PANC-1 Cells Research Articles

Naphthoquinone Derivatives from the Endophytic Fungus Fusarium solani Induce Pancreatic Cancer Cells Apoptosis via Targeting EGFR-Mediated PI3K/Akt Pathway.

Seven new polyketide compounds, four naphthoquinone derivatives, neofusarubins A-D (1, 3, 5, and 18) and three graminin-like compounds, fusofuranones A-C (19-21), together with 14 known naphthoquinone derivatives, were isolated from the solid fermentation of Fusarium solani, an endophytic fungus obtained from medicinal plant as tea, Camellia chrysantha. The structures of new compounds were elucidated based on chemical evidence and spectral data analysis (1D and 2D-NMR, HR-ESI-MS, ECD, SC-XRD). Among the isolated compounds tested, 2-acetonyl-3-methyl-5-hydroxy-7-methoxy-naphthazarin (11) exhibited the most potent inhibitory activity against pancreatic cancer in PANC-1, MiaPaCa-2, and BxPC-3 cells. Network pharmacology analysis revealed that compound 11 inhibited cell proliferation and promotion of apoptosis by targeting epidermal growth factor receptor (EGFR), which were confirmed by cellular thermal shift assay (CETSA), microscale thermophoresis (MST) and EGFR stably knockdown cells model assay, respectively. In addition, molecular mechanism studies in vitro showed that 11 could suppress the growth of pancreatic cancer cells by targeting EGFR and effectively inhibit downstream PI3K/Akt signaling pathway. Collectively, these findings provide a new EGFR targeting natural product for the treatment of pancreatic cancer.

Pancreatic cancer-derived exosomal miR-510 promotes macrophage M2 polarization and facilitates cancer cell aggressive phenotypes.

Extensive tumor microenvironment (TME) and tumor-associated macrophages (TAMs) contribute to the initiation and progression of pancreatic cancer (PC). Cancer cell-derived exosomal miRNAs that stimulate macrophage M2 polarization might play an important role in the process. In the current study, we observed significant upregulation of miR-510 in PC cell lines in comparison to normal HPDE cell line, with PANC-1 exhibiting the highest and MIA PaCa-2 the lowest miR-510 levels. Functional assays demonstrated that miR-510 overexpression enhanced, while its inhibition reduced, PC cell viability, migration, invasion, and EMT. In vivo, miR-510 mimics promoted tumor growth and macrophage M2 polarization, whereas miR-510 inhibition had the opposite effect. Exosomes from PANC-1 and MIA PaCa-2 cells, characterized by nanoparticle tracking analysis and TEM, contained significantly higher miR-510 levels than those from HPDE cells. Macrophages incubated with conditioned media from these PC cells showed increased M2 polarization markers, a process inhibited by the exosome inhibitor GW4869. The delivery of miR-510 via PC cell-derived exosomes facilitated macrophage M2 polarization and regulated the STAT signaling pathway, suggesting that exosomal miR-510 plays a crucial role in the tumor microenvironment of PC by modulating macrophage M2 polarization.

Dendritic cell maturation is induced by p53-armed oncolytic adenovirus via tumor-derived exosomes enhancing systemic antitumor immunity.

Dendritic cells (DCs) are crucial in cancer immunity, because they activate cytotoxic T cells by presenting tumor antigens. Recently, oncolytic virus therapy has been recognized as a systemic immune stimulator. We previously developed a telomerase-specific oncolytic adenovirus (OBP-301) and a p53-armed OBP-301 (OBP-702), demonstrating that these viruses strongly activate systemic antitumor immunity. However, their effects on DCs remained unclear. In the present study, the aim was to elucidate the mechanisms of DC activation by OBP-702, focusing particularly on tumor-derived exosomes. Exosomes (Exo53, Exo301, or Exo702) were isolated from conditioned media of human or murine pancreatic cancer cell lines (Panc-1, MiaPaCa-2, and PAN02) after treatment with Ad-p53, OBP-301, or OBP-702. Exo702 derived from Panc-1 and MiaPaCa-2 cells significantly upregulated CD86, CD80, CD83 (markers of DC maturation), and IFN-γ in DCs in vitro. Similarly, Exo702 derived from PAN02 cells upregulated CD86 and IFN-γ in bone marrow-derived DCs in a bilateral PAN02 subcutaneous tumor model. This DC maturation was inhibited by GW4869, an inhibitor of exosome release, and anti-CD63, an antibody targeting the exosome marker. Intratumoral injection of OBP-702 into PAN02 subcutaneous tumors significantly increased the presence of mature DCs and CD8-positive T cells in draining lymph nodes, leading to long-lasting antitumor effects through the durable activation of systemic antitumor immunity. In conclusion, tumor-derived exosomes play a significant role in DC maturation following OBP-702 treatment and are critical for the systemic activation of antitumor immunity, leading to the abscopal effect.

Identification of PSMD2 as a promising biomarker for pancreatic cancer patients based on comprehensive bioinformatics and in vitro studies

BackgroundPancreatic cancer patients have limited treatment options and extremely poor prognosis. Dysregulations of proteasome 26S subunit, non-ATPases (PSMDs) contribute to the development of various cancers, whereas the significance of PSMDs in pancreatic cancer is poorly understood. In the present study, we intended to explore the therapeutic potential of PSMDs in pancreatic cancer. MethodsBased on TCGA database, the expression of PSMDs was analyzed in pancreatic cancer patients. Multivariate Cox regression and Kaplan–Meier survival analyses were conducted to investigate the prognostic value of PSMDs. The correlations between the expression of PSMD2/14 and immune cell infiltration, immune checkpoint genes’ expression, enrichment of signaling pathways, and the sensitivity of chemotherapies were also evaluated. Knockdown and overexpression experiments were performed to explore the biological function of PSMD2/14. Immunoblotting was conducted to detect the downstream signaling pathway of PSMD2. ResultsMost of the PSMDs, except for PSMD5 and PSMD6, were significantly upregulated in pancreatic cancer tissues. Patients with higher grade tumor had increased mRNA levels of PSMD1/2/5/7/8/11/12/14. Survival and multivariate Cox regression analyses indicated that PSMD2 and PSMD14 were biomarkers of worse prognosis. High expression of PSMD2 and PSMD14 was positively correlated with the levels immune checkpoint genes but not with the infiltration of specific immune cell types. In vitro knockdown of PSMD2, but not PSMD14, increased the apoptosis, gemcitabine’s toxicity and inhibited the growth capacity of MIA cells. Conversely, decreased apoptosis and gemcitabine sensitivity along with accelerated cell proliferation ability were observed in PSMD2-overexpressing PANC-1 cells. Mechanistically, PSMD2 activated the AKT/mTOR signaling pathway, consistent with the findings from KEGG and GSEA analysis. The AKT specific inhibitor MK-2206 exhibited higher cytotoxicity in MIA and PANC-1 cells with high PSMD2 expression. Importantly, MK-2206 largely reversed the oncogenic functions of PSMD2 on the growth and proliferation of PANC-1 cells. ConclusionIn summary, our study provided a comprehensive bioinformatics analysis of PSMDs in pancreatic cancer. We identified that PSMD2 acted as a tumor-promoting protein in pancreatic cancer through the activation of the AKT/mTOR pathway. The overexpression of PSMD2 may be a potential biomarker that predicts the response of pancreatic cancer patients to AKT inhibitor treatments.

TGF-β-Induced PAUF Plays a Pivotal Role in the Migration and Invasion of Human Pancreatic Ductal Adenocarcinoma Cell Line Panc-1.

Pancreatic adenocarcinoma upregulated factor (PAUF) was initially identified as a secreted protein that is substantially expressed in pancreatic ductal adenocarcinoma (PDAC). PAUF also affects invasiveness, motility, and the proliferation of cells in several types of cancer. Recently, PAUF was reported to play a pivotal role in the TLR4-mediated migration and invasion of PDAC cells. However, the mechanism inducing PAUF expression and its functional role in TGF-β-stimulated PDAC cells have not yet been studied. Thus, we first assessed whether TGF-β regulates PAUF expression in several PDAC cell lines and found a significant increase in PAUF expression in Smad signaling-positive Panc-1 cells treated with TGF-β. We also found that the PAUF promoter region contains a Smad-binding element. TGF-β-treated Panc-1 cells showed an increase in PAUF promoter activity, but this effect was not observed in TGF-β-stimulated Smad4-null BxPC-3 cells. Restoring Smad4 expression increased the PAUF promoter activity and expression in Smad4-overexpressing BxPC-3 cells treated with TGF-β. We further found that PAUF aggravated the TGF-β-induced epithelial-mesenchymal transition (EMT) in Panc-1 and BxPC-3 cells via the activation of MEK-ERK signaling. These results indicate that TGF-β/Smad signaling-mediated upregulation of PAUF plays a crucial role in EMT progression by activating the TGF-β-mediated MEK-ERK signaling pathway.

The function of p97/valosin-containing protein (VCP) and small VCP-interacting protein (SVIP) in invasion and migration of pancreatic cancer cells.

Misfolded proteins are eliminated by a process known as endoplasmic reticulum-associated protein degradation (ERAD). ERAD has an impact on a variety of illnesses, such as diabetes, cystic fibrosis, cancer, and neurological conditions. As one of the many proteins involved in ERAD, this study is focused on p97/valosin-containing protein (VCP) and small VCP-interacting protein (SVIP). The existence and function of SVIP and p97/VCP in various types of pancreatic cancer have not yet been investigated. The study's objectives are to examine the expressions of SVIP and p97/VCP in two pancreatic cancer types and to show whether these proteins aid in the invasion and migration of pancreatic cancer cells. In this work, MIA PaCa-2 and PANC-1 human cell lines were examined. Immunocytochemistry and immunofluorescence were performed to detect the cellular localization and presence of p97/VCP and SVIP in pancreatic cancer cells. Following p97/VCP siRNA and SVIP siRNA transfection of the cells, protein expressions were assessed using Western blot analysis. The effects of this suppression on cell invasion and migration were determined using the xCELLigence real-time analysis system (RTAC). In the nucleus and cytoplasm of MIA PaCa-2 and PANC-1 cells, p97/VCP and SVIP immunoexpressions were seen. The decrease in protein expressions of p97/VCPsi and SVIPsi was significant in pancreatic cells compared to the controlsi. The p97/VCP siRNA transfection reduced the invasion and migration of MIA PaCa-2 and PANC-1 cells. In addition, the SVIP siRNA suppression resulted in increasing the invasion and migration ability of both cells. This study also demonstrated, for the first time, SVIP expression in MIA PaCa-2 and PANC-1 cells. Overall, the findings show the differential expression and function of p97/VCP and SVIP in pancreas ductal adenocarcinoma cells. The potential of the pancreatic cancer cells to migrate and invade altered when the two cell lines were transfected with p97/VCPsi and SVIPsi.

The long non-coding RNA NEAT1 contributes to aberrant STAT3 signaling in pancreatic cancer and is regulated by a metalloprotease-disintegrin ADAM8/miR-181a-5p axis.

Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers and several studies demonstrate that STAT3 has critical roles throughout the course of PDAC pathogenesis. TCGA, microarray, and immunohistochemistry data from a PDAC cohort were used for clinical analyses. Panc89 cells with ADAM8 knockout, re-expression of ADAM8 mutants, and Panc1 cells overexpressing ADAM8 were generated. Gene expression analyses of ADAM8, STAT3, long non-coding (lnc) RNA NEAT1, miR-181a-5p and ICAM1 were performed by quantitative PCR. Subcellular fractionation quantified NEAT1 expression in cytoplasm and nucleus of PDAC cell lines. Cell proliferation, scratch, and invasion assays were performed to detect growth rate, migration and invasion capabilities of cells. Gain and loss of function experiments were carried out to investigate the biological effects of lncRNA NEAT1 and miR-181a-5p on PDAC cells and downstream genes. Dual-luciferase reporter gene assay determined interaction and binding sites of miR-181a-5p in lncRNA NEAT1. Pull down assays, RNA binding protein immunoprecipitation (RIP), and ubiquitination assays explored the molecular interaction between lncRNA NEAT1 and STAT3. High ADAM8 expression causes aberrant STAT3 signaling in PDAC cells and is positively correlated with NEAT1 expression. NEAT1 binding to STAT3 was confirmed and prevents STAT3 degradation in the proteasome as increased degradation of STAT3 was observed in ADAM8 knockout cells and cells treated with bortezomib. Furthermore, miRNA-181a-5p regulates NEAT1 expression by direct binding to the NEAT1 promoter. ADAM8 regulates intracellular STAT3 levels via miR-181a-5p and NEAT1 in pancreatic cancer.

Differential regulation of expression of the protein kinases DYRK1A and DYRK1B in cancer cells

The protein kinases DYRK1A and DYRK1B are pivotal regulators of cell cycle progression by promoting cell cycle exit into quiescence. DYRK1B appears to play a more important role in cancer cell quiescence than DYRK1A, as evidenced by its overexpression or copy number variations in human tumour samples. Nonetheless, the stimuli driving DYRK1B upregulation and the potential divergence in expression patterns between DYRK1A and DYRK1B remain largely elusive. In the present study, we scrutinized the regulatory pathways modulating DYRK1B expression relative to DYRK1A in PANC-1 and A549 cancer cell lines across varying conditions. Serum deprivation, pharmacological mTOR inhibition and increased cell density resulted in the differential upregulation of DYRK1B compared to DYRK1A. We then aimed to assess the role of protein kinases MST1 and MST2, which are key transmitters of cell density dependent effects. Unexpectedly, exposure to the MST1/2 inhibitor XMU-MP-1 resulted in increased DYRK1B levels in A549 cells. Further investigation into the off-target effects of XMU-MP-1 unveiled the inhibition of Aurora kinases (AURKA and AURKB) as a potential causative factor. Consistently, AURK inhibitors VX-680 (tozasertib), MLN8237 (alisertib), AZD1152-HQPA (barasertib) resulted in the upregulation of DYRK1B expression in A549 cells. In summary, our findings indicate that the expression of DYRK1A and DYRK1B is differentially regulated in cancer cells and reveal that the kinase inhibitor XMU-MP-1 increases DYRK1B expression likely through off target inhibition of Aurora kinases.

Efficacy of photodynamic therapy using 5-aminolevulinic acid-induced photosensitization is enhanced in pancreatic cancer cells with acquired drug resistance

The use of 5-aminolevulinic acid (ALA) as a precursor for protoporphyrin IX (PpIX) is an established photosensitization strategy for photodynamic therapy (PDT) and fluorescence guided surgery. Ongoing studies are focused on identifying approaches to enhance PpIX accumulation as well as to identify tumor sub-types associated with high PpIX accumulation. In this study, we investigated PpIX accumulation and PDT treatment response with respect to nodule size in 3D cultures of pancreatic cancer cells (Panc1) and a derivative subline (Panc1OR), which has acquired drug resistance and exhibits increased epithelial mesenchymal transition. In monolayer and 3D culture dose response studies the Panc1OR cells exhibit significantly higher cell killing at lower light doses than the drug naïve cells. Panc1OR also exhibits increased PpIX accumulation. Further analysis of cell killing efficiency per molecule of intracellular PpIX indicates that the drug resistant cells are intrinsically more responsive to PDT. Additional investigation using exogenous delivery of PpIX also shows higher cell killing in drug resistant cells, under conditions which achieve approximately the same intracellular PpIX. Overall these results are significant as they demonstrate that this example of drug-resistant cells associated with aggressive disease progression and poor clinical outcomes, show increased sensitivity to ALA-PDT.

Honey Targets Ribosome Biogenesis Components to Suppress the Growth of Human Pancreatic Cancer Cells

Pancreatic cancer (PanCa) is one of the deadliest cancers, with limited therapeutic response. Various molecular oncogenic events, including dysregulation of ribosome biogenesis, are linked to the induction, progression, and metastasis of PanCa. Thus, the discovery of new therapies suppressing these oncogenic events and ribosome biogenesis could be a novel therapeutic approach for the prevention and treatment of PanCa. The current study was designed to investigate the anti-cancer effect of honey against PanCa. Our results indicated that honey markedly inhibited the growth and invasive characteristics of pancreatic cancer cells by suppressing the mRNA expression and protein levels of key components of ribosome biogenesis, including RNA Pol-I subunits (RPA194 and RPA135) along with its transcriptional regulators, i.e., UBTF and c-Myc. Honey also induced nucleolar stress in PanCa cells by reducing the expression of various nucleolar proteins (NCL, FBL, and NPM). Honey-mediated regulation on ribosome biogenesis components and nucleolar organization-associated proteins significantly arrested the cell cycle in the G2M phase and induced apoptosis in PanCa cells. These results, for the first time, demonstrated that honey, being a natural remedy, has the potential to induce apoptosis and inhibit the growth and metastatic phenotypes of PanCa by targeting ribosome biogenesis.

Combined PET Radiotracer Approach Reveals Insights into Stromal Cell-Induced Metabolic Changes in Pancreatic Cancer In Vitro and In Vivo.

Background/Objective Pancreatic stellate cells (PSCs) in pancreatic adenocarcinoma (PDAC) are producing extracellular matrix, which promotes the formation of a dense fibrotic microenvironment. This makes PDAC a highly heterogeneous tumor-stroma-driven entity, associated with reduced perfusion, limited oxygen supply, high interstitial fluid pressure, and limited bioavailability of therapeutic agents. Methods In this study, spheroid and tumor xenograft models of human PSCs and PanC-1 cells were characterized radiopharmacologically using a combined positron emission tomography (PET) radiotracer approach. [18F]FDG, [18F]FMISO, and [18F]FAPI-74 were employed to monitor metabolic activity, hypoxic metabolic state, and functional expression of fibroblast activation protein alpha (FAPα), a marker of activated PSCs. Results In vitro, PanC-1 and multi-cellular tumor spheroids demonstrated comparable glucose uptake and hypoxia, whereas FAPα expression was significantly higher in PSC spheroids. In vivo, glucose uptake as well as the transition to hypoxia were comparable in PanC-1 and multi-cellular xenograft models. In mice injected with PSCs, FAPα expression decreased over a period of four weeks post-injection, which was attributed to the successive death of PSCs. In contrast, FAPα expression increased in both PanC-1 and multi-cellular xenograft models over time due to invasion of mouse fibroblasts. Conclusion The presented models are suitable for subsequently characterizing stromal cell-induced metabolic changes in tumors using noninvasive molecular imaging techniques.

Adipose tissue-derived extracellular vesicles from obese mice suppressed splenocyte-mediated pancreatic cancer cell death.

Obesity is a risk factor for pancreatic cancer and negatively contributes to the immune system. However, the mechanisms by which obesity mediates these actions are still poorly understood. Recent studies have demonstrated that extracellular vesicles (EVs) are key mediators of communication between cells and may influence various aspects of cancer progression. We aim to explore the influence of EVs derived from adipose tissue of obese mice on cytokine production within the interactions between cancer cells and immune cells. We isolated EVs from the adipose tissue of both C57BL6/J mice and Ob/Ob mice. Subsequently, we treated EVs with Panc02 cells, the murine ductal pancreatic cancer cell line, which were co-cultured with splenocytes. Viability and SMAD4 gene expression were examined in Panc02 cells, and cytokine concentrations of IL-6, IL-4, IL-12, and IL-12p70 were measured in the cultured medium. Interestingly, we observed a significant reduction in splenocyte-mediated Panc02 cell death when treated with EVs derived from the adipose tissue of Ob/Ob mice, compared to those from C57BL6/J mice. Additionally, EVs from Ob/Ob mice-derived adipose tissue significantly increased the levels of IL-4, IL-2, and IL-12p70 in the culture media of Panc02 cells co-cultured with splenocytes, compared to EVs from C57BL6/J mice-derived adipose tissue. Adipose tissue-derived EVs from obese mice suppressed splenocyte-mediated Panc02 cell death and upregulated IL-4, IL-2, and IL-12p70 in cultured medium.

Dronedarone hydrochloride (DH) induces pancreatic cancer cell death by triggering mtDNA-mediated pyroptosis

Pancreatic cancer is one of the leading causes of cancer-associated mortality, with a poor treatment approach. Previous study has shown that inducing pyroptosis in pancreatic ductal adenocarcinoma (PDAC) slows the growth of PDACs, implying that pyroptosis inducers are potentially effective for PDAC therapy. Here, we found that Dronedarone hydrochloride (DH), an antiarrhythmic drug, induces pyroptosis in pancreatic cancer cells and inhibits PDAC development in mice. In PANC-1 cells, DH caused cell death in a dosage- and time-dependent manner, with only pyroptosis inhibitors and GSDMD silencing rescuing the cell death, indicating that DH triggered GSDMD-dependent pyroptosis. Further work revealed that DH increased mitochondrial stresses and caused mitochondrial DNA (mtDNA) leakage, activating the cytosolic STING-cGAS and pyroptosis pathways. Finally, we assessed the anti-cancer effects of DH in a pancreatic cancer mouse model and found that DH treatment suppressed pancreatic tumor development in vivo. Collectively, our investigation demonstrates that DH triggers pyroptosis in PDAC and proposes its potential effects on anti-PDAC growth.

Curcumin-loaded emulsome nanoparticles induces apoptosis through p53 signaling pathway in pancreatic cancer cell line PANC-1

Pancreatic cancer is a global health problem with a poor prognosis, limited treatment options and low survival rates of patients. Thus, the exploration of novel treatment approaches is crucial. Curcumin shows promise in pancreatic cancer. Curcumin has anticancer properties promoting apoptosis through the p53 pathway. However, adverse effects and low bioavailability are curcumin's main drawbacks and its delivery by nanoparticles could improve its effectiveness as a treatment option. Curcumin-loaded emulsome nanoparticles (CurEm) have shown promise in colorectal, hepatocellular, and prostate cancers. This study aims to evaluate the anticancer potential of CurEm in pancreatic cancer cell line PANC-1. The cytotoxic effects of CurEm on PANC-1 cells show cytotoxicity in dose and time-dependent manner. The selected dose 30 μM CurEm resulted spheroidal morphology in PANC-1 cells and colony forming and scratch assay conducted demonstrated significant growth inhibition and decrease in migration ability, respectively. Cell cycle analysis shows that CurEm induces G2/M arrest in PANC-1 cells. CurEm-treated PANC-1 cells showed a significant increase in p53 and Caspase 3 genes, while a significant decrease in Bcl-2 genes compared to untreated group. Western blot results showed parallel results to qPCR analysis for Bcl-2 protein levels. Interestingly, we saw low p53 protein levels in CurEm-treated PANC-1 cells. These findings shed light on the potential of CurEm as an effective and stable therapeutic approach for pancreatic cancer.

Folate-Functionalized Chitosan-PLGA Nanoparticles: A Novel approach for targeted osthole delivery in pancreatic cancer

Efficient drug delivery systems targeting cancer cells are crucial for enhancing cancer therapy. In this study, we developed PLGA nanoparticles coated with folate-conjugated chitosan (osthole-PLGA-NPs/CS-FA) to deliver osthole to cancer cells and investigated its inhibitory and molecular signaling mechanisms in the PANC-1 pancreatic cancer cell line. Field emission scanning electron microscopy (FESEM) revealed that osthole-PLGA-NPs/CS-FA had a spherical structure with a uniform size distribution. Dynamic light scattering (DLS) analysis showed an average size of 171.76 nm, a dispersion index 0.26, and a surface charge of + 33.08 mV, indicating stability and uniform dispersion. Fourier-transform infrared (FTIR) spectrum analysis confirmed the successful incorporation of osthole into the PLGA nanoparticles, with an encapsulation efficiency of 93.12 %. These physicochemical properties suggest efficient cellular uptake and targeted delivery. The antioxidant potential of osthole-PLGA-NPs/CS-FA was evaluated using the ABTS assay, showing concentration-dependent inhibition of free radicals with an IC50 value of 172.95 μg/mL. The anticancer properties were assessed using the MTT assay, demonstrating a significant and concentration-dependent cytotoxic effect on PANC-1 cells (IC50 = 31.2 μg/mL) with minimal impact on normal human foreskin fibroblast (HFF) cells. DAPI staining and flow cytometry analyses confirmed a concentration-dependent increase in apoptosis in PANC-1 cells. The nanoparticles induced upregulation of Bax and downregulation of Bcl2, indicating activation of the intrinsic mitochondrial apoptotic pathway. The anti-angiogenic activity of osthole-PLGA-NPs/CS-FA was evaluated using the chick chorioallantoic membrane (CAM) assay. The results showed significant inhibition of angiogenesis in a concentration-dependent manner, starting at 40 μg/mL and increasing up to 120 μg/mL. In conclusion, osthole-PLGA-NPs/CS-FA nanoparticles exhibit promising potential for targeted pancreatic cancer therapy by enhancing cellular uptake, inducing apoptosis, and inhibiting angiogenesis.

Blocking M2-Like Macrophage Polarization Using Decoy Oligodeoxynucleotide-Based Gene Therapy Prevents Immune Evasion for Pancreatic Cancer Treatment.

M2-like macrophages exhibit immunosuppressive activity and promote pancreatic cancer progression. Reactive oxygen species (ROS) affect macrophage polarization; however, the mechanism remains unclear. This study aimed to elucidate the underlying molecular basis and design a gene therapy to inhibit M2-like polarization. Microarray analysis and immunofluorescence staining were performed in M1-like and M2-like macrophages to ascertain the expression of CYBB, a major intracellular ROS source. Coculture assay and syngeneic orthotopic pancreatic cancer mice models were used to study the mechanism of M2-like skewing. Decoy oligodeoxynucleotides (ODNs) were designed to manipulate CYBB transcription to inhibit M2-like polarization and control tumor growth. Lipopolysaccharide treatment polarized U937 cells to M1-like macrophages in which CYBB expression was increased. In contrast, coculture with PANC-1 cells induced M2-like polarization in U937 cells with CYBB downregulation. High CD204 M2-like expression in combination with low CYBB expression was associated with the worst prognosis in patients with pancreatic cancer. STAT6 and HDAC2 in U937 cells were activated by cancer cell-derived IL4 after coculture and then bound to the CYBB promoter to repress CYBB expression, resulting in M2-like polarization. Diphenyleneiodonium, 8λ³-iodatricyclo[7.4.0.02,⁷]trideca-1(13),2,4,6,9,11-hexaen-8-ylium chloride that inhibits ROS production could block this action. Knockdown of STAT6 and HDAC2 also inhibited M2-like polarization and maintained the M1-like phenotype of U937 cells after coculture. Decoy ODNs interrupting the binding of STAT6 to the CYBB promoter counteracted M2-like polarization and tumor growth and triggered antitumor immunity in vivo. Gene therapy using STAT6-CYBB decoy ODNs can inhibit M2-like polarization, representing a potential therapeutic tool for pancreatic cancer.

Further Probing the Properties of a Unique Sponge-derived Alkaloid Through the Isolation of a New (-)-(5E)-(8R)-(14Z)-Mycothiazole Analogue.

Scale-up isolation of (+)-(5Z)-(8S)-(14Z)-mycothiazole (1) from Vanuatu specimens of C. mycofijiensis to semisynthesize (+)-(5Z)-(8S)-8-O-acetyl-(14Z)-mycothiazole (2) revealed a new diastereomer, (-)-(5E)-(8R)-(14Z)-mycothiazole (4). The structure of 4 was determined using HRMS, NMR, and comparing optical rotation to (-)-(5Z)-(8R)-(14Z)-mycothiazole (3) and 2. The maximum tolerated dose of 2 in mice was 0.1 mg/kg. The IC50 of 4 in PANC-1 and HepG2 cancer cell lines was 111.6 and 115.0 nM. Evaluation of 4 in C. elegans showed similar oxygen consumption compared to 1-2, and all compounds significantly increased the lifespan. The Z orientation at Δ5,6 is crucial for picomolar cytotoxicity but not for mitochondrial inhibition.

Growing Desmoplastic Three-Dimensional Pancreatic Cancer Spheroids from Co-Culture.

Pancreatic ductal adenocarcinoma (PDAC) is one of the deadliest cancers with a 5-year survival rate of <12%. The biggest barrier to therapy is the dense desmoplastic extracellular matrix (ECM) that surrounds the tumor and reduces vascularization, generally termed desmoplasia. A variety of drug combinations and formulations have been tested to treat the cancer, and although many of them show success pre-clinically, they fail clinically. It, therefore, becomes important to have a clinically relevant model available that can predict the response of the tumor to therapy. This model has been previously validated against resected clinical tumors. Here a simple protocol to grow desmoplastic three-dimensional (3D)-coculture spheroids is described that can naturally generating a robust ECM and do not require any external matrix sources or scaffold to support their growth. Briefly human pancreatic stellate cells (HPaSteC) and PANC-1 cells are used to prepare a suspension containing the cells in a 1:2 ratio, respectively. The cells are plated in a poly-HEMA coated, 96-well low attachment U-well plate. The plate is centrifuged to allow the cells to form an initial pellet. The plate is stored in the incubator at 37 °C with 5% CO2, and media is replaced every 3 days. Plates can be imaged at designated intervals to measure spheroid volume. Following 14 days of culture, mature desmoplastic spheroids are formed (i.e. average volume of 0.048 + 0.012 mm3(451 µm x 462.84 µm)) and can be utilized for experimental therapy assessment. Mature ECM components include collagen-I, hyaluronic acid, fibronectin, and laminin.

Systematic Evaluation of Affinity Enrichment Methods for O-GlcNAc Proteomics.

O-Linked β-N-acetylglucosamine (O-GlcNAc) modification (i.e., O-GlcNAcylation) on proteins plays critical roles in the regulation of diverse biological processes. However, protein O-GlcNAcylation analysis, especially at a large scale, has been a challenge. So far, a number of enrichment materials and methods have been developed for site-specific O-GlcNAc proteomics in different biological settings. Despite the presence of multiple methods, their performance for the O-GlcNAc proteomics is largely unclear. In this work, by using the lysates of PANC-1 cells (a pancreatic cancer cell line), we provided a head-to-head comparison of three affinity enrichment methods and materials (i.e., antibody, lectin AANL6, and an OGA mutant) for site-specific O-GlcNAc proteomics. The enriched peptides were analyzed by HCD product-dependent EThcD (i.e., HCD-pd-EThcD) mass spectrometry. The resulting data files were processed by three different data analysis packages (i.e., Sequest HT, Byonic, and FragPipe). Our data suggest that each method captures a subpopulation of the O-GlcNAc proteins. Besides the enrichment methods, we also observe complementarity between the different data analysis tools. Thus, combining different approaches holds promise for enhanced coverage of O-GlcNAc proteomics.

C-FOS inhibition promotes pancreatic cancer cell ferroptosis by transcriptionally regulating the expression of SLC7A11.

Cellular proto-oncogene C-Fos forms the AP-1 transcription factor by dimerizing with proto-oncogene c-Jun; this factor upregulates the transcription of genes associated with different malignancies. However, its functions in pancreatic adenocarcinoma (PAAD) remain poorly understood. In this study, the c-Fos was increased in PAAD cells and tissues through bioinformatic analysis, RT-PCR, and WB. In two PAAD cell lines, PANC-1 and BxPC-3, we performed c-Fos knockdown studies using short hairpin RNA (shRNA). Functional analysis indicated that c-Fos depletion in PAAD cells inhibits cell proliferation and promotes ferroptosis. Chromatin Immunoprecipitation (ChIP) and Dual-luciferase experiments showed that c-Fos coupled to the promoter region of SLC7A11 stimulated its transcription, providing mechanistic insight into the process. Moreover, SLC7A11 blocked the decline of proliferation and ferroptosis by c-Fos knockdown in PAAD cells. Furthermore, a xenograft nude mouse model was established to study the impact of c-Fos on tumorigenesis in vivo. Depletion of c-Fos could suppress PC tumor growth and the expressions of SLC7A11, ki-67, and 4HNE, but overexpression of SLC7A11 reversed this process. In summary, our investigation has shown that c-Fos acts as a transcriptional regulator of SLC7A11, which may enhance tumour growth in pancreatic cancer by inhibiting ferroptosis. These results indicate that c-Fos might be a promising target for treating ferroptosis in PAAD.