dependent on a high glucose turnover and suggest 3-bromopyruvate for therapeutic intervention.

Engineered adenoviruses combine enhanced oncolysis with improved virus production by mesenchymal stromal carrier cells

Oncolytic viruses have demonstrated in pre-clinical and clinical studies safety and a unique pleiotropic activity profile of tumor destruction. Yet, their delivery suffers from virus inactivation by blood components and sequestration to healthy tissues. Therefore, mesenchymal stromal cells (MSCs) have been applied as carrier cells for shielded virus delivery to tumors after ex vivo infection with oncolytic viruses. However, infection and particle production by MSCs have remained unsatisfying. Here, we report engineered oncolytic adenoviruses (OAds) for improved virus production and delivery by MSCs. OAds are uniquely amenable to molecular engineering, which has facilitated improved tumor cell destruction. But for MSC-mediated regimens, OAd engineering needs to achieve efficient infection and replication in both MSCs and tumor cells. We show that an Ad5/3 chimeric OAd capsid, containing the adenovirus serotype 3 cell-binding domain, strongly increases the entry into human bone marrow-derived MSCs and into established and primary pancreatic cancer cells. Further, we reveal that OAd with engineered post-entry functions-by deletion of the anti-apoptotic viral gene E1B19K or expression of the death ligand TRAIL--markedly increased virus titers released from MSCs, while MSC migration was not hampered. Finally, these virus modifications, or viral expression of FCU1 for local 5-FC prodrug activation, improved tumor cell killing implementing complementary cytotoxicity profiles in a panel of pancreatic cancer cell cultures. Together, our study establishes post-entry modification of OAd replication for improving virus delivery by carrier cells and suggests a panel of optimized OAds for future clinical development in personalized treatment of pancreatic cancer.

Sulforaphane counteracts aggressiveness of pancreatic cancer driven by dysregulated Cx43-mediated gap junctional intercellular communication

The extreme aggressiveness of pancreatic ductal adenocarcinoma (PDA) has been associated with blocked gap junctional intercellular communication (GJIC) and the presence of cancer stem cells (CSCs). We examined whether disturbed GJIC is responsible for a CSC phenotype in established and primary cancer cells and patient tissue of PDA using interdisciplinary methods based in physiology, cell and molecular biology, histology and epigenetics. Flux of fluorescent dyes and gemcitabine through gap junctions (GJs) was intact in less aggressive cells but not in highly malignant cells with morphological dysfunctional GJs. Among several connexins, only Cx43 was expressed on the cell surface of less aggressive and GJIC-competent cells, whereas Cx43 surface expression was absent in highly malignant, E-cadherin-negative and GJIC-incompetent cells. The levels of total Cx43 protein and Cx43 phosphorylated at Ser368 and Ser279/282 were high in normal tissue but low to absent in malignant tissue. si-RNA-mediated inhibition of Cx43 expression in GJIC-competent cells prevented GJIC and induced colony formation and the expression of stem cell-related factors. The bioactive substance sulforaphane enhanced Cx43 and E-cadherin levels, inhibited the CSC markers c-Met and CD133, improved the functional morphology of GJs and enhanced GJIC. Sulforaphane altered the phosphorylation of several kinases and their substrates and inhibition of GSK3, JNK and PKC prevented sulforaphane-induced CX43 expression. The sulforaphane-mediated expression of Cx43 was not correlated with enhanced Cx43 RNA expression, acetylated histone binding and Cx43 promoter de-methylation, suggesting that posttranslational phosphorylation is the dominant regulatory mechanism. Together, the absence of Cx43 prevents GJIC and enhances aggressiveness, whereas sulforaphane counteracts this process, and our findings highlight dietary co-treatment as a viable treatment option for PDA.

Ethical euthanasia and short-term anesthesia of the chick embryo

Fertilized chicken eggs are suggested as an alternative to mammalian models. The chorioallantoic membrane (CAM) of the chick embryo is widely used for examination of angiogenesis, xenotransplants and for virus production. Unfortunately, it is mostly not taken into account, that the chick embryo's ability to experience pain starts to develop at day 7 of breeding. In our view, this model is only in accordance with the 3 R principles, if an appropriate anesthesia of the chick embryo in potentially painful procedures is provided. Although many experimental approaches are performed on the none-innervated CAM, the euthanasia of the embryo strongly requires a more human technique than the usually used freezing at -20°C, decapitation or in ovo fixation with paraformaldehyde without prior anesthesia. However, protocols regarding feasible and ethical methods for anesthesia and euthanasia of avian embryos are currently not available. Therefore, we established an easy and reliable method for the euthanasia and short-term anesthesia of the chick embryo.

Interference of glucocorticoids with apoptosis signaling and host-tumor interactions

The cure of cancer is compromised by a variety of factors and mechanisms, which include tissue origin of the malignant cells, tumor load and hypoxia, impediment of drug access, and cellular resistance to treatment. Treatment resistance may be intrinsic, acquired, or induced, and it may occur to either radiation or a single drug alone, or simultaneously to multiple agents. Although the problem of corticosteroid-induced and hence, iatrogenic resistance to the treatment of cancer has continuously gained some interest over the past several years, no measures have been taken yet to diligently examine this problem in the clinical situation. In this review, we address several additional mechanisms through which glucocorticoids may influence the result of cytotoxic therapy of cancer, like: inducible interference of with apoptosis signaling; interference with immune response against malignant cells; issues relating to their impact on glucose metabolism in cancer patients.

Enrichment of c-Met+ tumorigenic stromal cells of giant cell tumor of bone and targeting by cabozantinib

Giant cell tumor of bone (GCTB) is a very rare tumor entity, which is little examined owing to the lack of established cell lines and mouse models and the restriction of available primary cell lines. The stromal cells of GCTB have been made responsible for the aggressive growth and metastasis, emphasizing the presence of a cancer stem cell population. To identify and target such tumor-initiating cells, stromal cells were isolated from eight freshly resected GCTB tissues. Tumorigenic properties were examined by colony and spheroid formation, differentiation, migration, MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay, immunohistochemistry, antibody protein array, Alu in situ hybridization, FACS analysis and xenotransplantation into fertilized chicken eggs and mice. A sub-population of the neoplastic stromal cells formed spheroids and colonies, differentiated to osteoblasts, migrated to wounded regions and expressed the metastasis marker CXC-chemokine receptor type 4, indicating self-renewal, invasion and differentiation potential. Compared with adherent-growing cells, markers for pluripotency, stemness and cancer progression, including the CSC surface marker c-Met, were enhanced in spheroidal cells. This c-Met-enriched sub-population formed xenograft tumors in fertilized chicken eggs and mice. Cabozantinib, an inhibitor of c-Met in phase II trials, eliminated CSC features with a higher therapeutic effect than standard chemotherapy. This study identifies a c-Met⁺ tumorigenic sub-population within stromal GCTB cells and suggests the c-Met inhibitor cabozantinib as a new therapeutic option for targeted elimination of unresectable or recurrent GCTB.

Sulforaphane, quercetin and catechins complement each other in elimination of advanced pancreatic cancer by miR-let-7 induction and K-ras inhibition

Pancreatic ductal adenocarcinoma (PDA) has the worst prognosis of all malignancies, and current therapeutic options do not target cancer stem cells (CSCs), which may be the reason for the extreme aggressiveness. The dietary agents sulforaphane and quercetin enriched e.g., in broccoli, and the main and best studied green tea catechin EGCG hold promise as anti-CSC agents in PDA. We examined the efficacy of additional catechins and the combination of these bioactive agents to stem cell features and miRNA signaling. Two established and one primary PDA cell line and non-malignant pancreatic ductal cells were used. Whereas each agent strongly inhibited colony formation, the catechins ECG and CG were more effective than EGCG. A mixture of green tea catechins (GTCs) significantly inhibited viability, migration, expression of MMP-2 and -9, ALDH1 activity, colony and spheroid formation and induced apoptosis, but the combination of GTCs with sulforaphane or quercetin was superior. Following treatment with bioactive agents, the expression of miR-let7-a was specifically induced in cancer cells but not in normal cells and it was associated with K-ras inhibition. These data demonstrate that sulforaphane, quercetin and GTC complement each other in inhibition of PDA progression by induction of miR-let7-a and inhibition of K-ras.

Establishment of hypoxia induction in an in vivo animal replacement model for experimental evaluation of pancreatic cancer

Transplantation of tumor xenografts to fertilized chicken eggs is a promising animal replacement method, which has successfully been used for xenotransplantation of pancreatic ductal adenocarcinoma (PDA) cells. PDA is characterized by a pronounced tumor hypoxia, which mediates aggressive growth, therapy resistance and cancer stem cell (CSC) features. For in vivo experimental evaluation of hypoxia-targeting therapeutic strategies, the xenografting of tumors to chicken eggs combined with the induction of hypoxia is necessary. However, the chicken embryos do not survive the conventional method of hypoxia induction by a gas mixture of 1% O2, 5% CO2, 94% N2, not even when hypoxia is applied for only 30 min. Therefore, we employed chemical induction of hypoxia by the hypoxia mimetic agent cobalt chloride (CoCl2). Whereas CoCl2 did not further increase tumor growth, it mediated the induction of carbonic anhydrase IX (CAIX) in the tumor xenografts and led to enhanced expression of the human CSC markers CD133, Sox2 and CD44. Side-effects in chicken embryos were not observed as evaluated by H&E staining of embryo-derived liver sections and the determination of the embryo weight. These results suggest the successful induction of hypoxia in chicken eggs and xenografted tumors by CoCl2. For therapeutic intervention and as a control, we treated the eggs with the plant-derived anti-inflammatory agent triptolide, which recently showed promising effects toward hypoxia-induced tumor progression in experimental PDA. Triptolide abolished tumor growth and the CoCl2-induced hypoxic effects, without inducing obvious side-effects. Collectively, our data present a new in vivo animal replacement method for the successful induction of tumor hypoxia in PDA.