HPDE6-C7 Cells Research Articles

USP33 promotes caerulein-induced apoptotic, oxidative and inflammatory injuries in acute pancreatitis by deubiquitinating TRAF3.

Background: Tumor necrosis factor receptor associated factor 3 (TRAF3) and deubiquitinating enzyme ubiquitin-specific protease 33 (USP33) have been identified to play important roles in inflammatory diseases, including acute pancreatitis (AP). Here, we aimed to explore whether USP33 affected AP progression by affecting TRAF3 expression through deubiquitination.Methods: Caerulein-treated HPDE6-C7 cells were used to mimic AP conditions in vitro. Levels of mRNAs and proteins were examined by qRT-PCR and Western blot. Cell proliferation and apoptosis were evaluated using CCK-8 assay, EdU assay and flow cytometry. Cell oxidative stress was assessed by detecting the production of superoxide dismutase and malonaldehyde. ELISA analysis detected IL-6 and TNF-α levels. Macrophage M1 polarization was evaluated by flow cytometry. Cellular ubiquitination analyzed the ubiquitination effect on TRAF3. Protein interaction between USP33 and TRAF3 was identified by immunofluorescence staining.Results: Caerulein dose-dependently induced apoptosis, oxidative stress, and inflammatory response in HPDE6-C7 cells and promoted macrophage M1 polarization to enhance inflammation (P < 0.05). TRAF3 was highly expressed in AP patients (3.5±1.10 vs. 1.0 ±0.74, P < 0.05) and caerulein-induced HPDE6-C7 cells (3.3 ±0.34 vs. 1.0 ±0.10, P < 0.05). Knockdown of TRAF3 protected HPDE6-C7 cells from caerulein-induced apoptotic, oxidative and inflammatory injuries. Mechanistically, USP33 interacted with TRAF3 and induced TRAF3 deubiquitination to up-regulate its expression (P < 0.05). Further analyses showed that USP33 knockdown reversed caerulein-induced apoptosis, oxidative stress and inflammation in HPDE6-C7 cells by TRAF3 (P < 0.05). Moreover, USP33-TRAF3 activated the NF-κB pathway (P < 0.05).Conclusion: USP33 promoted caerulein-induced apoptosis, oxidative stress and inflammation in pancreatic ductal cells by deubiquitinating TRAF3, indicating a novel insight into the pathogenesis of AP.

M6A-activated BACH1 exacerbates ferroptosis by epigenetic suppression HSPB1 in severe acute pancreatitis.

Severe acute pancreatitis (SAP) is characterized by acute inflammation of the pancreas. The transcription factor BTB and CNC homology 1 (BACH1) has been implicated in various biological processes, including oxidative stress, apoptosis, and cell cycle regulation. However, its involvement in the pathogenesis of SAP remains relatively understudied. In the present work, our data demonstrated that BACH1 level was significantly increased in SAP patients, cellular, and animal models, while heat shock protein B1 (HSPB1) expression was weakened. Mechanistic assays validated that BACH1 acted as a transcriptional inhibitor of HSPB1. Moreover, HPDE6-C7 cells were stimulated with cerulein (Cer) and LPS to mimic the pathological stages of SAP in vitro. Depletion of BACH1 remarkably improved cell survival and alleviated the oxidative stress, ferroptosis, and inflammatory responses in SAP cell models. However, these changes were dramatically reversed upon co-inhibition of HSPB1. Animal findings confirmed that loss of BACH1 decreased pancreatic injury, inflammatory responses, and ferroptosis, but these effects were weakened by HSPB1 silence. Overall, these findings elucidate that the overexpression of BACH1 favors the ferroptosis and inflammation by transcriptionally inhibiting HSBP1, thereby exacerbating SAP progression.

Redox proteomics of PANC-1 cells reveals the significance of HIF-1 signaling protein oxidation in pancreatic ductal adenocarcinoma pathogenesis

BackgroundProtein cysteine oxidation is substantially involved in various biological and pathogenic processes, but its implications in pancreatic cancer development remains poorly understood.Methods and resultsIn this study, we performed a global characterization of protein oxidation targets in PDAC cells through iodoTMT-based quantitative proteomics, which identified over 4300 oxidized cysteine sites in more than 2100 proteins in HPDE6c7 and PANC-1 cells. Among them, 1715 cysteine residues were shown to be differentially oxidized between HPDE6c7 and PANC-1 cells. Also, charged amino acids including aspartate, glutamate and lysine were significantly overrepresented in flanking sequences of oxidized cysteines. Differentially oxidized proteins in PANC-1 cells were enriched in multiple cancer-related biological processes and signaling pathways. Specifically, the HIF-1 signaling proteins exhibited significant oxidation alterations in PANC-1 cells, and the reduced PHD2 oxidation in human PDAC tissues was correlated with lower survival time in pancreatic cancer patients.ConclusionThese investigations provided new insights into protein oxidation-regulated signaling and biological processes during PDAC pathogenesis, which might be further explored for pancreatic cancer diagnosis and treatment.

Mitochondrial calcium uniporter promotes mitophagy by regulating the PINK1/Parkin pathway in caerulein‑treated pancreatic ductal epithelial cells invitro.

The mitochondrial calcium uniporter (MCU) is a major protein for the uptake of mitochondrial calcium to regulate intracellular energy metabolism, including processes such as mitophagy. The present study investigated the effect of the MCU on mitophagy in pancreatic ductal epithelial cells (PDECs) in acute pancreatitis (AP) in vitro. The normal human PDECs (HPDE6-C7) were treated with caerulein (CAE) to induce AP-like changes, with or without ruthenium red to inhibit the MCU. The mitochondrial membrane potentials (MMPs) and mitochondrial Ca2+ levels were analyzed by fluorescence. The expression levels of MCU, LC3, p62, and translocase of the outer mitochondrial membrane complex subunit 20 (TOMM20), putative kinase 1 (PINK1), and Parkin were measured by western blotting and immunofluorescence. Mitophagy was observed by confocal fluorescence microscopy and transmission electron microscopy. The results showed that CAE increased the MCU protein expression, mitochondrial Ca2+ levels, MMP depolarization and the protein expression of mitophagy markers including the LC3II/I ratio, PINK1, and Parkin. CAE decreased the protein expression of p62 and TOMM20, and promoted the formation of mitophagosomes in HPDE6-C7 cells. Notably, changes in these markers were reversed by inhibiting the MCU. In conclusion, an activated MCU may promote mitophagy by regulating the PINK1/Parkin pathway in PDECs in AP.

Graphene Nanocomposites in the Treatment of Pancreatic Cancer

The application value of titanium dioxide (TiO2)/graphene nanocomposites in photothermal therapy of pancreatic cancer (PC) was explored. Using scale graphite as raw material, graphene was obtained by Hummer oxidation method and hydrazine hydrate reduction method, and then TiO2/graphene nanocomposites were prepared by ultrasonic heating. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and degraded methyl orange solution were adopted to detect the surface structure, particle size, element morphology, and photocatalytic activity under different composite ratios, different sonication times, and different heating temperatures. Human normal pancreatic ductal epithelial cell line HPDE6-C7 and human metastatic PC cell AsPC-1 were adopted as research models. The cytotoxicity of TiO2/graphene nanocomposites and the killing effect of photothermal therapy based on TiO2/graphene nanocomposites were analyzed by water soluble tetrazolium salt colorimetric assay (WST-1) and methyl thiazolyl tetrazolium salt colorimetric assay (MTT). The results suggested that when the ratio of graphene to TiO2 was 50:1, the ultrasonic time was 100 min, and the heating temperature was 200 °C, TiO2 was better attached to the surface of graphene, the distribution of particles was relatively more uniform, and the concentration of methyl orange was relatively lowest. The XRD pattern showed that the diffraction peak of the doped TiO2/graphene nanocomposite was basically the same as that of the pure TiO2. When the ultrasonic time was 100 min, the diffraction peak intensity in the XRD pattern was the largest. As for AsPC-1 cells, the cell viability was obviously lower than 0.1/1/10/100 μm/mL when the concentration of TiO2/graphene nanocomposites was 500 μm/mL (P &lt;0.05). For HPDE6-C7 cells, when the concentration of TiO2/graphene nanocomposites was 100 and 500 μm/mL, the cell viability was obviously lower than 0.1/1/10 μm/mL (P &lt;0.05), and 500 μm/mL was the lowest. The cell killing rate in group D was clearly higher as against groups A, B, and C (P &lt;0.05). Graphene: The optimal preparation conditions of TiO2/graphene nanocomposites are 50:1, 100 min of ultrasound time, and 200 μC of composite temperature. The photothermal therapy based on TiO2/graphene nanocomposites can effectively kill PC cells, and has a good potential in the field of hyperthermia for pancreatic tumors.

Circadian Genes MBOAT2/CDA/LPCAT2/B4GALT5 in the Metabolic Pathway Serve as New Biomarkers of PACA Prognosis and Immune Infiltration.

Pancreatic cancer (PACA) is a highly malignant tumor with a poor prognosis. Recent studies have discovered substantial differences in the expression levels of several circadian genes in PACA samples compared to normal samples. The goal of this research was to find differentially expressed rhythm genes (DERGs) in PACA samples and determine their role in the development of PACA. A total of 299 DERGs were identified in PACA, including 134 downregulated genes and 165 upregulated genes. DERGs were significantly abundant in the metabolic pathway and immune response pathways, according to GO and KEGG analyses. Survival analyses showed that PACA patients who had higher expression levels of MBOAT2/CDA/LPCAT2/B4GALT5 had shorter overall survival times. Using cell assay verification, the mRNA levels of MBOAT2/CDA/LPCAT2/B4GALT5 in Patu-8988 and PNAC-1 cells were found to be significantly higher than those in HPDE6-C7 cells, which was in line with previous studies on PACA patient data. Through conducting univariate Cox analysis, it was determined that MBOAT2/CDA/LPCAT2/B4GALT5 expression, age and grade were all high-risk factors. The MBOAT2/CDA/LPCAT2/B4GALT5 genes were independently correlated with overall survival, according to the multivariate Cox analysis. The proportion of immune cells in PACA and normal samples significantly changed, according to the immune infiltration analysis. Furthermore, MBOAT2/CDA/LPCAT2/B4GALT5 expression levels were significantly related to the level of immune cell infiltration. The protein-protein interaction network of the MBOAT2/CDA/LPCAT2/B4GALT5 genes included 54 biological nodes and 368 interacting genes. In conclusion, the finding of these DERGs adds to the investigation of the molecular processes underlying the onset and progression of PACA. In the future, DERGs may serve as prognostic and diagnostic biomarkers as well as drug targets for chronotherapy in PACA patients.

Preparation and characterization of PLGA-based magnetic polymer nanoparticles for targeting pancreatic adenocarcinoma.

This study aims to develop a novel tumor-targeted molecular probe for pancreatic cancer imaging. The objective of this is to prepare a CKAAKN peptide-conjugated poly (lactic-co-glycolic acid)-poly (ethylene glycol) amphiphilic polymer (CKAAKN-PEG-PLGA) for the tumor-targeted delivery of magnetic resonance imaging (MRI) contrast agent ultrasmall superparamagnetic iron oxide (USPIO). The early diagnosis of pancreatic cancer is crucial for improving its prognosis, but the clinical application of many diagnostic methods is limited owing to a lack of specificity and sensitivity. Methods CKAAKN-PEG-PLGA was synthesized by the amidation reaction. USPIO-loaded polymeric magnetic nanoparticles (USPIO@CKAAKN-PEG-PLGA) were prepared by the emulsion solvent evaporation method. The in vitro tumor targeting and bio-safety of nanoparticles were evaluated by targeted cellular uptake, MR imaging and MTT assay. Results USPIO@CKAAKN-PEG-PLGA nanoparticles showed excellent biosafety with an average diameter of 104.5 ± 4.1 nm. Modification of CKAAKN peptide could improve USPIO binding ability to internalize into CKAAKN-positive BxPC-3 cells compared with non-targeting nanoparticles and the control group. The relative fluorescence intensity in BxPC-3 and HPDE6-C7 cells was 23.77 ± 4.18 and 6.44 ± 2.10 (p＜0.01), and respectively became 16.13 ± 0.83 and 11.74 ± 1.74 after the addition of free CKAAKN peptide. In vitro MR imaging studies showed that an obvious decrease in the signal intensity was observed in the targeted nanoparticles group incubated with BxPC-3 and HPDE6-C7 cells (P<0.05). Conclusion USPIO@CKAAKN-PEG-PLGA nanoparticles could significantly enhance the tumor specificity of USPIO in CKAAKN-positive pancreatic cancer cell BxPC-3, which is expected as a promising candidate of MRI contrast enhancement for the early diagnosis of pancreatic cancer.

Gelsolin inhibits autophagy by regulating actin depolymerization in pancreatic ductal epithelial cells in acute pancreatitis

Gelsolin (GSN) can sever actin filaments associated with autophagy. This study investigated how GSN-regulated actin filaments control autophagy in pancreatic ductal epithelial cells (PDECs) in acute pancreatitis (AP). AP was produced in a rat model and PDECs using caerulein (CAE). Rat pancreatic duct tissue and HPDE6-C7 cells were extracted at 6, 12, 24, and 48 h after CAE treatment. HPDE6-C7 cells in the presence of CAE were treated with cytochalasin B (CB) or silenced for GSN for 24 h. Pancreatic histopathology and serum amylase levels were analyzed. Cellular ultrastructure and autophagy in PDECs were observed by transmission electron microscopy after 24 h of CAE treatment. The expression of GSN and autophagy markers LC3, P62, and LAMP2 was evaluated in PDECs by immunohistochemistry and western blotting. Actin filaments were observed microscopically. Amylase levels were highest at 6 h of AP, and pancreatic tissue damage increased over time. Mitochondrial vacuolization and autophagy were observed in PDECs. CAE increased GSN expression in these cells over time, increased the LC3-II/LC3-I ratio and LAMP2 expression at 24 and 6 h of treatment, respectively, and decreased P62 expression at all time points. CB treatment for 24 h decreased the LC3-II/LC3-I ratio and LAMP2 expression, increased P62 levels, but had no impact on GSN expression in CAE-treated PDECs. CAE induced actin depolymerization, and CB potentiated this effect. GSN silencing increased the LC3-II/LC3-I ratio and LAMP2 expression and reduced actin depolymerization in CAE-treated PDECs. GSN may inhibit autophagosome biogenesis and autophagosome-lysosome fusion by increasing actin depolymerization in PDECs in AP.

Effect of SNHG11/miR-7-5p/PLCB1 Axis on Acute Pancreatitis through Inhibiting p38MAPK Pathway.

Acute pancreatitis (AP) is an inflammatory disease of the pancreas. A growing number of studies have shown that long noncoding RNAs (lncRNAs) play an important role in AP progression. Here, we aimed to elucidate the role of Small Nucleolar RNA Host Gene 11(SNHG11) and its underlying molecular mechanisms behind AP progression. The in vivo and in vitro AP cell models were established by retrograde injection of sodium taurocholate and caerulein stimulation into AR42J cells and HPDE6-C7 cells, respectively. A bioinformatics website predicted the relationship between SNHG11, miR-7-5p, and Phospholipase C Beta 1(PLCB1) and validated it with a dual-luciferase reporter assay and an RNA immunoprecipitation (RIP) assay. AR42J cells and HPDE6-C7 cells were transfected with an overexpression of plasmids or shRNA to investigate the effects of the SNHG11/miR-7-5p/PLCB1 axis on cell proliferation and apoptosis, inflammatory cytokine secretion, and acute pancreatitis. Low expression of SNHG11 and PLCB1 and high expression of miR-7-5p were observed in AP pancreatic tissue and AP cell models. SNHG11 overexpression inhibited apoptosis and inflammatory responses induced by caerulein. Simultaneously, we discovered that SNHG11 regulates PLCB1 expression by sponging miR-7-5p. PLCB1 overexpression abrogated inflammatory damage exacerbated by miR-7-5p enrichment. In addition, the SNHG11/miR-7-5p/PLCB1 axis could be involved in caerulein-induced inflammatory injury by participating in the p38MAPK signaling pathway. The overexpressed SNHG11/miR-7-5p/PLCB1 axis can inhibit AP progression by participating in the p38MAPK signaling pathway, thereby providing a potential therapeutic target and therapeutic direction for AP therapy.

HTR1D functions as a key target of HOXA10-AS/miR-340-3p axis to promote the malignant outcome of pancreatic cancer via PI3K-AKT signaling pathway

Competing endogenous RNAs (ceRNAs) are a newly discovered class of molecular regulators involved in many diseases, especially tumors. Therefore, exploration of the potential ceRNA regulatory network regarding the occurrence and development of pancreatic cancer will provide a new theoretical basis for its diagnosis and treatment. Based on the above background, we applied a bioinformatics approach to mine the public database The Cancer Genome Atlas (TCGA) and performed a series of subsequent molecular biology assays to confirm the hypothesis that HOXA10-AS/ miR-340-3p/HTR1D axis could modulate the malignant progression of pancreatic cancer. Here, our present study demonstrated that the expression level of HTR1D, positively correlated with the level of lncRNA HOXA10-AS and negatively associated with the level of miR-340-3p, was significantly increased in pancreatic cancer cell lines (PCs) compared with that in normal HPDE6-C7 cells. Knocking down HTR1D obviously inhibited the proliferation and migration of PCs and promoted apoptosis by upregulating p-AKT. Elevated miR-340-3p blocked the progression of pancreatic cancer by downregulating HTR1D. Lessened level of lncRNA HOXA10-AS reduced the sponging of miR-340-3p, resulting in an increase of miR-340-3p and a subsequent decrease of HTR1D to ultimately suppress the malignant biological behaviors of cancer. These data illustrated that the HOXA10-AS/miR-340-3p/HTR1D ceRNA axis acted a crucial part in the malignant biological behavior of pancreatic cancer in an AKT-dependent manner.

Interfering hsa_circ_0073748 alleviates caerulein-induced ductal cell injury in acute pancreatitis by inhibiting miR-132-3p/TRAF3/NF-κB pathway

ABSTRACT Circular RNA hsa_circ_0073748 (circ_0073748) is upregulated in patients with acute pancreatitis (AP), a clinically common sudden inflammatory response. MicroRNA (miR)-132-3p is a stress-induced factor with high conservation between species. Herein, expression and role of circ_0073748 and miR-132-3p in caerulein-induced pancreatitis were studied. Expression levels of circ_0073748, miR-132-3p, TNF receptor associated factor 3 (TRAF3), Bcl-2 and Bcl-2-associated X protein (Bax) were examined by reverse transcription-quantitative PCR and Western blotting. Cell proliferation was measured by MTS and EdU assays. Flow cytometry and assay kits detected apoptosis, inflammatory, and oxidative responses. Western blotting detected nuclear factor (NF)-κB signaling pathway. Circ_0073748 was upregulated and miR-132-3p was downregulated in AP patients’ plasma and human pancreatic ductal HPDE6-C7 cells with caerulein induction. Interfering circ_0073748 and reinforcing miR-132-3p improved cell viability, EdU incorporation, and superoxide dismutase (SOD) activity of caerulein-treated HPDE6-C7 cells but suppressed malonaldehyde (MDA), IL-6 and TNF-α levels and apoptosis rate. Moreover, TRAF3 downregulation was allied with circ_0073748 silencing and miR-132-3p overexpression in caerulein-induced HPDE6-C7 cells. Mechanically, circ_0073748 was identified as a sponge for miR-132-3p to modulate TRAF3 expression, thus establishing a competitive endogenous RNA (ceRNA) regulation model. Notably, circ_0073748 blockage could suppress expressions of phosphorylated P65 (p-P65) and p-IκB in caerulein-induced HPDE6-C7 cells by promoting miR-132-3p and inhibiting TRAF3. Silencing circ_0073748 and upregulating miR-132-3p could alleviate caerulein-induced HPDE6-C7 injury and inactivate canonical NF-κB signal by inhibiting TRAF3. Circ_0073748/miR-132-3p/TRAF3 ceRNA pathway might be one underlying mechanism and therapeutic target of caerulein-induced AP.

Combination therapy with low-frequency ultrasound irradiation and radiofrequency ablation as a synergistic treatment for pancreatic cancer

ABSTRACT We aim to evaluate the efficacies of combination therapy with low-frequency ultrasound-stimulated microbubbles (USMB) and radiofrequency ablation (RFA) on suppressing the proliferation of pancreatic cancer cell and treating Panc02 subcutaneous xenograft mice. The proliferation of HPDE6-C7 and Panc02 cells after the treatment of USMB and RFA alone or combination were evaluated by CCK-8 assay. Scratch test was performed to assess the cell migration capability. Panc02-bearing mice were received 14-day treatment of USMB and RFA alone or combination. Tumor size and survival rate were recorded once two days. The serum levels of immune-related factors and changes of apoptosis- and autophagy-related factors were detected by ELISA and western blotting methods. As a result, CKK-8 assays revealed significant inhibition on Panc02 cell proliferation in combination therapy with USMB and RFA relative to other groups (all p < 0.05). Strong synergistic effect of USMB combined with RFA was confirmed via the calculated combination index (CI) <0.4. In addition, combination therapy of USMB and RFA significantly inhibited the migration of Panc02 cells. Moreover, combined treatment remarkably inhibited the size and width of xenograft and improved the survival in Panc02-bearing mice. Furthermore, 14-day combination therapy of USMB and RFA in Panc02-bearing mice significantly facilitated the apoptosis and autophagy of tumor cells. In summary, combination therapy of USMB and RFA showed synergistic anti-tumor efficacies on Panc02 cells attributing to the promotion on apoptosis and autophagy in Panc02 subcutaneous xenograft mice.

Specificity protein 1-activated bone marrow stromal cell antigen 2 accelerates pancreatic cancer cell proliferation and migration.

Bone marrow stromal cell antigen 2 (BST2) has been reported to act as an oncogene in the tumorigenesis of numerous types of cancer. Bioinformatics analysis has predicted the binding interaction between BST2 and specificity protein 1 (SP1) and the involvement of SP1 in pancreatic cancer. Therefore, the present study set out to verify this interaction and determine how it may affect pancreatic cancer progression. Normal human pancreatic duct epithelial cells (HPDE6-C7) and pancreatic cancer cell lines (SW1990, BxPC3, PANC1 and PSN-1) were selected for western blotting and reverse transcription-quantitative PCR detection of BST2 expression. Colony formation, Cell Counting Kit-8 and wound healing assays were performed to detect the proliferative and migratory abilities of PANC1 cells following transfection with small interfering RNA against BST2. The expression of proliferation and migration markers were assayed using western blotting. Chromatin immunoprecipitation and luciferase reporter assays were employed to verify the bioinformatics prediction of BST2-SP1 binding. PANC1 cell proliferation and migration were analyzed following BST2 knockdown and SP1 overexpression. In comparison with HPDE6-C7 cells, all four pancreatic cancer cell lines were found to exhibit increased BST2 expression levels to varying degrees, with the highest levels observed in PANC1 cells. BST2 knockdown inhibited PANC1 cell colony formation, proliferation and migration. Additionally, SP1 was shown to bind to the BST2 promoter and could promote PANC1 cell proliferation and migration when overexpressed. However, BST2 knockdown rescued SP1 overexpression-induced PANC1 cell colony formation, proliferation and migration. In conclusion, activation of BST2 by the transcription factor SP1 was shown to accelerate pancreatic cancer cell proliferation and migration, suggesting that BST2 and SP1 may be plausible therapeutic targets in targeted therapy for pancreatic cancer.

Role of tumor necrosis factor receptor‑associated factor 6 in pyroptosis during acute pancreatitis.

Acute pancreatitis (AP) is hypothesized to be related to the activation of an inflammatory response induced by pyroptosis. The aim of the present study was to investigate the potential role of tumor necrosis factor receptor-associated factor 6 (TRAF6) in pyroptosis in an AP rat model and the human pancreatic ductal epithelial HPDE6C7 cell line. In vivo, AP was induced by intraperitoneal injection of caerulein (CAE) in rats. The rats were sacrificed at 24 or 48 h after the final CAE injection. In vitro, HPDE6C7 cells were treated with CAE for 12, 24 and 48 h. Moreover, TRAF6 was overexpressed and treated with CAE for 48 h. Histopathological changes of pancreatic, serum and supernatant inflammatory cytokines and pyroptosis-related mRNA and protein expression levels were determined by histopathological scores, ELISA, reverse transcription-quantitative PCR and western blotting. In addition, pyroptosis morphological changes were also determined by Hoechst/PI staining in HPDE6C7 cells. Results showed that AP was observed in the CAE-induced rat model, and that serum IL-1β and IL-18 levels, and TRAF6, NLR pyrin domain containing 3 (NLRP3), caspase-1 and caspase-3 mRNA and protein expression levels were increased. Similar in HPDE6C7 cells, CAE treatment caused supernatant IL-1β level, NLRP3 and caspase-1 mRNA expression levels to significantly increase. After TRAF6 overexpression and CAE treatment, supernatant IL-1β level, caspase-1 protein expression level, and NLRP3 and caspase-3 mRNA and protein expression levels were also significantly increased. Furthermore, cells exhibited red fluorescence in Hoechst/PI staining, which can be used as a method of detecting pyroptosis activation. The results also showed that the red fluorescence was stronger after CAE treatment or TRAF6 overexpression plus CAE treatment. In conclusion, TRAF6 and caspase-1/3 signaling pathways were involved in the pathogenesis of CAE-induced AP in rats. Pyroptosis was activated by CAE and TRAF6 overexpression via the caspase-1/3 signaling pathways in HPDE6C7 cells.

SiRNA-Loaded Hydroxyapatite Nanoparticles for KRAS Gene Silencing in Anti-Pancreatic Cancer Therapy.

Pancreatic carcinoma (PC) is greatly induced by the KRAS gene mutation, but effective targeted delivery for gene therapy has not existed. Small interfering ribonucleic acid (siRNA) serves as an advanced therapeutic modality and holds great promise for cancer treatment. However, the development of a non-toxic and high-efficiency carrier system to accurately deliver siRNA into cells for siRNA-targeted gene silencing is still a prodigious challenge. Herein, polyethylenimine (PEI)-modified hydroxyapatite (HAp) nanoparticles (HAp-PEI) were fabricated. The siRNA of the KRAS gene (siKras) was loaded onto the surface of HAp-PEI via electrostatic interaction between siRNA and PEI to design the functionalized HAp-PEI nanoparticle (HAp-PEI/siKras). The HAp-PEI/siKras was internalized into the human PC cells PANC-1 to achieve the maximum transfection efficiency for active tumor targeting. HAp-PEI/siKras effectively knocked down the expression of the KRAS gene and downregulated the expression of the Kras protein in vitro. Furthermore, the treatment with HAp-PEI/siKras resulted in greater anti-PC cells’ (PANC-1, BXPC-3, and CFPAC-1) efficacy in vitro. Additionally, the HAp-PEI exhibited no obvious in vitro cytotoxicity in normal pancreatic HPDE6-C7 cells. These findings provided a promising alternative for the therapeutic route of siRNA-targeted gene engineering for anti-pancreatic cancer therapy.

Combination therapy with interleukin-15 and metformin as a synergistic treatment for pancreatic cancer.

To investigate the efficacies and mechanisms of combination therapy with interleukin-15 (IL-15) and metformin (Met) on suppressing pancreatic cell proliferation and protecting Panc02-bearing mice. MTT assays were applied to assess the inhibitory effects of IL-15 combined Met or Met and IL-15 alone on proliferation of normal HPDE6-C7 and Panc02 cells. After tumor grew up to 150 mm3, the Panc02-bearing xenograft model mice were randomly divided into saline group, IL-15 and Met alone group and combined treatment group (n=8) with the administration of each agent every other day for three weeks, and survival rates were recorded. The changes in tumor size, expression levels of the apoptosis, autophagy as well as Akt/mTOR/STAT3-related factors in tumor tissues were all measured. MTT assays demonstrated significantly inhibiting efficacy of combination therapy with IL-15 and Met on Panc02 cell proliferation compared to other groups (all p<0.05) with combination index<1 showing evident synergistic effect. Moreover, the apoptosis rate of Panc02 cell under combined treatment were 95.5±3.2% and significantly higher than those of others (all p<0.01). In addition, combined administration remarkably inhibited the growth of pancreatic carcinoma, and improved survival rate of Panc02-bearing model with less body weight loss. Furthermore, combined treatment significantly downregulated anti-apoptotic proteins as well as Akt/mTOR/STAT3 signaling pathway and upregulated autophagy related factors, respectively, compared with those of monotherapy groups in both Panc02 cells and tumor tissues. Combined treatment of IL-15 with Met showed synergistic anti-tumor efficacies on Panc02 cells attributing to promotion on apoptosis, autophagy and inhibition on Akt/mTOR/STAT3 signaling-transduction in Panc02-bearing model mice.

The structure elucidation of novel arabinogalactan LRP1-S2 against pancreatic cancer cells growth in vitro and in vivo

The fruit of Lycium ruthenicum Murr is used as traditional medicine and functional food. Previously we reported that one RG-I pectin from this fruit might inhibit pancreatic cancer cells growth. We further hypothesized that there might be other type of polysaccharides in this fruit also have anti-tumor effect. Here, we showed novel structure of a homogeneous polysaccharide named LRP1-S2 from this fruit and its anti-pancreatic cancer effect. Structure analyses suggested that LRP1-S2 was a novel arabinogalactan with the molecular weight (Mw) of 17.0 kDa. Bioactivity test showed that LRP1-S2 might attenuate the proliferation of pancreatic cancer cells in vitro and in vivo without significant cytotoxicity to normal pancreatic HPDE6-C7 cells and LO2 liver cells. Mechanism study indicated that it might induce apoptosis of BxPC-3 by inactivating P38 MAPK/NF-κB and GSK-3β/β-Catenin signaling pathways. These results suggested that LRP1-S2 could be a potential anti-tumor leading compound for functional food and new drug development. Chemical compoundsarabinogalactan, pectin, galactan, arabinan, RN-1, HH1-1, LRP1-S2, LRP3-S1.

MiR-34a/SIRT1 Axis Modulating Therapeutic Effect of Olaparib on Pancreatic Cancer through Suppressing PARP1 and EMT

ABSTRACT This study analyzed functions of miR-34a and SIRT1 in modulating efficacy of Olaparib in pancreatic cancer in vitro. RNA expressions of miR-34a and SIRT1 were evaluated through RT-qPCR in HPDE6-C7, SW1990, PANC-1 and MIA PaCa-2 cells. MiR-34a was promoted in cancer cell lines while SIRT1 was decreased. Luciferase reporter assay verified bindings between miR-34a and SIRT1. Moreover, E-cadherin was promoted by miR-34a mimics and SIRT1 suppression while N-cadherin and Vimentin were both downregulated. Additionally, PARP1 protein expression was increased after miR- 34a promotion and SIRT1 downregulation. Besides that, PARP1 protein levels and EMT were significantly inhibited after treated by Olaparib (0, 0.5, 1 and 1.5ìM). In Olaparib-treated cancer cells, SIRT1, PARP1 and EMT were all distinctly decreased after SIRT1 suppression and overexpression of miR-34a induced much lower level of SIRT1.

Proteome-Wide Alterations of Asymmetric Arginine Dimethylation Associated With Pancreatic Ductal Adenocarcinoma Pathogenesis.

Arginine methylation catalyzed by protein arginine methyltransferases (PRMTs) performs essential roles in regulating cancer initiation and progression, but its implication in pancreatic ductal adenocarcinoma (PDAC) requires further elucidation. In this study, asymmetric dimethylarginine (ADMA)-containing peptides in PDAC cell line PANC-1 were identified by label-free quantitative proteomics combined with affinity purification, using human non-cancerous pancreatic ductal epithelium cell line HPDE6c7 as the control. In total, 289 ADMA sites in 201 proteins were identified in HPDE6c7 and PANC-1 cells, including 82 sites with lower dimethylation and 37 sites with higher dimethylation in PANC-1 cells compared with HPDE6c7 cells. These ADMA-containing peptides demonstrated significant enrichment of glycine and proline residues in both cell lines. Importantly, leucine residues were significantly enriched in ADMA-containing peptides identified only in HPDE6c7 cells or showing lower dimethylation in PANC-1 cells. ADMA-containing proteins were significantly enriched in multiple biological processes and signaling cascades associated with cancer development, such as spliceosome machinery, the Wnt/β-catenin, Hedgehog, tumor growth factor beta (TGF-β), and mitogen-activated protein kinase (MAPK) signaling pathways. Moreover, PDAC cell lines with enhanced cell viability showed lower PRMT4 protein abundance and global ADMA-containing protein levels compared with HPDE6c7. PRMT4 overexpression partially recovered ADMA-containing protein levels and repressed viability in PANC-1 cells. These results revealed significantly altered ADMA-containing protein profiles in human pancreatic carcinoma cells, which provided a basis for elucidating the pathogenic roles of PRMT-mediated protein methylation in pancreatic cancer.

RPL21 siRNA Blocks Proliferation in Pancreatic Cancer Cells by Inhibiting DNA Replication and Inducing G1 Arrest and Apoptosis.

BackgroundOur previous study showed that the ribosomal protein L21 (RPL21) may play an important role in the development and survival of pancreatic cancer. In this article, RNA interference (RNAi) experiments were performed with RPL21-specific small interfering RNA (siRNA) to elucidate the mechanism by which RPL21 controls PC PANC-1 and BxPC-3 cell proliferation.MethodsIn the present study, PANC-1, BxPC-3 cells, and BALB/c nude mice were used to investigate antitumor effect and mechanism by which RPL21 controls cell proliferation and apoptosis in vitro and in vivo. The effects of RPL21 knockdown on PANC-1 and BxPC-3 cell proliferation, cell cycle and cell apoptosis in vitro were determined using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assays and flow cytometry assay. The mechanism of RPL21 regulating cell proliferation was investigated using transcriptome sequencing analysis and luciferase reporter assay. The effects of RPL21 knockdown on PANC-1 and BxPC-3 cell proliferation in vivo were determined using BALB/c nude mice tumor model.ResultsIn PANC-1 and BxPC-3 cells, the knockdown of RPL21 expression with corresponding siRNA suppressed cell proliferation in vitro and in vivo, inhibited DNA replication, and induced arrests in the G1 phase of the cell cycle. Further results showed that the mini-chromosome maintenance (MCM) protein family (MCM2-7), CCND1 and CCNE1 were down-regulated significantly in PANC-1 and BxPC-3 cells after transfected with RPL21 siRNA, which suggests that the suppression of DNA replication is due to the reduced expression of MCM2-7 family, and the induction of G1 arrest is correlated with the inhibition of CCND1 and CCNE1. Luciferase reporter assay showed that RPL21 controls the DNA replication and G1-S phase progression possibly through the regulation of E2F1 transcription factor in PC cells. Moreover, RPL21 siRNA showed an apoptosis-inducing effect only in BxPC-3 and PANC-1 cells but not in normal HPDE6-C7 cells. The increase of caspase-8 activities and the loss of mitochondrial membrane potential after RPL21 silencing indicates that the RPL21 gene may be involved in caspase-8-related mitochondrial apoptosis.ConclusionOur findings suggest that siRNA against the RPL21 gene possesses a potential anti-cancer activity for PC cells by inhibiting their proliferation and DNA replication, as well as inducing cell cycle G1 arrest and cell apoptosis.