Gemcitabine In Pancreatic Cancer Research Articles

Evaluation of Helium Ion Radiotherapy in Combination with Gemcitabine in Pancreatic Cancer In Vitro.

Pancreatic cancer is one of the most aggressive and lethal cancers. New treatment strategies are highly warranted. Particle radiotherapy could offer a way to overcome the radioresistant nature of pancreatic cancer because of its biological and physical characteristics. Within particles, helium ions represent an attractive therapy option to achieve the highest possible conformity while at the same time protecting the surrounding normal tissue. The aim of this study was to evaluate the cytotoxic efficacy of helium ion irradiation in pancreatic cancer in vitro. Human pancreatic cancer cell lines AsPC-1, BxPC-3 and Panc-1 were irradiated with photons and helium ions at various doses and treated with gemcitabine. Photon irradiation was performed with a biological cabin X-ray irradiator, and helium ion irradiation was performed with a spread-out Bragg peak using the raster scanning technique at the Heidelberg Ion Beam Therapy Center (HIT). The cytotoxic effect on pancreatic cancer cells was measured with clonogenic survival. The survival curves were compared to the predicted curves that were calculated via the modified microdosimetric kinetic model (mMKM). The experimental relative biological effectiveness (RBE) of helium ion irradiation ranged from 1.0 to 1.7. The predicted survival curves obtained via mMKM calculations matched the experimental survival curves. Mainly additive cytotoxic effects were observed for the cell lines AsPC-1, BxPC-3 and Panc-1. Our results demonstrate the cytotoxic efficacy of helium ion radiotherapy in pancreatic cancer in vitro as well as the capability of mMKM calculation and its value for biological plan optimization in helium ion therapy for pancreatic cancer. A combined treatment of helium irradiation and chemotherapy with gemcitabine leads to mainly additive cytotoxic effects in pancreatic cancer cell lines. The data generated in this study may serve as the radiobiological basis for future experimental and clinical works using helium ion radiotherapy in pancreatic cancer treatment.

Abstract 2802: Enterococcus faecalis-derived X facilitates pancreatic tumor by regulating immune microenvironment

Abstract Previous research in human samples has found a link between the intratumoral microbiome and the development and progression of pancreatic cancer. Nevertheless, the bacterial strains that may have an effect, and the underlying mechanisms, are largely unknown. To identify potential bacterial species, microbiome sequencing was performed on fecal and tumor samples obtained from KPC mice and patients with pancreatic tumors in this study. To identify metabolites associated with bacteria, untargeted metabolomics were analyzed on serum and tumor samples. Furthermore, advanced and high-throughput techniques, such as single-cell RNA sequencing, tumor organoids, engineered bacteria and germ-free mouse models, were used to elucidate the specific influence on the immune microenvironment of pancreatic tumors. Our findings reveal an increased abundance of Enterococcus faecalis (E. faecalis) in the gut during the development of pancreatic cancer, accompanied by its accumulation in the tumor. Patient-derived E. faecalis strain and its metabolite X, facilitated pancreatic tumor growth, reduced the recruitment of CD8+T cells, and caused their dysfunction in the tumor, relying heavily on E. faecalis intratumoral colonization. We found that X inhibits the production of anti-tumor chemokines like CCL21 and CCL8 in tumor cells, reducing peripheral CD8+ T cell infiltration into the tumor. Furthermore, X was found to inhibit glycolysis and compromise the function of tumor-infiltrating CD8+ T cells by decreasing the activity of lactate dehydrogenase (LDH) in CD8+ T cells. Additionally, oral doxycycline, an antibiotic that targets intratumoral E. faecalis, effectively enhanced the therapeutic effect of gemcitabine in pancreatic cancer. Finally, we present evidence that X may predicts efficacy and survival in pancreatic cancer patients. Together, our findings provide new insights into the role of E. faecalis in mediating the immune environment of pancreatic tumors, highlighting E. faecalis and X as potential therapeutic targets for pancreatic cancer patients. Citation Format: Bin Wang, Chao Yang, Yongjie Xie, Tianxing Zhou, Jun Yu, Jihui Hao. Enterococcus faecalis-derived X facilitates pancreatic tumor by regulating immune microenvironment [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 2802.

Enhanced Anti-tumor Effect of Flavopiridol in Combination With Gemcitabine in Pancreatic Cancer.

The efficacy of current chemotherapies for pancreatic ductal adenocarcinoma (PDAC) is still unsatisfactory. Flavopiridol inhibits multiple cyclin-dependent kinases, causing cell cycle arrest and inducing cancer cell apoptosis. This study aimed to evaluate the anti-tumor effect of flavopiridol and gemcitabine in PDAC in vitro and in vivo. PANC-1 and MIA PaCa-2 cell lines were treated with gemcitabine and flavopiridol alone, in combination, and sequentially, and cell proliferation, apoptosis, and the cell cycle were evaluated. Proteins related to cell cycle progression (cyclin A, CDK2, E2F-1, and p53) were quantified using western blotting. A xenograft mouse model was generated, and the effects of gemcitabine and flavopiridol, administered alone or in combination, were evaluated by measuring tumor volume and apoptosis degree using the TUNEL assay. Sequential administration of gemcitabine and flavopiridol suppressed PDAC cell proliferation and induced apoptosis. Flavopiridol treatment led to an increase in the number of cells in the S and a decrease in those in the G0/G1 phases. Gemcitabine increased and decreased the number of S- and G2/M-phase cells, respectively. Furthermore, flavopiridol treatment decreased cyclin A and CDK2 expression and increased E2F-1 expression. In a xenograft mouse model, the combined administration of gemcitabine and flavopiridol demonstrated the most significant reduction in tumor volume and induction of apoptosis. Flavopiridol potentiates the anti-tumor activity of gemcitabine by inducing cell cycle arrest and apoptosis. Its synergistic inhibition of PDAC cell proliferation, when combined with gemcitabine, positions flavopiridol as a promising candidate for cancer treatment.

Combination therapy of niclosamide with gemcitabine inhibited cell proliferation and apoptosis via Wnt/β-catenin/c-Myc signaling pathway by inducing β-catenin ubiquitination in pancreatic cancer

ABSTRACT Pancreatic ductal adenocarcinoma (PDAC) is a type of cancer with high morbidity and mortality rates worldwide. Owing to a lack of therapeutic options, the overall survival rate of patients with pancreatic cancer is low. Gemcitabine has been mainly used to treat patients with pancreatic cancer, but its efficacy is limited by chemoresistance. Therefore, a novel therapeutic agent for PDAC therapy is urgently needed. An anthelminthic drug, niclosamide, has already been researched in breast, lung, colon, and pancreatic cancer as an anti-cancer purpose by re-positioning its original purpose. However, combination therapy of gemcitabine and niclosamide was not informed yet. Here, we found that niclosamide co-administered with gemcitabine significantly inhibited tumorigenesis of pancreatic cancer compared to gemcitabine alone. Further, combining niclosamide and gemcitabine inhibited cell proliferation and induced apoptosis. Niclosamide induced cell cycle arrest at the G1 phase, and the levels of CDK4/6 and cyclin D1 were lowered after gemcitabine treatment. In addition, the combination of these chemical compounds more effectively increased the binding level of activated β-catenin destruction complex and β-catenin to enable phosphorylation, compared to gemcitabine alone. After phosphorylation, niclosamide – gemcitabine upregulated the ubiquitin level, which caused phosphorylated β-catenin to undergo proteasomal degradation; the combination was more potent than gemcitabine alone. Finally, the combination more effectively suppressed tumor growth in vivo, compared to gemcitabine alone. Altogether, our results indicate that niclosamide synergistically enhances the antitumor effect of gemcitabine in pancreatic cancer, by inducing the degradation of β-catenin with ubiquitination. Therefore, this drug combination can potentially be used in PDAC therapy.

Flashback Foreword: Erlotinib and Gemcitabine in Pancreatic Cancer.

Flashback Foreword: Erlotinib and Gemcitabine in Pancreatic Cancer.

Resistance to Gemcitabine in Pancreatic Cancer Is Connected to Methylglyoxal Stress and Heat Shock Response

Pancreatic ductal adenocarcinoma (PDAC) is a fatal disease with poor prognosis. Gemcitabine is the first-line therapy for PDAC, but gemcitabine resistance is a major impediment to achieving satisfactory clinical outcomes. This study investigated whether methylglyoxal (MG), an oncometabolite spontaneously formed as a by-product of glycolysis, notably favors PDAC resistance to gemcitabine. We observed that human PDAC tumors expressing elevated levels of glycolytic enzymes together with high levels of glyoxalase 1 (GLO1), the major MG-detoxifying enzyme, present with a poor prognosis. Next, we showed that glycolysis and subsequent MG stress are triggered in PDAC cells rendered resistant to gemcitabine when compared with parental cells. In fact, acquired resistance, following short and long-term gemcitabine challenges, correlated with the upregulation of GLUT1, LDHA, GLO1, and the accumulation of MG protein adducts. We showed that MG-mediated activation of heat shock response is, at least in part, the molecular mechanism underlying survival in gemcitabine-treated PDAC cells. This novel adverse effect of gemcitabine, i.e., induction of MG stress and HSR activation, is efficiently reversed using potent MG scavengers such as metformin and aminoguanidine. We propose that the MG blockade could be exploited to resensitize resistant PDAC tumors and to improve patient outcomes using gemcitabine therapy.

Vactosertib, TGF-β receptor I inhibitor, augments the sensitization of the anti-cancer activity of gemcitabine in pancreatic cancer

Pancreatic ductal adenocarcinoma (PDAC) exhibits a pronounced extracellular matrix (ECM)-rich response, which is produced by an excessive amount of transforming growth factor β (TGF-β), resulting in tumor progression and metastasis. In addition, TGF-β signaling contributes to rapidly acquired resistance and incomplete response to gemcitabine. Recently, selective inhibitors of the TGF-β signaling pathway have shown promise in PDAC treatment, particularly as an option for augmenting responses to chemotherapy. Here, we investigated the synergistic anticancer effects of a small-molecule TGF-β receptor I kinase inhibitor (vactosertib/EW-7197) in the presence of gemcitabine, and its mechanism of action in pancreatic cancer. Vactosertib sensitized pancreatic cancer cells to gemcitabine by synergistically inhibiting their viability. Importantly, the combination of vactosertib and gemcitabine significantly attenuated the expression of major ECM components, including collagens, fibronectin, and α-SMA, in pancreatic cancer compared with gemcitabine alone. This resulted in potent induction of mitochondrial-mediated apoptosis, gemcitabine-mediated cytotoxicity, and inhibition of tumor ECM by vactosertib. Additionally, the combination decreased metastasis through inhibition of migration and invasion, and exhibited synergistic anti-cancer activity by inhibiting the TGF-β/Smad2 pathway in pancreatic cancer cells. Furthermore, co-treatment significantly suppressed tumor growth in orthotopic models. Therefore, our findings demonstrate that vactosertib synergistically increased the antitumor activity of gemcitabine via inhibition of ECM component production by inhibiting the TGF-β/Smad2 signaling pathway. This suggests that the combination of vactosertib and gemcitabine may be a potential treatment option for patients with pancreatic cancer.

Aspirin increases the efficacy of gemcitabine in pancreatic cancer by modulating the PI3K/AKT/mTOR signaling pathway and reversing epithelial‑mesenchymal transition.

Gemcitabine is regarded as a standard medication for patients with pancreatic cancer. The aim of the present study was to investigate the impact of aspirin (ASA) on the efficacy of gemcitabine in pancreatic cancer and the potential mechanism. The SW1990 and BxPC-3 human pancreatic cell lines were treated with 2 mmol/l ASA and/or 1 mg/l gemcitabine. The effects of the treatments were tested on the viability, migration and invasion of the cells using MTT, wound healing and Transwell invasion assays. In addition, cell apoptosis was evaluated via flow cytometry with Annexin V-FITC/PI and the western blotting of Bax and Bcl-2. The expression of epithelial-mesenchymal transition (EMT)-associated proteins and activation of the PI3K/AKT/mTOR pathway were also assessed using western blotting. The results reveal that ASA increased the efficacy of gemcitabine in reducing the proliferation, migration and invasion of pancreatic cancer cells and increasing their apoptosis. These effects are associated with inhibition of the PI3K/AKT/mTOR pathway and the reversal of EMT. Thus, the combined use of ASA and gemcitabine is suggested to be a potential therapeutic strategy for patients with pancreatic cancer.

Emodin reverses resistance to gemcitabine in pancreatic cancer by suppressing stemness through regulation of the epithelial‑mesenchymal transition.

The present study aimed to explore the effects and underlying mechanisms of emodin (Emo) on gemcitabine (GEM)-resistant pancreatic cancer. GEM-resistant SW1990 cells (SW1990/GZ) were established by successively doubling the concentration of GEM. Cell viability was measured using the CCK-8 assay and flow cytometry was used to measure cell apoptosis. Cell migration was assessed using a Transwell assay. Sphere and colony-formation assays were used to evaluate cell self-renewal. The expression levels of epithelial-mesenchymal transition (EMT) and stem cell biomarkers were determined using western blotting. Snail family transcriptional repressor 1 gene (Snail) was overexpressed by transfecting cells with pcDNA3.1-Snail plasmids. A xenograft model was established in nude mice by using SW1990/GZ and Snail-overexpressing SW1990/GZ cells. Proliferation, migration, self-renewal and EMT progression of GEM-treated SW1990/GZ cells were significantly suppressed in vitro by Emo treatment, whereas the overexpression of Snail abolished the aforementioned effects. In in vivo, the antitumor activity of GEM and the inhibitory effect of GEM against EMT progression and stem-like characteristics were enhanced by treatment with Emo, whilst overexpression of Snail reversed these effects. In conclusion, Emo reversed GEM resistance in pancreatic cancer by suppressing stemness and regulating EMT progression.

ARID1A promotes chemosensitivity to gemcitabine in pancreatic cancer through epigenetic silencing of RRM2.

Pancreatic cancer is one of the most common malignancies with very poor prognosis due to its broad resistance to chemotherapy. ARID1A, a subunit of SWI/SNF complex, is involved in pancreatic carcinogenesis through epigenetic silencing of oncogenes. In this study, we aimed to explore whether ARID1A was implicated in the gemcitabine resistance in pancreatic cancer patients via regulating RRM2. We examined the effect of ARID1A depletion on the gemcitabine sensitivity in pancreatic cancer cells and explored the role of RRM2 in ARID1A-mediated pancreatic cancer cells chemosensitivity to gemcitabine. We found that Knockout of ARID1A led to gemcitabine resistance in pancreatic cancer cells, effect of which could be reversed by RRM2, a gemcitabine resistance related gene. ARID1A decreased the transcription of RRM2, and directly bound to the promoter of RRM2. Moreover, expression of RRM2 was negatively correlated with ARID1A in pancreatic cancer tissues. Thus, ARID1A-mediated RRM2 epigenetic suppression is crucial for enhancement of pancreatic cancer chemosensitivity to gemcitabine, and ARID1A could be used as a biomarker to guide the gemcitabine chemotherapy of pancreatic cancer.

Anti-tumour activity and toxicological studies of combination treatment of Orthosiphon stamineus and gemcitabine on pancreatic xenograft model.

BACKGROUNDPancreatic cancer is the most aggressive cancer type. Gemcitabine is the first line chemo-drug used for pancreatic cancer but exerts a broad spectrum of organ toxicities and adverse effects in patients. AIMTo evaluate the anti-tumour activity and toxicological effects of Orthosiphon stamineus extract formulation (ID: C5EOSEW5050ESA trademarked as Nuva-staticTM), and gemcitabine combination on pancreatic xenograft model.METHODSMice were randomly divided into six groups of 6 mice each (n = 6) and given different treatments for 28 d. The study design consisted of a 2 x 3 factorial treatment structure, with gemcitabine (yes/no) by oral (at 1200 and 400 mg/kg per day). Human pancreatic cancer cells were injected subcutaneously into the flanks of athymic nude mice. C5EOSEW5050ESA (200 or 400 mg/kg per day) was administered orally, while gemcitabine (10 mg/kg per 3 d) was given intraperitoneally either alone or in combination treatment. Histopathological analyses of vital organs, tumour tissues, and incidence of lethality were analysed. Analyses of tumour necrosis and proliferation were determined by haematoxylin-eosin staining and immunohistochemistry for Ki-67, respectively. RESULTSNo signs of toxicity or damage to vital organs were observed in all treatment groups compared to the untreated group. C5EOSEW5050ESA at 200 mg/kg and gemcitabine combination had no additive antitumor effects compared to a single treatment. Remarkably, a comparably greater response in a reduction in tumour growth, Ki-67 protein expression, and necrosis was demonstrated by 400 mg/kg of C5EOSEW5050ESA and gemcitabine combination than that of the individual agents. CONCLUSIONThese results highlighted the synergistic activity of C5EOSEW5050ESA with gemcitabine to reduce pancreatic tumour growth in mice compared to a single treatment. Thus, this study provides valuable insights into using C5EOSEW5050ESA as a complementary treatment with gemcitabine for pancreatic cancer.

Ivermectin and gemcitabine combination treatment induces apoptosis of pancreatic cancer cells via mitochondrial dysfunction

Pancreatic cancer is an aggressive cancer characterized by high mortality and poor prognosis, with a survival rate of less than 5 years in advanced stages. Ivermectin, an antiparasitic drug, exerts antitumor effects in various cancer types. This is the first study to evaluate the anticancer effects of the combination of ivermectin and gemcitabine in pancreatic cancer. We found that the ivermectin–gemcitabine combination treatment suppressed pancreatic cancer more effectively than gemcitabine alone treatment. The ivermectin–gemcitabine combination inhibited cell proliferation via G1 arrest of the cell cycle, as evidenced by the downregulation of cyclin D1 expression and the mammalian target of rapamycin (mTOR)/signal transducer and activator of transcription 3 (STAT-3) signaling pathway. Ivermectin–gemcitabine increased cell apoptosis by inducing mitochondrial dysfunction via the overproduction of reactive oxygen species and decreased the mitochondrial membrane potential. This combination treatment also decreased the oxygen consumption rate and inhibited mitophagy, which is important for cancer cell death. Moreover, in vivo experiments confirmed that the ivermectin–gemcitabine group had significantly suppressed tumor growth compared to the gemcitabine alone group. These results indicate that ivermectin exerts synergistic effects with gemcitabine, preventing pancreatic cancer progression, and could be a potential antitumor drug for the treatment of pancreatic cancer.

Immunomodulatory antitumor effect of interferon‑beta combined with gemcitabine in pancreatic cancer.

Resistance to gemcitabine is common and critically limits its therapeutic efficacy in patients with pancreatic cancer. Interferon‑beta (IFN‑β) induces numerous antitumor effects and synergizes with gemcitabine treatment. The immunomodulatory effects of this treatment regimen have not yet been described. In the present study, the antitumor effect of IFN‑β combined with gemcitabine was investigated in immune competent mice. Mouse KPC3 cells were used in all experiments. Treatment effects were determined with cell proliferation assay. Reverse transcription‑quantitative PCR was used to measure gene expression. For invivo experiments, cells were subcutaneously injected in immune competent mice. For immune profiling, NanoString analysis was performed on tumor samples of treated and untreated mice. Baseline expression of Ifnar‑1 and Ifnar‑2c in KPC3 cells was 1.42±0.16 and 1.50±0.17, respectively. IC50 value of IFN‑β on cell growth was high (>1,000IU/ml). IFN‑β pre‑treatment increased the invitro response to gemcitabine (1.3‑fold decrease in EC50; P<0.001). Invivo, tumor size was not statistically significant smaller in mice treated with IFN‑β plus gemcitabine (707±92mm3 vs. 1,239±338 mm3 in vehicle‑treated mice; P=0.16). IFN‑β alone upregulated expression of numerous immune‑related genes. This effect was less pronounced when combined with gemcitabine. For the first time, to the best of our knowledge, the immunomodulatory effects of IFN‑β, alone and combined with gemcitabine, in pancreatic cancer were reported. Prognostic markers for predicting effective responses to IFN‑β therapy are urgently needed.

Is Artesunate the Best Partner of Gemcitabine in Pancreatic Cancer?

Pancreatic adenocarcinoma (PDAC) is still one of the most malignant and difficult to treat cancers. The therapeutic protocols in use, such as gemcitabine, gemcitabine associated with nab-paclitaxel and/or cisplatin or the FOLFIRINOX scheme have added very little to PDAC outcome. It is clear by now, that none of them can do the job alone. The more than 3,300 trials registered in clinicaltrials.gov is the best proof that research has not yet found an adequate response to tackle this disease. Thus, an innovative search is badly needed. As part of this investigation we came across a phytotherapeutic product that has been very successful for the treatment of falciparum- and vivax- caused malaria: artemisinin derivatives. These derivatives showed very low toxicity for humans and have been tested in millions of patients with paludism. &#x0D; Interestingly, they have also shown important anti-cancer properties. Regarding PDAC in particular there is strong evidence supporting not only an additive effect to gemcitabine without a concomitant increase in human toxicity, but also decreased resistance. This mini-review will discuss the evidence showing that artemisinin derivatives can be the best possible association with gemcitabine for PDAC chemotherapeutic treatment.

Real-World Assessment of Cancer Drugs Using Local Data Uploaded to the Systemic Anti-Cancer Therapy Dataset in England

AimsIn England, not all cancer drugs are routinely funded; new medicines are first appraised by the National Institute for Health and Care Excellence. Funding can be temporarily given through the Cancer Drugs Fund while further information is collected. The Systemic Anti-Cancer Therapy (SACT) dataset collects information on all patients receiving chemotherapy in England. To date, little has been published, despite concerns that real-world effectiveness of medicines may be inferior to that seen in clinical trials. The aim of the present study was to establish the feasibility of using our local copy of routinely collected SACT data for the evaluation of outcomes, using the data within the context of gastrointestinal cancers. Materials and methodsWe used our local SACT dataset submissions from three National Health Service trusts, with a reproducible method of data linkage, to undertake a cohort analysis of treatment duration and overall survival for cetuximab, panitumumab, trifluridine/tipiracil (all three in colorectal cancer), sorafenib (in hepatocellular cancer) and nab-paclitaxel (nanoparticle albumin-bound paclitaxel) with gemcitabine (in pancreatic cancer) for all patients treated from May 2016 to March 2021. ResultsIn our population, epidermal growth factor receptor inhibitors and trifluridine/tipiracil and sorafenib performed similarly to expected but nab-paclitaxel with gemcitabine in pancreatic cancer seemed to be no better than gemcitabine alone, when given within the current funding arrangements in England. ConclusionsOur results support the publication of national outcome data. If these results are confirmed on a larger cohort, it would support the reappraisal of certain drugs and provide further evidence to clinicians and patients when deciding the best treatment.

The Class I HDAC Inhibitor Valproic Acid Strongly Potentiates Gemcitabine Efficacy in Pancreatic Cancer by Immune System Activation.

Background: Gemcitabine efficacy in pancreatic cancer is often impaired due to limited intracellular uptake and metabolic activation. Epi-drugs target gene expression patterns and represent a promising approach to reverse chemoresistance. In this study, we investigate the chemosensitizing effect of different epi-drugs when combined with gemcitabine in pancreatic cancer. Methods: Mouse KPC3 cells were used for all experiments. Five different epi-drugs were selected for combination therapy: 5-aza-2′-deoxycytidine, hydralazine, mocetinostat, panobinostat, and valproic acid (VPA). Treatment effects were determined by cell proliferation and colony forming assays. Expression of genes were assessed by real-time quantitative PCR. The most promising epi-drug for combination therapy was studied in immune competent mice. Intratumor changes were defined using NanoString PanCancer panel IO360. Results: All epi-drugs, except hydralazine, potentiated the gemcitabine response in KPC3 cells (range decrease IC50 value 1.7–2-fold; p < 0.001). On colony formation, the cytotoxic effect of 0.5 ng/mL gemcitabine was 1.4 to 6.3 times stronger (p < 0.01). Two out of three drug-transporter genes were strongly upregulated following epi-drug treatment (a range fold increase of 17–124 and 9–60 for Slc28a1 and Slc28a3, respectively; all p < 0.001). VPA combined with gemcitabine significantly reduced tumor size with 74% compared to vehicle-treated mice and upregulated expression of immune-related pathways (range pathway score 0.86–1.3). Conclusions: These results provide a strong rationale for combining gemcitabine with VPA treatment. For the first time, we present intratumor changes and show activation of the immune system. Clinical trials are warranted to assess efficacy and safety of this novel combination in pancreatic cancer patients.

Arsenic trioxide-loaded nanoparticles enhance the chemosensitivity of gemcitabine in pancreatic cancer via the reversal of pancreatic stellate cell desmoplasia by targeting the AP4/galectin-1 pathway.

Pancreatic stellate cells (PSCs) constitute the fibrotic tumor microenvironment composed of the stroma matrix, which blocks the penetration of gemcitabine (GEM) in pancreatic adenocarcinoma (PDAC) and results in chemoresistance. We analyzed the expression of α-SMA, collagen type I, and fibronectin by immunohistochemistry of pancreatic cancer tissues and demonstrated that the abundant interstitial stroma is associated with dismal survival. Two desmoplastic pancreatic tumor models are treated with arsenic trioxide (ATO) and GEM to confirm the sensitizing effect of ATO on GEM. RNA-seq was performed to analyze the potential fibrotic genes regulated by ATO. Western blotting, CCK-8 methods, colony formation, and wound healing and transwell assays were utilized to verify that ATO attenuates the tumor-promoting ability of PSCs by inhibiting its activation and decreasing matrix secretion via the PI3K/AKT/AP4/galectin-1 pathway. Furthermore, we developed targeted ATO-loaded nanoparticles self-assembled by poly (D,L-lactide) and poly(ethylene glycol) (PEG-PDLLA) and modified by the single-chain antibody of FAP-α (scAbFAP-α) (scAb-ATO-NPs) to promote the delivery efficiency of ATO to PSCs and enhance anti-tumor effects with gemcitabine. Herein, we elucidate the mechanism of how ATO inhibits the activation of PSCs and enhances the therapeutic effect of GEM. We propose a novel cocktail therapy including scAb-ATO-NPs and GEM, indicating a new perspective in the treatment of PDAC.

MiR-199 Reverses the Resistance to Gemcitabine in Pancreatic Cancer by Suppressing Stemness through Regulating the Epithelial-Mesenchymal Transition.

Purpose: the present study aims to investigate the function of miR-199 on gemcitabine (GEM)-resistance in pancreatic cancer, as well as the underlying mechanism. Methods: the GEM-resistant SW1990 cell line (SW1990/SZ) was established. The CCK-8 assay was used to detect the cell viability. The self-renewal of SW1990/SZ cells was evaluated by sphere formation and the colony formation assay. The apoptosis was detected by flow cytometry and the migration ability was measured by the transwell assay. The dual-luciferase gene reporter assay was utilized to confirm the binding between miR-199 and Snail. The expression level of CD44, ALDH1, Nanog, E-cadherin, Vimentin, β-catenin, and Snail was determined by the Western blotting assay. Results: the cell sphere formation rate, number of spheres, and expression level of CD44, ALDH1, and Nanog in GEM-treated SW1990/SZ cells were significantly suppressed by miR-199, accompanied by declined proliferation ability, an increased apoptotic rate, inhibited migration ability, and suppressed EMT progression. The binding site between miR-199 and 3′-UTR of Snail was predicted and confirmed. The inhibitory effect of miR-199 on self-renewal of SW1990/GZ cells and the faciliating property of miR-199 on the inhibitory effect of GEM against the proliferation ability, migration ability, and EMT progression were abolished by overexpressing Snail. Conclusion: MiR-199 reversed the resistance to GEM in pancreatic cancer by suppressing stemness through regulating the EMT.

HENT1 Predicts Benefit from Gemcitabine in Pancreatic Cancer but Only with Low CDA mRNA.

Simple SummaryRecent clinical trials suggest that combination therapies that include either gemcitabine or 5-fluorouracil (5-FU) both give significant survival benefits for pancreatic cancer patients. The tumor level of the nucleoside transporter hENT1 is prognostic in patients treated with adjuvant gemcitabine but not adjuvant 5-FU. This work shows for the first time that hENT1 is only predictive of benefit from gemcitabine over 5-FU in patients with low levels of CDA transcript. A choice between adjuvant 5-FU based combination therapies (such as FOLFIRINOX) and gemcitabine-based therapy (e.g., GemCap) could be made based on a combination of hENT1 protein and CDA mRNA measured in a resected tumor.Gemcitabine or 5-fluorouracil (5-FU) based treatments can be selected for pancreatic cancer. Equilibrative nucleoside transporter 1 (hENT1) predicts adjuvant gemcitabine treatment benefit over 5-FU. Cytidine deaminase (CDA), inside or outside of the cancer cell, will deaminate gemcitabine, altering transporter affinity. ESPAC-3(v2) was a pancreatic cancer trial comparing adjuvant gemcitabine and 5-FU. Tissue microarray sections underwent in situ hybridization and immunohistochemistry. Analysis of both CDA and hENT1 was possible with 277 patients. The transcript did not correlate with protein levels for either marker. High hENT1 protein was prognostic with gemcitabine; median overall survival was 26.0 v 16.8 months (p = 0.006). Low CDA transcript was prognostic regardless of arm; 24.8 v 21.2 months with gemcitabine (p = 0.02) and 26.4 v 14.6 months with 5-FU (p = 0.02). Patients with low hENT1 protein did better with 5-FU, but only if the CDA transcript was low (median survival of 5-FU v gemcitabine; 29.3 v 18.3 months, compared with 14.2 v 14.6 with high CDA). CDA mRNA is an independent prognostic biomarker. When added to hENT1 protein status, it may also provide treatment-specific predictive information and, within the frame of a personalized treatment strategy, guide to either gemcitabine or 5FU for the individual patient.

Intraperitoneal siRNA Nanoparticles for Augmentation of Gemcitabine Efficacy in the Treatment of Pancreatic Cancer.

Pancreatic ductal adenocarcinoma is a deadly disease with limited treatment options due to late diagnosis and resistance to conventional chemotherapy. Among emerging therapeutic targets, the CXCR4 chemokine receptor and polo-like kinase 1 (PLK1) play critical roles in the progression, metastasis, and chemoresistance of pancreatic cancer. Here, we tested the hypothesis that combining CXCR4 inhibition by a polymeric CXCR4 antagonist PAMD-CHOL with PLK1 knockdown by siRNA will enhance the therapeutic effect of gemcitabine (GEM) in the orthotopic model of metastatic pancreatic cancer. We formulated nanoparticles with cholesterol-modified PAMD and siPLK1 and found strong synergism when combined with GEM treatment in vitro in both murine and human pancreatic cancer cell lines. The biodistribution of the nanoparticles in orthotopic pancreatic cancer models revealed strong accumulation in primary and metastatic tumors, with limited hepatic disposition. The cholesterol-containing nanoparticles showed not only increased tumor accumulation than the cholesterol-lacking control but also deeper penetration into the tumors. In a therapeutic study in vivo, the triple combination of PAMD-CHOL/siPLK1 and GEM showed superior anticancer activity when compared with single and dual combination controls. In conclusion, PAMD-CHOL/siPLK1 nanoparticles synergistically enhance anticancer activity of GEM in pancreatic cancer and represent a promising addition to the treatment arsenal.