MIA PaCa-2 Human Pancreatic Cells Research Articles

Metabolic plasticity underpins innate and acquired resistance to LDHA inhibition.

Metabolic reprogramming in tumors represents a potential therapeutic target. Herein we used shRNA depletion and a novel lactate dehydrogenase (LDHA) inhibitor, GNE-140, to probe the role of LDHA in tumor growth in vitro and in vivo. In MIA PaCa-2 human pancreatic cells, LDHA inhibition rapidly affected global metabolism, although cell death only occurred after 2 d of continuous LDHA inhibition. Pancreatic cell lines that utilize oxidative phosphorylation (OXPHOS) rather than glycolysis were inherently resistant to GNE-140, but could be resensitized to GNE-140 with the OXPHOS inhibitor phenformin. Acquired resistance to GNE-140 was driven by activation of the AMPK-mTOR-S6K signaling pathway, which led to increased OXPHOS, and inhibitors targeting this pathway could prevent resistance. Thus, combining an LDHA inhibitor with compounds targeting the mitochondrial or AMPK-S6K signaling axis may not only broaden the clinical utility of LDHA inhibitors beyond glycolytically dependent tumors but also reduce the emergence of resistance to LDHA inhibition.

Suppressive effects of exogenous regucalcin on the proliferation of human pancreatic cancer MIA PaCa-2 cells in vitro.

Regucalcin plays a pivotal role as a suppressor protein in signal transduction in various types of cells and tissues. The regucalcin gene is localized on the X chromosome. and its expression has been shown to be suppressed in various types of tumor tissue in animal and human subjects, suggesting a potential role of regucalcin in carcinogenesis. This study was undertaken to determine the effects of exogenous regucalcin on the proliferation of cloned human pancreatic cancer MIA PaCa-2 cells in vitro. The proliferation of the MIA PaCa-2 cells was suppressed following culture with regucalcin (0.01-10 nM). Such an effect was also observed in pancreatic cancer Pt45P1 cells, that highly expressed tissue factor (high TF), or Pt45P1 cells, that highly expressed alternativly spliced variants of tissue factor (asTF). In the MIA PaCa-2 cells, the suppressive effects of regucalcin on cell proliferation were not enhanced either in the presence of tumor necrosis factor-α (TNF-α), or in the presence of Bay K 8644, PD98059, staurosporine, wortmannin or 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB). However, this was not the case for gemcitabine, which was shown to suppress cell proliferation. Exogenous regucalcin did not cause apoptotic cell death in the MIA PaCa-2 cells in vitro. These findings demonstrate that exogenous regucalcin exerts suppressive effects on the proliferation of human pancreatic MIA PaCa-2 cells and that these effects are mediated through the inhibition of various signaling pathways related to nuclear factor-κB (NF-κB), extracellular signal-regulated kinase (ERK), protein kinase C, calcium signaling, phosphatidylinositol 3-kinase (PI3K) or nuclear transcription activity in vitro. Our data suggest that exogenous regucalcin exerts suppressive effects on the proliferation of human pancreatic cancer cells.

Cytotoxicity and modes of action of four Cameroonian dietary spices ethno-medically used to treat Cancers: Echinops giganteus, Xylopia aethiopica, Imperata cylindrica and Piper capense

Ethnopharmacological relevance.Echinops giganteus, Imperata cylindrica, Piper capense and Xylopia aethiopica are four medicinal spices used in Cameroon to treat cancers. Aim of the studyThe above plants previously displayed cytotoxicty against leukemia CCRF-CEM and CEM/ADR5000 cell lines as well as human pancreatic MiaPaCa-2 cells. The present study aims at emphasizing the study of the cytotoxicity and the modes of action of the above plants on a panel of ten cancer cell lines including various sensitive and drug-resistant phenotypes. The study has been extended to the isolation of the bioactive constituents from Echinops giganteus. Materials and methodsThe cytotoxicity of the extracts was determined using a resazurin reduction assay, whereas the caspase-Glo assay was used to detect the activation of caspases 3/7, caspase 8 and caspase 9 in cells treated with the four extracts. Flow cytometry was used for cell cycle analysis and detection of apoptotic cells, analysis of mitochondrial membrane potential (MMP) as well as measurement of reactive oxygen species (ROS). ResultsThe four tested extracts inhibited the proliferation of all tested cancer cell lines including sensitive and drug-resistant phenotypes. Collateral sensitivity of cancer cells to the extract of Echinops giganteus was generally better than to doxorubicin. The recorded IC50 ranges were 3.29µg/mL [against human knockout clones HCT116 (p53−/−) colon cancer cells] to 14.32µg/mL (against human liver hepatocellular carcinoma HepG2 cells) for the crude extract from Echinops giganteus, 4.17µg/mL (against breast cancer cells transduced with control vector MDA-MB231 cells) to 19.45µg/mL (against MDA-MB-231 BCRP cells) for that of Piper capense, 4.11µg/mL (against leukemia CCRF-CEM cells) to 30.60µg/mL (against leukemia HL60AR cells) for Xylopia aethiopica, 3.28µg/mL [against HCT116 (p53−/−) cells] to 33.43µg/mL (against HepG2 cells) for Imperata cylindica and 0.11µg/mL (against CCRF-CEM cells) to 132.47µg/mL (against HL60AR cells) for doxorubicin. The four tested extracts induced apoptosis in CCRF-CEM cells via the alteration loss of MMP whilst that of Piper capense also enhanced the production of ROS. ConclusionThe studied plants are potential cytotoxic drugs that deserve more detailed exploration in the future, to develop novel anticancer drugs against sensitive and otherwise drug-resistant phenotypes.

Induction of apoptosis in human pancreatic MiaPaCa-2 cells through the loss of mitochondrial membrane potential (ΔΨm) by Gentiana kurroo root extract and LC-ESI-MS analysis of its principal constituents

The objective of the current study was to evaluate the methanolic root extract of Gentiana kurroo for antioxidant and antiproliferative activities as well as to study the effect of the extract on the induction of apoptosis in human pancreatic cancer cell line (MiaPaCa-2). The extract exerted significant antioxidant activity as verified by DPPH, hydroxyl radical, lipid peroxidation and protective oxidative DNA damage assays. The results were comparable to standard antioxidants like α-tocopherol, catechin and BHT used in such experiments. Antioxidant potential of G. kurroo may be attributed to the presence of high phenolic and flavonoid content (73±1.02 and 46±2.05mg/g extract respectively). The anti-proliferative property of Gentiana kurroo root extract was determined by sulphorhodamine B (SRB) assay against Human colon cancer cell line (HCT-116), Lung carcinoma cell line (A-549), Pancreatic cancer cell line (MiaPaCa-2), Lung cancer cell line (HOP-62) and acute monocytic leukaemia cell line (THP-1). G. kurroo root extract inhibited cancer cell growth depending upon the cell line used and in a dose dependent manner. The extract induced potent apoptotic effects in MiaPaCa-2 cells. The population of apoptotic cells increased from 11.4% in case of control to 49.6% at 100μg/ml of G. kurroo root extract. The extract also induced a remarkable decrease in mitochondrial membrane potential (ΔΨm) leading to apoptosis of cancer cells used. The main chemical constituents identified by the liquid chromatography–tandem mass spectrometry (LC–ESI-MSMS) were found to be iridoid glucosides (iridoids and secoiridoids), xanthones and flavonoids. Iridoid glucosides are the bitter principles of Gentiana species. Loganic acid, Sweroside, Swertiamarin, Gentiopicroside, Gentisin, Isogentisin, Gentioside, Norswertianolin, Swertianolin, 4″-O-β-d-glucosyl-6′-O-(4-O-β-d-glucosylcaffeoyl)-linearoside and Swertisin were the principal compounds present in the methanol root extract of G. kurroo.

Gene expression profiling and pathway analysis identify the integrin signaling pathway to be altered by IL-1β in human pancreatic cancer cells: Role of JNK

The pro-inflammatory cytokine, IL-1β, is a critical component of the persistent inflammatory milieu that pancreatic cancer cells frequently encounter. Although several studies report diverse mechanisms responsible for this association, yet a comprehensive global analysis of the effect of IL-1β in these cells is not clearly evident. In this study, we performed whole genome transcriptome analysis of control and IL-1β treated human pancreatic MIA PaCa-2 cells, validated the most targeted pathway and evaluated the role of JNK therein. 225 Genes were up-regulated and 1215 were down-regulated and these were categorized into biological processes and cellular pathways using the PANTHER classification system. The altered genes categorized into significant biological processes that included those of cell cycle, mitosis, transport and intracellular protein trafficking. The integrin signaling pathway emerged as harboring the maximum number of differentially expressed genes. Two important genes of this pathway, namely vinculin and α5-integrin were validated and both depicted significant inhibition by IL-1β that was prevented in the presence of JNK siRNA. In a wound healing assay, IL-1β increased the migratory rate of MIA PaCa-2 and Panc-1 cells that was abrogated by JNK inhibition. Additionally, vinculin and α-integrin siRNAs also increased the migration of these cells along the wound edge. These results suggest that in these pancreatic cancer cells, IL-1β inhibits components of the integrin signaling pathway in a JNK dependent manner that contributes to their increased migratory potential. Therefore, JNK might be potentially targeted to prevent the migration and invasion of pancreatic cancer cells.

Mechanism and regulation of folate uptake by human pancreatic epithelial MIA PaCa-2 cells.

After the liver, the pancreas contains the second highest level of folate among human tissues, and folate deficiency adversely affects its physiological function. Despite that, nothing is currently known about the cellular mechanisms involved in folate uptake by cells of this important exocrine organ or about folate uptake regulation. We have begun to address these issues, and in this report we present the results of our findings on the mechanism of folate uptake by the human-derived pancreatic MIA PaCa-2 cells. Our results show folic acid uptake to be 1). temperature and energy dependent; 2). pH dependent, with a markedly higher uptake at acidic pH compared with neutral or alkaline pH; 3). Na(+) independent; 4). saturable as a function of substrate concentration (apparent K(m) = 0.762 +/- 0.10 microM); 5). inhibited (with similar affinity) by reduced, substituted, and oxidized folate derivatives; and 6). sensitive to the inhibitory effect of anion transport inhibitors. RT-PCR and Western blot analysis showed expression of the human reduced folate carrier (hRFC) at the RNA and protein levels, respectively. The functional contribution of hRFC in carrier-mediated folate uptake was confirmed by gene silencing using gene-specific small interfering RNA. Evidence also was found suggesting that the folate uptake process by MIA PaCa-2 cells is regulated by cAMP- and protein tyrosine kinase (PTK)-mediated pathways. These studies demonstrate for the first time the involvement of a specialized, acidic pH-dependent, carrier-mediated mechanism for folate uptake by human pancreatic MIA PaCa-2 cells. The results also show the involvement of hRFC in the uptake process and suggest the possible involvement of intracellular cAMP- and PTK-mediated pathways in the regulation of folate uptake.