Reactivation of p53 mutant protein by PRIMA-1 and induction of apoptosis in pancreatic cancer cells.

2012 ◽  
Vol 30 (15_suppl) ◽  
pp. e13546-e13546
Author(s):  
Patricia Izetti ◽  
Agnes Hautefeuille ◽  
Ana Lucia Abujamra ◽  
Caroline Brunetto de Farias ◽  
Rafael Roesler ◽  
...  

e13546 Background: Inactivating TP53 mutations are common events in different types of cancers, including pancreatic adenocarcinoma, where it occurs in as much as 70% of cases. Accumulation of mutant p53 provides a molecular target that may be reactivated into a conformation capable of arresting tumor growth. The small molecule PRIMA-1 (p53 reactivation and induction of massive apoptosis) has been shown to selectively induce apoptosis in tumor cells by reactivating some p53 mutants, but no previous studies have investigated its effects in pancreatic cancer. Methods: PANC-1 (mutant TP53 R273H) and CAPAN-2 (wild-type TP53) pancreatic cell lines were used as in vitro models. We tested the effects of PRIMA-1 on cell viability (MTT assay), apoptosis (morphology, AnnexinV/FITC-FACS), cell cycle (BrdU incorporation) and expression of p53 regulated proteins by western blotting. As control of p53-dependent effects, PANC-1 cell lines were transfected with siRNA against TP53 (sip53). Results: PRIMA-1 selectively induced apoptosis in PANC-1 cells compared to CAPAN-2 cells and this effect was concomitant with an increase in the levels of MDM2, Bax and cleaved caspase-3 as detected by western blot analysis. Treatment with PRIMA-1 for 24h induced a 50% reduction in DNA synthesis whereas G2/M arrest was detected after 12h of treatment. p53 silencing in PANC-1 decreased the cytotoxicity of PRIMA-1, characterizing a p53-dependent effect. Finally, N-acetylcysteine completely blocked PRIMA-1-induced growth suppression and apoptosis, suggesting that PRIMA-1 exerts its effect at least in part via restoring redox-dependent effects to mutant p53. Conclusions: Our data indicate that PRIMA-1 induces apoptosis in TP53 mutant pancreatic cancer cells by promoting the re-activation of p53 and subsequent of proapoptotic signaling pathways, suggesting a possible mechanism for effective targeting of pancreatic cancer.

2021 ◽  
Vol 8 ◽  
Author(s):  
Fei Xu ◽  
Heshui Wu ◽  
Jiongxin Xiong ◽  
Tao Peng

Gemcitabine (GEM) resistance remains a challenging clinical issue to overcome in chemotherapy against pancreatic cancer. We previously demonstrated that miR-210 derived from pancreatic cancer stem cells enhanced the GEM-resistant properties of pancreatic cancer cells, thus identifying miR-210 as an oncogenic miRNA. Herein, we report the existence of an upstream effector that acts as a competing endogenous RNA (ceRNA) to miR-210. Bioinformatic screening was performed to identify lncRNAs with a binding relationship to miR-210. Overexpression and interference vectors were constructed to demonstrate the effect of ceRNA activity in pancreatic cell behavior, both in vitro and in vivo. DLEU2L (deleted in lymphocytic leukemia 2-like), which is expressed at low levels in pancreatic cancer tissues, was shown to exhibit a binding relationship with miR-210-3p. Overexpression of DLEU2L and silencing of miR-210-3p suppressed the proliferation, migration, and invasion of pancreatic cancer cells while promoting apoptosis. These effects occurred via the inhibition of the Warburg effect (aerobic glycolysis) and AKT/mTOR signaling. In addition, we showed that BRCA2 is a target gene of miR-210-3p, and the downregulation of miR-210-3p by DLEU2L effectively induced an upregulation of BRCA2 via the ceRNA mechanism. In vivo, DLEU2L overexpression and miR-210-3p interference suppressed pancreatic tumor progression, consistent with the results of in vitro studies. The findings of our study establish DLEU2L as a ceRNA to miR-210-3p and reveal the critical role of the DLEU2L/miR-210-3p crosstalk in targeting GEM resistance.


1994 ◽  
Vol 266 (1) ◽  
pp. R277-R283 ◽  
Author(s):  
J. P. Smith ◽  
G. Liu ◽  
V. Soundararajan ◽  
P. J. McLaughlin ◽  
I. S. Zagon

The gastrointestinal peptide cholecystokinin (CCK) is known to stimulate growth of human pancreatic cancer in a receptor-mediated fashion. The purpose of this study was to characterize the receptor responsible for the trophic effects of CCK in cancer cells. With the use of homogenates of PANC-1 human pancreatic cancer cells grown in vitro, the binding characteristics and optimal conditions of radiolabeled selective CCK-receptor antagonists ([3H]L-365,260 and [3H]L-364,718) were examined. Specific and saturable binding was detected with [3H]L-365,260, and Scatchard analysis revealed that the data were consistent for a single site of binding with a binding affinity of 4.3 +/- 0.6 nM and a binding capacity (Bmax) of 283 +/- 68 fmol/mg protein in log phase cells. Binding was dependent on protein concentration, time, temperature, and pH and was sensitive to Na+, K+, Mg2+, and ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid. In contrast to log phase cells, Bmax decreased by 80 and 92% in confluent and postconfluent cultures, respectively. Subcellular fractionation studies revealed that binding was in the membrane fraction. Competition experiments indicated that L-365,260 and gastrin were more effective at displacing the radiolabeled L-365,260 than CCK. No binding was detected with the CCK-A antagonist [3H]L-364,718. Assays performed with [3H]L-365,260 on five additional human pancreatic cancer cell lines in vitro and tumor tissue from xenografts in nude mice also revealed specific and saturable binding. These results provide the first identification of a CCK-B/gastrin receptor in human pancreatic cancer cells and tumors and explain the effects of CCK on the growth of this malignancy.


2021 ◽  
Author(s):  
Bradley Schniers ◽  
Devaraja Rajasekaran ◽  
Ksenija Korac ◽  
Tyler Sniegowski ◽  
Vadivel Ganapathy ◽  
...  

PEPT1 is a proton-coupled peptide transporter that is upregulated in PDAC cell lines and PDXs, with little expression in normal pancreas. However, the relevance of this upregulation to cancer progression and the mechanism of upregulation have not been investigated. Herein, we show that PEPT1 is not just upregulated in a large panel of PDAC cell lines and PDXs but is also functional and transport-competent. PEPT2, another proton-coupled peptide transporter, is also overexpressed in PDAC cell lines and PDXs, but is not functional due to its intracellular localization. Using glibenclamide as a pharmacological inhibitor of PEPT1, we demonstrate in cell lines in vitro and mouse xenografts in vivothat inh­­ibition of PEPT1 reduces the proliferation of the cancer cells. These findings are supported by genetic knockdown of PEPT1 with shRNA, wherein the absence of the transporter significantly attenuates the growth of cancer cells, both in vitro and in vivo, suggesting that PEPT1 is critical for the survival of cancer cells. We also establish that the tumor-derived lactic acid (Warburg effect) in the tumor microenvironment supports the transport function of PEPT1 in the maintenance of amino acid nutrition in cancer cells by inducing MMPs and DPPIV to generate peptide substrates for PEPT1 and by generating a H+ gradient across the plasma membrane to energize PEPT1. Taken collectively, these studies demonstrate a functional link between PEPT1 and extracellular protein breakdown in the tumor microenvironment as a key determinant of pancreatic cancer growth, thus identifying PEPT1 as a potential therapeutic target for PDAC.


Metabolites ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 350
Author(s):  
Benedikt Feuerecker ◽  
Philipp Biechl ◽  
Christian Veltkamp ◽  
Dieter Saur ◽  
Wolfgang Eisenreich

In modern oncology, the analysis and evaluation of treatment response are still challenging. Hence, we used a 13C-guided approach to study the impacts of the small molecule dichloroacetate (DCA) upon the metabolic response of pancreatic cancer cells. Two different oncogenic PI3K-driven pancreatic cancer cell lines, 9580 and 10,158, respectively, were treated with 75 mM DCA for 18 h. In the presence of [U-13C6]glucose, the effects of DCA treatment in the core carbon metabolism were analyzed in these cells using gas chromatography–mass spectrometry (GC/MS). 13C-enrichments and isotopologue profiles of key amino acids revealed considerable effects of the DCA treatment upon glucose metabolism. The DCA treatment of the two pancreatic cell lines resulted in a significantly decreased incorporation of [U-13C6]glucose into the amino acids alanine, aspartate, glutamate, glycine, proline and serine in treated, but not in untreated, cancer cells. For both cell lines, the data indicated some activation of pyruvate dehydrogenase with increased carbon flux via the TCA cycle, but also massive inhibition of glycolytic flux and amino acid biosynthesis presumably by inhibition of the PI3K/Akt/mTORC axis. Together, it appears worthwhile to study the early treatment response in DCA-guided or accompanied cancer therapy in more detail, since it could open new avenues for improved diagnosis and therapeutic protocols of cancer.


Author(s):  
Sarah Brumskill ◽  
Lawrence N. Barrera ◽  
Peter Calcraft ◽  
Caroline Phillips ◽  
Eithne Costello

AbstractPancreatic ductal adenocarcinoma (PDAC) is characterised by a pro-inflammatory stroma and multi-faceted microenvironment that promotes and maintains tumorigenesis. However, the models used to test new and emerging therapies for PDAC have not increased in complexity to keep pace with our understanding of the human disease. Promising therapies that pass pre-clinical testing often fail in pancreatic cancer clinical trials. The objective of this study was to investigate whether changes in the drug-dosing regimen or the addition of cancer-associated fibroblasts (CAFs) to current existing models can impact the efficacy of chemotherapy drugs used in the clinic. Here, we reveal that gemcitabine and paclitaxel markedly reduce the viability of pancreatic cell lines, but not CAFs, when cultured in 2D. Following the use of an in vitro drug pulsing experiment, PDAC cell lines showed sensitivity to gemcitabine and paclitaxel. However, CAFs were less sensitive to pulsing with gemcitabine compared to their response to paclitaxel. We also identify that a 3D co-culture model of MIA PaCa-2 or PANC-1 with CAFs showed an increased chemoresistance to gemcitabine when compared to standard 2D mono-cultures a difference to paclitaxel which showed no measurable difference between the 2D and 3D models, suggesting a complex interaction between the drug in study and the cell type used. Changes to standard 2D mono-culture-based assays and implementation of 3D co-culture assays lend complexity to established models and could provide tools for identifying therapies that will match clinically the success observed with in vitro models, thereby aiding in the discovery of novel therapies.


2022 ◽  
Author(s):  
Guodong Chen ◽  
Chengming Ding ◽  
Weiping Tang ◽  
Shuo Qi ◽  
Pengyu Zhou ◽  
...  

Abstract Astragaloside IV (AS-IV) or 3-O-β-D-xylopyranosyl-6-O-β-D-glucopyranosylcyl-cloastragenol is a bioactive saponin extract from the root of Astragalus membranaceus. It has been proven to have an anti-tumor effect in a variety of tumors by inducing cell apoptosis and inhibiting cell proliferation. Its effects on pancreatic cancer have not been investigated. This study investigated the effects of AS-IV on proliferation, apoptosis and migration of pancreatic cancer cells in vitro and in vivo and explored its underlying mechanism. Pancreatic cancer cell lines SW1990 and Panc-1were treated with different doses of AS-IV. Plate clonality, CCK-8, EDU and flow cytometry were used to explore the effect of AS-IV on pancreatic cancer cell proliferation and cell cycle in vitro. Wound healing was used to investigate the effects of AS-IV on pancreatic cell migration. The protein expression levels of Bax/Bcl2, caspase3/7, cyclin D1, cyclin E and CDK4 were analyzed by western blotting. The results showed that AS-IV significantly inhibited tumor cell proliferation and cell cycle, induced apoptosis both in vitro and vivo on a dose-dependent basis and significantly inhibited the growth of pancreatic cell xenograft tumor in nude mice. Wound healing assays indicated that AS-IV also inhibited the migration of pancreatic cancer cells in a dose-dependent manner. This research confirmed that AS-IV inhibited pancreatic cancer cell proliferation by blocking the cell cycle and inducing apoptosis. It was hypothesized from this experiment that the potential mechanism of AS-IV inducing apoptosis of pancreatic cancer cells may be understood by activating the Bcl2/Bax/Caspase-3/Caspase-7 signaling pathway.


2018 ◽  
Vol 36 (4_suppl) ◽  
pp. 322-322 ◽  
Author(s):  
Zhijian Duan ◽  
Mei-Juan Tu ◽  
Qianyu Zhang ◽  
May Thet Cho ◽  
Jasmine Huynh ◽  
...  

322 Background: The ability of cancer cells to suppress apoptosis is critical for carcinogenesis. The Bcl-2-family of regulator proteins, including the anti-apoptotic members Bcl-2, Bcl-xL and Mcl-1, contributes to a complex network in control of apoptosis. BH3-mimetics (e.g. ABT-263) can inhibit anti-apoptotic Bcl-2 proteins and therefore have been developed as potential cancer therapeutics. Aurora Kinase A (AKA) is over-expressed in pancreatic cancer (PC) and is expressed to regulate G2-M transition during mitosis, making it an attractive target for PC. In this study we hypothesized that a combination of mitotic arrest using an AKA inhibitor (e.g. MLN8237) would sensitize PC to induction of apoptosis by a BH3-mimetic. Methods: Pancreatic cell lines (AsPC-1, PANC-1, MIA PaCa-2, HPAF-II) and patient-derived pancreatic cancer organoids (PDO) were treated with a BH3-mimetic (ABT-263) alone, an AKA inhibitor (MLN8237) alone, or the combination in comparison to untreated controls. Cell viability was measured using the CellTiter-Fluor (Promega) assay. Apoptosis was evaluated by Western blot (WB) for cleaved PARP, caspase 3 or caspase 7, and flow cytometry. Nude mice were implanted with pancreatic cancer cells to generate PC xenografts which were then treated with the same 4 treatment groups as in the in vitro studies. Results: ABT-263 combined with MLN8237 showed greater potency than either single drug alone, demonstrating synergy in inhibiting the growth of PC cells and PDOs. Combined treatment with MLN8237 and ABT-263 in PDOs suppressed organoid formation and proliferation by inducing apoptosis. Mechanistically, MLN8237 enhanced the activity of ABT-263 through reduction of Bcl-xL and Mcl-1 in pancreatic cancer cell lines and PDOs. The combination therapy also showed greater suppression of the growth of xenograft tumors, as compared with control treatments with single drug alone or vehicle. Conclusions: The combination of ABT-263 and MLN8237 appears to synergistically induce apoptosis via reduction of Bcl-2 family proteins in PC and should be further explored.


ChemMedChem ◽  
2017 ◽  
Vol 12 (19) ◽  
pp. 1637-1644 ◽  
Author(s):  
Anna K. Laskowska ◽  
Anna K. Puszko ◽  
Piotr Sosnowski ◽  
Krzysztof Różycki ◽  
Piotr Kosson ◽  
...  

2020 ◽  
Author(s):  
Yan Xu ◽  
Nanbin Liu ◽  
Yuhua Wei ◽  
Deren Zhou ◽  
Rui Lin ◽  
...  

Abstract Objective This study aims to explore the roles of miR-124 in pancreatic tumor and potential vehicles. Methods The expression of miR-124 and EZH2 was determined in both pancreatic cancer tissues and cell lines. miR-124 or EZH2 was overexpressed in AsPC-1 and PANC1 cells. Then, the effects on cell viability. apoptosis, invasion, migration and epithelial mesenchymal transition were evaluated. Afterwards, the roles of miR-124 on the expression and function of EZH2 in pancreatic tumors were determined by dual luciferase reporter assay. Subsequently, miR-124 was transfected to bone marrow mesenchymal stromal cells (BM-MSCs), and the BM-MSCs derived exosomes were isolated and co-cultured with AsPC-1 and PANC1 cells, or injected into pancreatic cancer tumor-bearing mice. Results The miR-124 expression levels decreased in pancreatic adenocarcinoma tissues and cancer cell lines AsPC-1, PANC1, BxPC-3 and SW1990. Furthermore, the elevated expression of miR-124 in AsPC-1 and PANC1 via miR-124 mimic transfection-induced apoptosis, metastasis and epithelial mesenchymal transition was suppressed, and the EZH2 overexpression partly reversed the protective effects of miR-124 against pancreatic tumors. In addition, the expression of miR-124 was detected in exosomes extracted from miR-124-transfected BM-MSCs, and these exosomes delivered miR-124 into pancreatic cancer cells, and presented the anti-tumor effects in vitro and in vivo. Conclusion MiR-124-carried BM-MSC-derived exosomes have potential applications for the treatment of pancreatic tumors.


2021 ◽  
Vol 17 (2) ◽  
pp. 263-278
Author(s):  
Maydelid Trujillo-Nolasco ◽  
Pedro Cruz-Nova ◽  
Guillermina Ferro-Flores ◽  
Brenda Gibbens-Bandala ◽  
Enrique Morales-Avila ◽  
...  

Pancreatic cancer is highly lethal and has a poor prognosis. The most common alteration during the formation of pancreatic tumors is the activation of KRAS (Kirsten rat sarcoma 2 viral oncogene homolog) oncogene. As a new therapeutic strategy, the C19 molecule ((2S)-N-(2,5-dichlorophenyl)-2-[(3,4-dimethoxyphenyl)-methylamine]propanamide) blocks the KRAS-membrane association in cancer cells. In addition, the chemokine receptor CXCR4 is overexpressed in pancreatic cancer. In this research, a new dendrimer-based nanoradiopharmaceutical (177Lu-DN(C19)-CXCR4L) encapsulating C19 and functionalized to target CXCR4 receptors is proposed as both, a targeted radiotherapy system (lutetium-177) and an oncotherapeutic approach by the stabilization of KRAS4b-PDESδ complex to produce dual-specific therapy in pancreatic cancer. 177The Lu-DN(C19)-CXCR4L was synthesized and characterized, C19 was encapsulated with 81% efficiency, the final nanosystem rendered a particle size of 67 nm and the specific uptake in pancreatic cell lines was demonstrated. The major cytotoxic effect was observed in the KRAS-dependent and radioresistant cell line Mia PaCa-2, which expresses a high density of CXCR4 receptors. The radiation dose of 3 Gy/Bq decreased viability to 7%, and this effect was attributed to the presence of C19. A synergistic effect (radio and chemotherapy) capable of reducing viability in pancreatic cancer cells through apoptotic mechanisms was demonstrated. Thus, 177Lu-DN(C19)-CXCR4L nanoradiopharmaceutical is efficacious in pancreatic cancer cell lines overexpressing the CXCR4 receptor.


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