MIA PaCa-2 and PANC-1 - pancreas ductal adenocarcinoma cell lines with neuroendocrine differentiation and somatostatin receptors

Design, synthesis and biological evaluation of sulfur-containing tetrahydroxanthones as potential anti-tumor agents

Given the rising incidence and mortality rates of cancer, the development of highly effective, low-toxicity therapeutics is critical. Xanthones, a class of natural secondary metabolites, are notable for their distinct structure and exhibit promising antitumor activity, underscoring their potential as scaffolds for drug design. Sulfur heterocycles are also valuable in the development of bioactive small molecules. Therefore, we explored the introduction of sulfur in the core structure of xanthones, leading to the synthesis of a series of sulfur-containing tetrahydroxanthones. The in vitro cytotoxicity of these compounds was evaluated using the CCK8 assay, revealing that several derivatives exhibit anti-proliferative effects against HepG2 cells. Among them, compound 4k displayed potent inhibitory activity with an IC50 value of 6.08 μM and showed favorable selectivity, exhibiting low toxicity toward normal cells. Further studies demonstrated that 4k inhibited colony formation and migration of HepG2 cells, and induced apoptosis.

Knockout of p21-Activated Kinase 4 Stimulates MHC I Expression of Pancreatic Cancer Cells via an Autophagy-Independent Pathway

BACKGROUND/OBJECTIVES

Pancreatic ductal adenocarcinoma (PDA) is one of the most malignant solid cancers. KRAS mutation accounts for over 90% of cases. p21-activated kinases (PAKs) act downstream of KRAS and are involved in tumorigenesis. The inhibition of PAK4 suppresses PDA by stimulating the tumor infiltration of cytotoxic T cells. The major histocompatibility complex class I (MHC I) is a key in presenting antigens to cytotoxic T cells. MHC I degradation via autophagy promotes the immune evasion of pancreatic cancer. We investigated the effect of PAK4 inhibition on MHC I expression and autophagy.

METHODS

In this study, using proteomic analysis, fluorescence-activated cell sorting (FACS), and immunoblotting, we examined the effect of PAK4 knockout (KO) in human PDA cells on the expression of MHC I and autophagy to identify the mechanism involved in the stimulation of cytotoxic T cells by PAK4 inhibition.

RESULTS

We found that PAK4 KO increased MHC I expression in two human PDA cell lines: MiaPaCa-2 and PANC-1. PAK4 KO also increased cancer cell autophagy. However, the inhibition of autophagy by chloroquine (CQ) did not affect the effect of PAK4 KO on apoptosis and cell death. More importantly, the inhibition of autophagy by CQ did not alter the expression of MHC I stimulated by PAK4 KO, indicating that PAK4 KO stimulated MHC I expression via an autophagy-independent pathway.

CONCLUSIONS

We identified a role of PAK4 in MHC I expression by PDA cells, which is independent of autophagy.

Synthetic CB1 Cannabinoids Promote Tunneling Nanotube Communication, Cellular Migration, and Epithelial-Mesenchymal Transition in Pancreatic PANC-1 and Colorectal SW-620 Cancer Cell Lines

Metastasizing cancer cells surreptitiously can adapt to metabolic activity during their invasion. By initiating their communications for invasion, cancer cells can reprogram their cellular activities to initiate their proliferation and migration and uniquely counteract metabolic stress during their progression. During this reprogramming process, cancer cells' metabolism and other cellular activities are integrated and mutually regulated by tunneling nanotube communications to alter their specific metabolic functional drivers of tumor growth and progression. Here, we investigated the in vitro effects of the synthetic CB1 cannabinoids AM-404, arvanil, and olvanil on human pancreatic PANC-1 and colorectal SW-620 cancer cell lines to understand further cellular behaviors and the potential risks of their use in cancer therapy. For the first time, the synthetic CB1 cannabinoids AM-404, arvanil, and olvanil significantly altered cancer cells in forming missile-like shapes to induce tunneling nanotube (TNT) communications in PANC-1 cells. Oseltamivir phosphate (OP) significantly prevented TNT formation. To assess the key survival pathways critical for pancreatic cancer progression, we used the AlamarBlue assay to determine synthetic CB1 cannabinoids to induce the cell's metabolic viability drivers to stage migratory intercellular communication. The synthetic CB1 cannabinoids significantly increased cell viability compared to the untreated control for PANC-1 and SW-620 cells, and this response was significantly reduced with the NMBR inhibitor BIM-23127, neuraminidase-1 inhibitor OP, and MMP-9 inhibitor (MMP-9i). CB1 cannabinoids also significantly increased N-cadherin and decreased E-cadherin EMT markers compared to the untreated controls, inducing the process of metastatic phenotype for invasion. BIM-23127, MMP9i, and OP significantly inhibited CB1 agonist-induced NFκB-dependent secretory alkaline phosphatase (SEAP) activity. To confirm this concept, we investigated the migratory invasiveness of PANC-1 and SW-620 cancer cells treated with the synthetic CB1 cannabinoids AM-404, arvanil, and olvanil in a scratch wound assay. CB1 cannabinoids significantly induced the rate of migration and invasiveness of PANC-1 cancer cells, whereas they had minimal effect on the rate of migration of already metastatic SW-620 cancer cells. Interestingly, olvanil-treated SW-620 cells significantly enhanced the migration rate and invasiveness of these cells. The data support the cellular and molecular mechanisms of the synthetic CB1 cannabinoids, orchestrating intercellular conduits to enhance metabolic drivers to stage migratory intercellular communication in pancreatic cancer cells.

Physalin A induces apoptosis through conjugating with Fas-FADD cell death receptor in human oral squamous carcinoma cells and suppresses HSC-3 cell xenograft tumors in NOD/SCID mice

IntroductionOral carcinoma cancer exhibits high global incidence and mortality. Physalin A (PA) was reported to induce programmed cell death in cancer cells. No study has yet investigated the influence of PA in oral squamous cell carcinoma. Herein, this study aims to explore PA-induced anti-cancer effects in human oral carcinoma.MethodsThis study used DNA gel electrophoresis and Annexin V/PI staining to detect DNA fragmentation and cell apoptosis. Western blotting and immunofluorescence analyzed protein expression. Flow cytometry measured Ca2+ release and mitochondrial membrane potential (∆Ψm). Moreover, molecular docking models predicted the molecular binding affinity.ResultsDNA gel electrophoresis and annexin V/PI staining confirmed PA-induced DNA fragmentation and apoptosis. Flow cytometry showed PA increased Ca2+ release and reduced ∆Ψm levels. PA activated cleaved caspase-3, -8, and -9, upregulated Bax and Bid, and downregulated Bcl-2. PA dose-dependently increased Fas (CD95/APO-1), apoptosis-inducing factor (AIF), and cytochrome c release in western blotting analysis. Confocal microscopy confirmed increased Bax, AIF, cleaved caspase-3, and Fas, with decreased Bcl-2. Molecular docking showed strong PA binding via hydrophobic interactions with the Fas-associated death domain (FADD). Compared with cisplatin, PA inhibited HSC-3 cell xenograft tumor growth in NOD/SCID mice.DiscussionWe reveal that PA binds to the Fas-FADD complex, inducing caspase-8 activation and triggering extrinsic and intrinsic mitochondria-dependent apoptosis in HSC-3 cells. It also suppresses HSC-3 cell xenograft tumors in NOD/SCID mice. These findings suggest PA as a potential anti-oral cancer agent in the future.

Novel Pt (II) Complexes With Anticancer Activity Against Pancreatic Ductal Adenocarcinoma Cells

Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive type of solid tumor that is becoming more common. cis-[PtCl2 (NH3)2] (in short cisplatin or CDDP) has been shown to be effective in treating various cancers, including PDAC. However, the development of resistance to chemotherapy drugs has created a need for the synthesis of new anticancer agents. Platinum-based drugs containing the bidentate ligand phenanthroline have been found to have strong antitumor activity due to their ability to cause DNA damage. In this study, we examined the ability of two Pt (II) cationic complexes, [Pt(η 1-C2H4OR) (DMSO) (phen)]+ (in short Pt-EtORSOphen; R = Me, 1; Et, 2), to inhibit the growth and spread of BxPC-3 PDAC cells, in comparison to CDDP. The length of the alkyl chain and its associated lipophilic properties did not affect the anticancer effects of complexes 1 and 2 in BxPC-3 cells. However, it did appear to influence the rapid loss of mitochondrial membrane potential (ΔΨM), suggesting that these complexes could potentially be used as mitochondria-targeted lipophilic cations in anticancer therapy.

Characterization of Epithelial-Mesenchymal and Neuroendocrine Differentiation States in Pancreatic and Small Cell Ovarian Tumor Cells and Their Modulation by TGF-β1 and BMP-7

Pancreatic ductal adenocarcinoma (PDAC) has an extremely poor prognosis, due in part to early invasion and metastasis, which in turn involves epithelial-mesenchymal transition (EMT) of the cancer cells. Prompted by the discovery that two PDAC cell lines of the quasi-mesenchymal subtype (PANC-1, MIA PaCa-2) exhibit neuroendocrine differentiation (NED), we asked whether NED is associated with EMT. Using real-time PCR and immunoblotting, we initially verified endogenous expressions of various NED markers, i.e., chromogranin A (CHGA), synaptophysin (SYP), somatostatin receptor 2 (SSTR2), and SSTR5 in PANC-1 and MIA PaCa-2 cells. By means of immunohistochemistry, the expressions of CHGA, SYP, SSTR2, and the EMT markers cytokeratin 7 (CK7) and vimentin could be allocated to the neoplastic ductal epithelial cells of pancreatic ducts in surgically resected tissues from patients with PDAC. In HPDE6c7 normal pancreatic duct epithelial cells and in epithelial subtype BxPC-3 PDAC cells, the expression of CHGA, SYP, and neuron-specific enolase 2 (NSE) was either undetectable or much lower than in PANC-1 and MIA PaCa-2 cells. Parental cultures of PANC-1 cells exhibit EM plasticity (EMP) and harbor clonal subpopulations with both M- and E-phenotypes. Of note, M-type clones were found to display more pronounced NED than E-type clones. Inducing EMT in parental cultures of PANC-1 cells by treatment with transforming growth factor-β1 (TGF-β1) repressed epithelial genes and co-induced mesenchymal and NED genes, except for SSTR5. Surprisingly, treatment with bone morphogenetic protein (BMP)-7 differentially affected gene expressions in PANC-1, MIA PaCa-2, BxPC-3, and HPDE cells. It synergized with TGF-β1 in the induction of vimentin, SNAIL, SSTR2, and NSE but antagonized it in the regulation of CHGA and SSTR5. Phospho-immunoblotting in M- and E-type PANC-1 clones revealed that both TGF-β1 and, surprisingly, also BMP-7 activated SMAD2 and SMAD3 and that in M- but not E-type clones BMP-7 was able to dramatically enhance the activation of SMAD3. From these data, we conclude that in EMT of PDAC cells mesenchymal and NED markers are co-regulated, and that mesenchymal-epithelial transition (MET) is associated with a loss of both the mesenchymal and NED phenotypes. Analyzing NED in another tumor type, small cell carcinoma of the ovary hypercalcemic type (SCCOHT), revealed that two model cell lines of this disease (SCCOHT-1, BIN-67) do express CDH1, SNAI1, VIM, CHGA, SYP, ENO2, and SSTR2, but that in contrast to BMP-7, none of these genes was transcriptionally regulated by TGF-β1. Likewise, in BIN-67 cells, BMP-7 was able to reduce proliferation, while in SCCOHT-1 cells this occurred only upon combined treatment with TGF-β and BMP-7. We conclude that in PDAC-derived tumor cells, NED is closely linked to EMT and TGF-β signaling, which may have implications for the therapeutic use of TGF-β inhibitors in PDAC management.

Discovery of novel TANK-Binding Kinase 1 (TBK1) inhibitor against pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) has limited treatment options, underscoring the urgent need for developing new therapies. The upregulation of TBK1 activity plays a crucial role in multiple pancreatic cancer-related signaling pathways, suggesting that inhibiting the kinase activity of TBK1 could be a promising strategy. Herein, we discovered a novel TBK1 inhibitor, LIB3S0280, using a structure-based virtual screening (SBVS) strategy. In the anti-proliferative and viability assays, LIB3S0280 showed significant inhibition against pancreatic cancer cell lines that highly express TBK1 with the GI50 values of 2.24 and 4.71 μM and IC50 values of 6.64 and 10.98 μM at 96 h. For the downstream targets, LIB3S0280 can inhibit TBK1 downstream signaling by decreasing the phosphorylation of IκBα and AKT better than a known TBK1 inhibitor, BX-795. Furthermore, PDAC cells were arrested in G2/M and underwent apoptosis or senescence with the treatment of LIB3S0280. These findings suggest that TBK1 inhibitor LIB3S0280 has great potential as a lead compound in the further development of a novel treatment for PDAC.

Unveiling the 4-aminoquinoline derivatives as potent agents against pancreatic ductal adenocarcinoma (PDAC) cell lines

Common antimalarials such as artemisinins, chloroquine and their derivatives also possess potent anti-inflamantory, antiviral and anticancer properties. In the search for new therapeutics to combat difficult-to-treat pancreatic carcinomas, we unveiled that 4-aminoquinoline derivatives, with significant antiplasmodial properties and a great safety profile in vivo, have remarkable anticancer activity against pancreatic ductal adenocarcinoma (PDAC) and considerable efficacy in the xenograft model in vivo. The aim of the present study was to further investigate anticancer properties of these compounds in a drug-repurposing manner. The compounds showed profound cytotoxic effects at nanomolar to low micromolar concentration in 2D cultured cells (in vitro) and in the zebrafish PDAC xenograft model (in vivo). A deeper insight into their mechanisms of cytotoxic action showed these compounds induce apoptosis while increasing reactive oxygen species levels along with autophagy inhibition. Additional investigation of the autophagy modulation proved that tested quinoline derivatives cause P62 and LC3-II accumulation in PDAC cells alongside lysosomal alkalinization. Further, in vivo toxicity studies in the zebrafish model showed low toxicity without developmental side effects of the investigated 4-aminoquinolines, while the applied compounds effectively inhibited tumor growth and prevented the metastasis of xenografted pancreatic cells. Taken together, these results highlight the 4-aminoquinolines as privileged structures that ought to be investigated further for potential application in pancreatic carcinoma treatment.

uPAR Immuno-PET in Pancreatic Cancer, Aging, and Chemotherapy-Induced Senescence

Identifying cancer therapy resistance is a key time-saving tool for physicians. Part of chemotherapy resistance includes senescence, a persistent state without cell division or cell death. Chemically inducing senescence with the combination of trametinib and palbociclib (TP) yields several tumorigenic and prometastatic factors in pancreatic cancer models with many potential antibody-based targets. In particular, urokinase plasminogen activator receptor (uPAR) has been shown to be a membrane-bound marker of senescence in addition to an oncology target. Methods: Here, 2 antibodies against murine uPAR and human uPAR were developed as immuno-PET agents to noninvasively track uPAR antigen abundance. Results: TP treatment increased cell uptake both in murine KPC cells and in human MiaPaCa2 cells. In vivo, subcutaneously implanted murine KPC tumors had high tumor uptake with the antimurine uPAR antibody independently of TP in young mice, yet uPAR uptake was maintained in aged mice on TP. Mice xenografted with human MiaPaCa2 tumors showed a significant increase in tumor uptake on TP therapy when imaged with the antihuman uPAR antibody. Imaging with either uPAR antibody was found to be more tumor-selective than imaging with [18F]FDG or [18F]F-DPA-714. Conclusion: The use of radiolabeled uPAR-targeting antibodies provides a new antibody-based PET imaging candidate for pancreatic cancer imaging as well as chemotherapy-induced senescence.

The Role of Heat Shock Factor 1 in Preserving Proteomic Integrity During Copper-Induced Cellular Toxicity

Copper is crucial for many physiological processes across mammalian cells, including energy metabolism, neurotransmitter synthesis, and antioxidant defense mechanisms. However, excessive copper levels can lead to cellular toxicity and "cuproptosis", a form of programmed cell death characterized by the accumulation of copper within mitochondria. Tumor cells are less sensitive to this toxicity than normal cells, the mechanism for which remains unclear. We address this important issue by exploring the role of heat shock factor 1 (HSF1), a transcription factor that is highly expressed across several types of cancer and has a crucial role in tumor survival, in protecting against copper-mediated cytotoxicity. Using pancreatic ductal adenocarcinoma cells, we show that excessive copper triggers a proteotoxic stress response (PSR), activating HSF1 and that overexpressing HSF1 diminishes intracellular copper accumulation and prevents excessive copper-induced cell death and amyloid fibrils formation, highlighting HSF1's role in preserving proteasomal integrity. Copper treatment decreases the lipoylation of dihydrolipoamide S-acetyltransferase (DLAT), an enzyme necessary for cuproptosis, induces DLAT oligomerization, and induces insoluble DLAT formation, which is suppressed by overexpressing HSF1, in addition to enhancing the interaction between HSF1 and DLAT. Our findings uncover how HSF1 protects against copper-induced damage in cancer cells and thus represents a novel therapeutic target for enhancing copper-mediated cancer cell death.

Phenotypic, Genomic, and Transcriptomic Heterogeneity in a Pancreatic Cancer Cell Line

OBJECTIVE

To evaluate the suitability of the MIA PaCa-2 cell line for studying pancreatic cancer intratumor heterogeneity, we aim to further characterize the nature of MIA PaCa-2 cells' phenotypic, genomic, and transcriptomic heterogeneity.

MATERIALS AND METHODS

MIA PaCa-2 single-cell clones were established through flow cytometry. For the phenotypic study, we quantified the cellular morphology, proliferation rate, migration potential, and drug sensitivity of the clones. The chromosome copy number and transcriptomic profiles were quantified using SNPa and RNA-seq, respectively.

RESULTS

Four MIA PaCa-2 clones showed distinctive phenotypes, with differences in cellular morphology, proliferation rate, migration potential, and drug sensitivity. We also observed a degree of genomic variations between these clones in form of chromosome copy number alterations and single nucleotide variations, suggesting the genomic heterogeneity of the population, and the intrinsic genomic instability of MIA PaCa-2 cells. Lastly, transcriptomic analysis of the clones also revealed gene expression profile differences between the clones, including the uniquely regulated ITGAV , which dictates the morphology of MIA PaCa-2 clones.

CONCLUSIONS

MIA PaCa-2 is comprised of cells with distinctive phenotypes, heterogeneous genomes, and differential transcriptomic profiles, suggesting its suitability as a model to study the underlying mechanisms behind pancreatic cancer heterogeneity.

Impact of stroma remodeling on forces experienced by cancer cells and stromal cells within a pancreatic tumor tissue

Remodeling (re-engineering) of a tumor's stroma has been shown to improve the efficacy of anti-tumor therapies, without destroying the stroma. Even though it still remains unclear which stromal component/-s and what characteristics hinder the reach of nanoparticles deep into cancer cells, we hypothesis that mechanisms behind stroma's resistance to the penetration of nanoparticles rely heavily on extrinsic mechanical forces on stromal cells and cancer cells. Our hypothesis has been formulated on the basis of our previous study which has shown that changes in extracellular matrix (ECM) stiffness with tumor growth influence stresses exerted on fibroblasts and cancer cells, and that malignant cancer cells generate higher stresses on their stroma. This study attempts to establish a distinct identification of the components' remodeling on the distribution and magnitude of stress within a tumor tissue which ultimately will impact the resistance of stroma to treatment. In this study, our objective is to construct a three-dimensional in silico model of a pancreas tumor tissue consisting of cancer cells, stromal cells, and ECM to determine how stromal remodeling alters the stresses distribution and magnitude within the pancreas tumor tissue. Our results show that changes in mechanical properties of ECM significantly alter the magnitude and distribution of stresses within the pancreas tumor tissue. Our results revealed that these stresses are more sensitive to ECM properties as we see the stresses reaching to a maximum of 22,000 Pa for softer ECM with Young's modulus of 250 Pa. The stress distribution and magnitude within the pancreas tumor tissue does not show high sensitivity to the changes in mechanical properties of stromal cells surrounding stiffer cancer cells (PANC-1 with Young's modulus of 2400 Pa). However, softer cancer cells (MIA-PaCa-2 with (Young's modulus of 500 Pa) increase the stresses experienced by stiffer stromal cells and for stiffer ECM. By providing a unique platform to dissect and quantify the impact of individual stromal components on the stress distribution within a tumor tissue, this study serves as an important first step in understanding of which stromal components are vital for an efficient remodeling. This knowledge will be leveraged to overcome a tumor's resistance against the penetration of nanoparticles on a per-patient basis.

A highly fluorescent and readily accessible all-organic photosensitizer model for advancing image-guided cancer PDT

The potential of using image-guided photodynamic therapy (ig-PDT) for cancer, especially with highly biocompatible fluorescent agents free of heavy atoms, is well recognized. This is due to key advantages related to minimizing adverse side effects associated with standard cancer chemotherapy. However, this theragnostic approach is strongly limited by the lack of synthetically-accessible and easily-modulable chemical scaffolds, enabling the rapid design and construction of advanced agents for clinical ig-PDT. In fact, there are still very few ig-PDT agents clinically approved. Herein we report a readily accessible, easy-tunable and highly fluorescent all-organic small photosensitizer, as a model design for accelerating the development and translation of advanced ig-PDT agents for cancer. This scaffold is based on BODIPY, which assures high fluorescence, accessibility, and ease of performance adaptation by workable chemistry. The optimal PDT performance of this BODIPY dye, tested in highly resistant pancreatic cancer cells, despite its high fluorescent behavior, maintained even after fixation and cancer cell death, is based on its selective accumulation in mitochondria. This induces apoptosis upon illumination, as evidenced by proteomic studies and flow cytometry. All these characteristics make the reported BODIPY-based fluorescent photosensitizer a valuable model for the rapid development of ig-PDT agents for clinical use.

Canniprene B, a new prenylated dihydrostilbene with cytotoxic activities from the leaves of Cannabis sativa

A new, canniprene B (4), along with five known (1-3 and 5-6) dihydrostilbenes were isolated from the leaves of Cannabis sativa collected at CSIR - IIIM, Jammu, India. Structures of all isolated compounds were elucidated by spectroscopic data analysis, including 1D and 2D NMR, and HR-ESI-MS. Canniprene B is a new prenylated dihydrostilbenes, a positional isomer of the known compound canniprene (5). The cytotoxic activities of these compounds (1-6) were evaluated using the SRB assay against a panel of five human cancer cell lines. Notably, canniprene B (4) exhibited varying levels of cytotoxicity with IC50 values ranging from 2.5 to 33.52 μM, demonstrating the most potent activity against pancreatic cancer cells.

Pd(II) complexes bearing NNS pincer ligands: unveiling potent cytotoxicity against breast and pancreatic cancer

The continuously increasing rate of breast cancer is one of the major threats to female health worldwide. Recently, palladium complexes have emerged as impressive candidates with effective biocompatibility and anticancer activities. Hence, in the present study, we report a new series of palladium complexes bearing NNS pincer ligands for cytotoxicity studies. The reaction of thiophenol/4-chlorothiophenol/4-methylthiophenol/4-methoxythiophenol with 2-bromo-N-quinolin-8-yl-acetamide in the presence of sodium hydroxide in ethanol at 80 °C gave [C9H6N-NH-C(O)-CH2-S-Ar] [Ar = C6H5 (L1), C6H4Cl-4 (L2), C6H4Me-4 (L3), and C6H4-OMe-4 (L4)]. The corresponding reaction of L1-L4 with Na2PdCl4 in methanol at room temperature for 3 h resulted in complexes [(L1-H)PdCl] (C1), [(L2-H)PdCl] (C2), [(L3-H)PdCl] (C3), and [(L4-H)PdCl] (C4). All new compounds have been characterized by spectroscopic analyses. The structures of complexes C1, C3, and C4 have also been determined from single-crystal X-ray diffraction data. The cytotoxicities of L1-L4 and C1-C4 have been investigated for breast cancer 4T1 and pancreatic cancer MIA-PaCa-2 cells. The IC50 values for complexes C2 and C3 were observed to be comparable to or higher than those of cisplatin. The stressed morphology and cell death of cancerous cells were successfully observed through cellular morphology analysis and the assessment of cytoskeleton damage.

Surface Engineering of Natural Killer Cells with CD44-targeting Ligands for Augmented Cancer Immunotherapy

Adoptive immunotherapy utilizing natural killer (NK) cells has demonstrated remarkable efficacy in treating hematologic malignancies. However, its clinical intervention for solid tumors is hindered by the limited expression of tumor-specific antigens. Herein, lipid-PEG conjugated hyaluronic acid (HA) materials (HA-PEG-Lipid) for the simple ex-vivo surface coating of NK cells is developed for 1) lipid-mediated cellular membrane anchoring via hydrophobic interaction and thereby 2) sufficient presentation of the CD44 ligand (i.e., HA) onto NK cells for cancer targeting, without the need for genetic manipulation. Membrane-engineered NK cells can selectively recognize CD44-overexpressing cancer cells through HA-CD44 affinity and subsequently induce in situ activation of NK cells for cancer elimination. Therefore, the surface-engineered NK cells using HA-PEG-Lipid (HANK cells) establish an immune synapse with CD44-overexpressing MIA PaCa-2 pancreatic cancer cells, triggering the "recognition-activation" mechanism, and ultimately eliminating cancer cells. Moreover, in mouse xenograft tumor models, administrated HANK cells demonstrate significant infiltration into solid tumors, resulting in tumor apoptosis/necrosis and effective suppression of tumor progression and metastasis, as compared to NK cells and gemcitabine. Taken together, the HA-PEG-Lipid biomaterials expedite the treatment of solid tumors by facilitating a sequential recognition-activation mechanism of surface-engineered HANK cells, suggesting a promising approach for NK cell-mediated immunotherapy.

Nanotechnology-Based Strategy for Enhancing Therapeutic Efficacy in Pancreatic Cancer: Receptor-Targeted Drug Delivery by Somatostatin Analog

A novel nanotechnology-based drug delivery system (DDS) targeted at pancreatic cancer cells was developed, characterized, and tested. The system consisted of liposomes as carriers, an anticancer drug (paclitaxel) as a chemotherapeutic agent, and a modified synthetic somatostatin analog, 5-pentacarbonyl-octreotide, a ligand for somatostatin receptor 2 (SSTR2), as a targeting moiety for pancreatic cancer. The cellular internalization, cytotoxicity, and antitumor activity of the DDS were tested in vitro using human pancreatic ductal adenocarcinoma (PDAC) cells with different expressions of the targeted SSTR2 receptors, and in vivo on immunodeficient mice bearing human PDAC xenografts. The targeted drug delivery system containing paclitaxel exhibited significantly enhanced cytotoxicity compared to non-targeted DDS, and this efficacy was directly related to the levels of SSTR2 expression. It was found that octreotide-targeted DDS proved exceptionally effective in suppressing the growth of PDAC tumors. This study underscores the potential of octreotide-targeted liposomal delivery systems to enhance the therapeutic outcomes for PDAC compared with non-targeted liposomal DDS and Paclitaxel-Cremophor® EL, suggesting a promising avenue for future cancer therapy innovations.

PW06 suppresses cancer cell metastasis in human pancreatic carcinoma MIA PaCa-2 cells via the inhibitions of p-Akt/mTOR/NF-κB and MMP2/MMP9 signaling pathways in vitro

PW06 [(E)-3-(9-ethyl-9H-carbazol-3-yl)-1-(2,5-dimethoxyphenyl) prop-2-en-1-one], a kind of the carbazole derivative containing chalcone moiety, induced cell apoptosis in human pancreatic carcinoma in vitro. There is no investigation to show that PW06 inhibits cancer cell metastasis in human pancreatic carcinoma in vitro. Herein, PW06 (0.1-0.8 μM) significantly exists in the antimetastatic activities of human pancreatic carcinoma MIA PaCa-2 cells in vitro. Wound healing assay shows PW06 at 0.2 μM suppressed cell mobility by 7.45 and 16.55% at 6 and 24 hours of treatments. PW06 at 0.1 and 0.2 μM reduced cell mobility by 14.72 and 21.8% for 48 hours of treatment. Transwell chamber assay indicated PW06 (0.1-0.2 μM) suppressed the cell migration (decreased 26.67-35.42%) and invasion (decreased 48.51-68.66%). Atomic force microscopy assay shows PW06 (0.2 μM) significantly changed the shape of cell morphology. The gelatin zymography assay indicates PW06 decreased MMP2's and MMP9's activities at 48 hours of treatment. Western blotting assay further confirms PW06 reduced levels of MMP2 and MMP9 and increased protein expressions of EGFR, SOS1, and Ras. PW06 also increased the p-JNK, p-ERK, and p-p38. PW06 increased the expression of PI3K, PTEN, Akt, GSK3α/β, and E-cadherin. Nevertheless, results also show PW06 decreased p-Akt, mTOR, NF-κB, p-GSK3β, β-catenin, Snail, N-cadherin, and vimentin in MIA PaCa-2 cells. The confocal laser microscopy examination shows PW06 increased E-cadherin but decreased vimentin in MIA PaCa-2 cells. Together, our findings strongly suggest that PW06 inhibited the p-Akt/mTOR/NF-κB/MMPs pathways, increased E-cadherin, and decreased N-cadherin/vimentin, suppressing the migration and invasion in MIA PaCa-2 cells in vitro.

Development of novel pyrimidine nucleoside analogs as potential anticancer agents: Synthesis, characterization, and In-vitro evaluation against pancreatic cancer

The present study proposed modification of 5-FU by conjugation with an acyl chloride and a 5-membered heterocyclic ring to improve its in-vitro cytotoxicity and metabolic stability. XYZ-I-71 and XYZ-I-73 were synthesized by introducing a tetrahydrofuran ring on 5-fluorocytosine (a precursor of 5-FU) and conjugation with octanoyl chloride and lauroyl chloride, respectively. The structure of the synthesized compounds was validated using NMR and micro-elemental analysis. The antiproliferative activity of the analogs was determined against MiaPaCa-2, PANC-1, and BxPC-3 pancreatic cancer cells. The analog's stability in human liver microsomes was quantified by HPLC. We found that the XYZ-I-73 (IC50 3.6 ± 0.4 μM) analog was most effective against MiaPaCa-2 cells compared to XYZ-I-71(IC50 12.3 ± 1.7 μM), GemHCl (IC50 24.2 ± 1.3 μM), Irinotecan (IC50 10.1 ± 1.5 μM) and 5-FU (IC50 13.2 ± 1.1 μM). The antiproliferative effects of this analog in Miapaca-2 cells is evident based on it having a 7-fold,3-fold, and 4-fold increased cytotoxic effect over Gem-HCl, Irinotecan, and 5-FU, respectively. On the other hand, XYZ-I-71 exhibited a 2-fold increased cytotoxic effect over Gem-HCl but a comparable cytotoxic effect to 5-FU and Irinotecan in MiaPaCa-2 cells. A similar trend of higher XYZ-I-73 inhibition was observed in PANC-1 and BxPC-3 cultures. For 48-h MiaPaCa-2 cell migration studies, XYZ-I-73 (5 μM) significantly reduced migration (# of migrated cells, 168 ± 2.9), followed by XYZ-I-71(315±2.1), Gem-HCl (762±3.1) and 5-FU (710 ± 3.2). PARP absorbance studies demonstrated significant inhibition of PARP expression of XYZ-I-73 treated cells compared to 5-FU, GemHCl, and XYZ-I-71. Further, BAX and p53 expressions were significantly increased in cells treated with XYZ-I-73 compared to 5-FU, GemHCl, and XYZ-I-71. In-vitro, metabolic stability studies showed that 80 ± 5.9% of XYZ-I-71 and XYZ-I-73 remained intact after 2 h exposure in liver microsomal solution compared to 5-FU. The XYZ-I-73 analog demonstrated a remarkable cytotoxic effect and improved in-vitro metabolic stability over the selected standard drugs and may have potential anticancer activity against pancreatic cancer.

Targeted Nanoparticle-Based Diagnostic and Treatment Options for Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC), one of the deadliest cancers, presents significant challenges in diagnosis and treatment due to its aggressive, metastatic nature and lack of early detection methods. A key obstacle in PDAC treatment is the highly complex tumor environment characterized by dense stroma surrounding the tumor, which hinders effective drug delivery. Nanotechnology can offer innovative solutions to these challenges, particularly in creating novel drug delivery systems for existing anticancer drugs for PDAC, such as gemcitabine and paclitaxel. By using customization methods such as incorporating conjugated targeting ligands, tumor-penetrating peptides, and therapeutic nucleic acids, these nanoparticle-based systems enhance drug solubility, extend circulation time, improve tumor targeting, and control drug release, thereby minimizing side effects and toxicity in healthy tissues. Moreover, nanoparticles have also shown potential in precise diagnostic methods for PDAC. This literature review will delve into targeted mechanisms, pathways, and approaches in treating pancreatic cancer. Additional emphasis is placed on the study of nanoparticle-based delivery systems, with a brief mention of those in clinical trials. Overall, the overview illustrates the significant advances in nanomedicine, underscoring its role in transcending the constraints of conventional PDAC therapies and diagnostics.

Modeling Physical Forces Experienced by Cancer and Stromal Cells Within Different Organ-Specific Tumor Tissue

Mechanical force exerted on cancer cells by their microenvironment have been reported to drive cells toward invasive phenotypes by altering cells' motility, proliferation, and apoptosis. These mechanical forces include compressive, tensile, hydrostatic, and shear forces. The importance of forces is then hypothesized to be an alteration of cancer cells' and their microenvironment's biophysical properties as the indicator of a tumor's malignancy state. Our objective is to investigate and quantify the correlation between a tumor's malignancy state and forces experienced by the cancer cells and components of the microenvironment. In this study, we have developed a multicomponent, three-dimensional model of tumor tissue consisting of a cancer cell surrounded by fibroblasts and extracellular matrix (ECM). Our results on three different organs including breast, kidney, and pancreas show that: A) the stresses within tumor tissue are impacted by the organ specific ECM's biophysical properties, B) more invasive cancer cells experience higher stresses, C) in pancreas which has a softer ECM (Young modulus of 1.0 kPa) and stiffer cancer cells (Young modulus of 2.4 kPa and 1.7 kPa) than breast and kidney, cancer cells experienced significantly higher stresses, D) cancer cells in contact with ECM experienced higher stresses compared to cells surrounded by fibroblasts but the area of tumor stroma experiencing high stresses has a maximum length of 40 μm when the cancer cell is surrounded by fibroblasts and 12 μm for when the cancer cell is in vicinity of ECM. This study serves as an important first step in understanding of how the stresses experienced by cancer cells, fibroblasts, and ECM are associated with malignancy states of cancer cells in different organs. The quantification of forces exerted on cancer cells by different organ-specific ECM and at different stages of malignancy will help, first to develop theranostic strategies, second to predict accurately which tumors will become highly malignant, and third to establish accurate criteria controlling the progression of cancer cells malignancy. Furthermore, our in silico model of tumor tissue can yield critical, useful information for guiding ex vivo or in vitro experiments, narrowing down variables to be investigated, understanding what factors could be impacting cancer treatments or even biomarkers to be looking for.

The protein phosphatase-2A subunit PR130 is involved in the formation of cytotoxic protein aggregates in pancreatic ductal adenocarcinoma cells

As a major source of cellular serine and threonine phosphatase activity, protein phosphatase-2A (PP2A) modulates signaling pathways in health and disease. PP2A complexes consist of catalytic, scaffolding, and B-type subunits. Seventeen PP2A B-type subunits direct PP2A complexes to selected substrates. It is ill-defined how PP2A B-type subunits determine the growth and drug responsiveness of tumor cells. Pancreatic ductal adenocarcinoma (PDAC) is a disease with poor prognosis. We analyzed the responses of murine and human mesenchymal and epithelial PDAC cells to the specific PP2A inhibitor phendione. We assessed protein levels by immunoblot and proteomics and cell fate by flow cytometry, confocal microscopy, and genetic manipulation. We show that murine mesenchymal PDAC cells express significantly higher levels of the PP2A B-type subunit PR130 than epithelial PDAC cells. This overexpression of PR130 is associated with a dependency of such metastasis-prone cells on the catalytic activity of PP2A. Phendione induces apoptosis and an accumulation of cytotoxic protein aggregates in murine mesenchymal and human PDAC cells. These processes occur independently of the frequently mutated tumor suppressor p53. Proteomic analyses reveal that phendione upregulates the chaperone HSP70 in mesenchymal PDAC cells. Inhibition of HSP70 promotes phendione-induced apoptosis and phendione promotes a proteasomal degradation of PR130. Genetic elimination of PR130 sensitizes murine and human PDAC cells to phendione-induced apoptosis and protein aggregate formation. These data suggest that the PP2A-PR130 complex dephosphorylates and thereby prevents the aggregation of proteins in tumor cells.

Characterisation of the cell and molecular biological effect of peptide-based daunorubicin conjugates developed for targeting pancreatic adenocarcinoma (PANC-1) cell line

Pancreatic adenocarcinoma is one of the tumours with the worst prognosis, with a 5-year survival rate of 5-10%. Our aim was to find and optimise peptide-based drug conjugates with daunorubicin (Dau) as the cytotoxic antitumour agent. When conjugated with targeting peptides, the side effect profile and pharmacokinetics of Dau can be improved. The targeting peptide sequences (e.g. GSSEQLYL) we studied were originally selected by phage display. By Ala-scan technique, we identified that position 6 in the parental sequence (Dau=Aoa-LRRY-GSSEQLYL-NH2, ConjA) could be modified without the loss of antitumour activity (Dau=Aoa-LRRY-GSSEQAYL-NH2, Conj03: 14. 9% viability). Our results showed that the incorporation of p-chloro-phenylalanine (Dau=Aoa-LRRY-GSSEQF(pCl)YL-NH2, Conj16) further increased the antitumour potency (10-5 M: 9.7% viability) on pancreatic adenocarcinoma cells (PANC-1). We found that conjugates containing modified GSSEQLYL sequences could be internalised to PANC-1 cells and induce cellular senescence in the short term and subsequent apoptotic cell death. Furthermore, the cardiotoxic effect of Dau was markedly reduced in the form of peptide conjugates. In conclusion, Conj16 had the most effective antitumor activity on PANC-1 cells, which makes this conjugate promising for developing new targeted therapies without cardiotoxic effects.

Caffeic acid, a dietary polyphenol, pre-sensitizes pancreatic ductal adenocarcinoma to chemotherapeutic drug

Resistance to chemotherapeutics is an eminent cause that leads to search for options that help in diminution of pancreatic ductal adenocarcinoma (PDAC) by overcoming resistance issues. Caffeic acid (CFA), a polyphenol occurring in many dietary foods, is known to show antidiabetic and anticancer properties potential. To unveil the effect of CFA on PDAC, we carried out this research in PDAC cells, following which we checked the combination effect of CFA and chemotherapeutics and pre-sensitization effects of CFA. Multitudinous web-based approaches were applied for identifying CFA targets in PDAC and then getting their interconnections. Subsequently, we manifested CFA effects by in-vitro analysis showing IC50 concentrations of 37.37 and 15.06 µM on Panc-1 and Mia-PaCa-2, respectively. The combination index of CFA with different drugs was explored which showed the antagonistic effects of combination treatment leading to further investigation of the pre-sensitizing effects. CFA pre-sensitization reduced IC50 concentration of doxorubicin in both PDAC cell lines which also triggered ROS generation determined by 2',7'-dichlorofluorescin diacetate assay. The differential gene expression analysis after CFA treatment showed discrete genes affected in both cells, i.e. N-Cad and Cas9 in Panc-1 and Pi3K/AkT/mTOR along with p53 in Mia-PaCa-2. Collectively, this study investigated the role of CFA as PDAC therapeutics and explored the mechanism in mitigating resistance of PDAC by sensitizing to chemotherapeutics.

Gluing GAP to RAS Mutants: A New Approach to an Old Problem in Cancer Drug Development

Mutated genes may lead to cancer development in numerous tissues. While more than 600 cancer-causing genes are known today, some of the most widespread mutations are connected to the RAS gene; RAS mutations are found in approximately 25% of all human tumors. Specifically, KRAS mutations are involved in the three most lethal cancers in the U.S., namely pancreatic ductal adenocarcinoma, colorectal adenocarcinoma, and lung adenocarcinoma. These cancers are among the most difficult to treat, and they are frequently excluded from chemotherapeutic attacks as hopeless cases. The mutated KRAS proteins have specific three-dimensional conformations, which perturb functional interaction with the GAP protein on the GAP-RAS complex surface, leading to a signaling cascade and uncontrolled cell growth. Here, we describe a gluing docking method for finding small molecules that bind to both the GAP and the mutated KRAS molecules. These small molecules glue together the GAP and the mutated KRAS molecules and may serve as new cancer drugs for the most lethal, most difficult-to-treat, carcinomas. As a proof of concept, we identify two new, drug-like small molecules with the new method; these compounds specifically inhibit the growth of the PANC-1 cell line with KRAS mutation G12D in vitro and in vivo. Importantly, the two new compounds show significantly lower IC50 and higher specificity against the G12D KRAS mutant human pancreatic cancer cell line PANC-1, as compared to the recently described selective G12D KRAS inhibitor MRTX-1133.

Design, Synthesis, and Antitumor Evaluation of an Opioid Growth Factor Bioconjugate Targeting Pancreatic Ductal Adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) presents a formidable challenge with high lethality and limited effective drug treatments. Its heightened metastatic potential further complicates the prognosis. Owing to the significant toxicity of current chemotherapeutics, compounds like [Met5]-enkephalin, known as opioid growth factor (OGF), have emerged in oncology clinical trials. OGF, an endogenous peptide interacting with the OGF receptor (OGFr), plays a crucial role in inhibiting cell proliferation across various cancer types. This in vitro study explores the potential anticancer efficacy of a newly synthesized OGF bioconjugate in synergy with the classic chemotherapeutic agent, gemcitabine (OGF-Gem). The study delves into assessing the impact of the OGF-Gem conjugate on cell proliferation inhibition, cell cycle regulation, the induction of cellular senescence, and apoptosis. Furthermore, the antimetastatic potential of the OGF-Gem conjugate was demonstrated through evaluations using blood platelets and AsPC-1 cells with a light aggregometer. In summary, this article demonstrates the cytotoxic impact of the innovative OGF-Gem conjugate on pancreatic cancer cells in both 2D and 3D models. We highlight the potential of both the OGF-Gem conjugate and OGF alone in effectively inhibiting the ex vivo pancreatic tumor cell-induced platelet aggregation (TCIPA) process, a phenomenon not observed with Gem alone. Furthermore, the confirmed hemocompatibility of OGF-Gem with platelets reinforces its promising potential. We anticipate that this conjugation strategy will open avenues for the development of potent anticancer agents.

Microfluidic Organoid Cultures Derived from Pancreatic Cancer Biopsies for Personalized Testing of Chemotherapy and Immunotherapy

Patient-derived cancer organoids (PDOs) hold considerable promise for personalizing therapy selection and improving patient outcomes. However, it is challenging to generate PDOs in sufficient numbers to test therapies in standard culture platforms. This challenge is particularly acute for pancreatic ductal adenocarcinoma (PDAC) where most patients are diagnosed at an advanced stage with non-resectable tumors and where patient tissue is in the form of needle biopsies. Here the development and characterization of microfluidic devices for testing therapies using a limited amount of tissue or PDOs available from PDAC biopsies is described. It is demonstrated that microfluidic PDOs are phenotypically and genotypically similar to the gold-standard Matrigel organoids with the advantages of 1) spheroid uniformity, 2) minimal cell number requirement, and 3) not relying on Matrigel. The utility of microfluidic PDOs is proven by testing PDO responses to several chemotherapies, including an inhibitor of glycogen synthase kinase (GSKI). In addition, microfluidic organoid cultures are used to test effectiveness of immunotherapy comprised of NK cells in combination with a novel biologic. In summary, our microfluidic device offers considerable benefits for personalizing oncology based on cancer biopsies and may, in the future, be developed into a companion diagnostic for chemotherapy or immunotherapy treatments.

Intratumoral Biosynthesis of Gold Nanoclusters by Pancreatic Cancer to Overcome Delivery Barriers to Radiosensitization

Nanoparticle delivery to solid tumors is a prime challenge in nanomedicine. Here, we approach this challenge through the lens of biogeochemistry, the field that studies the flow of chemical elements within ecosystems as manipulated by living cellular organisms and their environments. We leverage biogeochemistry concepts related to gold cycling against pancreatic cancer, considering mammalian organisms as drivers for gold nanoparticle biosynthesis. Sequestration of gold nanoparticles within tumors has been demonstrated as an effective strategy to enhance radiotherapy; however, the desmoplasia of pancreatic cancer impedes nanoparticle delivery. Our strategy overcomes this barrier by applying an atomic-scale agent, ionic gold, for intratumoral gold nanoparticle biosynthesis. Our comprehensive studies showed the cancer-specific synthesis of gold nanoparticles from externally delivered gold ions in vitro and in a murine pancreatic cancer model in vivo; a substantial colocalization of gold nanoparticles (GNPs) with cancer cell nuclei in vitro and in vivo; a strong radiosensitization effect by the intracellularly synthesized GNPs; a uniform distribution of in situ synthesized GNPs throughout the tumor volume; a nearly 40-day total suppression of tumor growth in animal models of pancreatic cancer treated with a combination of gold ions and radiation that was also associated with a significantly higher median survival versus radiation alone (235 vs 102 days, respectively).

Integrin β1 regulates the perineural invasion and radioresistance of oral squamous carcinoma cells by modulating cancer cell stemness

Perineural invasion and radioresistance are the main determinants of treatment outcomes in oral squamous cell carcinoma (OSCC), but the exact mechanism is still unknown. We conducted an in vitro experiment to evaluate the role of integrin β1 (ITGB1) in the perineural invasion, radioresistance, and tumor aggressiveness of OSCC. Two OSCC cell lines (SCC25, SCC15) and radiation-induced radioresistant OSCC cell lines were used in this study. The expression of ITGB1 was compared between control radiosensitive and radioresistant OSCC cell lines. ITGB1 was inhibited by small hairpin RNA, and then the adhesion to neuronal cells, responsiveness to radiation, and aggressiveness of both OSCC cell lines were evaluated. Expression of ITGB1 and adhesion to neuronal cells were increased in radioresistant OSCC compared with control radiosensitive OSCC, and increased ITGB1 expression was more prominent in cancer stem cell-like cells. When the expression of ITGB1 was inhibited, the adhesion to neuronal cells, resistance to radiation, and invasion and migration of radioresistant OSCC were significantly reduced. Moreover, the expression of cancer stem cell markers and size of spheroid formations were also significantly attenuated by inhibiting ITGB1. These findings suggest that ITGB1 may be a significant contributor to perineural invasion and the maintenance of radioresistance in OSCC cells, and is associated with cancer stem cell-like cells. Furthermore, our results suggest a possible relationship between perineural invasion and radioresistance of OSCC. More detailed research is warranted to evaluate the role of ITGB1 as a novel emerging therapeutic target for radioresistant OSCC.

Evofosfamide and Gemcitabine Act Synergistically in Pancreatic Cancer Xenografts by Dual Action on Tumor Vasculature and Inhibition of Homologous Recombination DNA Repair

Aims: Pancreatic ductal adenocarcinomas (PDACs) form hypovascular and hypoxic tumors, which are difficult to treat with current chemotherapy regimens. Gemcitabine (GEM) is often used as a first-line treatment for PDACs but has issues with chemoresistance and penetration in the interior of the tumor. Evofosfamide, a hypoxia-activated prodrug, has been shown to be effective in combination with GEM, although the mechanism of each drug on the other has not been established. We used mouse xenografts from two cell lines (MIA Paca-2 and SU.86.86) with different tumor microenvironmental characteristics to probe the action of each drug on the other. Results: GEM treatment enhanced survival times in mice with SU.86.86 leg xenografts (hazard ratio [HR] = 0.35, p = 0.03) but had no effect on MIA Paca-2 mice (HR = 0.91, 95% confidence interval = 0.37-2.25, p = 0.84). Conversely, evofosfamide did not improve survival times in SU.86.86 mice to a statistically significant degree (HR = 0.57, p = 0.22). Electron paramagnetic resonance imaging showed that oxygenation worsened in MIA Paca-2 tumors when treated with GEM, providing a direct mechanism for the activation of the hypoxia-activated prodrug evofosfamide by GEM. Sublethal amounts of either treatment enhanced the toxicity of other treatment in vitro in SU.86.86 but not in MIA Paca-2. By the biomarker γH2AX, combination treatment increased the number of double-stranded DNA lesions in vitro for SU.86.86 but not MIA Paca-2. Innovation and Conclusion: The synergy between GEM and evofosfamide appears to stem from the dual action of GEMs effect on tumor vasculature and inhibition by GEM of the homologous recombination DNA repair process. Antioxid. Redox Signal. 39, 432-444.

A Peptidisc-Based Survey of the Plasma Membrane Proteome of a Mammalian Cell

Membrane proteins play critical roles at the cell surface and their misfunction is a hallmark of many human diseases. A precise evaluation of the plasma membrane proteome is therefore essential for cell biology and for discovering novel biomarkers and therapeutic targets. However, the low abundance of this proteome relative to soluble proteins makes it difficult to characterize, even with the most advanced proteomics technologies. Here, we apply the peptidisc membrane mimetic to purify the cell membrane proteome. Using the HeLa cell line as a reference, we capture 500 different integral membrane proteins, with half annotated to the plasma membrane. Notably, the peptidisc library is enriched with several ABC, SLC, GPCR, CD, and cell adhesion molecules that generally exist at low to very low copy numbers in the cell. We extend the method to compare two pancreatic cell lines, Panc-1 and hPSC. Here we observe a striking difference in the relative abundance of the cell surface cancer markers L1CAM, ANPEP, ITGB4, and CD70. We also identify two novel SLC transporters, SLC30A1 and SLC12A7, that are highly present in the Panc-1 cell only. The peptidisc library thus emerges as an effective way to survey and compare the membrane proteome of mammalian cells. Furthermore, since the method stabilizes membrane proteins in a water-soluble state, members of the library, here SLC12A7, can be specifically isolated.

A Cyclodiaryliodonium NOX Inhibitor for the Treatment of Pancreatic Cancer via Enzyme-Activatable Targeted Delivery by Sulfated Glycosaminoglycan Derivatives

Pancreatic cancer renders a principal cause of cancer mortalities with a dismal prognosis, lacking sufficiently safe and effective therapeutics. Here, diversified cyclodiaryliodonium (CDAI) NADPH oxidase (NOX) inhibitors are rationally designed with tens of nanomolar optimal growth inhibition, and CD44-targeted delivery is implemented using synthesized sulfated glycosaminoglycan derivatives. The self-assembled nanoparticle-drug conjugate (NDC) enables hyaluronidase-activatable controlled release and facilitates cellular trafficking. NOX inhibition reprograms the metabolic phenotype by simultaneously impairing mitochondrial respiration and glycolysis. Moreover, the NDC selectively diminishes non-mitochondrial reactive oxygen species (ROS) but significantly elevates cytotoxic ROS through mitochondrial membrane depolarization. Transcriptomic profiling reveals perturbed p53, NF-κB, and GnRH signaling pathways interconnected with NOX inhibition. After being validated in patient-derived pancreatic cancer cells, the anticancer efficacy is further verified in xenograft mice bearing heterotopic and orthotopic pancreatic tumors, with extended survival and ameliorated systemic toxicity. It is envisaged that the translation of cyclodiaryliodonium inhibitors with an optimized molecular design can be expedited by enzyme-activatable targeted delivery with improved pharmacokinetic profiles and preserved efficacy.

Gemcitabine‑fucoxanthin combination in human pancreatic cancer cells

Gemcitabine is a chemotherapeutic agent for pancreatic cancer treatment. It has also been demonstrated to inhibit human pancreatic cancer cell lines, MIA PaCa-2 and PANC-1. The aim of the present study was to investigate the suppressive effect of fucoxanthin, a marine carotenoid, in combination with gemcitabine on pancreatic cancer cells. MTT assays and cell cycle analysis using flow cytometry were performed to study the mechanism of action. The results revealed that combining a low dose of fucoxanthin with gemcitabine enhanced the cell viability of human embryonic kidney cells, 293, while a high dose of fucoxanthin enhanced the inhibitory effect of gemcitabine on the cell viability of this cell line. In addition, the enhanced effect of fucoxanthin on the inhibitory effect of gemcitabine on PANC-1 cells was significant (P<0.01). Fucoxanthin combined with gemcitabine also exerted significant enhancement of the anti-proliferation effect in MIA PaCa-2 cells in a concentration dependent manner (P<0.05), compared with gemcitabine treatment alone. In conclusion, fucoxanthin improved the cytotoxicity of gemcitabine on human pancreatic cancer cells at concentrations that were not cytotoxic to non-cancer cells. Thus, fucoxanthin has the potential to be used as an adjunct in pancreatic cancer treatment.

Biological evaluation of novel gemcitabine analog in patient-derived xenograft models of pancreatic cancer

Gemcitabine (Gem) has been a standard first-line drug for pancreatic cancer (PCa) treatment; however, Gem's rapid metabolism and systemic instability (short half-life) limit its clinical outcome. The objective of this study was to modify Gem into a more stable form called 4-(N)-stearoyl-gemcitabine (4NSG) and evaluate its therapeutic efficacy in patient-derived xenograft (PDX) models from PCa of Black and White patients.Methods 4NSG was synthesized and characterized using nuclear magnetic resonance (NMR), elemental analysis, and high-performance liquid chromatography (HPLC). 4NSG-loaded solid lipid nanoparticles (4NSG-SLN) were developed using the cold homogenization technique and characterized. Patient-derived pancreatic cancer cell lines labeled Black (PPCL-192, PPCL-135) and White (PPCL-46, PPCL-68) were used to assess the in vitro anticancer activity of 4NSG-SLN. Pharmacokinetics (PK) and tumor efficacy studies were conducted using PDX mouse models bearing tumors from Black and White PCa patients.Results 4NSG was significantly stable in liver microsomal solution. The effective mean particle size (hydrodynamic diameter) of 4NSG-SLN was 82 ± 6.7 nm, and the half maximal inhibitory concentration (IC50) values of 4NSG-SLN treated PPCL-192 cells (9 ± 1.1 µM); PPCL-135 (11 ± 1.3 µM); PPCL-46 (12 ± 2.1) and PPCL-68 equaled to 22 ± 2.6 were found to be significantly lower compared to Gem treated PPCL-192 (57 ± 1.5 µM); PPCL-135 (56 ± 1.5 µM); PPCL-46 (56 ± 1.8 µM) and PPCL-68 (57 ± 2.4 µM) cells. The area under the curve (AUC), half-life, and pharmacokinetic clearance parameters for 4NSG-SLN were 3-fourfold higher than that of GemHCl. For in-vivo studies, 4NSG-SLN exhibited a two-fold decrease in tumor growth compared with GemHCl in PDX mice bearing Black and White PCa tumors.Conclusion 4NSG-SLN significantly improved the Gem's pharmacokinetic profile, enhanced Gem's systemic stability increased its antitumor efficacy in PCa PDX mice bearing Black and White patient tumors.

Aspergillus niger CJ6 extract with antimicrobial potential promotes in-vitro cytotoxicity and induced apoptosis against MIA PaCa-2 cell line

Nowadays, the increased number of multidrug-resistant strains among pathogens is a severe public health concern and cancer is posing a great threat for humans. These problems should be tackled with the development of novel and broad-spectrum antimicrobials from microbial origin. During the present study, the bioactive secondary metabolites from Aspergillus niger CJ6 were extracted, characterized; their biological properties were evaluated by subjecting them for antimicrobial, antifungal and anticancer activities. The potent isolate Aspergillus niger CJ6 with nucleotide sequence of 959 base pairs showed antagonistic activity against fungal pathogens in dual culture. The chemical profiling of crude ethyl acetate extract indicated the presence of various bioactive molecules belonging to phenolic, hydrocarbons, and phthalate derivative classes. In antimicrobial activity, the crude extract displayed increasing activity with increased concentration; the highest activity observed against Shigella flexneri with 15 ± 1.0, 19 ± 0.5, 20 ± 1.0 and 24 ± 1.0 mm zones of inhibition at 25, 50, 75 and 100 μl concentrations. The MTT assay illustrated deformed cells of MIA PaCa-2 cell line in in-vitro cytotoxic activity; outflow of cell matrix and membrane rupture; the IC₅₀ of 90.78 μg/ml suggested moderate potential of extract to prevent cancer cell growth. The apoptosis/necrosis study by flow cytometer exhibited 8.98 ± 0.85% early and 73 ± 0.7% of late apoptotic population with 3.8 ± 1.1% necrotic cells; only 14.22 ± 0.6% of healthy cells suggested the increased apoptosis inducing capacity of Aspergillus niger CJ6 crude extract. The outcomes of this study persuade further exploration on the identification, purification and development of novel bioactive agents that could help battle fatal diseases in humans.

Discovery of BAR502, as potent steroidal antagonist of leukemia inhibitory factor receptor for the treatment of pancreatic adenocarcinoma

Introduction

The leukemia inhibitory factor (LIF), is a cytokine belonging to IL-6 family, whose overexpression correlate with poor prognosis in cancer patients, including pancreatic ductal adenocarcinoma (PDAC). LIF signaling is mediate by its binding to the heterodimeric LIF receptor (LIFR) complex formed by the LIFR receptor and Gp130, leading to JAK1/STAT3 activation. Bile acids are steroid that modulates the expression/activity of membrane and nuclear receptors, including the Farnesoid-X-Receptor (FXR) and G Protein Bile Acid Activated Receptor (GPBAR1).

Methods

Herein we have investigated whether ligands to FXR and GPBAR1 modulate LIF/LIFR pathway in PDAC cells and whether these receptors are expressed in human neoplastic tissues.

Results

The transcriptome analysis of a cohort of PDCA patients revealed that expression of LIF and LIFR is increased in the neoplastic tissue in comparison to paired non-neoplastic tissues. By in vitro assay we found that both primary and secondary bile acids exert a weak antagonistic effect on LIF/LIFR signaling. In contrast, BAR502 a non-bile acid steroidal dual FXR and GPBAR1 ligand, potently inhibits binding of LIF to LIFR with an IC50 of 3.8 µM.

Discussion

BAR502 reverses the pattern LIF-induced in a FXR and GPBAR1 independent manner, suggesting a potential role for BAR502 in the treatment of LIFR overexpressing-PDAC.

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.

New Insights into the Biological Response Triggered by Dextran-Coated Maghemite Nanoparticles in Pancreatic Cancer Cells and Their Potential for Theranostic Applications

Iron oxide nanoparticles are one of the most promising tools for theranostic applications of pancreatic cancer due to their unique physicochemical and magnetic properties making them suitable for both diagnosis and therapy. Thus, our study aimed to characterize the properties of dextran-coated iron oxide nanoparticles (DIO-NPs) of maghemite (γ-Fe₂O₃) type synthesized by co-precipitation and to investigate their effects (low-dose versus high-dose) on pancreatic cancer cells focusing on NP cellular uptake, MR contrast, and toxicological profile. This paper also addressed the modulation of heat shock proteins (HSPs) and p53 protein expression as well as the potential of DIO-NPs for theranostic purposes. DIO-NPs were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), dynamic light scattering analyses (DLS), and zeta potential. Pancreatic cancer cells (PANC-1 cell line) were exposed to different doses of dextran-coated ɣ-Fe₂O₃ NPs (14, 28, 42, 56 μg/mL) for up to 72 h. The results revealed that DIO-NPs with a hydrodynamic diameter of 16.3 nm produce a significant negative contrast using a 7 T MRI scanner correlated with dose-dependent cellular iron uptake and toxicity levels. We showed that DIO-NPs are biocompatible up to a concentration of 28 μg/mL (low-dose), while exposure to a concentration of 56 μg/mL (high-dose) caused a reduction in PANC-1 cell viability to 50% after 72 h by inducing reactive oxygen species (ROS) production, reduced glutathione (GSH) depletion, lipid peroxidation, enhancement of caspase-1 activity, and LDH release. An alteration in Hsp70 and Hsp90 protein expression was also observed. At low doses, these findings provide evidence that DIO-NPs could act as safe platforms in drug delivery, as well as antitumoral and imaging agents for theranostic uses in pancreatic cancer.

Islet amyloid polypeptide does not suppress pancreatic cancer

OBJECTIVES

Pancreatic cancer risk is elevated approximately two-fold in type 1 and type 2 diabetes. Islet amyloid polypeptide (IAPP) is an abundant beta-cell peptide hormone that declines with diabetes progression. IAPP has been reported to act as a tumour-suppressor in p53-deficient cancers capable of regressing tumour volumes. Given the decline of IAPP during diabetes development, we investigated the actions of IAPP in pancreatic ductal adenocarcinoma (PDAC; the most common form of pancreatic cancer) to determine if IAPP loss in diabetes may increase the risk of pancreatic cancer.

METHODS

PANC-1, MIA PaCa-2, and H1299 cells were treated with rodent IAPP, and the IAPP analogs pramlintide and davalintide, and assayed for changes in proliferation, death, and glycolysis. An IAPP-deficient mouse model of PDAC (Iapp^-/-; Kras^+/LSL-G12D; Trp53^flox/flox; Ptf1a^+/CreER) was generated for survival analysis.

RESULTS

IAPP did not impact glycolysis in MIA PaCa-2 cells, and did not impact cell death, proliferation, or glycolysis in PANC-1 cells or in H1299 cells, which were previously reported as IAPP-sensitive. Iapp deletion in Kras^+/LSL-G12D; Trp53^flox/flox; Ptf1a^+/CreER mice had no effect on survival time to lethal tumour burden.

CONCLUSIONS

In contrast to previous reports, we find that IAPP does not function as a tumour suppressor. This suggests that loss of IAPP signalling likely does not increase the risk of pancreatic cancer in individuals with diabetes.

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.

Trends in Subcutaneous Tumour Height and Impact on Measurement Accuracy

Tumour volume is typically calculated using only length and width measurements, using width as a proxy for height in a 1:1 ratio. When tracking tumour growth over time, important morphological information and measurement accuracy is lost by ignoring height, which we show is a unique variable. Lengths, widths, and heights of 9522 subcutaneous tumours in mice were measured using 3D and thermal imaging. The average height:width ratio was found to be 1:3 proving that using width as a proxy for height overestimates tumour volume. Comparing volumes calculated with and without tumour height to the true volumes of excised tumours indeed showed that using the volume formula including height produced volumes 36X more accurate (based off of percentage difference). Monitoring the height:width relationship (prominence) across tumour growth curves indicated that prominence varied, and that height could change independent of width. Twelve cell lines were investigated individually; the scale of tumour prominence was cell line-dependent with relatively less prominent tumours (MC38, BL2, LL/2) and more prominent tumours (RENCA, HCT116) detected. Prominence trends across the growth cycle were also dependent on cell line; prominence was correlated with tumour growth in some cell lines (4T1, CT26, LNCaP), but not others (MC38, TC-1, LL/2). When pooled, invasive cell lines produced tumours that were significantly less prominent at volumes >1200 mm³ compared to non-invasive cell lines (P < .001). Modelling was used to show the impact of the increased accuracy gained by including height in volume calculations on several efficacy study outcomes. Variations in measurement accuracy contribute to experimental variation and irreproducibility of data, therefore we strongly advise researchers to measure height to improve accuracy in tumour studies.

Tissue-Specific Human Extracellular Matrix Scaffolds Promote Pancreatic Tumour Progression and Chemotherapy Resistance

Over 80% of patients with pancreatic ductal adenocarcinoma (PDAC) are diagnosed at a late stage and are locally advanced or with concurrent metastases. The aggressive phenotype and relative chemo- and radiotherapeutic resistance of PDAC is thought to be mediated largely by its prominent stroma, which is supported by an extracellular matrix (ECM). Therefore, we investigated the impact of tissue-matched human ECM in driving PDAC and the role of the ECM in promoting chemotherapy resistance. Decellularized human pancreata and livers were recellularized with PANC-1 and MIA PaCa-2 (PDAC cell lines), as well as PK-1 cells (liver-derived metastatic PDAC cell line). PANC-1 cells migrated into the pancreatic scaffolds, MIA PaCa-2 cells were able to migrate into both scaffolds, whereas PK-1 cells were able to migrate into the liver scaffolds only. These differences were supported by significant deregulations in gene and protein expression between the pancreas scaffolds, liver scaffolds, and 2D culture. Moreover, these cell lines were significantly more resistant to gemcitabine and doxorubicin chemotherapy treatments in the 3D models compared to 2D cultures, even after confirmed uptake by confocal microscopy. These results suggest that tissue-specific ECM provides the preserved native cues for primary and metastatic PDAC cells necessary for a more reliable in vitro cell culture.

Investigations of an organic-inorganic nanotheranostic hybrid for pancreatic cancer therapy using cancer-in-a-dish andin vivomodels

The incidence of highly aggressive pancreatic cancer is increasing across the globe and is projected to increase to 18.6% by 2050. The mortality rate for this form of cancer is very high and the 5 y relative survival rate is only about 9%-10%. The 3D pancreatic cancer microenvironment exerts a major influence on the poor survival rate. A key factor is the prevention of the penetration of the chemotherapeutic drugs in the three-dimensional (3D) microenvironment leading to the development of chemoresistance which is a major contributor to the survival rates. Hence,in vitrostudies using 3D cultures represent a better approach to understand the effect of therapeutic formulations on the cancer cells when compared to conventional 2D cultures. In the present study, we have explored three different conditions for the development of a 3D pancreatic tumour spheroid model from MiaPaCa-2 and PanC1 cells cultured for 10 days using Matrigel matrix. This optimized spheroid model was employed to evaluate a multi-functional nanotheranostic system fabricated using chitosan nanoparticles co-encapsulated with the chemotherapeutic agent gemcitabine and gold-capped iron oxide nanoparticles for multimodal imaging. The effect of the single and multiple-dose regimens of the theranostic system on the viability of 3D spheroids formed from the two pancreatic cancer cell lines was studied. It was observed that the 3D tumour spheroids cultured for 10 days exhibited resistance towards free gemcitabine drug, unlike the 2D culture. The administration of the multifunctional nanotheranostic system on alternate days effectively reduced the cancer cell viability after five doses to about 20% when compared with other groups. The repeated doses of the nanotheranostic system were found to be more effective than the single dose. Cell line-based differences in internalization of the carrier was also reflected in their response to the nanocarrier with PanC1 showing better sensitivity to the treatment.In vivostudies revealed that the combination of gemcitabine and magnetic field induced hypothermia produced superior regression in cancer when compared with the chemotherapeutic agent alone by a combination of activating the pro-apoptotic pathway and heat-induced necrosis. Our results reveal that this multi-functional system holds promise to overcome the current challenges to treat pancreatic cancers.

Repositioning Mifepristone as a Leukaemia Inhibitory Factor Receptor Antagonist for the Treatment of Pancreatic Adenocarcinoma

Pancreatic cancer is a leading cause of cancer mortality and is projected to become the second-most common cause of cancer mortality in the next decade. While gene-wide association studies and next generation sequencing analyses have identified molecular patterns and transcriptome profiles with prognostic relevance, therapeutic opportunities remain limited. Among the genes that are upregulated in pancreatic ductal adenocarcinomas (PDAC), the leukaemia inhibitory factor (LIF), a cytokine belonging to IL-6 family, has emerged as potential therapeutic candidate. LIF is aberrantly secreted by tumour cells and promotes tumour progression in pancreatic and other solid tumours through aberrant activation of the LIF receptor (LIFR) and downstream signalling that involves the JAK1/STAT3 pathway. Since there are no LIFR antagonists available for clinical use, we developed an in silico strategy to identify potential LIFR antagonists and drug repositioning with regard to LIFR antagonists. The results of these studies allowed the identification of mifepristone, a progesterone/glucocorticoid antagonist, clinically used in medical abortion, as a potent LIFR antagonist. Computational studies revealed that mifepristone binding partially overlapped the LIFR binding site. LIF and LIFR are expressed by human PDAC tissues and PDAC cell lines, including MIA-PaCa-2 and PANC-1 cells. Exposure of these cell lines to mifepristone reverses cell proliferation, migration and epithelial mesenchymal transition induced by LIF in a concentration-dependent manner. Mifepristone inhibits LIFR signalling and reverses STAT3 phosphorylation induced by LIF. Together, these data support the repositioning of mifepristone as a potential therapeutic agent in the treatment of PDAC.

Novel compound C150 inhibits pancreatic cancer through induction of ER stress and proteosome assembly

Pancreatic cancer is a devastating disease with a dismal prognosis and poor treatment outcomes. Searching for new agents for pancreatic cancer treatment is of great significance. We previously identified a novel activity of compound C150 to inhibit pancreatic cancer epithelial-to-mesenchymal transition (EMT). Here, we further revealed its mechanism of action. C150 induced ER stress in pancreatic cancer cells and subsequently increased proteasome activity by enhancing proteasome assembly, which subsequently enhanced the degradation of critical EMT transcription factors (EMT-TFs). In addition, as cellular responses to ER stress, autophagy was elevated, and general protein synthesis was inhibited in pancreatic cancer cells. Besides EMT inhibition, the C150-induced ER stress resulted in G2/M cell cycle arrest, which halted cell proliferation and led to cellular senescence. In an orthotopic syngeneic mouse model, an oral dose of C150 at 150 mg/kg 3× weekly significantly increased survival of mice bearing pancreatic tumors, and reduced tumor growth and ascites occurrence. These results suggested that compound C150 holds promises in comprehensively inhibiting pancreatic cancer progression.

Efficient Correction of Oncogenic KRAS and TP53 Mutations through CRISPR Base Editing

KRAS is the most frequently mutated oncogene in human cancer, and its activating mutations represent long-sought therapeutic targets. Programmable nucleases, particularly the CRISPR-Cas9 system, provide an attractive tool for genetically targeting KRAS mutations in cancer cells. Here, we show that cleavage of a panel of KRAS driver mutations suppresses growth in various human cancer cell lines, revealing their dependence on mutant KRAS. However, analysis of the remaining cell population after long-term Cas9 expression unmasked the occurence of oncogenic KRAS escape variants that were resistant to Cas9-cleavage. In contrast, the use of an adenine base editor to correct oncogenic KRAS mutations progressively depleted the targeted cells without the appearance of escape variants and allowed efficient and simultaneous correction of a cancer-associated TP53 mutation. Oncogenic KRAS and TP53 base editing was possible in patient-derived cancer organoids, suggesting that base editor approaches to correct oncogenic mutations could be developed for functional interrogation of vulnerabilities in a personalized manner for future precision oncology applications.

SIGNIFICANCE

Repairing KRAS mutations with base editors can be used for providing a better understanding of RAS biology and may lay the foundation for improved treatments for KRAS-mutant cancers.

Wild type and gain of function mutant TP53 can regulate the sensitivity of pancreatic cancer cells to chemotherapeutic drugs, EGFR/Ras/Raf/MEK, and PI3K/mTORC1/GSK-3 pathway inhibitors, nutraceuticals and alter metabolic properties

TP53 is a master regulator of many signaling and apoptotic pathways involved in: aging, cell cycle progression, gene regulation, growth, apoptosis, cellular senescence, DNA repair, drug resistance, malignant transformation, metastasis, and metabolism. Most pancreatic cancers are classified as pancreatic ductal adenocarcinomas (PDAC). The tumor suppressor gene TP53 is mutated frequently (50-75%) in PDAC. Different types of TP53 mutations have been observed including gain of function (GOF) point mutations and various deletions of the TP53 gene resulting in lack of the protein expression. Most PDACs have point mutations at the KRAS gene which result in constitutive activation of KRas and multiple downstream signaling pathways. It has been difficult to develop specific KRas inhibitors and/or methods that result in recovery of functional TP53 activity. To further elucidate the roles of TP53 in drug-resistance of pancreatic cancer cells, we introduced wild-type (WT) TP53 or a control vector into two different PDAC cell lines. Introduction of WT-TP53 increased the sensitivity of the cells to multiple chemotherapeutic drugs, signal transduction inhibitors, drugs and nutraceuticals and influenced key metabolic properties of the cells. Therefore, TP53 is a key molecule which is critical in drug sensitivity and metabolism of PDAC.

The Quasimesenchymal Pancreatic Ductal Epithelial Cell Line PANC-1-A Useful Model to Study Clonal Heterogeneity and EMT Subtype Shifting

Simple Summary

Malignant tumors often escape therapy due to clonal propagation of a subfraction of drug-resistant cancer cells. The underlying phenomenon of intratumoral heterogeneity is driven by epithelial–mesenchymal plasticity (EMP) involving the developmental programs, epithelial–mesenchymal transition (EMT), in which epithelial cells are converted to invasive mesenchymal cells, and the reverse process, mesenchymal–epithelial transition (MET), which allows for metastatic outgrowth at distant sites. For therapeutic targeting of EMP, a better understanding of this process is required; however, cellular models with which to study EMP in pancreatic ductal adenocarcinoma (PDAC) are scarce. Using single-cell clonal analysis, we have found the PDAC cell line, PANC-1, to consist of cells with different E/M phenotypes and functional attributes. Parental PANC-1 cultures could be induced in vitro to shift towards either a more mesenchymal or a more epithelial phenotype, and this bidirectional shift was controlled by the small GTPases RAC1 and RAC1b, together identifying PANC-1 cells as a useful model with which to study EMP.

Abstract

Intratumoral heterogeneity (ITH) is an intrinsic feature of malignant tumors that eventually allows a subfraction of resistant cancer cells to clonally evolve and cause therapy failure or relapse. ITH, cellular plasticity and tumor progression are driven by epithelial–mesenchymal transition (EMT) and the reverse process, MET. During these developmental programs, epithelial (E) cells are successively converted to invasive mesenchymal (M) cells, or back to E cells, by passing through a series of intermediate E/M states, a phenomenon termed E–M plasticity (EMP). The induction of MET has clinical potential as it can block the initial EMT stages that favor tumor cell dissemination, while its inhibition can curb metastatic outgrowth at distant sites. In pancreatic ductal adenocarcinoma (PDAC), cellular models with which to study EMP or MET induction are scarce. Here, we have generated single cell-derived clonal cultures of the quasimesenchymal PDAC-derived cell line, PANC-1, and found that these differ strongly with respect to cell morphology and EMT marker expression, allowing for their tentative classification as E, E/M or M. Interestingly, the different EMT phenotypes were found to segregate with differences in tumorigenic potential in vitro, as measured by colony forming and invasive activities, and in circadian clock function. Moreover, the individual clones the phenotypes of which remained stable upon prolonged culture also responded differently to treatment with transforming growth factor (TGF)β1 in regard to regulation of growth and individual TGFβ target genes, and to culture conditions that favour ductal-to-endocrine transdifferentiation as a more direct measure for cellular plasticity. Of note, stimulation with TGFβ1 induced a shift in parental PANC-1 cultures towards a more extreme M and invasive phenotype, while exposing the cells to a combination of the proinflammatory cytokines IFNγ, IL1β and TNFα (IIT) elicited a shift towards a more E and less invasive phenotype resembling a MET-like process. Finally, we show that the actions of TGFβ1 and IIT both converge on regulating the ratio of the small GTPase RAC1 and its splice isoform, RAC1b. Our data provide strong evidence for dynamic EMT–MET transitions and qualify this cell line as a useful model with which to study EMP.

CD109 expression in tumor cells and stroma correlates with progression and prognosis in pancreatic cancer

CD109 is a glycosylphosphatidylinositol-anchored glycoprotein, whose expression is upregulated in some types of malignant tumors. High levels of CD109 in tumor cells have been reported to correlate with poor prognosis; however, significance of CD109 stromal expression in human malignancy has not been elucidated. In this study, we investigated the tumorigenic properties of CD109 in pancreatic ductal adenocarcinoma (PDAC). Immunohistochemical analysis of 92 PDAC surgical specimens revealed that positive CD109 expression in tumor cells was significantly associated with poor prognosis (disease-free survival, p = 0.003; overall survival, p = 0.002), and was an independent prognostic factor (disease-free survival, p = 0.0173; overall survival, p = 0.0104) in PDAC. Furthermore, CD109 expression was detected in the stroma surrounding tumor cells, similar to that of α-smooth muscle actin, a histological marker of cancer-associated fibroblasts. The stromal CD109 expression significantly correlated with tumor progression in PDAC (TNM stage, p = 0.033; N factor, p = 0.024; lymphatic invasion, p = 0.028). In addition, combined assessment of CD109 in tumor cells and stroma could identify the better prognosis group of patients from the entire patient population. In MIA PaCa-2 PDAC cell line, we demonstrated the involvement of CD109 in tumor cell motility, but not in PANC-1. Taken together, CD109 not only in the tumor cells but also in the stroma is involved in the progression and prognosis of PDAC, and may serve as a useful prognostic marker in PDAC.

Microfluidics Formulated Liposomes of Hypoxia Activated Prodrug for Treatment of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) presents as an unmet clinical challenge for drug delivery due to its unique hypoxic biology. Vinblastine-N-Oxide (CPD100) is a hypoxia-activated prodrug (HAP) that selectively converts to its parent compound, vinblastine, a potent cytotoxic agent, under oxygen gradient. The study evaluates the efficacy of microfluidics formulated liposomal CPD100 (CPD100Li) in PDAC. CPD100Li were formulated with a size of 95 nm and a polydispersity index of 0.2. CPD100Li was stable for a period of 18 months when freeze-dried at a concentration of 3.55 mg/mL. CPD100 and CPD100Li confirmed selective activation at low oxygen levels in pancreatic cancer cell lines. Moreover, in 3D spheroids, CPD100Li displayed higher penetration and disruption compared to CPD100. In patient-derived 3D organoids, CPD100Li exhibited higher cell inhibition in the organoids that displayed higher expression of hypoxia-inducible factor 1 alpha (HIF1A) compared to CPD100. In the orthotopic model, the combination of CPD100Li with gemcitabine (GEM) (standard of care for PDAC) showed higher efficacy than CPD100Li alone for a period of 90 days. In summary, the evaluation of CPD100Li in multiple cellular models provides a strong foundation for its clinical application in PDAC.