Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0376358 (prostate cancer)
 59,338 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Angiotensin II receptor blockers (ARBs) are widely used as hypertensive therapeutic agent. Recent studies have reported that ARBs have the potential to inhibit the growth of prostate cancer (PC) cells. Moreover, it was recently reported that Telmisartan (a kind of ARB) has peroxisome proliferator-activated receptor (PPAR)-gamma activation. We previously reported that PPAR-gamma ligand induces growth arrest of PC cells through apoptosis. In this study, we evaluated the effects of the Telmisartan and other ARBs on cell proliferation in several PC cell lines. We used normal prostate stromal cell (NPC), human hormone-refractory PC (PC3), androgen-independent PC (DU-145) and androgen-dependent PC (LNCaP) cell lines. Effects of Telmisartan and other ARBs (Candesartan, Valsartan, Irbesartan and Losartan) on PC cell growth were examined by MTT assay. Flow cytometry and Hoechst staining were used to determine whether or not ARBs induce apoptosis. Telmisartan caused marked inhibition of PC cells in concentration-dependent and time-dependent manner. PC cells with treatment of 100 microM Telmisartan induced early apoptosis and DNA fragmentation. However, NPC with treatment of 100 microM Telmisartan did not induce apoptosis or DNA fragmentation. Furthermore, other ARBs had no effect on cell proliferation in the PC cells and NPC. Telmisartan may mediate potent antiproliferative effects against PC cells through PPAR-gamma. Thus, Telmisartan is a potent target for prevention and treatment in PC.
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PMID:Telmisartan is a potent target for prevention and treatment in human prostate cancer. 1863 89

This study identifies a novel mechanism by which thiazolidinediones mediate cyclin D1 repression in prostate cancer cells. Based on the finding that the thiazolidinedione family of peroxisome proliferator-activated receptor gamma (PPARgamma) agonists mediated PPARgamma-independent cyclin D1 degradation, we developed a novel PPARgamma-inactive troglitazone derivative, STG28, with high potency in cyclin D1 ablation. STG28-mediated cyclin D1 degradation was preceded by Thr-286 phosphorylation and nuclear export, which however, were independent of glycogen synthase kinase 3beta. Mutational analysis further confirmed the pivotal role of Thr-286 phosphorylation in STG28-induced nuclear export and proteolysis. Of several kinases examined, inhibition of IkappaB kinase alpha blocked STG28-mediated cytoplasmic sequestration and degradation of cyclin D1. Pulldown of ectopically expressed Cul1, the scaffold protein of the Skp-Cullin-F-box E3 ligase, in STG28-treated cells revealed an increased association of cyclin D1 with beta-TrCP, whereas no specific binding was noted with other F-box proteins examined, including Skp2, Fbw7, Fbx4, and Fbxw8. This finding represents the first evidence that cyclin D1 is targeted by beta-TrCP. Moreover, beta-TrCP expression was up-regulated in response to STG28, and ectopic expression and small interfering RNA-mediated knock-down of beta-TrCP enhanced and protected against STG28-facilitated cyclin D1 degradation, respectively. Because cyclin D1 lacks the DSG destruction motif, mutational and modeling analyses indicate that cyclin D1 was targeted by beta-TrCP through an unconventional recognition site, (279)EEVDLACpT(286), reminiscent to that of Wee1. Moreover, we obtained evidence that this beta-TrCP-dependent degradation takes part in controlling cyclin D1 turnover when cancer cells undergo glucose starvation, which endows physiological relevance to this novel mechanism.
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PMID:A novel mechanism by which thiazolidinediones facilitate the proteasomal degradation of cyclin D1 in cancer cells. 1865 Apr 23

PPARgamma is a therapeutic target that has been exploited for treatment of type II diabetes mellitus (T2DM) with agonist drugs. Since PPARgamma is expressed by many hematopoietic, mesodermal and epithelial cancers, agonist drugs were tested and shown to have both preclinical and clinical anticancer activities. While preclinical activity has been observed in many cancer types, clinical activity has been observed only in pilot and phase II trials in liposarcoma and prostate cancer. Most studies address agonist compounds, with substantially fewer reports on anticancer effects of PPARgamma antagonists. In cancer model systems, some effects of PPARgamma agonists were not inhibited by PPARgamma antagonists, suggesting noncanonical or PPARgamma-independent mechanisms. In addition, PPARgamma antagonists, such as T0070907 and GW9662, have exhibited antiproliferative effects on a broad range of hematopoietic and epithelial cell lines, usually with greater potency than agonists. Also, additive antiproliferative effects of combinations of agonist plus antagonist drugs were observed. Finally, there are preclinical in vivo data showing that antagonist compounds can be administered safely, with favorable metabolic effects as well as antitumor effects. Since PPARgamma antagonists represent a new drug class that holds promise as a broadly applicable therapeutic approach for cancer treatment, it is the subject of this review.
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PMID:Potential of peroxisome proliferator-activated receptor gamma antagonist compounds as therapeutic agents for a wide range of cancer types. 1877 71

Although 15-deoxy-Delta(12,14)-prostaglandin J(2) (15dPGJ(2)) was reported to up-regulate death receptor 5 (DR5) protein expression and sensitize TRAIL-induced cytotoxicity, its action mechanism remains unclear. Using HCT116 colon cancer cells, we found that sensitization of TRAIL-induced cytotoxicity by 15dPGJ(2) resulted from up-regulation of DR5 via gene transcription but was not associated with PPAR-gamma activation. Moreover, 15dPGJ(2) induced GRP78, XBP1, and C/EBP homologous transcription factor (CHOP) expression in HCT116 cells, confirming that 15dPGJ(2) is an endoplasmic reticulum stress inducer. Knockdown of the CHOP gene by siRNA attenuated DR5 up-regulation and the sensitized cytotoxicity in colon cancer HCT116 and SW480. With deletion plasmids of DR5 promoters, we found that the CHOP-binding site was involved in activating the DR5 gene by 15dPGJ(2). A mechanistic study showed the contributions of reactive oxygen species (ROS) and intracellular calcium in CHOP and DR5 gene up-regulation. 15dPGJ(2) was also found to induce DR5 in two prostate cancer cell lines, LNCaP and PC3. Although in LNCaP DR5 up-regulation was accompanied by CHOP expression by 15dPGJ(2), no significant increase in CHOP expression or DR5 promoter activity was observed in PC3 cells. Intriguingly, 15dPGJ(2) induced ROS and calcium production in PC3 cells. This inability to induce CHOP was not due to the p53-null in PC3 cells, as similar extents of increase in CHOP protein were found due to 15dPGJ(2) in both wild-type and p53-null HCT116 cells. In summary, the effect of up-regulation of DR5 by 15dPGJ(2) in colon cancer cells is independent of PPAR-gamma and p53 but relies on CHOP induction through gene transcription involving ROS and calcium.
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PMID:15-deoxy-Delta12,14-prostaglandin J2 up-regulates death receptor 5 gene expression in HCT116 cells: involvement of reactive oxygen species and C/EBP homologous transcription factor gene transcription. 1885 46

Peroxisome proliferator activator-receptor (PPAR)-gamma is a ligand-activated transcriptional factor belonging to a steroid receptor superfamily. PPAR-gamma plays a role in both adipocyte differentiation and carcinogenesis. Up-date, PPAR-gamma is expressed in various cancer tissues, and PPAR-gamma ligand induces growth arrest of these cancer cells. In this study, we examined the expression of PPAR-gamma in human urological cancer (including renal cell carcinoma, bladder tumor, prostate cancer and testicular cancer) by RT-PCR and immunohistochemistry, and we also examined the effect of PPAR-gamma ligand in these cells by MTT assay, flow cytometry and hoechest staining. PPAR-gamma expression was significantly more extensive and intense in malignant tissues than in normal tissues. PPAR-gamma ligand induced the reduction of malignant cell viability through early apoptosis. These results demonstrated that generated PPAR-gamma in urological cancer cells may play an important role in carcinogensis and become a new target therapy in the treatment of urological cancer.
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PMID:A novel approach to anticancer therapies: peroxisome proliferator activator-receptor-gamma as a new target therapy in the treatment of human urological cancer. 1927 83

Peroxisome proliferator-activated receptor (PPAR) is a member of the nuclear hormone receptor superfamily of transcription factors. Peroxisome proliferator-activated receptor gamma (PPARgamma) plays an important role in the regulation of lipid homeostasis, adipogenesis, insulin resistance, and development of various organs. Agonists of PPARgamma have been also reported to inhibit proliferation of prostate carcinoma cells as in other human malignancies, and these synthetic ligands have been used in differentiation-mediated therapy of various human carcinomas associated with high levels of PPARgamma. The significance of PPARgamma expression, however, was unknown in human prostate carcinoma tissues. The purpose of the present study was therefore to examine the immunolocalization of PPARgamma in human prostate cancer tissues (40 cases) and correlate the findings with clinicopathological features of the patients in order to evaluate its possible biological significance. Twenty-nine patients were positive for PPARgamma immunoreactivity (73%) and a significant inverse correlation was detected between PPARgamma immunoreactivity, pT stage (P = 0.036), and serum concentration of prostate-specific antigen (P = 0.0004). In conclusion, PPARgamma immunoreactivity is considered to be a new clinicopathological parameter of human prostate cancer.
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PMID:Peroxisome proliferator-activated receptor gamma in human prostate carcinoma. 1943 69

Thiol reactive cyclopentenone prostaglandin, 15-deoxy-Delta(12,14)-prostaglandin J(2) (15d-PGJ2), induced a novel, nonapoptotic and microtubule-associated protein 1 light chain 3 (MAP1 LC3) dependent but nonautophagic form of cell death in colon, breast and prostate cancer cell lines, characterized by extensive cytoplasmic vacuolation with dilatation of endoplasmic reticulum (ER). Disruption of sulfhydryl homeostasis, which resulted in ER stress, accumulation of ubiquitinated proteins and subsequent ER dilation, contributed to peroxisome proliferator-activated receptor gamma (PPARgamma)-independent cell death by 15d-PGJ2. Absence of intracellular organelles in these vacuoles, shown by electron microscopy and unique fragmentation of lamin B, suggested this form of cell death to be different from autophagy and apoptosis. Cell death induced by 15d-PGJ2 is prevented by cycloheximide and actinomycin D, suggesting a requirement of new protein synthesis for death with cytoplasmic vacuolation. Here, we report for the first time that upregulation and processing of autophagy marker LC3 is an important event in nonautophagic cytoplasmic vacuolation and cell death. Notably, knockdown of LC3 conferred significant protection against 15d-PGJ2-induced cytoplasmic vacuolation and cell death, suggesting a novel role of LC3 in a death process other than autophagy.
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PMID:A novel role for MAP1 LC3 in nonautophagic cytoplasmic vacuolation death of cancer cells. 1944 71

There is growing interest in the possible health threat posed by endocrine-disrupting chemicals (EDCs), which are substances in our environment, food, and consumer products that interfere with hormone biosynthesis, metabolism, or action resulting in a deviation from normal homeostatic control or reproduction. In this first Scientific Statement of The Endocrine Society, we present the evidence that endocrine disruptors have effects on male and female reproduction, breast development and cancer, prostate cancer, neuroendocrinology, thyroid, metabolism and obesity, and cardiovascular endocrinology. Results from animal models, human clinical observations, and epidemiological studies converge to implicate EDCs as a significant concern to public health. The mechanisms of EDCs involve divergent pathways including (but not limited to) estrogenic, antiandrogenic, thyroid, peroxisome proliferator-activated receptor gamma, retinoid, and actions through other nuclear receptors; steroidogenic enzymes; neurotransmitter receptors and systems; and many other pathways that are highly conserved in wildlife and humans, and which can be modeled in laboratory in vitro and in vivo models. Furthermore, EDCs represent a broad class of molecules such as organochlorinated pesticides and industrial chemicals, plastics and plasticizers, fuels, and many other chemicals that are present in the environment or are in widespread use. We make a number of recommendations to increase understanding of effects of EDCs, including enhancing increased basic and clinical research, invoking the precautionary principle, and advocating involvement of individual and scientific society stakeholders in communicating and implementing changes in public policy and awareness.
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PMID:Endocrine-disrupting chemicals: an Endocrine Society scientific statement. 1950 15

Recent epidemiological studies and animal experiments have demonstrated that nonsteroidal anti-inflammatory drugs (NSAIDs) reduce the incidence of colorectal carcinoma. Cyclooxygenase (COX) is the principal target of NSAIDs. COX is the first oxidase in the process of prostaglandin production from arachidonic acid. COX enzyme may be involved in the initiation and/or the promotion of carcinogenesis due to NSAIDs inhibition of COX. Lipoxygenase (LOX) is also an initial enzyme in the pathway for producing leukotrienes from arachidonic acid. Similar to COX, LOX enzyme may also be involved in the initiation and/or promotion of carcinogenesis. Peroxisome proliferator activator-receptor (PPAR)-gamma is a ligand-activated transcriptional factor belonging to the steroid receptor superfamily. PPAR-gamma plays a role in both adipocyte differentiation and carcinogenesis. PPAR-gamma is one target for cell growth modulation of NSAIDs. In this review, we report the expression of COX-2, LOX and PPAR-gamma in human prostate cancer tissues as well as the effects of COX-2 and LOX inhibitors and PPAR-gamma ligand.
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PMID:The target of arachidonic acid pathway is a new anticancer strategy for human prostate cancer. 1970 53

Chronic inflammation and dietary fat consumption correlates with an increase in prostate cancer. Our previous studies in the colon have demonstrated that gamma-tocopherol treatment could upregulate the expression of peroxisome proliferator-activated preceptors (PPAR) gamma, a nuclear receptor involved in fatty acid metabolism as well modulation of cell proliferation and differentiation. In this study, we explored the possibility that gamma-tocopherol could induce growth arrest in PC-3 prostate cancer cells through the regulation of fatty acid metabolism. Growth arrest (40%) and PPAR gamma mRNA and protein upregulation was achieved with gamma-tocopherol within 6 h. gamma-Tocopherol-mediated growth arrest was demonstrated to be PPAR gamma dependent using the agonist GW9662 and a PPAR gamma dominant negative vector. gamma-tocopherol was shown not to be a direct PPAR gamma ligand, but rather 15-S-HETE (an endogenous PPAR gamma ligand) was upregulated by gamma-tocopherol treatment. 15-Lipoxygenase-2, a tumor suppressor and the enzyme that converts arachidonic acid to 15-S-HETE, was upregulated at 3 h following gamma-tocopherol treatment. Expression of proteins downstream of the PPAR gamma pathway were examined. Cyclin D1, cyclin D3, bcl-2, and NFkappa B proteins were found to be downregulated following gamma-tocopherol treatment. These data demonstrate that the growth arrest mediated by gamma-tocopherol follows a PPAR-gamma-dependent mechanism.
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PMID:Gamma tocopherol upregulates the expression of 15-S-HETE and induces growth arrest through a PPAR gamma-dependent mechanism in PC-3 human prostate cancer cells. 1983 39


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