15-deoxy-delta(12-14)-prostaglandin-j2 and Adenocarcinoma

There is growing evidence that stress-coping mechanisms represent tumor cell vulnerabilities that may function as therapeutically beneficial targets. Recent work has delineated an integrated stress adaptation mechanism that is characterized by the formation of cytoplasmic mRNA and protein foci, termed stress granules (SGs). Here, we demonstrate that SGs are markedly elevated in mutant KRAS cells following exposure to stress-inducing stimuli. The upregulation of SGs by mutant KRAS is dependent on the production of the signaling lipid molecule 15-deoxy-delta 12,14 prostaglandin J2 (15-d-PGJ2) and confers cytoprotection against stress stimuli and chemotherapeutic agents. The secretion of 15-d-PGJ2 by mutant KRAS cells is sufficient to enhance SG formation and stress resistance in cancer cells that are wild-type for KRAS. Our findings identify a mutant KRAS-dependent cell non-autonomous mechanism that may afford the establishment of a stress-resistant niche that encompasses different tumor subclones. These results should inform the design of strategies to eradicate tumor cell communities.

Topics: Adenocarcinoma; Animals; Cell Line, Tumor; Colonic Neoplasms; Cytoplasmic Granules; Drug Resistance, Neoplasm; Eukaryotic Initiation Factor-4A; Female; Heterografts; Humans; Mice; Mutation; Neoplasm Transplantation; Pancreatic Neoplasms; Prostaglandin D2; Proto-Oncogene Proteins p21(ras); Up-Regulation

Helicobacter pylori deregulates the genes that control homeostasis between apoptosis and cell proliferation of gastric epithelial cells. Nuclear factor-kappaB (NF-kappaB) has an important role in H. pylori-induced apoptosis in gastric epithelial cells. The peroxisome proliferator-activated receptor-gamma ligand 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ(2)) regulates growth and the signaling cascade in H. pylori-infected gastric epithelial cells. In the present study, we determined whether 15d-PGJ(2) inhibits apoptosis by regulating apoptotic gene expression and NF-kappaB activation in gastric epithelial cells infected with CagA+, VacA+H. pylori in a Korean isolate (HP99). 15d-PGJ(2) was found to inhibit H. pylori-induced DNA fragmentation and cell death. 15d-PGJ(2) induced downregulation of proapoptotic Bax and upregulation of antiapoptotic Bcl-2 as well as suppression of NF-kappaB activation caused by H. pylori in gastric epithelial cells. The results suggest that 15d-PGJ(2) inhibits apoptotic cell death by inhibiting NF-kappaB activation and apoptotic gene expression in gastric epithelial cells.

Topics: Adenocarcinoma; Antigens, Bacterial; Apoptosis; Bacterial Proteins; bcl-2-Associated X Protein; Blotting, Western; Cell Line, Tumor; DNA Fragmentation; Electrophoretic Mobility Shift Assay; Enzyme-Linked Immunosorbent Assay; Helicobacter pylori; Humans; NF-kappa B; Oligonucleotides; Prostaglandin D2; Protein Binding; Proto-Oncogene Proteins c-bcl-2; Stomach Neoplasms

Cyclooxygenase-2 (COX-2) expression and peroxisome proliferator-activated receptor-gamma (PPARgamma) inactivation are linked to increased risk of human breast cancer. The purpose of our study was to examine the relationship between COX-2 (with the resulting prostaglandins E(2), PGE(2)) and PPARgamma (and its natural endogenous ligand 15-Deoxy-Delta(12,14)-prostaglandin J(2), 15d-PGJ(2)) at various stages during the development of human breast cancer and its progression to metastasis. Human breast tissue specimens were collected from normal breasts or from individuals with fibrocystic disease and served as controls (n = 22). Tissues were also collected from uninvolved (n = 25), tumor (n = 25) and lymph node metastasis (n = 15) regions from breast cancer patients. COX-2 and PPARgamma mRNA expression were increased and downregulated, respectively, in tissues from cancer patients compared to controls. Metastatic tissues tended to have higher alterations compared to non-metastatic tissues (p < 0.05). These altered expressions in COX-2 and PPARgamma were paralleled by increases in the tissue levels of PGE(2) and decreases in 15d-PGJ(2). A significant inverse correlation was found between PGE(2) and 15-d-PGJ(2) (r = -0.51, p < 0.05). Significant correlations (p < 0.05) were also obtained between COX-2 and PPARgamma mRNA (inverse, r = -0.72) and between COX-2 and PGE(2) (direct, r = 0.68). Increases in COX-2 mRNA expression and levels of PGE(2) and down-regulation of PPARgamma mRNA expression and 15d-PGJ(2) levels were characterized as predictors of breast cancer risk (p < 0.05). Our results suggest that the altered expression of COX-2 and PPARgamma and the subsequent modulation in the tissue levels of PGE(2) and 15-d-PGJ(2) may influence the development of human breast cancer and its progression to metastasis.

Topics: Adenocarcinoma; Breast Neoplasms; Case-Control Studies; Cyclooxygenase 2; Dinoprostone; DNA Primers; Female; Humans; Isoenzymes; Lymphatic Metastasis; Membrane Proteins; Middle Aged; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Receptors, Cytoplasmic and Nuclear; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; RNA, Neoplasm; Transcription Factors

Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a nuclear receptor for eicosanoids that promotes differentiation of human epithelial and mesenchymal cells in vitro and in vivo. PPARgamma was proposed as a target for drug-induced differentiation therapy of cancer. Caveolin-1 is a constituent of plasma membrane caveolae in epithelial cells that is often downregulated upon oncogenic transformation. Caveolin-1 has growth-inhibitory activities and its disruption is sufficient to induce transformation in fibroblasts. Herein we have tested the hypothesis that caveolins are transcriptional target genes for PPARgamma. In human HT-29 colon carcinoma cells, thiazolidinedione PPARgamma ligands increased the levels of caveolin-1 and caveolin-2 proteins two to fivefold in a concentration-dependent manner within 24 h. In human MCF-7 breast adenocarcinoma cells, nonthiazolidinedione PPARgamma ligands elevated caveolin-2 protein three to fourfold, while the thiazoli-dinediones were less effective. Caveolin-1 mRNA levels were found to be upregulated by PPARgamma ligands already after 3 h in both the cell lines. Ectopic expression of a dominant-negative PPARgamma construct attenuated ligand-induced upregulation of caveolins in both HT-29 and HEK-293T cells, indicating that ligand action is mediated by PPARgamma. Ligand-treated MCF-7 cells exhibited a differentiated phenotype, as evinced by analysis of cell-specific differentiation markers: protein levels of maspin were elevated and perinuclear lipid droplets accumulated. In contrast, in HT-29 cells, caveolin expression was not correlated with differentiation. Interestingly, PPARgamma partially cofractionated in lipid rafts and could be coimmunoprecipitated from cell lysates with caveolin-1, indicating that PPARgamma and caveolin-1 may coexist in a complex. Our data indicate that PPARgamma participates in the regulation of caveolin gene expression in human carcinoma cells and suggest that caveolin-1 may mediate some of the phenotypic changes induced by this nuclear receptor in cancer cells. These findings may have potentially important functional implications in the context of cancer differentiation therapy and multidrug resistance.

Topics: Adenocarcinoma; Antigens, Differentiation; Antigens, Neoplasm; Breast Neoplasms; Caveolin 1; Caveolin 2; Caveolins; Cell Differentiation; Cell Line; Chromans; Colonic Neoplasms; Dimerization; Drug Resistance, Multiple; Drug Resistance, Neoplasm; Female; Gene Expression Regulation, Neoplastic; Genes, Dominant; Humans; Kidney; Ligands; Macromolecular Substances; Membrane Microdomains; Neoplasm Proteins; Phenotype; Phenylacetates; Prostaglandin D2; Protein Structure, Tertiary; Receptors, Cytoplasmic and Nuclear; RNA, Messenger; RNA, Neoplasm; Rosiglitazone; Thiazoles; Thiazolidinediones; Transcription Factors; Transcription, Genetic; Troglitazone; Tumor Cells, Cultured

Peroxisome proliferator-activated receptor gamma (PPARgamma) is expressed in certain human cancers; ligand-induced PPARgamma activation can result in growth inhibition and differentiation in these cells. However, the precise mechanism for the antiproliferative effect of PPARgamma ligands is not entirely known.. The purpose of this study was to examine the effect of PPARgamma ligands on pancreatic cancer cell growth and invasiveness.. The effect of two PPARgamma ligands, 15 deoxy-delta12,14 prostaglandin J2 (15d-PGJ2) and ciglitazone, on the growth of four human pancreatic cancer cell lines (BxPC-3, MIA PaCa-2, Panc-1, and L3.6) was assessed. Expression of cell-cycle and apoptotic-related proteins was measured. Finally, the effect of 15d-PGJ2 on pancreatic cancer cell invasiveness and matrix metalloproteinase expression was determined.. Both 15d-PGJ2 and ciglitazone inhibited the growth of all four pancreatic cancer cell lines in a dose- and time-dependent fashion. Treatment of BxPC-3 cells with 15d-PGJ2 resulted in a time-dependent decrease in cyclin D1 expression associated with a concomitant induction of p21waf1 and p27kip1. In addition, 15d-PGJ2 treatment induced apoptosis through activation of caspase-8, -9, and -3. Moreover, pancreatic cancer cell invasiveness was significantly suppressed after treatment with a nontoxic dose of 15d-PGJ2, which was associated with a reduction of MMP-2 and MMP-9 protein levels and activity.. These results demonstrate that PPARgamma ligands have the dual advantage of inhibiting pancreatic cancer cell growth while reducing the invasiveness of the tumor cells, suggesting a potential role for these agents in the adjuvant treatment of pancreatic cancer.

Topics: 3T3 Cells; Adenocarcinoma; alpha Catenin; Animals; Antineoplastic Agents; Apoptosis; beta Catenin; Cadherins; Caspase 3; Caspase 8; Caspase 9; Caspases; Cell Cycle; Cell Cycle Proteins; Cell Division; Collagen; Cyclin D1; Cyclin-Dependent Kinase Inhibitor p21; Cyclin-Dependent Kinase Inhibitor p27; Cyclins; Cyclooxygenase 2; Cytoskeletal Proteins; Drug Combinations; Enzyme Induction; Gene Expression Regulation, Neoplastic; Humans; Isoenzymes; Laminin; Ligands; Matrix Metalloproteinase 2; Matrix Metalloproteinase 9; Membrane Proteins; Mice; Neoplasm Invasiveness; Neoplasm Proteins; Pancreatic Neoplasms; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Proteoglycans; Receptors, Cytoplasmic and Nuclear; Thiazoles; Thiazolidinediones; Trans-Activators; Transcription Factors; Tumor Cells, Cultured; Tumor Suppressor Proteins

Peroxisome proliferator-activated receptor gamma (PPAR-gamma), a member of the nuclear hormone receptor superfamily, is involved in suppression of growth of several types of tumors such as liposarcoma, breast cancer, prostate cancer, and colon cancer, possibly through induction of cell cycle arrest and/or apoptosis. In this study, we demonstrated expression of PPAR-gamma mRNA and protein in human esophageal carcinoma cells. Expression of PPAR-gamma protein was higher in an adenocarcinoma cell line (TE-7 cells) than in a squamous cell carcinoma cell line (TE-1 cells). PPAR-gamma ligands such as 15-deoxy-Delta12,14-prostaglandin J2 and troglitazone significantly inhibited the growth of TE-7 cells but had less or no effect on growth of TE-1 cells. 15d-PGJ2 and troglitazone induced apoptosis in TE-7 cells but not in TE-1 cells. Troglitazone caused G1 cell cycle arrest and reduced ornithine decarboxylase activity (ODC) in TE-7 cells but not in TE-1 cells. Inhibition by PPAR-gamma ligands of growth of esophageal adenocarcinoma cells may thus be due to induction of apoptosis, G1 cell cycle arrest and reduction of ODC activity.

Topics: Adenocarcinoma; Antineoplastic Agents; Apoptosis; Blotting, Western; Carcinoma, Squamous Cell; Cell Cycle; Cell Division; Chromans; DNA Primers; Esophageal Neoplasms; Flow Cytometry; Humans; Immunologic Factors; Ligands; Ornithine Decarboxylase; Prostaglandin D2; Receptors, Cytoplasmic and Nuclear; Reverse Transcriptase Polymerase Chain Reaction; RNA, Messenger; Tetrazolium Salts; Thiazoles; Thiazolidinediones; Thymidine; Transcription Factors; Troglitazone; Tumor Cells, Cultured

The efficacy of non-steroidal anti-inflammatory drugs (NSAIDs) is considered to be a result of their inhibitory effect on cyclooxygenase (COX) activity. Here, we report that flufenamic acid shows two opposing effects on COX-2 expression; it induces COX-2 expression in the colon cancer cell line (HT-29) and macrophage cell line (RAW 264.7); conversely, it inhibits tumor necrosis factor alpha (TNFalpha)- or lipopolysaccharide (LPS)-induced COX-2 expression. This inhibition correlates with the suppression of TNFalpha- or LPS-induced NFkappaB activation by flufenamic acid. The inhibitor of extracellular signal-regulated protein kinase, p38, or NFkappaB does not affect the NSAID-induced COX-2 expression. These results suggest that the NSAID-induced COX-2 expression is not mediated through activation of NFkappaB and mitogen-activated protein kinases. An activator of peroxisome proliferator-activated receptor gamma, 15-deoxy-Delta(12,14)-prostaglandin J(2), also induces COX-2 expression and inhibits TNFalpha-induced NFkappaB activation and COX-2 expression. Flufenamic acid and 15-deoxy-Delta(12,14)-prostaglandin J(2) also inhibit LPS-induced expression of inducible form of nitric-oxide synthase and interleukin-1alpha in RAW 264.7 cells. Together, these results indicate that the NSAIDs inhibit mitogen-induced COX-2 expression while they induce COX-2 expression. Furthermore, the results suggest that the anti-inflammatory effects of flufenamic acid and some other NSAIDs are due to their inhibitory action on the mitogen-induced expression of COX-2 and downstream markers of inflammation in addition to their inhibitory effect on COX enzyme activity.

Topics: Adenocarcinoma; Animals; Anti-Inflammatory Agents, Non-Steroidal; Colonic Neoplasms; Cyclooxygenase 2; Enzyme Induction; Flufenamic Acid; Gene Expression Regulation, Enzymologic; Humans; Isoenzymes; Lipopolysaccharides; Macrophages; Membrane Proteins; Nitric Oxide Synthase; Nitric Oxide Synthase Type II; Prostaglandin D2; Prostaglandin-Endoperoxide Synthases; Receptors, Cytoplasmic and Nuclear; Sulindac; Transcription Factors; Tumor Cells, Cultured; Tumor Necrosis Factor-alpha

The biological modifier delta12-prostaglandin J2 and related prostaglandins have been reported to have significant growth-inhibitory activity with induction of heat shock proteins (Hsps). Tumor-derived Hsps have been shown previously to elicit specific immunity to tumors from which they are isolated. In this study, 15-deoxy-delta12,14-prostaglandin J2 (15d-PGJ2)-induced Hsp70 was purified from transgenic adenocarcinoma mouse prostate cells (TRAMP-C2). It was then tested for its ability to activate specific CTLs and induce protective immunity against prostate cancer in C57BL/6 mice. Treatment of cells with 8.0 microM 15d-PGJ2 for 24 h caused significant induction of Hsp70 expression. The yield of Hsp70 purified from 15d-PGJ2-treated cells was 4-5-fold higher when compared with untreated TRAMP-C2 cells. Vaccination of mice with Hsps isolated from TRAMP-C2 cells elicited tumor-specific CTLs and prevented the growth of TRAMP-C2 tumors. These results indicate that the induced heat shock proteins may have promising applications for antitumor, T-cell immunotherapy. In particular, these findings have important implications for the development of novel anticancer therapies aimed at promoting an immune response to prostate tumors.

Topics: Adenocarcinoma; Animals; Cancer Vaccines; Dose-Response Relationship, Drug; HSP70 Heat-Shock Proteins; Immunity, Innate; Immunologic Factors; Male; Mice; Mice, Inbred C57BL; Mice, Transgenic; Prostaglandin D2; Prostatic Neoplasms; T-Lymphocytes, Cytotoxic; Tumor Cells, Cultured