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

Prostate cancer is the most common solid tumor in men, and it shares with all cancers the hallmark of elevated, nonhomeostatic cell proliferation. Here we have tested the hypothesis that the SONIC HEDGEHOG (SHH)-GLI signaling pathway is implicated in prostate cancer. We report expression of SHH-GLI pathway components in adult human prostate cancer, often with enhanced levels in tumors versus normal prostatic epithelia. Blocking the pathway with cyclopamine or anti-SHH antibodies inhibits the proliferation of GLI1+/PSA+ primary prostate tumor cultures. Inversely, SHH can potentiate tumor cell proliferation, suggesting that autocrine signaling may often sustain tumor growth. In addition, pathway blockade in three metastatic prostate cancer cell lines with cyclopamine or through GLI1 RNA interference leads to inhibition of cell proliferation, suggesting cell-autonomous pathway activation at different levels and showing an essential role for GLI1 in human cells. Our data demonstrate the dependence of prostate cancer on SHH-GLI function and suggest a novel therapeutic approach.
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PMID:Inhibition of prostate cancer proliferation by interference with SONIC HEDGEHOG-GLI1 signaling. 1531 19

Sonic hedgehog (SHH), Desert hedgehog (DHH) and Indian hedgehog (IHH) bind to Patched family receptors (PTCH1 and PTCH2) to transduce signals to GLI1, GLI2 and GLI3. GLI family transcription factors then activate transcription of Hedgehog target genes, such as FOXE1 and FOXM1 encoding Forkhead-box transcription factors. Hedgehog signaling pathway plays a pivotal role in a variety of human tumors, such as gastric cancer, pancreatic cancer, colorectal cancer, breast cancer, prostate cancer, basal cell carcinoma and brain tumors. Rat orthologs for human DHH and IHH remain to be identified. Here, we identified and characterized rat Dhh and Ihh genes by using bioinformatics. Rat Dhh complete coding sequence (CDS) was determined by assembling nucleotide positions 426397-426963, 429715-429976 and 430244-430898 of the AC114446.3 genome sequence. Rat Ihh complete CDS was determined by assembling nucleotide positions 63433-64033, 66432-66693 and 68242-69169 of AC095777.6 genome sequence. Rat Dhh mRNA was expressed in prostate, duodenum and dorsal root ganglia, while rat Ihh mRNA was expressed in cartilage. Rat Dhh showed 99.7% total-amino-acid identity with mouse Dhh, and 96.5% total-amino-acid identity with human DHH. Rat Ihh and human IHH were shorter than mouse Ihh by 38 amino acids. Rat Ihh showed 97.6% total-amino-acid identity with mouse Ihh and 94.4% total-amino-acid identity with human IHH. Hedgehog family proteins consist of signal peptide, Hedgehog ligand peptide and C-terminal peptide. Hedgehog ligand peptides derived from mammalian Hedgehog family proteins were conserved well, while C-terminal peptides were relatively divergent. The HPLGMXXXXS motif in the C-terminus was conserved in Shh orthologs and Ihh orthologs, but not in Dhh orthologs.
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PMID:Identification and characterization of rat Desert hedgehog and Indian hedgehog genes in silico. 1564 42

The Hedgehog-GLI signaling pathway is important in animal development and tumorigenesis. Recent findings indicate that the growth and survival of human prostate cancer cells rely upon sustained signaling from the Hedgehog-GLI pathway. These findings have prompted a novel rational strategy for therapeutic treatment of prostate tumors, including metastatic tumors.
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PMID:Therapeutic targeting of the Hedgehog-GLI pathway in prostate cancer. 1583 20

Although the blockade of the hedgehog cascade by using cyclopamine has been reported to inhibit the growth of some cancer cell types, few studies on the mechanism by which this drug alone or in combination with other cytotoxic agents induces its cytotoxic effect have been reported. In our study, we evaluate, for the first time, the antiproliferative and cytotoxic effects induced by a combination of selective SMO inhibitor, cyclopamine and epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, gefitinib on metastatic prostate cancer (PC) cells. The results revealed that cyclopamine, alone or at a lower concentration in combination with gefitinib, inhibited the growth of sonic hedgehog- (SHH), epidermal growth factor- (EGF) and serum-stimulated androgen-sensitive LNCaP-C33 and LNCaP-LN3 and androgen-independent LNCaP-C81, DU145 and PC3 cells. The antiproliferative effect of cyclopamine and gefitinib, alone or in combination, was mediated via a blockade of the PC3 cells in the G1 phase of the cell cycle. Importantly, the combined cyclopamine and gefitinib also caused a higher rate of apoptotic death of PC cells compared to single agents. The cytotoxic effect induced by these drugs in PC3 cells appears to be mediated at least, in part, via the mitochondrial pathway through the depolarization of the mitochondrial membrane and the release of cytochrome c and reactive oxygen species into the cytosol. This was also accompanied by the activation of caspase cascades, PARP cleavage and DNA fragmentation. Additionally, the combined cyclopamine and gefitinib were more effective at suppressing the invasiveness of PC3 cells through matrigel in vitro as the drugs alone. These findings indicate that the simultaneous blockade of SHH-GLI-1 and EGF-EGFR signaling, which results in the growth arrest and massive rate of apoptotic cell death, represents a promising strategy for a more effective treatment of metastatic PC forms.
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PMID:Cytotoxic effects induced by a combination of cyclopamine and gefitinib, the selective hedgehog and epidermal growth factor receptor signaling inhibitors, in prostate cancer cells. 1610 16

The developmentally important Hedgehog (Hh) signaling pathway has recently been implicated in several forms of solid cancer. Current drug development programs focus on targeting the protooncogene Smoothened, a key transmembrane pathway member. These drug candidates, albeit promising, do not address the scenario in which pathway activation occurs downstream of Smoothened, as observed in cases of medulloblastoma, glioma, pericytoma, breast cancer, and prostate cancer. A cellular screen for small-molecule antagonists of GLI-mediated transcription, which constitutes the final step in the Hh pathway, revealed two molecules that are able to selectively inhibit GLI-mediated gene transactivation. We provide genetic evidence of downstream pathway blockade by these compounds and demonstrate the ineffectiveness of upstream antagonists such as cyclopamine in such situations. Mechanistically, both inhibitors act in the nucleus to block GLI function, and one of them interferes with GLI1 DNA binding in living cells. Importantly, the discovered compounds efficiently inhibited in vitro tumor cell proliferation in a GLI-dependent manner and successfully blocked cell growth in an in vivo xenograft model using human prostate cancer cells harboring downstream activation of the Hh pathway.
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PMID:Inhibition of GLI-mediated transcription and tumor cell growth by small-molecule antagonists. 1749 66

With increasing incidence of cancer at most of the sites, and growing economic burden and associated psychological and emotional trauma, it is becoming clearer that more efforts are needed for cancer cure. Since most of the chemotherapeutic drugs are non-selective because they are also toxic to the normal cells, new and improved strategies are needed that selectively target the killing of cancer cells. Since aberrant activation of numerous signaling pathways is a key element of cancer cell survival and growth, blocking all of them is not that practical, which leads to the step where most of them commonly converge; the transcription factors. Recent research efforts, therefore, are also directed on targeting the activity and activation of transcription factors, which ultimately control the expression of genes that are involved in almost all aspects of cell biology. One class of agents that is becoming increasingly successful, not only in targeting signaling cascades, but also transcription factors is phytochemicals present in diet and those consumed as supplement. The added advantage with these agents is that they are mostly non-toxic when compared to chemotherapeutic agents. This review focuses on the efficacy of various phytochemicals in targeting transcription factors such as AR, Sp1, STATs, E2F, Egr1, c-Myc, HIF-1 alpha, NF-kappaB, AP-1, ETS2, GLI and p53 in the context of prostate cancer intervention.
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PMID:Transcription factors: molecular targets for prostate cancer intervention by phytochemicals. 1797 30

The aberrant hedgehog (Hh)/GLI signaling pathway causes the formation and progression of a variety of tumors. By screening tropical plant extracts by using our screening system, Zizyphus cambodiana was found to include Hh/GLI signaling inhibitors. Bioassay-guided fractionation of this plant extract led to the isolation of three active pentacyclic triterpenes, colubrinic acid (1), betulinic acid (2) and alphitolic acid (3), as potent inhibitors. The inhibition of GLI-related protein expression with 1 or 2 was observed in HaCaT cells with exogenous GLI1, or human pancreatic cancer cells (PANC1), which express Hh/GLI components aberrantly. The expressions of GLI-related proteins PTCH and BCL2 were clearly inhibited by 1 or 2. We also examined the cytotoxicity of these active compounds against PANC1, human prostate cancer cells (DU145) and mouse embryo fibroblast cells (C3H10T1/2). The cytotoxicity against cancer cells (PANC1 and DU145) by 1 or 2 would be caused by inhibition of the expression of the anti-apoptosis protein BCL2. These pentacyclic triterpene inhibitors showed an important relationship between Hh/GLI signaling inhibition, the decrease of BCL2, and cytotoxicity against cancer cells.
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PMID:Hedgehog/GLI-mediated transcriptional inhibitors from Zizyphus cambodiana. 1884 18

CXCR4, CD133, CD44 and ABCG2 are representative transmembrane proteins expressed on the surfaces of normal and/or cancer stem cells. CXCR4 is co-expressed with POU5F1 in endodermal precursors and adult-tissue stem cells. CXCR4 is expressed in a variety of human tumors, such as breast cancer, prostate cancer, pancreatic cancer, and gastric cancer. CXCR4 is a G protein-coupled receptor (GPCR) for CXCL12 (SDF1) chemokine, and the CXCL12-CXCR4 signaling axis is involved in proliferation, survival, migration, and homing of cancer cells. Integrative genomic analyses of CXCR4 gene were carried out to elucidate the mechanisms of CXCR4 expression in stem cells, because CXCR4 is a key molecule occupying the crossroads of oncology, immunology, gerontology and regenerative medicine. Human CXCR4 promoter region with binding sites for HIF1alpha, ETS1, NF-kappaB and GLI was not conserved in mouse and rat Cxcr4 orthologs. Proximal enhancer region with palindromic Smad-binding sites, FOX-binding site, POU-binding site, triple SOX17-binding sites, bHLH-binding site, TCF/LEF-binding site, and double GFI1-binding sites was almost completely conserved among human, chimpanzee, mouse, and rat CXCR4 orthologs. TGFbeta, Nodal, and Activin signals induce CXCR4 upregulation based on Smad2/3 and FOX family members, such as FOXA2, FOXC2, and FOXH1. CXCR4 is expressed in endodermal precursors due to the existence of triple SOX17-binding sites around the POU-binding site instead of the POU5F1-SOX2 joint motif. Because CXCR4 is downregulated by p53-GFI1 signaling axis, p53 mutation in cancer stem cells leads to CXCR4 upregulation. CXCR4 is also upregulated by TGFbeta and Hedgehog signals in tumor cells at the invasion front. Small molecule compound or human antibody targeted to CXCR4 will be applied for cancer therapeutics focusing on cancer stem cells at the primary lesion as well as metastasis or recurrence niches, such as bone marrow and peritoneal cavity.
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PMID:Integrative genomic analyses of CXCR4: transcriptional regulation of CXCR4 based on TGFbeta, Nodal, Activin signaling and POU5F1, FOXA2, FOXC2, FOXH1, SOX17, and GFI1 transcription factors. 2004 76

The present study has been undertaken to establish the therapeutic benefit of cotargeting epidermal growth factor receptor (EGFR) and sonic hedgehog pathways by using gefitinib and cyclopamine, respectively, for improving the efficacy of the current chemotherapeutic drug docetaxel to counteract the prostate cancer progression from locally invasive to metastatic and recurrent disease stages. The data from immuofluorescence analyses revealed that EGFR/Tyr(1173)-pEGFR, sonic hedgehog ligand, smoothened coreceptor, and GLI-1 were colocalized with the CD133(+) stem cell-like marker in a small subpopulation of prostate cancer cells. These signaling molecules were also present in the bulk tumor mass of CD133(-) prostate cancer cells with a luminal phenotype detected in patient's adenocarcinoma tissues. Importantly, the results revealed that the CD133(+)/CD44(high)/AR(-/low) side population (SP) cell fraction endowed with a high self-renewal potential isolated from tumorigenic and invasive WPE1-NB26 cells by the Hoechst dye technique was insensitive to the current chemotherapeutic drug, docetaxel. In contrast, the docetaxel treatment induced significant antiproliferative and apoptotic effects on the CD133(-)/CD44(low)/AR(+) non-SP cell fraction isolated from the WPE1-NB26 cell line. Of therapeutic interest, the results have also indicated that combined docetaxel, gefitinib, and cyclopamine induced greater antiproliferative and apoptotic effects on SP and non-SP cell fractions isolated from WPE1-NB26 cells than individual drugs or two-drug combinations. Altogether, these observations suggest that EGFR and sonic hedgehog cascades may represent the potential therapeutic targets of great clinical interest to eradicate the total prostate cancer cell mass and improve the current docetaxel-based therapies against locally advanced and invasive prostate cancers, and thereby prevent metastases and disease relapse.
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PMID:Cytotoxic effects induced by docetaxel, gefitinib, and cyclopamine on side population and nonside population cell fractions from human invasive prostate cancer cells. 2017 63

Sonic hedgehog (SHH) signaling, acting in a combinatorial manner with androgen signaling, is essential for prostate patterning and development. Recently, elevated activation of SHH signaling has been shown to play important roles in proliferation, progression and metastasis of prostate cancer. In this report, we demonstrate for the first time, that GLI1, which has been shown to play a central role in SHH signaling in prostate cancer, can act as a co-repressor to substantially block androgen receptor (AR)-mediated transactivation, at least in part, by directly interacting with AR. Our observations suggest that the SHH-GLI pathway might be one of determinants governing the transition of prostate cancer from anandrogen-dependent to an androgen-independent state by compensating, or even superseding androgen signaling.
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PMID:GLI1, a crucial mediator of sonic hedgehog signaling in prostate cancer, functions as a negative modulator for androgen receptor. 2117 5


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