Pachymic acid inhibits growth and induces apoptosis of pancreatic cancer in vitro and in vivo by targeting ER stress
ABSTRACT: Background: Pachymic acid (PA) is a purified triterpene extracted from medicinal fungus Poria cocos. In this paper, we investigated the anticancer effects of PA on human chemotherapy resistant pancreatic cancer cells. Methods: Gemcitabine-resistant pancreatic cancer cells PANC-1 and MIA PaCa-2 were used, along with a xenograft model of MIA PaCa-2 cells implanted in mice. Apoptosis was assessed by quantitation of cytoplasmic histone-associated DNA fragments and expression of cleaved PARP. Differential expression of genes was identified using comparative DNA microarray analysis. Protein levels were determined by immunoblotting. Toxicology studies in vivo were assessed by detecting pathological changes in organs and liver enzyme profiles in plasma. Tumor tissues were analyzed by quantification of apoptotic bodies, qRT-PCR and immunoblotting. Principal Findings: PA induced endoplasmic reticulum (ER) stress in chemotherapy resistant pancreatic cancer cells through activation of heat shock response and unfolded protein response related genes, which further triggered apoptosis. The involvement of ER stress was confirmed by increasing expression of XBP-1s, ATF4, Hsp70, CHOP and phospho-eIF2α. Moreover, 25 mg kg−1 of PA significantly suppressed MIA PaCa-2 tumor growth in vivo without toxicity, which correlated with induction of apoptosis, ER stress related genes and proteins expression. Conclusions: Growth inhibition and induction of apoptosis by PA in chemotherapy resistant pancreatic cancer cells were associated with ER stress activation both in vitro and in vivo. Pancreatic cancer cell line treated with pachymic acid vs. control (untreated)
Project description:No reliable predictors of susceptibility to gemcitabine chemotherapy exist in pancreatic ductal adenocarcinoma. MicroRNAs (miR) are epigenetic gene regulators with tumorsuppressive or oncogenic roles in various carcinomas. This study assesses chemoresistant PDAC for its specific miR expression pattern. Gemcitabine-resistant variants of two mutant p53 human pancreatic adenocarcinoma cell lines were established. MicroRNA screening was investigated by microarray. Gemcitabine-resistant PANC-1 (PANC-1-GR) and MIA-PaCa-2 (MIA-PaCa-2-GR) cell clones were produced by exposing the parental cells to repeated pulsatile gemcitabine treatment over 3 days with constant sublethal concentrations followed by recovery-periods with agent-free medium until the cells recovered exponentially. Parental PANC-1 cells were treated with 0.4µM gemcitabine cycles for approximately 9 months. Parental MIA-PaCa-2 cells were exposed to 0.06µM gemcitabine cycles for approximately 12 months. Affymetrix GeneChip miRNA microarrays (Affymetrix UK Ltd., High Wycombe, UK) were performed in parental and chemoresistant PANC-1 and MIA-PaCa-2 cells after 29 chemotherapy cycles using the manufacturers´ protocols. The samples were prepared from 1µg of total-RNA in accordance with the Affymetrix FlashTag Biotin HSR RNA Labeling Kit. The targets were hybridized overnight to Affymetrix GeneChip miRNA arrays. Following hybridization, the arrays were washed and stained using the Affymetrix GeneChip Fluidics Station 450 and scanned using the Affymetrix GeneChip Scanner 3000 7G. Microarray data quality was checked as recommended by the manufacturer and by the quality metrics in the Partek Genomics Suite software (Partek Inc., St. Louis, MO).
Project description:Annexin A1 (ANXA1) is a Ca2+-binding protein involved in pancreatic cancer (PC) progression. It is able to mediate cytoskeletal organization maintaining a malignant phenotype. ANXA1 Knock-Out (KO) MIA PaCa-2 cells partially lost their migratory and invasive capabilities and also the metastatization process is affected in vivo. Here, we investigated the microRNA (miRNA) profile in ANXA1 KO cells. The analysis of the modification in miRNA expression remarked the significant involvement of ANXA1 in PC progression. In this study, we focused on miR-196a which is a well known oncogenic factor in several tumour models and it appeared down-modulated in absence of ANXA1. Furthermore, both ANXA1 and miR-196a are able to trigger the mechanisms of the epithelial to mesenchymal transition (EMT). Our results show that the reintroduction of miR-196a through the mimic sequence restored the early aggressive phenotype of MIA PaCa-2. Then, ANXA1 seems to support the expression of miR-196a and its role. On the other hand, this miRNA is able to mediate some of protein functions in PC progression. This work elucidates the correlation between ANXA1 and specific miRNA sequences, particularly miR-196a, and provides new knowledge about the protein intracellular role.
Project description:GNAS, a gene encoding G-protein stimulating alpha subunit, is frequently mutated in intraductal papillary mucinous neoplasms (IPMNs), which is an indolent and slow-growing pancreatic neoplasm that secretes abundant mucin. GNAS mutation is not observed in conventional ductal adenocarcinomas of the pancreas. To determine the functional significance of GNAS mutation in pancreatic ductal cells, we examined in vitro phenotypes and gene expression profiles of cells of pancreatic ductal lineage, HPDE, PK-8, PCI-35, and MIA PaCa-2, with exogenous expression of either wild-type or mutated (R201H) GNAS. We found that exogenous GNAS upregulated intracellular cyclic-adenine monophosphate, particularly in the mutated GNAS transfectants. Exogenous GNAS induced no obvious cell-growth promotion, but induced suppression in some cells. The exogenous GNAS upregulated MUC2 and MUC5AC in HPDE and PK-8, and the latter was most sensitive to exogenous GNAS, exhibiting drastic alteration of the global gene expression that is consistent with that of IPMN. Hence, PK-8 expressing exogenous mutated GNAS may be an ideal in vitro model of IPMN. On the other hand, exogenous GNAS downregulated expression of mucin genes and produced modest alteration of gene expression profiles in PCI-35 and MIA PaCa-2, indicating lower sensitivity to exogenous GNAS. Furthermore, we showed diverse and cell-type specific mucin expression pathways with complicated interactions between signaling pathways of the G-protein coupled receptor (GPCR), the mitogen-activated protein kinase (MAPK), and the phosphatidylinositol 3 kinase (PI3K), in which the GPCR pathway appeared to be dominant in some and the MAPK pathway in others. In conclusion, mutated GNAS found in IPMNs may extensively alter gene expression profiles, including expression of mucin genes, with the interaction with MAPK and PI3K pathways in pancreatic ductal-lineage cells, which may determine the characteristic phenotype of the neoplasm. Cells of pancreatic cancer cell lines, PK-8, PCI-35,and MIA PaCa-2, were seeded at 4 × 10^5 cells/well in 6-well plates and incubated for 24 hours at 37°C in 5% CO2 with humid atmosphere. Then the cells were transfected with either pcDNA 3.1/V5-His vector or pcDNA3.1-GNAS(R201H)-V5-His vector using Lipofectamine 2000 reagent (Life Technologies) according to the manufacturer’s recommendations. The cells were incubated for 24 hours and collected by dissociation using trypsin. Total RNAs were isolated using the RNeasy Mini kit (Qiagen, Hilden, Germany). Serial analysis of gene expression (SAGE) library was constructed using a SOLiD SAGE Kit (Life Technologies) according to the manufacture’s instruction. The constructed libraries were analysed by means of the massively parallel sequencing method using SOLiD 4 System (Life Technologies). The SAGE analysis was performed for samples obtained from single transfection experiment.
Project description:This microarray is an analysis of differentially expressed genes in three pancreatic ductal adenocarcinoma cell lines treated with LXR-agonist GW 3965. We first report that GW 3965 has antiproliferative effects in three PDAC cell lines. This microarray was designed to identify key mechanisms of the antiproliferative effect of LXR agonists within pancreatic cancer cell lines. Total RNA obtained from BxPC-3, MIA-PaCa-2, and PANC-1 pancreatic cancer cells grown in culture treated GW 3965 or ethanol (vehicle control) for 72 hours.
Project description:Transcriptional profiling of Mia PaCa 2 cells treated with 5-Aza for 96 h. Relative abundance to untreated control cells was used to estimate the effect of DNA demethylation on the expression of the RNAs. Two-condition experiment, 5-Aza-treated vs. untretated Mia PaCa 2 cells. Biological replicates: 2. Technical replicates: 2.
Project description:Searching of target genes of miR-193b by transcriptome assay using 44K Whole Human Genome Microarray system (Agilent Technologies, Palo Alto, CA) resulted in finding of several candidate genes. To search of targets genes of miR-193b, we performed transcriptome analysis to compare expression profiles between human pancreatic cancer cells, MIA PaCa-2, transfected with precursor of miR-193b and those transfected with a negative control precursor.
Project description:In order to determine the role of HOXB7 gene in cell lines derived from pancreatic ductal adenocarcinoma (MIA PaCa-2 e Capan-1), we performed its silencing utilizing the technique of RNA interference (RNAi). Total RNA derived from the inhibition as well as from parental cells was quantified in Bioanalyzer (Agilent,Santa Clara, CA, USA) and employed in the Agilent platform (4x44K). Proceeded with the guidelines of the One Color Microarray-Based Gene Expression Protocol (Agilent) and with the use of the Agilent Low Input Quick Amp Labeling Kit. HOXB7 knockdown elicited the modulation of several biological processes, especially in the MIA Paca-2 cell line, such as proteasomal ubiquitin-dependent catabolic process, synthesis of amines and cell cycle. Moreover, it showed induction of apoptosis and reduction in cell proliferation by flow cytometry and MTT assay, respectively. In this context, HOXB7 represents another component associated with the extensive network of molecules involved in the tumorigenesis of pancreatic cancer and could be a promising target for future biologic therapies. The procedure was performed in duplicate for both cell lines, which were sorted into treated and untreated with RNAi.
Project description:Purpose: The goals of this study were to identify quantitative gene expression differences between wild type, Musashi1 null, Msuashi2 null and Musashi1/Musashi2 null MIAPaCa2 pancreatic cancer cells mRNA profiles of MIA PaCa-2 cancer cells were generated by deep sequencing, in triplicate, using Illumina HiSeq2500.
Project description:Statins, potent lipid-lowering drugs, were also shown to exert anti-proliferative activity. The aim of this study was to identify the biological pathways affected by changes in gene expression activity after statins treatment and to compare the results with observed anti-proliferative effects. The study was performed in vitro on a pancreatic cancer cell line MIA PaCa-2. The changes in gene expression were measured after 24 h of treatment by the statins (atorvastatin, lovastatin, simvastatin, fluvastatin, cerivastatin, pravastatin, rosuvastatin, and pitavastatin). The statins affected expression of a significant number of genes with mevalonate pathway, cell cycle regulation, and DNA replication being the most affected metabolic/signalling pathways.
Project description:Simvastatin has been widely used for treatment of hypercholesterolemia due to its ability to inhibit HMG-CoA reductase, the rate limiting enzyme of de novo cholesterol synthesis via mevalonate pathway. Its inhibitory action causes also depletion of pathway intermediates, farnesyl pyrophosphate (FPP) and geranyl-geranyl pyrophosphate (GGPP), which are inevitable for proper targeting of small GTPases (e.g. Ras proteins) to their site of action. We profiled by array the gene expression of MIA PaCa-2 cells treated with simvastatin, FPP, GGPP and their combinations. The inhibitory effect of statins on GFP-K-Ras protein trafficking were partially prevented by addition of the mevalonate pathway intermediates. We conclude that the anticancer effect of simvastatin is to a large extent mediated through isoprenoid intermediates of the mevalonate pathway.