PANC-1 Human Pancreatic Cancer Cells Research Articles

Copper based azo dye catalysts for phenoxazinone synthase mimicking efficiency: Structure characterization and bioactivity evaluation

The ligands, 4-(2-Hydroxy-naphthalen-1-ylazo)-N-thiazol-2-yl-benzenesulfonamide (H2TNBS) and N-(3,4-Dimethyl-isoxazol-5-yl)-4-(2-hydroxy-naphthalen-1-ylazo)-benzenesulfonamide (H2INBS), synthesized in the current investigation have been characterized and used for synthesizing divalent copper complexes by their reaction with a number of Cu(II) salts. Spectral and analytical methods have been applied for structures’ investigation. Morphology of the synthesized compounds have been investigated using TEM technique which joint with the results of X-ray powder diffraction spectroscopy confirmed the precipitation of both ligands and their complexes in the nanometric scale. Formation of the synthesized complexes in 1:1 or 2:1 (M:L) ratio was asserted by analytical results. Ultraviolet–visible spectra and magnetic moment were used to demonstrate the geometry around the Cu centers to be 4 coordinated square planar. The compounds under interest have been screened against selected microorganisms including Gram-positive and Gram-negative bacteria, unicellular and multicellular fungus showing, in most compounds, enhancement of activity upon chelation. The cell lines A-549 (human lung cancer cell line) and Panc-1 (human pancreatic cancer cell line) have been chosen to check the antitumor efficiency of the synthesized compounds; Vinblastine was used as standard. Finally, the Cu(II) chelates were investigated toward mimicking the protein phenoxazinone synthase using o- aminophenol (OAP) as substrate and DMF is the solvent. The results presented extremely high activity for the chloro complex 4 and nitro complex 6 with TOF numbers from 390.48 and 467.01 h−1, respectively. The least activity afforded by the acetato complexes 2 and 5.

Nicolaioidesin C: An Antiausterity Agent Shows Promising Antitumor Activity in a Pancreatic Cancer Xenograft Mouse Model.

Human pancreatic tumors are hypovascular in nature, and their tumor microenvironment is often characterized by hypoxia and severe nutrient deprivation due to uncontrolled heterogeneous growth, a phenomenon known as "austerity". However, pancreatic tumor cells have the inherent ability to adapt and thrive even in such low nutrient and hypoxic microenvironments. Anticancer drugs such as gemcitabine and paclitaxel, which target rapidly proliferating cells, are often ineffective against nutrient-deprived pancreatic cancer cells. In order to overcome this limitation, the search for novel agents that can eliminate cancer cells' adaptations to nutrition starvation, also known as "antiausterity" agents, represents a promising strategy to make the cancer cells susceptible to treatment. The natural product (+)-nicolaioidesin C (Nic-C) was found to have potent antiausterity activity against the PANC-1 human pancreatic cancer cell line in a nutrient-deprived condition. However, its efficacy in vivo remained untested. To address this, we synthesized Nic-C in its racemic form and evaluated its antitumor potential in a human pancreatic cancer xenograft model. Nic-C inhibited pancreatic cancer cell migration and colony formation and significantly inhibited tumor growth in MIA PaCa-2 xenografts in a dose-dependent manner. Furthermore, Nic-C inhibited the Akt/mTOR and autophagy signaling pathways in both in vitro and in vivo studies. Metabolomic profiling of in vivo tumor samples suggests that Nic-C downregulates amino acid metabolism while upregulating sphingolipid metabolism.

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

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

Dioncophyllidine E: The first configurationally semi-stable, 7,3′-coupled naphthyldihydroisoquinoline alkaloid, from Ancistrocladus abbreviatus, with antiausterity activity against PANC-1 human pancreatic cancer cells

The discovery of a new naphthylisoquinoline alkaloid, dioncophyllidine E (4), from the tropical liana Ancistrocladus abbreviatus (Ancistrocladaceae) is described. Due to its rare 7,3′-coupling type, combined with the lack of an oxygen function at C-6, it is configurationally semi-stable at the biaryl axis, and thus occurs as a pair of slowly interconverting atropo-diastereomers, 4a and 4b. Its constitution was assigned mainly by 1D and 2D NMR. The absolute configuration at the stereocenter, C-3, was elucidated by oxidative degradation. The absolute axial configuration of the individual atropo-diastereomers was established by their HPLC resolution, combined with online electronic circular dichroism (ECD) investigations, providing nearly mirror-imaged LC-ECD spectra. These were assigned to the respective atropisomers by ECD comparison with a related, but configurationally stable alkaloid, ancistrocladidine (5). Dioncophyllidine E (4a/4b) exhibits a strong preferential cytotoxicity against PANC-1 human pancreatic cancer cells under nutrient-deprived conditions, with a PC50 value of 7.4 µM, suggesting its potential as an agent against pancreatic cancer.

Boric Acid Shows ER Stress and Apoptosis Mediated Anticancer Activity in Human Pancreatic Cancer MIA PaCa-2 and PANC-1 Cells

Amaç: Bu çalışmada borik asitin insan pankreas kanseri MIA PaCa-2 ve PANC-1 hücrelerinde endoplazmik retikulum (ER) stresi ve apoptoz aracılı antikanser etkisinin araştırılması amaçlanmıştır. Gereçler ve Yöntem: Borik asitin pankreas kanseri hücrelerinin canlılığı üzerine etkisi ve IC50 değeri XTT testi ve CompuSyn version 1.0 yazılımı kullanılarak hesaplanmıştır. Apoptotik, anti-apoptotik ve ER stresi ile ilişkili genlerin ifadesi belirlenmiştir. Borik asitin bu hücrelerin koloni oluşum kapasitesi üzerine etkisi ise koloni oluşum testi ile değerlendirilmiştir. Bulgular: Borik asit zaman ve doz bağımlı olarak her iki hücre hattında da hücre canlılığını baskılamıştır. XTT testi sonucunda MIA PaCa-2 ve PANC-1 hücrelerinde borik asitin IC50 dozlarının sırasıyla 15707,5 ve 14248,8 μM olduğu bulunmuştur. Borik asitin her iki hücre hattında da apoptoz ile ilişkili genlerden BAX, CASP3, CASP8, CYCS ve FAS genlerinin ifadelerini anlamlı derecede arttırdığı gözlenmiştir. PANC- 1 hücrelerinde CASP9 ve FADD genlerinin ifadeleride anlamlı derecede yükselmiştir. Borik asitin her iki hücre hattında da ER stresi ile ilişkili ATF4, HSP47 ve XBP1 genlerinin ifadesini istatistiksel olarak anlamlı derecede arttırdığı görülmüştür. Ayrıca borik asit muamelesi sadece PANC-1 hücrelerinde ATF6, CHOP ve EIF2A ifadelerini anlamlı derecede arttırmıştır. MIA PaCa-2 hücrelerinde ise borik asit GRP78 gen ifadesinin istatistiksel olarak artmasına neden olmuştur. Koloni oluşum testi sonuçları borik asitin her iki hücre hattında da koloni oluşum kapasitelerinin anlamlı derecede baskılandığını göstermiştir. Sonuç: Borik asit her iki insan pankreas kanseri hücrelerinde hücre canlılığı ve koloni oluşumunu azaltmış olup apoptoz ve ER stresi ile ilişkili genlerin ifadesini değiştirmiştir. Bu bulgular, borik asitin insan pankreas kanseri hücrelerinde ER stresi ve apoptoz aracılı antikanser etkisini göstermektedir.

Bioactive Piperazic Acid-Bearing Cyclodepsipeptides, Lydiamycins E-H, from an Endophytic Streptomyces sp. Associated with Cinnamomum cassia.

A chemical investigation of the endophytic Streptomyces sp. HBQ95, associated with the medicinal plant Cinnamomum cassia Presl, enabled the discovery of four new piperazic acid-bearing cyclodepsipeptides, lydiamycins E-H (1-4), and one known compound (lydiamycin A). Their chemical structures, including absolute configurations, were defined by a combination of spectroscopic analyses and multiple chemical manipulations. Lydiamycins F-H (2-4) and A (5) exhibited antimetastatic activity against PANC-1 human pancreatic cancer cells without significant cytotoxicity.

Metformin Induces Apoptosis in Human Pancreatic Cancer (PC) Cells Accompanied by Changes in the Levels of Histone Acetyltransferases (Particularly, p300/CBP-Associated Factor (PCAF) Protein Levels).

Accumulating evidence (mainly from experimental research) suggests that metformin possesses anticancer properties through the induction of apoptosis and inhibition of the growth and proliferation of cancer cells. However, its effect on the enzymes responsible for histone acetylation status, which plays a key role in carcinogenesis, remains unclear. Therefore, the aim of our study was to evaluate the impact of metformin on histone acetyltransferases (HATs) (i.e., p300/CBP-associated factor (PCAF), p300, and CBP) and on histone deacetylases (HDACs) (i.e., SIRT-1 in human pancreatic cancer (PC) cell lines, 1.2B4, and PANC-1). The cells were exposed to metformin, an HAT inhibitor (HATi), or a combination of an HATi with metformin for 24, 48, or 72 h. Cell viability was determined using an MTT assay, and the percentage of early apoptotic cells was determined with an Annexin V-Cy3 Apoptosis Detection Assay Kit. Caspase-9 activity was also assessed. SIRT-1, PCAF, p300, and CBP expression were determined at the mRNA and protein levels using RT-PCR and Western blotting methods, respectively. Our results reveal an increase in caspase-9 in response to the metformin, indicating that it induced the apoptotic death of both 1.2B4 and PANC-1 cells. The number of cells in early apoptosis and the activity of caspase-9 decreased when treated with an HATi alone or a combination of an HATi with metformin, as compared to metformin alone. Moreover, metformin, an HATi, and a combination of an HATi with metformin also modified the mRNA expression of SIRT-1, PCAF, CBP, and p300. However, metformin did not change the expression of the studied genes in 1.2B4 cells. The results of the Western blot analysis showed that metformin diminished the protein expression of PCAF in both the 1.2B4 and PANC-1 cells. Hence, it appears possible that PCAF may be involved in the metformin-mediated apoptosis of PC cells.

Synthesis of Small Peptide Nanogels Using Radiation Crosslinking as a Platform for Nano-Imaging Agents for Pancreatic Cancer Diagnosis.

Nanoparticle-based drug delivery systems (DDS) have been developed as effective diagnostic and low-dose imaging agents. Nano-imaging agents with particles greater than 100 nm are difficult to accumulate in pancreatic cancer cells, making high-intensity imaging of pancreatic cancer challenging. Peptides composed of histidine and glycine were designed and synthesized. Additionally, aqueous peptide solutions were irradiated with γ-rays to produce peptide nanogels with an average size of 25-53 nm. The mechanisms underlying radiation-mediated peptide crosslinking were investigated by simulating peptide particle formation based on rate constants. The rate constants for reactions between peptides and reactive species produced by water radiolysis were measured using pulse radiolysis. HGGGHGGGH (H9, H-histidine; G-glycine) particles exhibited a smaller size, as well as high formation yield, stability, and biodegradability. These particles were labeled with fluorescent dye to change their negative surface potential and enhance their accumulation in pancreatic cancer cells. Fluorescent-labeled H9 particles accumulated in PANC1 human pancreatic cancer cells, demonstrating that these particles are effective nano-imaging agents for intractable cancers.

In Vitro Antioxidant and Pancreatic Anticancer Activity of Novel 5-Fluorouracil-Coumarin Conjugates.

Molecular hybridization consists of the combination of two or more non-identical pharmacophores in a single molecule. It has emerged as a promising strategy that allows the design of molecular frameworks with enhanced activity and affinity compared to their parent drugs. In this work, two novel hybrids that combine the well-known anticancer chemotherapeutic agent 5-fluorouracil with antioxidant coumarin derivatives have been synthesized and characterized by means of a copper-catalyzed azide-alkyne cycloaddition (CuAAC). The conjugates showed good antioxidant properties and a high tendency to aggregate and form stable nanoparticles in aqueous media, with regular shape and uniform size. These materials have proven to be preferential cytotoxic agents in vitro against human pancreatic cancer cells PANC-1, with an activity superior to free 5-fluorouracil. These results open up the possibility of exploiting the synergistic combination between 5-fluorouracil and coumarin derivatives and warrant further investigation of these hybrids as promising pancreatic anticancer agents.

Downregulation of MMP1 functions in preventing perineural invasion of pancreatic cancer through blocking the NT-3/TrkC signaling pathway.

Pancreatic cancer (PC) is a fatal malignancy that frequently involves perineural invasion (PNI). This study aims to investigate the function and underlying mechanisms of matrix metalloproteinase-1 (MMP1) in PNI of PC. Human pancreatic cancer PANC-1 cells were co-cultured with dorsal root ganglion in vitro. The expression of MMP1, epithelial-mesenchymal transition (EMT) markers, Schwann cell markers, neurotrophic factors, NT-3, and TrkC was measured by qRT-PCR or Western blot. Transwell assay was performed to evaluate cell migration and invasion. In vivo model of PNI was established via inoculating PANC-1 cells into mice. PANC-1 cells and mice were also treated with LM22B-10 (an activator of TrkC) to confirm the mechanisms involving NT-3/TrkC in PNI of PC both in vivo and in vitro. The expression of MMP1 was significantly higher in PDAC tissues than non-cancerous tissues, which was positively associated with PNI. MMP1 knockdown repressed the migration and invasion of PANC-1 cells. Except for E-cadherin, the expression of EMT markers, Schwann cell markers, neurotrophic factors, NT-3, and TrkC was inhibited by MMP1 silencing. The same effects of MMP1 knockdown on the above factors were also observed in the PNI model. Moreover, MMP1 knockdown elevated the sciatic nerve function and reduced PNI in the model mice. LM22B-10 partially abolished the effects of MMP1 knockdown both in vivo and in vitro. Silencing of MMP1 prevents PC cells from EMT and Schwann-like cell differentiation via inhibiting the activation of the NT-3/TrkC signaling pathway, thus alleviating the PNI of PC.

Chemical Constituents of Callistemon subulatus and Their Anti-Pancreatic Cancer Activity against Human PANC-1 Cell Line.

An n-hexane extract of Callistemon subulatus was found to exhibit potent cytotoxicity against PANC-1 human pancreatic cancer cells, preferentially under nutrition starvation conditions, with a PC50 value of 6.2 µg/mL. Phytochemical investigation of this bioactive extract resulted in the isolation of fifteen compounds (1–15), including a new compound, subulatone A (–). The structure of compound 1 was elucidated using HRFABMS and NMR spectroscopic analyses. The isolated compounds were tested for their preferential cytotoxicity against the PANC-1 human pancreatic cancer cell line, using an anti-austerity strategy. Among these, myrtucommulone A (2) showed highly potent preferential cytotoxicity, with a PC50 value of 0.28 µM. Myrtucommulone A (2) was found to alter PANC-1 cell morphology, inhibit cell migration, and downregulate the PI3K/Akt/mTOR and autophagy signaling pathways in nutrient-deprived media, leading to cancer cell death. Therefore, myrtucommulone A (2) is a lead compound for anticancer drug development based on an anti-austerity strategy.

Design and synthesis of novel pipernonaline derivatives as anti-austerity agents against human pancreatic cancer PANC-1 cells

Pipernonaline (1), one of the components of the spice pepper, preferentially reduced the survival of human pancreatic cancer PANC-1 cells under nutrient-deprived conditions witha PC50 value of 7.2 μM, suggesting that1couldpotentially lead to the development ofnew anticanceragents basedon theanti-austerity strategy. We have synthesized a total of 31 pipernonaline derivatives, revealing clear structure–activity relationships. Compound 9, which showed the strongest preferential cytotoxicity among synthesized derivatives, inhibited Akt activation and cancer cell migration, making it an extremely promising candidate compound for new pancreatic cancer agents based on the anti-austerity strategy.

Self-assembled coumarin- and 5-fluorouracil-PEG micelles as multifunctional drug delivery systems

The copper(I)-catalyzed azide/alkyne cycloaddition is recognized as one of the most successful click reactions to access self-assembling amphiphilic polymer-drug conjugates (PDCs). In this way, poor water-soluble drugs can be linked covalently to hydrophilic poly(ethylene glycol) (PEG) to obtain PEGylated drug micelles that can be used as versatile carriers for the delivery of diverse therapeutic agents. In this work, two novel amphiphilic PDCs that combine PEG with privileged scaffolds well-known for their anticancer properties, such as coumarin and 5-fluorouracil, have been synthesized and characterized. These conjugates were able to self-assemble into micelles at relatively high critical micellar concentration, probably due to the large portion of hydrophilic PEG. The micelles allowed to load other anticancer drugs (paclitaxel, curcumin, and gemcitabine), providing a unique opportunity to develop promising co-delivery carriers for synergistic cancer therapy. The Korsmeyer-Peppas mathematical model was used for describing the in vitro kinetics of drug release from the micelles. Similar sustained and controlled drug release profiles were obtained for paclitaxel and curcumin in both conjugates, which was attributed to the excellent stability driven by the strong interaction between polymeric conjugates and drugs in the micelle core. In contrast, the high instability observed for the gemcitabine-loaded micelles provided an initial uncontrolled burst release of drug. A preliminary in vitro cytotoxicity study of the micelles against human pancreatic cancer cells PANC-1 and BxPC-3 was also carried out, demonstrating that both coumarin and 5-fluorouracil retain their anticancer properties after conjugation with PEG.

Rare Carbon-Bridged Citrinin Dimers from the Starfish-Derived Symbiotic Fungus Penicillium sp. GGF16-1-2.

Four novel, rare carbon-bridged citrinin dimers, namely dicitrinones G–J (1–4), and five known analogs (5–9) were isolated from the starfish-derived fungus Penicillium sp. GGF 16-1-2. Their structures were elucidated by extensive spectroscopic analysis and quantum chemical calculations. Compounds 1–9 exhibited strong antifungal activities against Colletotrichum gloeosporioides with LD50 values from 0.61 μg/mL to 16.14 μg/mL. Meanwhile, all compounds were evaluated for their cytotoxic activities against human pancreatic cancer BXPC-3 and PANC-1 cell lines; as a result, compound 1 showed more significant cytotoxicities than the positive control against both cell lines. In addition, based on the analyses of the protein-protein interaction (PPI) network and Western blot, 1 could induce apoptosis by activating caspase 3 proteins (CASP3).

Apoptotic and Anti-Metastatic Effect of Carvacrol in PANC-1 Human Pancreatic Cancer Cells

Pancreatic cancer is known to have one of the highest mortality rates among other cancer. Monoterpenes are natural compounds obtained from essential oils of plants. Carvacrol is a monoterpene phenolic derived from essential oils of various aromatic plants.In this study, the effects of carvacrol on proliferation, apoptosis and metastasis of PANC-1 human pancreatic cancer cells were investigated. XTT assay was used to determine cell proliferation and viability. mRNA level expression levels of BAX, BCL2, CASP3, CASP7, CASP8, CASP9, CYCS, FADD, FAS and P53 were evaluated for determining the effect of carvacrol on apoptosis by qRT-PCR analysis. In addition, gene expressions of CDH1, CDH2, TIMP1, TIMP2, TIMP3, ZEB1 and ZEB2 were analyzed to evaluate its effect onmetastasis. Carvacrol inhibited the PANC-1 pancreatic cancer cell proliferation in dose and time dependent manner. Carvacrol treatment induced apoptosis by changing the expressions of genes important in apoptosis. Moreover, it suppressed the metastasis by effecting CDH1, CDH2, TIMP2, TIMP3 and ZEB2 expressions. In conclusion, carvacrol showed apoptotic and anti-metastatic effects in PANC-1 human pancreatic cancer cells. It is thereby concluded that carvacrol may have a therapeutic potential in pancreatic cancer.

Abstract 5382: Biofield therapy suppressed the growth of human pancreatic cancer cells by modulation of cell cycle and cell voltage potentials

Abstract Biofield therapies have gained popularity and are being explored as possible treatments for cancer. In some cases, devices have been developed that mimic the electromagnetic fields (EMF) that are emitted from people delivering biofield therapies. However, it is not clear if EMFs are the mechanism of action. We previously reported that biofield therapy significantly inhibited the growth of lung cancer cells in vitro and their relevant animal model mediated through inflammatory and immune pathways. We expanded this research to examine the effects of human biofield therapy on the growth of pancreatic ductal adenocarcinoma (PDAC) cells and explored relevant mechanisms. Cell viability of human pancreatic cancer Panc-1 and mouse pancreatic cancer Panc02 cells was measured by PrestoBlue assay. Cell cycle was measured by PI staining and cell voltage potentials were assessed using DiBAC4 staining. It is well-established that cancer cells have distinct bioelectrical properties and most have depolarized cell voltage potentials that support cell proliferation. Expression of cell signaling proteins was determined by Western blot. We found that Panc-1 and Panc02 cells exposed to biofield treatment for 15 and 30 mins, respectively, resulted in significantly lower viability compared to that of sham control. These experiments were replicated 12 times for Panc-1 cells and 6 times for Panc02 cells. We further observed that the experimental exposure significantly increased G1 phase population of Panc-1 cells (sham control=43.7% (0.8) vs treatment=55.0% (0.8%), p<0.001). In contrast, Panc02 cells exposed to biofield therapy had significantly higher population of G2/M cells than that of sham control group (sham control=22.5% (0.5) vs treatment=27.7% (1.1), p<0.001). We found that biofield therapy resulted in a 36.7% reduction in cell voltage potentials as measured by the intensity of DiBAC4 staining in Panc-1 cells compared to that of sham controls (p<0.01). Finally, the treatment down-regulated pAkt expression and the pAkt/Akt ratio by 45.3% and 43.8%, respectively, in Panc-1 cells in comparison with the sham control group. The effect of biofield therapy on cell signaling proteins measured by Reverse Phase Proteomic Array in Panc-1 cells and the growth of human Panc-1 mouse orthotopic model is ongoing and the results will be presented at the meeting. Together, these findings suggest that exposure to biofield therapy results in reduced growth of pancreatic cancer cells which might be in part mediated through modification of the cell cycle - differentially for different cell types, reductions in cell voltage potentials suggesting hyperpolarization of cells, and down regulation of PI3K/Akt pathways. Citation Format: Peiying Yang, Sharmistha Chakraborty, Phuong Nguyen, Meng Cui, Andrew Cusimano, Daoyan Wei, Sarah Prinsloo, Lorenzo Cohen. Biofield therapy suppressed the growth of human pancreatic cancer cells by modulation of cell cycle and cell voltage potentials [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 5382.

Abstract 6285: MicroRNA-217 affects tumor microenvironment and enhances the chemosensitivity of pancreatic cancer

Abstract Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignancies and an inherently chemoresistant tumor. Dense fibrotic stroma is a major obstacle for drug delivery to the tumor cells in PDAC. Pancreatic stellate cells (PSCs) are the major stromal cells responsible for fibrotic microenvironment. MicroRNA-217 (miR-217) is known mainly as a tumor suppressor. However, the detailed roles of miR-217 on pathophysiology of PDAC remain unclarified. Methods: Expressions levels of miR-217 were measured in surgically resected human PDAC samples. Using Lipofectamine RNAiMAX, miR-217 or negative control miR (NC) were transfected in human pancreatic cancer cells, Panc-1, MIApaca-2, BxPC-3 and murine PAN02 cells, and chemosensitivities to gemcitabine and paclitaxel were investigated by MTS assay. Human hPSC-1 (obtained from Riken cell bank, Japan) was cultured in 20%FBS+DMEM and the changes of phenotypes and expression levels of miR-217 after the stimulation with TGF-β1 was measured by fluorescein microscope and digital PCR, respectively. Results: The expression level of miR-217 was markedly downregulated in PDAC tissues than in noncancerous pancreatic tissues (P<0.001, n=9). Overexpression of miR-217 significantly inhibited the proliferation of Panc-1, MIApaca-2 and BxPC-3 (P<0.001) and migration of Panc-1, MIApaca-2 and PAN02 (P<0.05). Lipofection of miR-217 further reduced the number of PAN02 exposed to 1-5nM gemcitabine (P<0.0001) and 0.01-0.1uM paclitaxel (P=0.0085) which resulted in the reduced the IC-50 as compared with NC. Human PSC-1 stimulated with TGF-β1 (10ng/ml) significantly reduced miR-217 expression compared to nascent cells. The stimulation with TGF-β1 upregulated the expression of cancer associated fibroblast (CAF) markers, α-smooth muscle actin (SMA) and vimentin. However, the expression levels of these markers were significantly reduced by the kipofection of miR-217. Conclusion: MiR-217 affects both cancer and stromal cells in PDAC which may regulate chemosensitivity in PDAC. Restoring miR-217 levels in tumor cells and/or PSCs could be a future therapeutic strategy. Citation Format: Yuki Kaneko, HIdeyuki Ohzawa, Yuki Kimura, Kohei Tamura, Yurie Futoh, Kazuya Takahashi, Akira Saito, Mineyuki Tojo, Hideyo Miyato, Naohiro Sata, Joji Kitayama. MicroRNA-217 affects tumor microenvironment and enhances the chemosensitivity of pancreatic cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6285.

New callistrilone epimers from Callistemon citrinus and their antiausterity activity against the PANC-1 human pancreatic cancer cell line

Phytochemical investigation of Callistemon citrinus leaves resulted in the isolation of two new structurally unique callistrilone epimers named callistrilone Q (1) and epicallistrilone Q (2). Both epimers were found to exist in the form of equilibrium conformational isomers. The structural elucidation of the new compounds was achieved by HREIMS in addition to extensive 1D and 2D NMR spectroscopic analyses. The absolute configuration was determined using computational ECD and optical rotation calculations. Both isolated compounds displayed unprecedented preferential cytotoxic activities against PANC-1 human pancreatic cancer cells at the nanomolar level. These compounds also were found to inhibit PANC-1 cell migration under normal nutrient-rich conditions. Both compounds downregulated key proteins involved in the PI3K/Akt/mTOR signaling pathway.

Plant Alkaloid Tetrandrine Is a Nuclear Receptor 4A1 Antagonist and Inhibits Panc-1 Cell Growth In Vitro and In Vivo.

The orphan nuclear receptor 4A1 (NR4A1) is highly expressed in human pancreatic cancer cells and exerts pro-oncogenic activity. In a previous study, we demonstrated that fangchinoline (FCN), a natural inhibitor of nuclear NR4A1, induces NR4A1-dependent apoptosis in human pancreatic cancer cells. In this study, we evaluated FCN and its structural analogs (berbamine, isotetrandrine, tetrandrine, and tubocurarine) for their inhibitory effects on NR4A1 transactivity, and confirmed that tetrandrine (TTD) showed the highest inhibitory effect in pancreatic cancer cells. Moreover, in a tryptophan fluorescence quenching assay, TTD directly bound to the ligand binding domain (LBD) of NR4A1 with a KD value of 10.60 μM. Treatment with TTD decreased proliferation and induced apoptosis in Panc-1 human pancreatic cancer cells in part through the reduced expression of the Sp1-dependent anti-apoptotic gene survivin and induction of ROS-mediated endoplasmic reticulum stress, which are the well-known NR4A1-dependent proapoptotic pathways. Furthermore, at a dose of 25 mg/kg/day, TTD reduced tumor growth in an athymic nude mouse xenograft model bearing Panc-1 cells. These data show that TTD is an NR4A1 antagonist and that modulation of the NR4A1-mediated pro-survival pathways is involved in the antitumor effects of TTD.

Reactive oxygen species-inducing titanium peroxide nanoparticles as promising radiosensitizers for eliminating pancreatic cancer stem cells

BackgroundDespite recent advances in radiotherapy, radioresistance in patients with pancreatic cancer remains a crucial dilemma for clinical treatment. Cancer stem cells (CSCs) represent a major factor in radioresistance. Developing a potent radiosensitizer may be a novel candidate for the eradication of pancreatic CSCs.MethodsCSCs were isolated from MIA PaCa-2 and PANC1 human pancreatic cancer cell lines. Titanium peroxide nanoparticles (TiOxNPs) were synthesized from titanium dioxide nanoparticles (TiO2NPs) and utilized as radiosensitizers when added one hour prior to radiation exposure. The antitumor activity of this novel therapeutic strategy was evaluated against well-established pancreatic CSCs model both in vitro and in vivo.ResultsIt is shown that TiOxNPs combined with ionizing radiation exhibit anti-cancer effects on radioresistant CSCs both in vitro and in vivo. TiOxNPs exhibited a synergistic effect with radiation on pancreatic CSC-enriched spheres by downregulating self-renewal regulatory factors and CSC surface markers. Moreover, combined treatment suppressed epithelial-mesenchymal transition, migration, and invasion properties in primary and aggressive pancreatic cancer cells by reducing the expression of proteins relevant to these processes. Notably, radiosensitizing TiOxNPs suppressed the growth of pancreatic xenografts following primary or dissociating sphere MIA PaCa-2 cell implantation. It is inferred that synergy is formed by generating intolerable levels of reactive oxygen species (ROS) and inactivating the AKT signaling pathway.ConclusionsOur data suggested the use of TiOxNPs in combination with radiation may be considered an attractive therapeutic strategy to eliminate pancreatic CSCs.