Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0699790 (colon cancer)
 28,837 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Bowel diseases reveal the complex interplay of sensing and signalling pathways in maintaining healthy homeostasis of the intestine. Recent studies of the xenobiotic nuclear receptor, pregnane X receptor and the inflammatory mediator nuclear transcription factor kappaB (NF-kappaB) reveal a functional link between xenobiotic neutralization and inflammation and explain how certain xenobiotics can affect the immune response. Furthermore, another nuclear receptor, peroxisome proliferator-activated receptor gamma (PPAR gamma) has been shown to produce beneficial effects in experimental inflammatory bowel diseases by repression of NF-kappaB thereby reducing inflammation, whilst its close relative PPAR beta/delta appears at a central position in signalling pathways involved in the progression of colon cancer. Recently accumulated knowledge on the action of these nuclear receptors and NF-kappaB in intestinal homeostasis may provide the rationale for the development of innovative treatment strategies with selective receptor modulators.
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PMID:A gut feeling of the PXR, PPAR and NF-kappaB connection. 1847 61

The involvement of peroxisome proliferator-activated receptors (PPARs) in the cancer cell elimination through apoptosis is a generally accepted fact. However, some reports indicate that the activation of PPARgamma is directly responsible for carcinogenesis. Caco-2 cells, a human adenocarcinoma cells, were used as a model of colon cancer. Cell cultures (5 x 10(6) cell per dish) were pretreated for 24 h with PPAR gamma agonists ciglitazone (CI, 1 x 10(-6)M) and retinoic acid (RA, 1 x 10(-6)M) and part of the cultures were subsequently subjected to gamma-radiation (photons) with therapeutic dose of 2,5 Gy. Total cellular RNA and proteins (cytoplasmic and nuclear) were isolated 24h after cultures irradiation or 48 h after stimulation in the non irradiated part of experiment to preserve the equal growth time for all samples. gamma-Irradiation of the cells abolished nuclear translocation of PPARgamma under its agonists treatment and preserved PPARgamma in the cytoplasmic pool. But it did not affect the HSP 70 expression in response to ciglitazone and retinoic acid. Moreover, combined gamma-irradiation and CI/RA treatment of the cells changed the equilibrium between Bax and Bcl-2 mRNA to anti apoptotic state with increased expression of Bcl-2 and almost abolished expression of Bax. In conclusion, this paper provides an evidence for the anti-apoptotic action of PPARgamma agonists used along with the gamma-radiation. Moreover, it shows that the up-regulated HSP70, in response to PPARgamma agonists in gamma-irradiated cultures promotes cell survival.
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PMID:Molecular mechanism of protection against chemically and gamma-radiation induced apoptosis in human colon cancer cells. 1881 38

Troglitazone (TGZ) is a synthetic thiazolidinedione drug belonging to a group of potent peroxisome proliferator-activated receptor gamma (PPAR gamma) agonists known to inhibit proliferation, alter cell cycle regulation, and induce apoptosis in various cancer cell types. TGZ is an oral anti-type II diabetes drug that can reverse insulin resistance. For more then 100 yr, aspirin, a nonselective cyclooxygenase (COX) inhibitor, has been successfully used as an anti-inflammatory drug. Recently, Aspirin (ASA) and some other nonsteroidal anti-inflammatory drugs (NSAIDs) have drawn much attention for their protective effects against colon cancer and cardiovascular disease; it has been observed that ASA's anti-tumor effect can be attributed to inhibition of cell cycle progression, induction of apoptosis, and inhibition of angiogenesis. In this report we demonstrate for the first time that, when administered in combination, TGZ and ASA can produce a strong synergistic effect in growth inhibition and G(1) arrest in lung cancer CL1-0 and A549 cells. Examination by colony formation assay revealed an even more profound synergy. In Western blot, combined TGZ and ASA also could downregulate Cdk2, E2F-1, cyclin B1, cyclin D3 protein, and the ratio of phospho-Rb/Rb. Importantly, apoptosis was synergistically induced by the combination treatment, as evidenced by caspase-3 activation and PARP cleavage. The involvement of PI3K/Akt inhibition and p27 upregulation, as well as hypophosphorylation of Rac1 at ser71, were demonstrated. Taken together, these results suggest that clinically achievable concentrations of TGZ and ASA used in combination may produce a strong anticancer synergy that warrants further investigation for its clinical applications.
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PMID:The synergistic anticancer effect of troglitazone combined with aspirin causes cell cycle arrest and apoptosis in human lung cancer cells. 1990 41

In both colon cancer and type 2 diabetes, metabolic changes induced by upregulation of the Wnt/beta-catenin signaling and downregulation of peroxisome proliferator-activated receptor gamma (PPAR gamma) may help account for the frequent association of these two diseases. In both diseases, PPAR gamma is downregulated while the canonical Wnt/beta-catenin pathway is upregulated. In colon cancer, upregulation of the canonical Wnt system induces activation of pyruvate dehydrogenase kinase and deactivation of the pyruvate dehydrogenase complex. As a result, a large part of cytosolic pyruvate is converted into lactate through activation of lactate dehydrogenase. Lactate is extruded out of the cell by means of activation of monocarboxylate lactate transporter-1. This phenomenon is called Warburg effect. PPAR gamma agonists induce beta-catenin inhibition, while inhibition of the canonical Wnt/beta-catenin pathway activates PPAR gamma.
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PMID:Interactions between PPAR Gamma and the Canonical Wnt/Beta-Catenin Pathway in Type 2 Diabetes and Colon Cancer. 2829 22


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