MIA PaCa-2 Research Articles

ATF4/TXNIP/REDD1/mTOR signaling mediates the antitumor activities of liver X receptor in pancreatic cancers.

Limited by difficulties in early detection and availabilities of effective treatments, pancreatic cancer is a highly malignant disease with poor prognosis. Nuclear receptors are a family of ligand-dependent transcription factors that are highly druggable therapeutic targets playing critical roles in human physiological and pathological development, including cancer. In this study, we explored the therapeutic potential as well as the molecular mechanisms of liver X receptor (LXR) agonist GW3965 in pancreatic cancer. Soft-agar colony formation assay, xenograft tumors, Oligonucleotide microarray, Reverse transcription real-time polymerase chain reaction, Western immunoblotting and Immunohistochemistry were used in this study. We demonstrated pleotropic in vitro activities of GW3965 in pancreatic cell lines MIA PaCa-2 and BXPC3 including reduction of cell viability, inhibition of cell proliferation, stimulation of cell death, and suppression of colony formation, which translated to significant inhibition of xenograft tumor growth in vitro. By mapping the gene expression profiles, we identified the up-regulations of 188 and the down-regulations of 92 genes common to both cell lines following GW3965 treatment. Genes responsive to GW3965 represent a variety of biological pathways vital for multiple cellular functions. Specifically, we identified that the activating transcription factor 4/thioredoxin-interacting protein/regulated in development and DNA damage responses 1/mechanistic target of rapamycin (ATF4/TXNIP/REDD1/mTOR) signaling critically controls GW3965-mediated regulation of cell proliferation/death. The significance of the ATF4/TXNIP/REDD1/mTOR pathway was further supported by associated expressions in xenograft tumors as well as human pancreatic cancer samples. This study provides the pre-clinical evidence that LXR agonist is a promising therapy for pancreatic cancer.

Gossypol Induces Apoptosis of Human Pancreatic Cancer Cells via CHOP/Endoplasmic Reticulum Stress Signaling Pathway.

Gossypol, a natural phenolic aldehyde present in cotton plants, was originally used as a means of contraception, but is currently being studied for its anti-proliferative and anti-metastatic effects on various cancers. However, the intracellular mechanism of action regarding the effects of gossypol on pancreatic cancer cells remains unclear. Here, we investigated the anti-cancer effects of gossypol on human pancreatic cancer cells (BxPC-3 and MIA PaCa-2). Cell counting kit-8 assays, annexin V/propidium iodide staining assays, and transmission electron microscopy showed that gossypol induced apoptotic cell death and apoptotic body formation in both cell lines. RNA sequencing analysis also showed that gossypol increased the mRNA levels of CCAAT/enhancer-binding protein homologous protein (CHOP) and activating transcription factor 3 (ATF3) in pancreatic cancer cell lines. In addition, gossypol facilitated the cleavage of caspase-3 via protein kinase RNA-like ER kinase (PERK), CHOP, and Bax/Bcl-2 upregulation in both cells, whereas the upregulation of ATF was limited to BxPC-3 cells. Finally, a three-dimensional culture experiment confirmed the successful suppression of cancer cell spheroids via gossypol treatment. Taken together, our data suggest that gossypol may trigger apoptosis in pancreatic cancer cells via the PERK-CHOP signaling pathway. These findings propose a promising therapeutic approach to pancreatic cancer treatment using gossypol.

P73α1, a p73 C-terminal isoform, regulates tumor suppression and the inflammatory response via Notch1

p73, a p53 family member, undergoes alternative splicing at the 3′ end to produce multiple isoforms, but their expression and activity are largely unknown. Thus, CRISPR was used to knock out exon 12 (E12) in human cancer cell lines and mice, leading to isoform switch from p73α to isoform p73α1. We found that p73α1 is naturally expressed and induced by DNA damage. We also found that knockout of E12 suppresses cell growth and migration in H1299 and MIA PaCa-2 cells and promotes cellular senescence in mouse embryonic fibroblasts. Similarly, ectopic expression of p73α1 suppresses cell proliferation, whereas knockdown of p73α1 restores the cell proliferative and migratory capacities of E12−/− cells. Consistently, we found that E12+/− mice are not prone to spontaneous tumors. Instead, E12+/− mice are prone to systemic inflammation and exhibit elevated TNFα expression in inflamed tissues. Moreover, we found that Notch1, a master regulator of the inflammatory response, is regulated by p73α1 and highly expressed in E12−/− cells and inflamed E12+/− mouse tissues. Furthermore, through knockdown of p73α1 and/or Notch1 in E12−/− cells, we found that Notch1 is necessary for p73α1-mediated growth suppression. Together, these data suggest that p73α1 plays a critical role in tumor suppression and the inflammatory response via Notch1.

Potential of phenothiazines to synergistically block calmodulin and reactivate PP2A in cancer cells.

Phenothiazines (PTZ) were developed as inhibitors of monoamine neurotransmitter receptors, notably dopamine receptors. Because of this activity they have been used for decades as antipsychotic drugs. In addition, they possess significant anti-cancer properties and several attempts for their repurposing were made. However, their incompletely understood polypharmacology is challenging. Here we examined the potential of the PTZ fluphenazine (Flu) and its mustard derivative (Flu-M) to synergistically act on two cancer associated targets, calmodulin (CaM) and the tumor suppressor protein phosphatase 2A (PP2A). Both proteins are known to modulate the Ras- and MAPK-pathway, cell viability and features of cancer cell stemness. Consistently, we show that the combination of a CaM inhibitor and the PP2A activator DT-061 synergistically inhibited the 3D-spheroid formation of MDA-MB-231 (K-Ras-G13D), NCI-H358 (K-Ras-G12C) and A375 (B-raf-V600E) cancer cells, and increased apoptosis in MDA-MB-231. We reasoned that these activities remain combined in PTZ, which were the starting point for PP2A activator development, while several PTZ are known CaM inhibitors. We show that both Flu and Flu-M retained CaM inhibitory activity in vitro and in cells, with a higher potency of the mustard derivative in cells. In line with the CaM dependence of Ras plasma membrane organization, the mustard derivative potently reduced the functional membrane organization of oncogenic Ras, while DT-061 had a negligible effect. Like DT-061, both PTZ potently decreased c-MYC levels, a hallmark of PP2A activation. Benchmarking against the KRAS-G12C specific inhibitor AMG-510 in MIA PaCa-2 cells revealed a higher potency of Flu-M than combinations of DT-061 and a CaM inhibitor on MAPK-output and a strong effect on cell proliferation. While our study is limited, our results suggest that improved PTZ derivatives that retain both, their CaM inhibitory and PP2A activating properties, but have lost their neurological side-effects, may be interesting to pursue further as anti-cancer agents.

Enhanced stability and oral bioavailability of erlotinib by solid self nano emulsifying drug delivery systems

The present investigation demonstrates the preparation of solid self nanoemulsfying drug delivery system (sSNEDDS) to enhance stability and bioavailability of Erlotinib (ERL) via the oral route. Capmul®MCM EP (CPM EP, oil), Cremophor® RH 40 (CMR RH 40, surfactant), and LBF CS (LBF CS, cosurfactant) were chosen as chief components for preparing Liquids SNEDDS (L-ERL-SNEDDS) based on solubility and emulsion forming ability. Pseudo ternary phase diagram and constrained mixture designs were applied to identify the self-emulsifying area and it was found that CPM EP, CMR RH 40, and LBF CS in the ratio of 59:11:30 showed optimized particle size (110.08 nm), with narrow PDI (0.114) and high ERL loading capacity (14.31 mg/g). Adsorption method was implemented for solidification of L-ERL-SNEDDS. Among various solid carriers were studied, Aerosil® 200 (A200) was finalized based on free flowing property and reconstitution ability. DSC and XRD studies revealed that crystallinity of drug was reduced in developed system. The developed formulation (named as, A200-ERL-sSNEDDS) showed increased cytotoxicity and apoptosis in PANC-1 and MIA PaCa-2 cells. Pharmacokinetic studies revealed ∼2.2 times increase in AUC0-∞values in case of A200-ERL-sSNEDDS as compared to free ERL. Thus current strategy can be extrapolated for delivering of poorly soluble drugs via oral route.

A New C22-Quassinoid with Anti-Pancreatic Adenocarcinoma Activity from Seeds of Brucea javanica.

An undescribed C22-quassinoid named sergeolide A (1) and fifteen known quassinoids (2-16) were obtained from the seeds of Brucea javanica (Simaroubaceae). All chemical structures were established based on spectroscopic data and X-ray diffraction analysis. Sergeolide A (1) is the first example of a naturally occurring C22-quassinoid bearing a butenolide group fused the A ring of the bruceolide skeleton from Brucea genus. And this is the first report of the NMR data for desmethyl-bruceines B (2) and C (3) and the crystal structure for bruceolide (11). In addition, all isolates were evaluated for their anti-pancreatic adenocarcinoma activity by measuring the growth inhibitory of the MIA PaCa-2 cell lines. Consequently, compounds 1, 7-10, and 12-16 exhibited potent anti-pancreatic cancer activity in vitro (IC50 =0.054∼0.357 μM).

Ultrasound assisted one-pot synthesis of rosuvastatin based novel azaindole derivatives via coupling–cyclization strategy under Pd/Cu-catalysis: Their evaluation as potential cytotoxic agents

Addressing the increasing incidences of cancer worldwide along with the multifaceted problem of drug resistance via development of new anticancer agents has become an essential goal. Due to the known cytotoxic effects and reported Akt inhibitory potential of azaindoles we designed a new framework incorporating the structural features of rosuvastatin and 5- or 7-azaindole. The framework was used to construct a library of small molecules for further pharmacological evaluation. The design was supported by the docking studies of two representative molecules in silico. A one-pot sonochemical approach was established for the synthesis of these rosuvastatin based azaindoles that involved the coupling–cyclization of a rosuvastatin derived terminal alkyne with appropriate 3-iodopyridine derivatives under Pd/Cu-catalysis. When tested using an MTT assay, some of the synthesized compounds showed desirable cytotoxic effects against three cancer cell lines e.g. HCT 116, Hep G2 and PA-1 but no significant effects against the non-cancerous HEK cell line. According to the SAR the 5-azaindole ring appeared to be marginally better than the 7-azaindole whereas the activity was varied with the variation of sulfonamide moiety attached to the N-1 atom of the azaindole ring. Among all the groups present in the sulfonamide moiety the p-MeC6H4 group appeared to be most effective in terms of activity. While 3b and 5b were identified as initial hit molecules the compound 5b (in addition to 3b) also showed significant inhibition of Akt1 in vitro that was reflected by its strong interaction with Akt1 in silico (with the docking score −11.7 kcal/mol) involving two H-bonding interactions with Ser7 and Asp439 residues. Further, a reasonable ADME was predicted for 5bin silico. Being a potent inhibitor (MIA Paca-2 IC50 = 18.79 ± 0.17 nM) and with NOAEL (No Observed Adverse Effect Level) > 100 µM in Zebrafish, 5b emerged as a promising compound.

KIF22 Promotes Development of Pancreatic Cancer by Regulating the MEK/ERK/P21 Signaling Axis.

The study is aimed at exploring the potential biological process and molecular mechanism of KIF22 involved in the development and progression of pancreatic cancer. First, we used the GEPIA database and tissue qRT-PCR to examine the expression of KIF22 mRNA in pancreatic cancer. Meanwhile, immunohistochemistry revealed the presence of KIF22 in 71 pancreatic cancer tissues versus 30 paracarcinoma tissues. Then, we also explored the relationship between KIF22 expression level and clinical prognosis. Furthermore, in pancreatic cancer cells, we silenced KIF22 by transfecting KIF22 SiRNA, and we investigated the effect of KIF22 on the proliferation of pancreatic cancer cells with MTT and colony formation assays. Finally, we used Gene Set Enrichment Analysis (GSEA) to look at the effect of KIF22 on the cell cycle regulation of pancreatic cancer cells, and we used Western blot to look at the relationship between KIF22 and the phosphorylated MEK1/2, ERK1/2 (p-MEK1/2, p-ERK1/2), and the cyclin-dependent kinase inhibitor (P21). In this study, we found that KIF22 was highly expressed in pancreatic cancer tissues, and patients with high expression of KIF22 demonstrated significantly worse clinical prognosis outcomes (P < 0.05). When the KIF22 gene was silenced in pancreatic cancer cells (PANC-1 and MIA PaCa-2), the cells' ability to proliferate was significantly reduced. Furthermore, GSEA confirmed that KIF22 is involved in cell cycle regulation in pancreatic cancer patients (FDR = 0.00158, P < 0.0001). Besides, the level of KIF22 expression was positively correlated with Ki67 (r = 0.8043, P < 0.0001), and KIF22 can promote the transmutation of G1/S. The expression of p-MEK1/2 and p-ERK1/2 was significantly downregulated, while P21 expression was significantly upregulated (P < 0.05). According to our findings, KIF22 is highly expressed in pancreatic cancer and demonstrates a poor clinical prognosis. It regulates the cell cycle via the MEK/ERK/P21 signaling axis and promotes the development of pancreatic cancer.

Cytoglobin attenuates pancreatic cancer growth via scavenging reactive oxygen species

Pancreatic cancer is a highly challenging malignancy with extremely poor prognosis. Cytoglobin (CYGB), a hemeprotein involved in liver fibrosis and cancer development, is expressed in pericytes of all organs. Here, we examined the role of CYGB in the development of pancreatic cancer. CYGB expression appeared predominately in the area surrounding adenocarcinoma and negatively correlated with tumor size in patients with pancreatic cancer. Directly injecting 7, 12-dimethylbenz[a]anthracene into the pancreatic tail in wild-type mice resulted in time-dependent induction of severe pancreatitis, fibrosis, and oxidative damage, which was rescued by Cygb overexpression in transgenic mice. Pancreatic cancer incidence was 93% in wild-type mice but only 55% in transgenic mice. Enhanced CYGB expression in human pancreatic stellate cells in vitro reduced cellular collagen synthesis, inhibited cell activation, increased expression of antioxidant-related genes, and increased CYGB secretion into the medium. Cygb-overexpressing or recombinant human CYGB (rhCYGB) -treated MIA PaCa-2 cancer cells exhibited dose-dependent cell cycle arrest at the G1 phase, diminished cell migration, and reduction in colony formation. RNA sequencing in rhCYGB-treated MIA PaCa-2 cells revealed downregulation of cell cycle and oxidative phosphorylation pathways. An increase in MIA PaCa-2 cell proliferation and reactive oxygen species production by H2O2 challenge was blocked by rhCYGB treatment or Cygb overexpression. PANC-1, OCUP-A2, and BxPC-3 cancer cells showed similar responses to rhCYGB. Known antioxidants N-acetyl cysteine and glutathione also inhibited cancer cell growth. These results demonstrate that CYGB suppresses pancreatic stellate cell activation, pancreatic fibrosis, and tumor growth, suggesting its potential therapeutic application against pancreatic cancer.

Cell type specificity on integrin α2 mediated functions in pancreatic cancer

BackgroundAmong the various cancers, pancreatic cancer has the third highest mortality rate per 100,000 population each year. In 2021, an estimated 60,430 people will be diagnosed with pancreatic cancer in the United States, with more than 48,220 deaths. Desmoplasia is a hallmark of pancreatic cancer. Cell surface receptor integrin promotes tumor progression by modulating the reciprocal signaling between the actin‐cytoskeleton and the desmoplastic tumor microenvironment. Integrin’s are heterodimeric cell surface receptors consisting of non‐covalently associated α and β subunits. Integrin β1 forms heterodimers with 12 different α subunits, and its expression is upregulated in pancreatic cancer. Integrin α2 is one of the α subunits that shows both pro and anti‐tumorigenic properties in cancer and belongs to the I domain group of integrin where the I domain in α subunit mediates the binding to matrix proteins. This study tested the hypothesis that in pancreatic cancer, upregulation of integrin β1 differentially regulates integrin α2 mediated cell functions in a cell‐specific manner.MethodTwo of the major pancreatic cancer types, Mia Paca‐2 and Panc‐1 cell lines were used in this study. The protein level of integrin β1 was downregulated using genetic approaches and confirmed by immunoblotting, immunocytochemistry, and qRT‐PCR. Cell spreading and adhesion assays were performed with WT cells and clones with lower integrin β1 expression. Cells were grown on the 3D matrix to see the ability of cells to proliferate in the presence of matrix proteins.ResultsDownregulation of integrin β1 in both Mia Paca‐2 and Panc‐1 cells decreased tumor growth in the collagen‐Matrigel 3D matrix significantly (n=10, p&lt;0.0001). With the reduction of expression of integrin β1, there is a significant decrease in the expression of integrin α5 in Mia paca‐2 and Panc‐1 cell, which resulted in a significant decrease in cell adhesion (n=3; P&lt;0.05) and spreading (n=40; p&lt;0.05) on fibronectin and vitronectin. However, there were contrasting results in the case of integrin α2 expression and functions with integrin β1 downregulation. An increase in integrin α2 expression was recorded in Miapaca‐2 cells (n=3, p&lt;0.05) with increased cell adhesion (n=3; p&lt;0.05) and cell spreading (n=3; p&lt;0.05) on collagen‐1 by the deletion of integrin β1. In the case of Panc‐1, there is reduced expression of integrin α2 that resulted in decreased cell adhesion (n=3; p&lt;0.05) and cellular spreading (n=30; p&lt;0.05) on collagen 1 with the knock‐down of integrin β1.ConclusionThe results indicate that the tumor suppressor property of integrin α2 varies between different tumor types in pancreatic cancer. Further studies are required to understand the mechanism of the anti‐tumorigenic property of integrin α2 in pancreatic cancer.

Sumac Induces Mitochondria‐Dependent Cellular Toxicity in Human Pancreatic Cancer Cell Lines

Pancreatic cancer is a devastating disease that kills about 57,000 Americans and 250,000 people worldwide each year. Chemoresistance, lack of symptoms, and ineffective therapy have resulted in gaps in our understanding of the molecular events underlying its etiology. We aim to identify natural small molecule compounds that are synthetic lethal in cellular models of mutant KRAS‐dependent pancreatic adenocarcinoma. Our preliminary experiments demonstrate that aqueous extracts of the Middle Eastern spice‐plant sumac induce cytotoxicity in two cultured human pancreatic cancer cell lines with KRAS gene mutations; MIA PaCa‐2 (G12C) and PANC‐1 (G12V and G12D) but not in normal fibroblasts. Pancreatic cancer patients, 90% of whom have mutations in the KRAS oncogene, do not respond well to traditional chemotherapy. We hypothesized that the phytochemical sumac added as an adjunct to the therapeutic regimen would skew the otherwise chemoresistant pancreatic cancer cells into an apoptotic phenotype. We hypothesized that sumac’s cytotoxicity was a consequence of mitochondrial targeting, specifically a derangement of mitochondrial membrane potential, leading to mitochondrial compromise, and eventually apoptosis. To test our hypothesis, we treated MIA PaCa‐2 and PANC‐1 cells in vitro with increasing concentrations of aqueous extracts of sumac (0, 0.03, 0.3, and 3.0 mg/mL) for varying time points and measured 1) mitochondrial membrane potential using TMRE assays, 2) ROS production using DHT assays, 3) ATP levels using fluorimetry, and 4) activated caspases 3 and 7. Our data show that sumac treatment 1) ameliorated ROS production, 2) abrogated mitochondrial membrane potential, 3) activated caspases 3 and 7, and 4) reduced cellular ATP levels in a dose‐dependent manner. These changes were accompanied by a dose‐dependent change in the protein expression of the energy‐sensing mitochondrial PGC‐1α, which increased in both cell lines, the anti‐apoptotic protein Bcl‐2, which decreased in the PANC‐1 cell line but not in the MIA PaCa‐2 cell line, the pro‐apoptotic Bax, and mitofusin‐1, which is responsible for the fusion of the mitochondrial outer membranes. These data suggest that sumac mediates “synthetic lethality” in pancreatic cancer cells based on the type of KRAS gene mutation. We also hypothesized that the observed ATP reduction would alter levels of SIRT3, which is major mitochondrial physiology regulating deacetylase enzyme. Immunoblot data show a paradoxical increase in SIRT3 in a dose‐dependent manner, suggesting other roles for SIRT‐3 in this pathway. Furthermore, using HPLC‐based NMR spectroscopy, we identified the active compound in the aqueous sumac extract to be [(2R, 3R, 4S, 5R)‐3, 4, 5, 6‐tetrakis [(2‐deuterio‐3, 4, 5‐trihydroxybenzoyl)oxy]oxan‐2‐yl] methyl‐2‐deuterio‐3, 4, 5‐trihydroxybenzoate. In conclusion, sumac targets hitherto unknown mitochondrial signal transduction pathways and is synthetic lethal for the KRAS mutant G12V and G12D.

Synthesis and anticancer screening of some novel Pd-catalysed 3-methyl indole based analogues on Mia PaCa-2 cell line

Indole is a most prerogative moiety in the evaluation of anticancer agents for its versatility and bio-diversity. The indole based compounds have been reported by the researchers in the last decade with potent anticancer activities. The coupled indole ring system with other biodynamic moieties is known to increase the bio-efficiency. Hence, a series of 3-methyl-indole-2-pyrindine coupled secondary amines have been synthesized via Suzuki-Miyaura and Buchwald Hartwig coupling. The compounds 9a-e have been docked against Hypoxia-inducible factor 1α (HIF-1α) enzyme to demonstrate the binding interactions with the active site, shown the binding affinity from -7.5 to -8.1 Kcal/mol and disclosed the potentiality of synthesized compounds to bind and inhibits the HIF-1α (Pdb Id: 3KCX) pathway and predicted several in silico ADMET descriptors for the 3-methyl Indole analogues. The molecules were screened for their anti-pancreatic cancer activity and tested against Mia PaCa-2 cell line by MTT assay, revealed that; compound 9d exhibited a greater antiproliferation activity in the series, with IC50 of 73.63±2.05 µM. Our present findings revealed that 9d might be a pursuable lead for further anti-pancreatic cancer studies.

The recombinant defensin/HSA fusion protein that inhibits NF-κb associated with intensive macropinocytosis shows potent efficacy against pancreatic cancer

KRAS mutation and NF-κB both play crucial role in pancreatic cancer; in addition, defensin, the peptide mediator in innate immunity, can inhibit NF-κB. Assuming a strategy that targets both NF-κB and concomitantly the mutated KRAS indirectly via intensive macropinocytosis, we designed and generated a recombinant protein DF2-HSA which consists of two molecules of human beta-defensin 2 (HBD2) and a moiety of human serum albumin (HSA). As shown, the recombinant protein DF2-HSA markedly down-regulated NF-κB in both KRAS mutant MIA PaCa-2 cells and wild type BxPC-3 cells. Determined by confocal microscopy, the uptake of DF2-HSA in MIA PaCa-2 cells was more intense than that in BxPC-3 cells. The uptake was blocked by the specific inhibitor EIPA, indicating that DF2-HSA internalized via macropinocytosis. DF2-HSA displayed more potent cytotoxicity to cancer cells than HBD2. DF2-HSA induced apoptosis in cancer cells. Notably, DF2-HSA inhibited tumor cell spheroid formation, an effect comparable to that of salinomycin. DF2-HSA inhibited tumor cell migration and invasion. As detected with scanning electron microscopy, DF2-HSA strongly depleted filopodia on cell surface; and salinomycin induced similar changes. By in vivo imaging, DF2-HSA displayed intense tumor-site accumulation and lasting retention for over 14 days; however, HBD2 showed much less tumor-site accumulation and a shorter retention time for only 24 h. DF2-HSA suppressed the growth of pancreatic cancer MIA PaCa-2 xenograft in athymic mice; and its combination with gemcitabine achieved higher antitumor efficacy. In summary, the recombinant defensin/HSA fusion protein that inhibits NF-κb associated with intensive macropinocytosis is highly effective against pancreatic cancer.

Discovery of METTL3 Small Molecule Inhibitors by Virtual Screening of Natural Products.

N6-Methyladenosine (m6A) is the most prevalent mRNA modification in mammalian cells that is mainly catalyzed by the methyltransferase complex of methyltransferase-like 3 and methyltransferase-like 14 (METTL3-METTL14). Many lines of evidence suggest that METTL3 plays important roles in several diseases such as cancers and viral infection. In the present study, 1,042 natural products from commercially available sources were chosen to establish a screening library, and docking-based high-throughput screening was performed to discover potential METTL3 inhibitors. The selected compounds were then further validated by an in vitro methyltransferase inhibition assay in which m6A content was determined by LC-MS/MS. A cellular assay of the inhibition of m6A methylation was performed to determine the METTL3 inhibitory activity of the selected compound. CCK-8 assay was applied to evaluate the effects of the selected compound on tumor cell viability. Additionally, binding mode analysis, molecular dynamics (MD) simulation, and binding free energy analysis were performed to study the process and characteristics of inhibitor binding. Finally, quercetin was identified as a METTL3 inhibitor with an IC50 value of 2.73 μM. The cellular assay of m6A methylation inhibition showed that quercetin decreased m6A level in a dose-dependent manner in MIA PaCa-2 pancreatic cancer cells. CCK-8 assay showed quercetin efficiently inhibited the proliferation of MIA PaCa-2 and Huh7 tumor cells, with IC50 values 73.51 ± 11.22 μM and 99.97 ± 7.03 μM, respectively. Molecular docking studies revealed that quercetin filled the pocket of the adenosine moiety of SAM but not the pocket of the SAM methionine in the METTL3 protein, and hydrogen bonds, hydrophobic interactions, and pi-stacking were formed. The values of the root mean square deviation (RMSD), the root mean square fluctuations (RMSF), and binding free energy suggested that quercetin can efficiently bind to the pocket of the METTL3 protein and form a stable protein-ligand complex. The present study is the first to identify METTL3 inhibitors from natural products, thus providing a basis for subsequent research and facilitating the development of METTL3-targeting drugs for diseases.

Design and synthesis of novel tetrazolo quinoline bridged isatin derivatives as potential anticancer leads against MIA PaCa-2 human pancreatic cancer cell line

Human pancreatic carcinoma is known for its aggressiveness, low survival rate, and attractive target for anticancer evaluation. To target pancreatic cancer, new anticancer scaffolds are necessary. Hence, biodynamically potent tetrazole fused quinoline bridged isatin molecules (TQI) were considered for design and further synthesized. As a preliminary step, in silico pharmacokinetic properties were screened, followed by molecular docking against cyclooxygenase-2 (PDB ID:1CX2). The TQI (1-8) molecules were found to be drugable, in silico and docking results of compounds TQI1, TQI2, TQI6, and TQI7 were found to have higher binding affinity (-9.5 to -10.8 kcal/mol) and also greater interaction with the active site; HIS207 residue of COX-2. As a result of the influx of in silico evaluation, synthesis was carried out and characterized by spectroscopic techniques like FTIR, LCMS and NMR. The in vitro cytotoxicity study of TQI1, TQI2, TQI6, and TQI7 molecules shows a 60.17±3.12 µM, 74.49±3.45 µM, 93.63±4.10 µM, and 93.63±4.10 µM IC50 against the MIA PaCa-2 cancer cell line. The results suggest that they can be considered as potential leads for next level evaluation.

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.

Mechanical Cues, E-Cadherin Expression and Cell "Sociality" Are Crucial Crossroads in Determining Pancreatic Ductal Adenocarcinoma Cells Behavior.

E-cadherin, an epithelial-to-mesenchymal transition (EMT) marker, is coupled to actin cytoskeleton and distributes cell forces acting on cells. Since YAP transduces mechanical signals involving actin cytoskeleton, we aimed to investigate the relationship between YAP and mechanical cues in pancreatic ductal adenocarcinoma (PDAC) cell lines, characterized by different EMT-related phenotypes, cultured in 2D monolayers and 3D spheroids. We observed that the YAP/p-YAP ratio was reduced in HPAC and MIA PaCa-2 cell lines and remained unchanged in BxPC-3 cells when cultured in a 3D setting. CTGF and CYR61 gene expression were down-regulated in all PDAC 3D compared to 2D cultures, without any significant effect following actin cytoskeleton inhibition by Cytochalasin B (CyB) treatment. Moreover, LATS1 mRNA, indicating the activation of the Hippo pathway, was not influenced by CyB and differed in all PDAC cell lines having different EMT-related phenotype but a similar pattern of CTGF and CYR61 expression. Although the role of YAP modulation in response to mechanical cues in cancer cells remains to be completely elucidated, our results suggest that cell arrangement and phenotype can determine variable outcomes to mechanical stimuli in PDAC cells. Moreover, it is possible to speculate that YAP and Hippo pathways may act as parallel and not exclusive inputs that, converging at some points, may impact cell behavior.

Abietane diterpenes from Abies spectabilis and their anti-pancreatic cancer activity against the MIA PaCa-2 cell line

An ethanolic extract of the stem of Abies spectabilis exhibited strong cytotoxicity against MIA PaCa-2 human pancreatic cancer cells preferentially under nutrient-deprived conditions. Therefore, phytochemical investigation of this bioactive extract was carried out, and that led the isolation of ten compounds (1–10) including a new abietane-type diterpene (1). The structure of the new compound (1) was elucidated by combined spectroscopic techniques, including HRFABMS, NMR and quantum ECD calculation. All the isolated compounds were evaluated for their efficacy against MIA PaCa-2 human pancreatic cancer cell line by employing an anti-austerity strategy. Among the tested compounds, dehydroabietinol (5) displayed the most potent activity with a PC50 value of 6.6 μM. Dehydroabietinol (5) was also found to retard the MIA PaCa-2 cell migration under normal nutrient-rich conditions displaying its anti-metastatic potential. Investigation on the mechanism suggested that dehydroabietinol (5) is an inhibitor of the key cancer cell survival Akt/mTOR/autophagy signaling pathway.

205 Targeting Homologous Repair to Overcome Genotoxic Therapy Resistance in Pancreatic Cancer

OBJECTIVES/GOALS: Pancreatic ductal adenocarcinoma (PDAC) is a relatively radioresistant disease, and inhibition of DNA homologous recombination (HR) repair in combination with radiation therapy (RT) is a potentially attractive strategy to overcome radioresistance. We have found that the expression of the HR protein RAD18 is upregulated in PDAC cells. METHODS/STUDY POPULATION: Standard clonogenic assays, γH2aX foci staining, HR-GFP reporter assay, and western blot analysis of DNA damage response proteins were performed in MIA-PaCa2 (MP2) and PANC-1 cells following knockdown of RAD18 in cells via short hairpin RNA (shRNA). Drug targeting of RAD18 was achieved through the use of a USP-7 inhibitor, P5091. Cells with or without stable knockdown of RAD18 were implanted orthotopically in the pancreas of athymic nude mice and treated with sham radiation or radiation to a dose of 20 Gy in 5 daily fractions once tumors reached 100-150 mm3. RESULTS/ANTICIPATED RESULTS: Stable knockdown of RAD18 in MP2 and PANC-1 resulted in decreased radiation clonogenic survival in vitro (dose enhancement factor (DEF)=1.52 and 1.51, respectively), decreased DNA repair after radiation as measured by the increased number of γH2aX nuclear foci assay at 6, 12, and 24 hours (all p&lt;0.05), decreased HR activation following DNA damage via an HR-GFP reporter assay (p=0.039), and increased tumor growth delay following radiation in vivo (p&lt;0.001). P5091 treatment of both MP2 and PANC-1 resulted in efficient knockdown of RAD18, which was confirmed through western blotting, qRT-PCR, and luciferase reporter assays. P5091 increased radiosensitization, yH2aX nuclear foci remained elevated at 12 and 24 hours (p&lt;0.05), and HR repair was also reduced (p=0.014). DISCUSSION/SIGNIFICANCE: Herein, we show the HR repair protein RAD18, and that modulation of RAD18 expression correlates with in vitro and in vivo radiosensitization through altered HR-mediated DNA repair. USP7 inhibition successfully reduced RAD18 expression and resulted in enhanced radiosensitization.

CuO NPs@Starch as a novel chemotherapeutic drug for the treatment of several types of gastrointestinal system cancers including gastric, pancreatic, and colon cancers

Copper oxide nanoparticles were successfully synthesized through a simple and ‘green’ route using starch as a capping and stabilizing agent under ultrasonic irradiation in alkaline medium. Unique reaction condition was prepared by ultrasonic irradiation, releasing the stored energy in the collapsed bubbles and heats the bubble contents that leads to Cu(II) reduction in the presence of starch. The obtained nanoparticle (CuO [email protected]) was characterized by advanced physical and chemical techniques like Transmission Electron Microscope (TEM), Fourier-transform infrared spectroscopy (FTIR), Uv–Vis spectroscopy, scanning electron microscopy (SEM), X-ray Diffraction (XRD) and energy-dispersive X-ray analysis (EDX). The properties of CuO [email protected] against gastric cancer (AGS and KATO III), pancreatic cancer (AsPC-1 and MIA PaCa-2), and colon cancer (HCT 116 and HCT-8) were evaluated. The viability of malignant cancer cell lines reduced dose-dependently in the presence of CuO [email protected] After clinical study, CuO [email protected] can be utilized as an efficient drug in the treatment of gastric, pancreatic, and colon cancers in humans.